Ф. 7.03-03 Iztleuov G.M., Tanashev S.T., Mamitova G., Sataeva L.M. METHODICAL INSTRUCTIONS FOR LABORATORY WORK on the discipline « CHEMOTOLOGY » Shymkent, 2017 1 2 MINISTRY OF EDUCATION AND SCIENCE OF THE REPUBLIC OF KAZAKHSTAN M. AUEZOV SOUTH KAZAKHSTAN STATE UNIVERSITY DEPARTMENT “OIL REFINING AND PETROCHEMISTRY” Iztleuov G.M., Tanashev S.T., Mamitova G., Sataeva L.M. METHODICAL INSTRUCTIONS FOR LABORATORY WORK On the discipline « CHEMOTOLOGY » For students of a speciality 5В072100 – Chemical technology of organic substances Mode of study: full-time and part-time Shymkent, 2017 3 УДК 676.08 ББК 63.288-2я71 С63 Author: Iztleuov G.M., Tanashev S.T., Mamitova G., Sataeva L.M. The methodical instruction for laboratory works on the discipline « CHEMOTOLOGY » for students of a speciality 5В072100 – Chemical technology of organic substances Shymkent: SKSU, 2014. - 32 p The methodical instruction is composed according to requirements of the curriculum and the program of the discipline «Environmental Monitoring» and includes all necessary data on laboratory work performance. The reviewers: Eshibaev A.- doc.biol.scie, "Biotechnology", M.Auezov SKSU professor of department Shingisbaev B. – cand.chem.scie, rector of Shymkent University The methodical instructions considered and recommended for print by meeting the department «Geoecology and natural management)) (The protocol #8 from «27» _03 _ 2014 ) and The methodical commission of Chemical-technological faculty (The protocol #7 from «28» 03 2014 ) Recommended for edition by study-methodical council of M.Auezov SKSU, the protocol # from « » 20 @ M.Auezov South Kazakhstan State University 2014 Editor: Iztleuov G. 4 CONTENTS PREFACE................................................................................................... GOALS AND OBJECTIVES OF LABORATORY WORK Lab # 1– Laboratory safety...................................................................... Lab # 2- Special Laboratory Equipment............................................. Lab # 3. – MEASURING THE DENSITY OF GASOLINE Lab # 4. – DETERMINATION OF THE POUR POINT Lab # 5. – DETERMINATION OF FLASHPOINT AND IGNITION OF PETROLEUM PRODUCTS Lab # 6. DETERMINATION OF THE FRACTIONAL COMPOSITION OF GASOLINE BY DISTILLATION........................................................... Lab # 7 DETERMINATION OF THE OCTANE NUMBER BY THE CALCULATION METHOD ........................................................ Lab # 8 DETERMINATION OF THE MAIN INDICATORS OF DIESEL FUEL QUALITY DETERMINATION OF KINEMATIC VISCOSITY DETERMINATION OF THE VISCOSITY INDEX Lab # 9 DETERMINATION OF THE MAIN INDICATORS OF THE QUALITY OF PLASTIC LUBRICANTS LITERATURE............................................................................................ 5 PREFACE HIMMOTOLOGY (from chemistry and Latin motor - driving and Greek logos - science), the field of knowledge about the qualities, quality and rational use of combustible and lubricating materials (fuel) in machinery (engines, especially internal combustion, machines and mechanisms). The term "chymotology" was first proposed in the USSR (KK Papok, 1964). Himmotology arose and develops at the junction of org., Fiz. and colloid chemistry, petrochemistry, physics, economics and ecology. Formation of the chemomotor in the self. the direction of science is due to the increase in fuel consumption, the increase in their importance in ensuring the reliability and durability of machinery. In addition, before chemomotology recently, two relatively new problems have sharply risen: 1) the stabilization of oil production and the production of motor fuels from alternative raw materials (see Alternative Fuels), and 2) the study and improvement of environmental standards. in fuel and lubricants due to the fact that the influence of many. types of transport on the environment depends on the composition and type of fuels and oils used (cessation of the production of ethyl benzene, the development of so-called urban diesel fuel, a reduction in the consumption of lubricating oils in coal fumes, etc.). The tasks of chemotherapy can be conditionally divided into 3 groups. The first of these is related to the optimization of fuel quality, full conformity of the exploit. sv-in HMS requirements of engines. The solution of the problems of this group is based on the study of the complex of phys.-chemical. processes occurring during the use of petroleum products (evaporation, mixture formation, combustion, lacquer and carbon formation, corrosive and mechanical wear, etc.). The same group includes work to assess the effectiveness of ways to improve the quality of fuel (new components, cleaning methods, additives, additives, etc.) and expand their resources (eg, alternative fuels, synthetic lubricants). The purpose of the tasks of the second group is to increase the efficiency of the use of fuels and lubricants in operating conditions. This group includes the development and scientific justification of fuel consumption rates, the terms of their storage, the principles of classification, the unification of varieties and brands, the interchangeability, methods of restoring the quality of substandard fuels and the regeneration of used lubricants. The third group of tasks is devoted to the development and improvement of methods for assessing the quality of fuels and lubricants. This group also includes studies on the improvement of instruments and methods of analyte. quality control of fuels and oils, improvement of standards and technical standards. conditions on them and methods for their analysis. One of the most. major achievements in chemothermology - the development of a new system for the initial evaluation of exploiters. in fuel, socalled. complexes of their qualifications. tests. Previously, these sv-va were evaluated gl. arr. When tested on full-size machines in bench or field operations. conditions for 2-3 years with the cost of large material costs. In accordance with the new system, each fuel or oil is "dismembered" or "divided" into simple 6 components, the assessment of which is possible by accelerated labs. methods that received the name. qualifying. The summation of the results of the determination of these components makes it possible to objectively and comprehensively assess, in general, any exploiters. St.. Complex qualifications. methods for all types of fuels and lubricants makes it possible to assess its suitability for use for 1.5-2 months at low cost. Fatherland. qualification system. The evaluation of fuel and oil has been used for more than 20 years and has already given a large economic value. Effect. Basic. the task of chemotherapy for the future remains the creation of scientific foundations and recommendations on saving fuel and energy. resources and providing engines, machines and mechanisms of high quality. Fuels and lubricants with wide raw materials resources. 7 GOALS AND OBJECTIVES OF LABORATORY WORK Goal of laboratory work - deepening and broadening of knowledge in the implementation of specific practical problems , the development of initiative and independence of students, mastery of modern techniques , skills, experimenting with the use of modern equipment , instruments, acquisition of skills to analyze the experimental results . Tasks labs : - Mastering the technique of experimentation studying the latest in the relevant field of science , engineering and technology ; - Gain experience of the experiment ; - The acquisition of skills and operational skills of special laboratory equipment and techniques; - With the formation of skills of processing the results of the research ; - Formation of skills execution and presentation of the research results ; - Analysis and discussion of the results and drawing conclusions. Function laboratory ( studio ) classes - Formation of cognitive skills of independent research , study and protect their viewpoints; - Developing - identification of individual difficulties in training and organization of independent work ; - Educational - education conscious attitude to learning , the desire to work independently of the comprehensive mastery of the profession , and to activate the students thinking . Responsibilities of students in all kinds of training sessions. The student must: • timely attend classes ; • comply with labor discipline in the classroom ; • perform appropriate tasks for independent work; • timely complete objectives on CDS ; • familiarize yourself with the safety and health; before performing the lab read the assignment, its purpose and objectives ; • elaborate theoretical material needed for assimilation of knowledge on laboratory work ; • the teacher to get admission to perform laboratory work ; perform the work according to the instructions and guidelines ( the workshop ); • formalize the work according to the methodical instructions ( practicum ) and protect it from a teacher . The procedure for conducting laboratory research Laboratory studies conducted in specialized training or research laboratories of the University, if necessary - in industrial and research laboratories, companies, organizations and institutions ( ESPC ) involved in the educational process SKSU. Laboratories must comply with health and safety standards , safety requirements and technical aesthetics. Safety instructions and internal regulations in the lab 8 instructor held on the first lab session. Procedure for conducting laboratory studies include: • Self extracurricular training student to perform each individual laboratory work in accordance with the syllabus ; • introductory briefing (acquaintance of students with the content of the work , analysis of technological documentation showing how to perform certain operations , a reminder of certain provisions of the safety warning about possible errors ) . • Tutor control the degree of preparedness of each student to perform laboratory work; • preparation of the report and its protection of each student in the terms established timetable for the implementation and delivery of tasks the results of each laboratory work , evaluated the relevant points , which are exhibited in the Journal of the teacher and lecturer transferred to target dates . № Names of modules and labs Forms and methods of lab process Module 1. Introduction 1. Lab # 1– Laboratory safety Analytical 2. Lab # 2- Special Laboratory Equipment Analytical 3. lab # 3. – measuring the density of gasoline Analytical 4. lab # 4. – determination of the pour point Analytical 5. lab # 5. – determination of flashpoint and ignition Analytical of petroleum products Module 2. Environmental Monitoring 6. Lab # 6. Determination of the fractional Analytical composition of gasoline by distillation........................................................... 7. Lab # 7 determination of the octane number by the Analytical calculation method ........................................................ 8. Lab # 8 determination of the main indicators of Analytical diesel fuel quality determination of kinematic viscosity determination of the viscosity index 9. Lab # 9 determination of the main indicators of the Analytical quality of plastic lubricants 9 Control form Report the lab Report the lab Report the lab Report the lab Report the lab on on on on on Report the lab on Report the lab on Report the lab on Report the lab on LABORATORY WORK № 1 Object: LABORATORY SAFETY1.1 The aims of the employment: 1. To give information about the definitions “Coagulation” 2. To explain the new importance words 1.2 The form of carrying out of employment: spending experiments, discussion The chemistry laboratory is one of the safest environments in an academic or industrial facility. Every chemist, trained to be aware of the potential dangers of chemicals, is additionally careful in handling, storing, and disposing of chemicals. Laboratory safety should be a constant concern and practice for everyone in the laboratory. This section of the manual has guidelines for making laboratory work a safe and meaningful venture. Depending on the specific laboratory setting or experiment, other guidelines for a safe laboratory may be enforced. Study the following guidelines carefully before answering the questions on the Report Sheet of Dry Lab 1. 1. Locate the laboratory safety equipment such as eye wash fountains, safety showers, fire extinguishers, and fume hoods. Identify their locations on the inside front cover of this manual. 2. Report all accidents or injuries, even if considered minor, immediately to your instructor. A written report of any/all accidents that occur in the laboratory may be required. Consult with your laboratory instructor. 3. If an accident occurs, do not panic! The most important first action after an accident is the care of the individual. Alert your laboratory instructor immediately! If a person is injured, provide or seek aid immediately; clothing and books can be replaced and experiments can be performed again later. Second, take the appropriate action regarding the accident: clean up the chemical (see B.8, page 3), use the fire extinguisher (see B.6 below), and so on. 4. Whenever your skin (hands, arms, face, etc.) comes into contact with chemicals, quickly flush the affected area for several minutes with tap water followed by thorough washing with soap and water. Use the eyewash fountain to flush chemicals from the eyes and face. Get help immediately. Do not rub the affected area, especially the face or eyes, with your hands before washing. 5. Chemical spills over a large part of the body require immediate action. Using the safety shower, flood the affected area for at least 5 minutes. Remove all contaminated clothing if necessary. Use a mild detergent and water only (no salves, creams, lotions, etc.). Get medical attention as directed by your instructor. 6. In case of fire, discharge a fire extinguisher at the base of the flames and move it from one side to the other. Small flames can be smothered with a watchglass 10 (do not use a towel, it may catch on fire). Do not discharge a fire extinguisher when a person’s clothing is on fire—use the safety shower. Once the fire appears to be out of control, immediately evacuate the laboratory. 7. For abrasions or cuts, flush the affected area with water. Any further treatment should be given only after consulting with the laboratory instructor. For burns, the affected area should be rubbed with ice, submerged in an ice/ water bath, and/or placed under running water for several minutes to withdraw heat from the burned area. More serious burns require immediate medical attention. Consult with your laboratory instructor. Treat chemical spills in the laboratory as follows: Alert your neighbors and the laboratory instructor. Clean up the spill as directed by the laboratory instructor. If the substance is volatile, flammable, or toxic, warn everyone of the accident. Technique 4, page 15, provides information for the proper disposal of chemicals after being used in the experiment. Improper disposal can result in serious laboratory accidents. Read that section carefully—it may prevent an “undesirable” laboratory accident. If you are uncertain of the proper procedure for the disposing of a chemical, ask! In addition to the guidelines for self-protection (Part A), the following rules must be followed. 1. Smoking, drinking, eating, and chewing (including gum and tobacco) are not permitted at any time because chemicals may inadvertently enter the mouth or lungs. Your hands may be contaminated with an “unsafe” chemical. Do not place any objects, including pens or pencils, in your mouth during or after the laboratory period. These objects may have picked up a contaminant from the laboratory bench. 2. Do not work in the laboratory alone. The laboratory instructor must be present. 3. Assemble your laboratory apparatus away from the edge of the lab bench (> 8 inches or > 20 cm) to avoid accidents. 4. Do not leave your experiment unattended during the laboratory period . . . this is often a time in which accidents happened. 5. Inquisitiveness and creativeness in the laboratory are encouraged. However, variations or alterations of the Experimental Procedure are forbidden without prior approval of the laboratory instructor. If your chemical intuition suggests further experimentation, first consult with your laboratory instructor. 6. Maintain an orderly, clean laboratory desk and drawer. Immediately clean up all chemical spills, paper scraps, and glassware. Discard wastes as directed by your laboratory instructor. 7. Keep drawers or cabinets closed and the aisles free of any obstructions. Do not place book bags, athletic equipment, or other items on the floor near any lab bench. 11 At the end of the laboratory period, completely clear the lab bench of equipment, clean it with a damp sponge or paper towel (and properly discard), and clean the sinks of all debris. Also clean all glassware used in the Laboratory Safety and Guidelines 3 1. Be aware of your neighbors’ activities; you may be a victim of their mistakes. Advise them of improper techniques or unsafe practices. If necessary, tell the instructor. 2. For all other rules, listen to your instructor! Additional laboratory rules and guidelines can be added to this list at the bottom of this page. 3. Maintain a wholesome, professional attitude. Horseplay and other careless acts are prohibited. No personal audio or other “entertainment” equipment is allowed in the laboratory. 4. Do not entertain guests in the laboratory. Your total concentration on the experiment is required for a safe, meaningful laboratory experience. You may socialize with others in the lab, but do not have a party! You are expected to maintain a learning, scientific environment. 5. Scientists learn much by discussion with one another. Likewise, you may profit by discussion with your laboratory instructor or classmates, but not by copying from them. 6. Prepare for each experiment. Review the Objectives and Introduction to determine the “chemistry” of the experiment, the chemical system, the stoichiometry of the reactions, the color changes to anticipate, and the calculations that will be required. A thorough knowledge of the experiment will make the laboratory experience more time-efficient and scientifically more meaningful (and result in a better grade!). Complete the Prelaboratory Assignment. 7. Review the Experimental Procedure. 8. Try to understand the purpose of each step. 9. Determine if any extra equipment is needed and be ready to obtain it all at once from the stockroom. 10.Determine what data are to be collected and how it is to be analyzed (calculations, graphs, etc.). 11.Review the Laboratory Techniques and the Cautions, as they are important for conducting a safe and rewarding experiment. 12.Review the Report Sheet. Complete any calculations required before data collection can begin during the laboratory period. Determine the data to be collected, the number of suggested trials, and the data analysis required (e.g., calculations, graphs). 13.Review the Laboratory Questions at the conclusion of the Report Sheet before and as you perform the experiment. These questions are intended to enhance your understanding of the chemical principles on which the experiment is based. 14.Above all, enjoy the laboratory experience . . . be prepared, observe, think, and anticipate during the course of the experiment. Ultimately you will be rewarded. 12 LABORATORY WORK № 2 OBJECT: SPECIAL LABORATORY EQUIPMENT 1.1 The aims of the employment: 1. To give information about the definitions “Measurement of Nitrates in Water ” 2. To explain the new importance words 1.2 The form discussion of carrying out of employment: spending experiments, Laboratory glassware refers to a variety of equipment, traditionally made of glass, used for scientific experiments and other work in science, especially in chemistry and biology laboratories.Contents [hide] Applications Brown glass jars with some clear lab glassware in the background Glass use in laboratory applications is not as commonplace as it once was because of cheaper, less breakable, plasticware; however, certain applications still require glassware because glass is relatively inert, transparent, heat-resistant, and easy to customize. The type of glass used is dependent on the application. Borosilicate glass, which is commonly used in reagent bottles, can withstand thermal stress. Quartz glass, which is common in cuvettes, can withstand high temperatures and is transparent in certain parts of the electromagnetic spectrum. Darkened brown or amber (actinic) glass, which is common in dark storage bottles, can block ultraviolet and infrared radiation. Heavy-wall glass, which is common in glass pressure reactors, can withstand pressurized applications. When in use, laboratory glassware is often held in place with clamps made for that purpose, which are likewise attached and held in place by stands or racks. This article covers aspects of laboratory glassware which may be common to several kinds of glassware and may briefly describe a few glassware items not covered in other articles. Describing glassware can be complicated since manufacturers provide conflicting names for glassware. For example ChemGlass calls a glass stopcock what Kontes calls a glass plug. Beakers are simple cylindrical shaped containers used to hold reagents or samples. Flasks are narrow-necked glass containers, typically conical or spherical, used in a laboratory to hold reagents or samples. Bottles are containers with narrow openings generally used to store reagents or samples. Small bottles are called vials. Jars are cylindrical containers with wide openings that may be sealed. Bell jars are used to contain vacuums. Watch glasses are shallow glass dishes used as an evaporating surface or to cover a beaker. Graduated cylinders are cylindrical containers used for volumetric measurements. Stirring rods are used to mix chemicals. Burettes are used to disperse precise amounts of liquid reagents. Condensers are used to cool hot liquids or vapors. Funnels are used to get materials through a narrow opening. Desiccators of glass construction are used to dry materials or keep material dry. Glass tubes are cylindrical pieces of glassware used 13 to hold or transport materials. Glass retorts are used for distillation. Glass pipettes are used to transport precise quantities of fluids. Glass petri dishes are used to culture living cells. Drying pistols are used to free samples from traces of water, or other impurities. Glass evaporating dishes are used to evaporate materials. Microscope slides are thin strips used to hold items under a microscope. Threaded plug valves are used significantly in air-sensitive chemistry as well as when a vessel must be closed completely as in the case of Schlenk bombs. The construction of a threaded plug valve involves a plug with a threaded cap which are made so that they fit with the threading on a corresponding piece of female glass. Screwing the plug in part-way first engages one or more O-rings, made of rubber or plastic, near the plug's base, which seals the female joint off from the outer atmosphere. Screwing the plug valve all the way in engages the plug's tip with a beveled constriction in the glass, which provides a second seal. This seal separates the region beyond the bevel and the O-rings already mentioned. Fritted glass is finely porous glass through which gas or liquid may pass. Applications in laboratory glassware include use in fritted glass filter items, scrubbers, or spargers. Other laboratory applications of fritted glass include packing in chromatography columns and resin beds for special chemical synthesis. Laboratory glassware may be part of a sophisticated apparatus, as is the case with certain types of condensers, and it may be used in conjunction with other laboratory equipment such as ring stands, burette clamps, and bunsen burners. 14 15 Fill this blank There are many different kinds of laboratory glassware items: 1. ________are simple cylindrical shaped containers used to hold reagents or samples. 2. ________ are narrow-necked glass containers, typically conical or spherical, used in a laboratory to hold reagents or samples. 3. ________ are containers with narrow openings generally used to store reagents or samples. Small bottles are called vials. 4. ________with wide openings that may be sealed. Bell jars are used to contain vacuums. 5. ________are shallow glass dishes used as an evaporating surface or to cover a beaker. 6. ________are cylindrical containers used for volumetric measurements. 7. ________ are used to mix chemicals. 8. ________are used to disperse precise amounts of liquid reagents. 9. ________ are used to cool hot liquids or vapors. 10.________ are used to get materials through a narrow opening. 11.________of glass construction are used to dry materials or keep material dry. 12.________are cylindrical pieces of glassware used to hold or transport materials. 13.________are used for distillation. 14.________are used to transport precise quantities of fluids. 15.________are used to culture living cells. 16.________are used to free samples from traces of water, or other impurities. 17.________are used to evaporate materials. 1. Beakers 2 Flasks 3 Bottles 4 Jars are cylindrical containers 5 Watch glasses 6 Graduated cylinders 7 Stirring rods 8 Burettes 9 Condensers 10 Funnels 11 Desiccators 12 Glass tubes 13 Glass retorts 14 Glass pipettes 15 Glass petri dishes 16 Drying pistols 17 Glass evaporating dishes LABORATORY WORK № 3 DETERMINATION OF THE MAIN INDICATORS OF QUALITY OF GASOLINE 1.1 The purpose of the work: to familiarize and consolidate knowledge of the basic brands of benzine, with the normative and technical documentation on the quality of gasoline (GOSTs for quality indicators and methods for determining them), to familiarize and study methods for conducting a control analysis of gasoline (determination of the corrosive properties of gasoline, including for the presence of water-soluble acids and alkalis, active sulfur, density and fractional 16 composition, assessment of their detonation resistance), and acquire skills for monitoring and assessing the quality of gasoline, and, by definition, and for use in internal combustion engines. 1.2 As a result of performing laboratory work, preparing and protecting the report, students must: know: - The main grades of gasoline used in road transport, their properties and features; - the basic normative and technical documents on the quality of gasoline (GOSTs on quality indicators and methods for their determination); - the main methods for conducting a control analysis of gasoline: the determination of the corrosive properties of gasoline, including the presence of water-soluble acids and alkalis, active sulfur, density and fractional composition, an assessment of their detonation resistance, and others. be able to: - give a description of certain types of motor gasolines; - use normative and technical documents for the quality of bin-zins (GOSTs for quality indicators and methods for their determination); - apply the basic methods of conducting a control analysis of benzine: the determination of the corrosive properties of gasoline, including the presence of water-soluble acids and alkalis, active sulfur, density and fractional composition, an assessment of their detonation resistance, and others; - apply skills to control, assess the quality of gasoline and establish the conditions for their use in road transport as a fuel for internal combustion engines. 1. 3 The order of performance of work 1. To consider the requirements for the quality of gasoline, the properties and the indices of gasoline, which affect the mixture formation, fuel supply, the combustion process, the formation of deposits and corrosive activity, the main grades of gasoline and their use. 2. To evaluate the test fuel sample according to external characteristics: transparency, color, odor, presence of water and visible to the naked eye of mehanic impurities, the nature of evaporation of the drop from the filter paper. To get acquainted with the collection of standard benzines available in the laboratory, and then compare them with the external characteristics of the test fuel sample and give a preliminary opinion about the belonging of the sample to this or that brand of gasoline. 3. Conduct an experimental analysis of the content of water-soluble acids and alkalis. 4. Conduct an experimental analysis for the presence of active sulfur. 5. Measure the density of gasoline. 6. Determine the fractional composition of gasoline by distillation. 7. Calculate the octane number of the fuel to be examined. 17 8. To establish according to the available standard parameters the brand of the tested gasoline, its compliance with GOST and to solve the problem of its use for cars as a fuel for internal combustion engines. 9. Perform the necessary work specified in the assignment. 10. To issue a report, to make a technical conclusion. 1.4 Brief theoretical information, composition and sequence of the work. Estimation of gasoline by external characteristics Gasolines should not contain mechanical impurities and water. Determination of their absence or presence is carried out by external signs or by means of special devices. To assess the external characteristics, it is enough to inspect the sample of gasoline in a glass cylinder. In this case, the unguided eye should not be detected solid particles, both in the suspended state and in the sediment. In small quantities (hundredths of a percent), water can dissolve in gasoline, and it does not lose its transparency. Excessive amount of water in gasoline with stirring will cause turbidity of gasoline, and when settled due to a greater specific gravity will lead to its accumulation on the bottom of the tank by a separate layer. Therefore, when evaluating gasoline for water, it is sufficient to examine it in a glass cylinder and fix the presence or absence of a turbidity or a separate layer of water on the bottom. When shipped from oil refineries, fuels do not contain mechanical impurities and water. However, they can get impurities and water during transportation, storage, refueling. Therefore, the fuel is periodically checked for presence of impurities and water by the simplest methods or by means of special devices. The simplest method consists of examining the samples in a glass cylinder with a diameter of 40-60 mm, while in the entire mass of gasoline, the naked eye should not show any suspended or settled solid particles or water. The presence of water in the fuel is dangerous in winter, when the ice crystals that are formed break the fuel dosage and can cause complete stoppage of its supply, the oxidation processes increase, the corrosive effect of the fuel increases. Mechanical impurities cause clogging of the fuel-dosing system. All gasolines, including which consume in their composition ethyl liquid, are colored in yellow, orange (orange-red), blue (blue) or pink-colored. Gasoline obtained directly from oil by overclocking or by two-step cracking is usually colorless and does not tint for a long time after their manufacture. Unleaded thermal cracking gasolines are also colorless for several weeks from the date of their manufacture, but when stored, they are stained with resins that are continuously formed in them, first into light yellow, then into transitional yellow, and into a dark yellow color .Benzines, in comparison with other petroleum products, have a specific odor. The thermal cracking fuels, the two-stage catalytic cracking fuels, containing a significant number of aromatic hydrocarbons, have a weak and fragrant smell. The petrol, compared to kerosene, diesel fuel and oil, have the easiest fractional composition, so they can easily be differentiated. from 18 other refined products. A drop of the test fuel is applied to the filter paper or finger of the hand and the evaporation pattern is observed. Aviation and winter automobile gasolines completely evaporate within 1 minute, leaving no trace. Summer automotive gasolines evaporate more slowly - after 1 minute, on the skin or paper from them, an incompletely dry stain can be preserved. Noticeable evaporation of kerosene, di-green fuels and oils for 1 min. is not observed, for several minutes the trace from the applied drop remains practically unchanged. 1.5 Equipment: a glass cylinder with a diameter of 40-55 mm; sample of tested gasoline. Order of work: 1. Pour the sample of the analyzed gasoline into a glass cylinder. 1.6 Determine by visual inspection the presence or absence of suspended or settled solids, while evaluating the color, odor and volatility of the fuel. Determine the presence or absence of an aqueous layer at the bottom of the cylinder and a characteristic turbidity. The results of the assessment are recorded in the report. Determination of the content of water-soluble acids and alkalies The evaluation of the quality of carburetor fuel by its corrosive properties is of practical importance not only when it is used in the engine, but also when storing, pumping, transporting, etc. Incoming to The fuel hydrocarbons do not corrode. Corrosion is caused by the content of substances such as water-soluble acids and alkalis that remain in the fuel during purification; organic acids, mainly naphthenic, sulfur and sulfur compounds; water. Due to the strong corrosive effect of water-soluble acids on metals, and alkalis on aluminum, their presence in the fuel is not allowed. The qualitative determination of water-soluble acids and alkalis is carried out according to GOST 6307-75. Equipment: separatory funnel; test tubes; tripod; cylinder measuring 10 ml; distilled water; a chemical glass; phenolphthalein (1% alcohol solution); methyl orange (0.02% aqueous solution); A sample of fuel. Order of work: 1. The sample of fuel prepared for testing, mix well with a three-minute shaking in the bottle. From the mixed sample, measure the measuring cylinder with 10 ml of fuel and drain into the separatory funnel. Measure 10 ml of distilled water and also drain into funnel. The separatory funnel should be closed with a stopper, removed from a tripod and mixed with stirring (but not too vigorously) for 30-40 s. After shaking, the funnel should be reinforced on a tripod, wait until the emulsion has formed. After settling, the bottom layer, called water extract, is to be drained into a glass. Pour the water extract from the glass into two test tubes. In one of the test tubes with the aqueous extract of the test fuel add two drops of methylorange solution, and in the other - three drops of alcohol solution of phenolphthalein and the contents in both test tubes shake well. Comparing the resulting colors of indicators with the data of Table. 1.1, to draw a conclusion about the presence or absence in the test sample of water-soluble acids or alkalis. Table 1.1. Coloring of indicators in various environments. Medium Methylorange Phenolphthalein Alkaline Yellow Raspberry Neutral Orange Colorless Acid Red Colorless9. Fuel is considered to have passed the test, if the water aging is neutral. Otherwise, the experiment should 19 be repeated, thoroughly wash the dishes thoroughly and rinse it with distilled water. If, as a result of the second test, the water extract is acidic or alkaline, the fuel is rejected. The result of the test is recorded in the report. Qualitative determination of olefins in fuels. Fuel for engines that have thermal cracking or single-stage catalytic cracking products may contain a significant amount of olefins capable of being converted to resins during trans-porting and storage, because of oxidation-polymerization processes, an extremely high concentration of which adversely affects the operation of internal combustion engines. 1.7 The study is based on the fact that the olefins are easily oxidized, restoring the derivatives with them oxidants. Equipment: laboratory tube; potassium permanganate; The sample of fuel to be tested. The order of the work: 1. The tested gasoline should be poured into the test tube to a height of 30-40 mm from the level of its bottom2. Add approximately the same amount of an aqueous solution of potassium permanganate (potassium permanganate) to the tube and vigorously shake the contents of the tube for 10-15 seconds. After this, the test tube is allowed to settle. After settling, the separated lower crimson-violet stripe will indicate the absence of olefins in the fuel, and the discoloration of the water layer or the color change from crimson violet to yellow indicates the presence of olefins in the test gasoline. 2.1 Determination of the presence of active sulfur The presence of sulfur compounds and elemental sulfur in gasoline determines the corrosive properties of gasoline itself, and the products of sulfur combustion cause additional corrosion of engine parts. The strongest corrosive effects on the metal are hydrogen sulphide, elemental sulfur and lower mercaptans, which cause corrosion of the tanks and the fuel-supply system of the engine even under normal conditions. In this regard, the presence of these sulfur compounds in gasoline is not allowed. The activity of sulfur compounds in the fuel is checked by testing on a copper plate. To this end, a well-cleaned and polished copper plate is placed in a test tube with test fuel and heated for 3 hours in a water bath at a temperature of 50 ° C. Then the plate is washed. If there is then a black, dark brown or gray coating on it, this indicates the presence of active sulfur compounds in the fuel. Inactive sulfur compounds - sulfides, thiophenes, etc. - practically do not act on metals under normal conditions. However, when they are burned, SO2 sulfide and sulfuric SO3 anhydrides are obtained which, in the presence of even a small amount of water, form sulfurous and sulfuric acid slots, which causes severe corrosion of the parts. Thus, the more sulfuric compounds are contained in the fuel, the stronger the corrosion and the wear of the engine parts caused by it. Increased wear and carbon formation in the engine when it operates on sulphurous fuel causes a decrease in engine power and economy. The sulfur content in automotive fuels should not exceed 0.1 ... 0.12% by technical requirements. Corrosivity of fuel increases with increasing water content in it. In addition, in winter, the presence of water in gasoline can cause blockages in the fuel lines due to the formation of ice 20 crystals, resulting in disrupted fuel supply and engine operation. It is highly unreasonable that there are mechanical impurities in the fuel, which block the carburetor jets and contribute to increasing the wear of the engine parts. Two methods of testing fuels on a copper plate have been adopted: standard and accelerated. The standard test method lasts 3 hours at a temperature of 50 ° C, with accelerated - 18 minutes at a temperature of 100 ° C. Below is a description of the accelerated method, with completely reliable results in accordance with GOST 6321-69. 2.2 Equipment: a conical flask with a volume of 260 ml; a reflux condenser, a water bath, a plate 40x10x2 mm in size made of electrolytic copper, a copper rod, an electric stove. 2.3 The order of the work: 1. The test fuel is poured into the conical flask to a height of 20-25 mm. 2. A carefully ground electroplated plastic plate is suspended on the copper wire so that the plate is immersed in fuel approximately half its height (it is not possible to touch the plate with hands while preparing it and lowering it into the flask). 3. The flask is closed with a cork stopper with a reflux condenser installed in it, cooled by running water, and lowered exactly for 18 minutes into a boiling water bath (100 ° C). 4. After 18 minutes, the flask is quickly removed from the bath, the copper plate is removed and thoroughly inspected. If, after the test, the copper plate is covered with black, dark brown or gray steel steels and stains, it is considered that the fuel does not stand the test. The positive results of the gasoline test indicate that the hydrogen sulphide content does not exceed 0.0003, and that of free sulfur does not exceed 0.0015% (by mass). 3.1 Measuring the density of gasoline Density of fuels depends on their chemical composition, molecular weight and temperature. Its influence on the operation of power systems is noticeably manifested by a change in the level in the float chamber of the carburettor and the fuel consumption in the dosing systems (jets, nozzles, dispensers, etc.). Density is usually determined by oil meters - special hydrometers. But there are other methods used in laboratory studies of petroleum products, such as weighing on analytical scales of small special flasks (pycnometers) having a strictly defined volume of fuel contained in them, or immersing in fuel bodies of a certain volume and mass suspended to special very accurate scales. The density of fuel for gasoline brands is not standardized, but it is necessary to know it accurately not only when calculating the metering systems of power supplies, but also when converting volumetric units into mass and mass in volume when determining fuel consumption during engine testing (Appendix 1). In terms of the density of automotive fuel, we can only roughly judge the type of fuel: 21 gasoline, kerosene, diesel fuel, etc., since many brands of different fuels have the same density. Density is one of the mandatory indicators included in the passport for engine fuels. It is used in the conversion of volume units of petroleum products into bulk and vice versa. To recalculate the amount of gasoline in volume units in weight it is sufficient to multiply the volumetric amount of gasoline at the same temperature, i.e. , (1.1) where Gt is the amount of gasoline in weight units, kg, Vt is the amount of gasoline in volumetric units, l, ρt is the density of gasoline at the same temperature, g / cm3. 3.2 Equipment: 250 ml glass measuring cylinders; a set of hydrometers (oil meters); Mercury glass thermometer (in the case if the hydrometer without a thermometer) to +50 ° C with a division price of 1 ° C. 3.3 Order of work: 1. Place the glass cylinder in a level place and gently, using a glass rod, pour the test oil (benzine) into it to a level that is 5-6 cm from the top of the cylinder. Withstand oil for 2-3 minutes in order to accept the ambient temperature (no more than ± 5 ° C) .3. Pure and dry hydrometer slowly and carefully lowered into the cylinder with oil until its free buoyancy, holding it by the upper end. After the hydrometer is established and its oscillations stop, prolime count on the upper edge of the meniscus to within a third sign. In this case, the eye should be at the level indicated . After at least 1 minute after immersing the hydrometer record the temperature of the fuel, counting it to within a degree of the thermometer. In this operation, the test ends. To remove the hydrometer from the cylinder, wipe it, put it into the case, and pour oil into the same bottle from which the cylinder filled. In standards and other documents, the density of the oil product is indicated at a temperature of 20 ° C (ρ20). In connection with this, the measurement data at a different temperature (ρ) must be brought to a temperature of 20 ° C according to the formula, (1.2) where γ is the temperature-dependent temperature correction, which is taken from Table. A.1, t is the oil product temperature at a density reading, ° C. The density should be rounded to the third decimal place. 4.1 Determination of the fractional composition of gasoline by distillation Evaporation is the ability of liquid fuel to pass into a steam-different state under given conditions. Evaporation determines the efficiency of mixture formation and fuel supply when starting and operating the engine in low and high temperatures or low pressure. Starting the engine, its warm-up time and acceleration, fuel consumption and wear of the cylinder-piston group depend to a large extent on the volatility of the fuel. The process of evaporation not only precedes ignition and combustion, but largely determines the speed of these processes, and, consequently, the reliability and efficiency of the engine. The volatility of the fuel is estimated by the combination of two main indicators: the heat of evaporation and the fractional composition. 22 The fractional composition of fuel is understood as the content in it of various fractions boiling out in certain temperature ranges. The fractional composition is expressed in volume% or mass%. Fraction of fuel is a part of fuel, characterized by certain temperature limits of boiling. The fractional composition is determined by the methods of GOST 2177-82 by distillation of 100 cm3 of gasoline in the conditions regulated by the standard on a special instrument. The standard unit indicators of the fractional composition of domestic motor gasoline in accordance with GOST 2084-77 are: the temperature of the beginning of distillation of tnp, distillation of 10, 50 and 90% (respectively, temperatures t10, t50, t90) and the end of boiling (distillation) volume of residue in the flask; the sum of the distillation losses and the remainder in the flask, which is equal to the difference between the volume of gasoline filled in the flask and the volume of the distillate in the graduated cylinder after the distillation is over. Gasoline fractions are conventionally divided into start-up, containing the most volatile hydrocarbons, included in the first 10% of the distillate; Working, including the subsequent 80% of the composition of gasoline, and the end, which includes the last 10% of gasoline. In accordance with this division, the operating properties of gasoline are evaluated at five characteristic points of the fractional composition curve: the distillation start temperature, the distillation temperature of 10%, 50%, 90% of the amount of gasoline and the distillation end temperature. The temperatures of the beginning of distillation (tnp) and distillation of 10% (t10) characterize the starting qualities of gasoline, i.e. ability to provide engine start-up at low temperatures and propensity of fuel to form steam-air plugs in the fuel system of the engine. The lower the ambient air temperature when starting the engine, the more gasoline of light fractions should be and the lower should be their boiling point. This quality of gasoline is characterized by temperatures of the beginning of its distillation and distillation of 10%. However, an extremely low 10% distillation temperature leads to the formation of "steam plugs" in the heated engine in the fuel lines and channels of the carburetor. At the same time, the combustible mixture is significantly impoverished. In practice, this leads to the fact that the engine loses power, starts "chi-hath" and because of interruptions in the fuel supply can stop. With temperature t10, it is possible to determine the minimum ambient temperature at which the engine can be started: t = 0.5t10 - 50.5. (1.3) The distillation temperature of 50% gasoline (t50) characterizes its ability to provide rapid warming up and acceleration (rapid engine switching to high speed) of the engines. The lower the distillation temperature of 50% of gasoline, the higher its volatility, the better the acceleration and stability of the engine on this gasoline. An increase in t50 leads to a decrease in the engine resource, especially at low ambient temperatures. The distillation temperatures of 90% (t90) and the end of the distillation (tcp) characterize the presence in the gasoline of heavy fractions, which evaporate to the last stage. With an increase in these temperatures, the consumption of 23 gasoline increases, since heavy fractions do not have time to burn. More gasoline penetrates into the crankcase, flushing oil from the cylinder walls and liquefying oil in the crankcase, which leads to wear parts and increased oil consumption. To determine the fractional composition of gasoline by distillation, the apparatus (GOST 1393-63) for distilling oil products is used (Figure 1.2). The analyzed gasoline sample is first dehydrated to dry. Dilution of gasoline is made by shaking it for 10-15 minutes with granulated calcium chloride and filtration after sludge through a paper filter. Then, after measuring 100 ml, this amount is poured into the kol-bu, into which the thermometer is inserted. The flask is placed in a tin casing, in the lower part of which an asbestos gasket with an opening for the bottom of the bulb is reinforced. When distilling gasoline and other light fuels, the diameter of the hole should be 30 mm, and when distilling kerosene and diesel fuel - 50 mm. The outlet end of the tube is prop rushes through the refrigerator and sinks into the graduated cylinder. The inner cavity of the cylinder is filled with a mixture of water with snow or pieces of ice or is connected to running water, the temperature of which at the outlet of the refrigerator should not be more than 30 ° C. The burner for heating the bulb is ignited far from the device, the flame height is set to 50-60 mm and placed in a special holder so that the tip of the flame barely touches the bulb (Figure 1.2). At the appearance of the first drop of condensate at the end of the discharge tube, the temperature of the start of the distillation is fixed. After the drop of the first drop of fuel, distillation is carried out at a uniform rate of 4-5 ml per minute, which corresponds to 20-25 drops in 10 seconds. Violation of the established mode of distillation leads to a distortion of the test result. So, with an increase in speed above the established accuracy, the separation of fuel into fractions deteriorates and, along with light fractions, the heavier ones are overdriven. As a result, the fractional composition of the fuel will seem easier. At a low rate of distillation, the fractional composition of the fuel will appear to be heavier. After stripping 90% of the fuel, the heating of the bulb is intensified until the blue flame flames appear from the windows of the lower part of the casing. At the same time, the mercury table of the thermometer starts to rise at first, and then stops and, after standing for a while at this level, begins to drop. Equipment: a device for distillation of oil refining; 100 ml flask; fridge; a graduated cylinder per 100 ml; a graduated cylinder on a 10 ml funnel; tripod; a heater; thermometer; A sample of fuel. Order of work: 1. With a clean, dry cylinder, note 100 ml of the test fuel and put it in the flask, holding it in such a position that the branch pipe is pointing upwards. Place a thermometer in the neck of the bulb so that the thermometer's axis coincides with the axis of the bulb. (The thermometer is installed with a plug so that the upper edge of the thermometer ball is at the level of the lower edge of the discharge tube, in the place of its fast ice.) 3. Place the flask in the stove (on the electric stove) and combine it with the refrigerator. Install the measuring cylinder (not drying) under the lower end of the refrigerator tube. The cylinder is installed so that the tube of the refrigerator enters into it at least 25 mm, but not below the 100 ml mark and does not touch its walls. The cylinder for 24 the time of distillation is covered with cotton so as to reduce losses due to evaporation. When the gasoline is distilled, place the cylinder in a glass vessel with water, the temperature of which is maintained within 20 ± 3 ° C. Switch on the heater (electric stove). Heat the lead so that the first drop of fuel falls from the end of the refrigerator tube not earlier than 5 and not later than 10 minutes from the beginning of the heating. Otherwise, adjust the height of the burner flame. Mark the temperature at which the first drop of fuel falls, as the temperature of the start of distillation (tn.p) .7. After the drop of the first drop of fuel, the distillation is conducted at a uniform rate of 4-5 ml per minute, which corresponds to 20-25 drops in 10 s. Record the temperature readings after removing every 10 ml of fuel. To facilitate measurements, it is necessary that the distillable fuel from the lower end of the refrigerator tube flows down the wall of the receiving cylinder. To do this, after dropping the first drop, move the graduated cylinder so that the end of the refrigerator tube touches the inner wall of the cylinder. To check the speed of distillation by counting the drops, the cylinder is briefly set aside from the end of the refrigerator tube so that the drops of fuel fall on the center of the cylinder. As the temperature rises, intensify the heating of the bulb so that the distillation rate is constant. After distillation of 90 ml of fuel (90% distillate), the heating of the flask is increased (to regulate the heating of the hot plate) until the blue tabs of the flame appear from the windows of the lower part of the casing so that the distillation takes 3 to 5 minutes to complete. Without reducing the size of the flame, follow the thermometer (stopping the mercury ball) and with a decrease in temperature by 510 ° C from the maximum value, the burner should be extinguished and drain condensate for 5 minutes.11. The maximum temperature reached during the distillation is marked as the temperature of the distillation end (t.c.) .12. After stopping the distillation, remove the upper part of the casing and cool it for 5 minutes.13. After cooling the bulb from it, remove the thermometer and remove it from the device. Remove the hot residue from the flask into a graduated cylinder with a capacity of 10 ml, cool it to room temperature and determine the remaining amount (to an accuracy of 0.1 ml). Then calculate the losses that make up the difference between 100 ml (100%) of gasoline filled in the flask and the sum of the volumes (percentages) of the collected condensate and the residue and record as losses during distillation. The results of overclocking should be recorded in the report. Construct a graph of fractional fuel composition. To do this, the values of distillation temperatures are plotted along the horizontal axis, and the corresponding volumes of evaporated fuel are plotted along the vertical axis. 5.1 Determination Of The Octane Number By The Calculation Method One of the main indicators of the quality of motor gasolines is their detonation resistance, on which the reliability and duration of operation of piston engines depend to the greatest extent. De-toning resistance characterizes the ability of gasoline to burn in the engine without detonation and is estimated in units of 25 octane number: the higher the octane number, the higher the detonation resistance of gasoline. In Fig. 1.3. A detailed indicator diagram is presented, that is, the dependence of the change in pressure P in the engine cylinder from the angle of rotation of the crankshaft φpv, under normal and detonating combustion of the mixture. The octane number is a conventional indicator of the antiknock resistance of gasoline, numerically equal to the percentage content of iso-octane C8H18, the octa-new number of which is taken to be 100, in its mixture with n-heptane C7H16, the octane number of which is 0, equivalent in detonation resistance to the tested gasoline . Mixtures of isooctane and n-heptane of different ratios will have detonation resistance from 0 to 100. For example, the octane number of gasoline is 80. This means that this gasoline is detonation-proof equivalent to a mixture of isooctane and n-heptane, in which isooctane is 80%. There are two methods for determining the octane number: motor and research. The motor method is used to determine the octane number at the UIT-65 installation (Figure 1.4), which allows to change the compression ratio from 4 to 9, where the detonation resistance of the tested gasoline is compared with the reference samples at a mixture temperature of 150 ° C and a rotation speed of 900 min-1 . The detonation resistance is determined by the research method at a fuel mixture temperature of 25-35 ° C (the mixture is not heated) and a rotational speed of 600 min-1. In this case, the letter "AND" is present in the petrol mark. For example, AI-92 - automobile gasoline with an octane number according to the research method is not lower than 92. Since the determination of detonation resistance by the motor method takes place under more stringent conditions, the result will be somewhat lower than it would have been obtained in determining by the research method (Table 1.2). In both cases, after warming up the engine, the compression ratio gradually increases until a detonation of a certain standard intensity is detected, determined by the scale of the detonation indicator. An approximate relationship has been established between the required octane number of gasoline, the compression ratio and the cylinder diameter of the engine: OC = 125.4-413 / ε + 0.183D, (1.4) where OC is the octane number; ε is the compression ratio; D is the diameter of the cylinder. To increase the compression ratio by one, it is necessary to increase the octanew number by 4-8 units. The octane number depends not only on the degree of compression. A noticeable influence is exerted by the ambient temperature, atmospheric pressure and humidity. Thus, the octane number can be reduced by one with a decrease in air temperature by 10 ° C or atmospheric pressure by 10 mm Hg. For example, if the ambient temperature is -20 ° C and atmospheric pressure is 760 mm. Hg. the engine required gasoline with an octane rating of 90, then at an ambient temperature of -10 ° C and an atmospheric pressure of 700 mm. Hg. it is enough to use gasoline with an octane rating of 80. 26 LABORATORY WORK № 2 DETERMINATION OF THE MAIN INDICATORS OF DIESEL FUEL QUALITY The purpose of the work: to familiarize and consolidate knowledge on the main brands of diesel fuels, with the normative and technical documentation on the quality of diesel fuels (GOSTs for quality indicators and methods for their determination), to familiarize and study methods for carrying out a control analysis of diesel fuels (density, viscosity and temperature of solidification of fuel), and also acquire skills to control and assess the quality of diesel fuels, and to determine their suitability for use in internal combustion engines. As a result of performing laboratory work, preparing and protecting the report, students must: know: - The main brands of diesel fuels (DTs) used in automobile transport, their properties and features; - Basic normative and technical documents on the quality of diesel fuels (GOSTs on quality indicators and methods for their determination); - the main methods for conducting a control analysis of diesel fuel: determination of density, viscosity, pour point of fuel and others. be able to: - give a description of certain types of automobile diesel fuels; - use normative and technical documents on the quality of diesel fuels (GOSTs on quality indicators and methods for their determination); - to apply the basic methods of conducting control analysis of diesel fuels: determination of density, viscosity, pour point of fuel and others; - apply skills to control, evaluate the quality of diesel fuels and establish the conditions for their use in road transport as a fuel for internal combustion engines. The order of performance of work 1. Consider the requirements for the quality of diesel fuels, the properties and indicators of diesel fuels affecting the mixture formation, fuel supply, combustion process, sedimentation and corrosion activity, the main brands of diesel fuels and their application. 2. To evaluate the test sample of fuel according to external signs: transparency, color, odor, the presence of water and visible to the naked eye of mechanical impurities. To get acquainted with the collection of standard diesel fuels available in the laboratory, and then compare with them by external factors the test fuel sample and give a preliminary conclusion about the suitability of the sample to a particular brand of diesel fuel. 3. Determine the density of diesel fuel at 20 ° C. 4. Determine the kinematic viscosity at 20 ° C. 5. Determine the temperature of turbidity and congealing. 27 6. Calculate the cetane number of the fuel to be tested. 7. To establish according to the available standard parameters the brand of the tested diesel fuel, its compliance with GOST and to solve the problem of its use for cars as a fuel for internal combustion engines. 8. Perform the necessary work specified in the assignment. 9. To issue a report, to make a technical conclusion. Answer the control questions. Brief theoretical information, composition and sequence of the work. Estimation of diesel fuels by external characteristics Diesel fuels (DT) are designed for diesel engines and are petroleum fractions boiling at a temperature of 200 to 350 ° C. In chemical composition, they are a mixture of normal alkanes, iso-alkanes, cycloalkanes and a small amount of aromatic hydrocarbons. DT must meet the following requirements: to have a certain density, surface tension, volatility and self-ignition; keep fluidity at low temperatures; be chemically and physically stable; have a minimum corrosive effect; do not contain water and mechanical impurities. Estimation of diesel fuels by external characteristics should be carried out by the same methods that are considered for gasoline in the description of work No. 1, in addition to the characteristic features related to the color and smell of fuels. All diesel fuels are colored, which is due to the presence of dissolved resins in them. Depending on the nature and amount of tar, the color of the fuel varies from yellow to light brown (determined by means of glass cylinders 40-55 mm in diameter). The less the intensity of the color of the fuel (ie, the lighter it is), the less resinous substances in it and the higher its quality. In most cases, the smell of diesel fuels is not sharp. In its nature it is typical for many petroleum products (with the exception of gasolines and kerosene). Winter and especially Arctic varieties of diesel fuel differ little in their fractional composition from kerosene, and therefore they are similar in smell to kerosene. Equipment: glass cylinder with a diameter of 40-55 mm; sample of the tested diesel fuel. The order of the work: It is carried out by the same methods that are considered in work No. 1. 2.1.1 Measurement Of Diesel Fuel Density Equipment: glass measuring cylinders for 250 ml; a set of hydrometers (oil meters); a mercury-glass thermometer (in the case of a hydrometer without a thermometer) to 50 ° C with a fission rate of 1 ° C. The order of the work: Carried out the same methods that are considered in work No. 1. 2.1.2 Determination Of Kinematic Viscosity Viscosity refers to the property of a fluid to resist when she sheared or slid its layers. The obstacle to the movement of the layers of the fluid creates the forces 28 of intermolecular attraction. Externally, the viscosity is manifested in the degree of mobility: the lower the viscosity, the fluid is more mobile, and vice versa. The viscosity value is expressed in units of dynamic or ki-nematic viscosity. For the unit of dynamic viscosity η, the viscosity of such a fluid is assumed to exert a resistance of 1 N, caused by a mutual shift of two layers of this liquid of area 1 m2, located 1 m apart and moving at a speed of 1 m / from. The dynamic viscosity is measured in Pa • s. In GOSTs for petroleum products, the kinematic viscosity υ is indicated, which is equal to the ratio of the dynamic viscosity of the substance to its density ρ. The kinematic viscosity is measured in mm2 / s. υ = η / ρ (2.1) In practical activity, as a rule, kinematic viscosity is used which characterizes the operational properties of fuels and oils in relation to temperature and allows to decide the suitability of petroleum products for this engine and the reliability of its operation in all possible operating modes. The kinematic viscosity is determined in accordance with GOST 33-2000 in a capillary viscometer (Figure 2.1) over the time of flow of a certain volume of liquid (from label A to mark B) under the action of gravity at a given temperature. The longer the time of fluid flow through the capillary, the higher its viscosity. The kinematic viscosity υ, mm2 / s, is calculated by the formula: υ = C • τ (2.2) where C is the calibration constant of the viscometer, which depends on the length and diameter of the capillary mm2 / c2; τ is the time of flow (outflow) of the liquid, sec. The relationship between the kinematic viscosity and the dynamic viscosity is expressed by the formula η = υ • ρ • 10-3 (2.3) where η is the dynamic viscosity of the liquid, MPa • s; ρ is the density of the liquid at the same temperature at which the kinematic viscosity, kg / m3, was determined. To determine the viscosity of petroleum products, viscosimeters such as VPZH-2, VPZhT-2 or the Pinkevich type (VPZh-4, VPZhT-4) are used. At the same time viscosimeters type VPZh-2, VPZHT-2 are used to determine the kinematic viscosity of transparent petroleum products with a viscosity of 0.6 to 30000mm2 / s, and viscosimeters of the type VPZH-4, VPZHT-4 for liquids with viscosity limits of 0 , 6-10000mm2 / s. Each range of kinematic viscosity requires a number of viscometers. The capillary viscometer is a U-shaped tube with three extensions, the capillary of which is capped. Viscosimeters are produced with different capillary diameters (0.4, 0.6, 0.8, 1.0, 1.2, 4.0 mm). Above the capillary there are two extensions, between which and above the capillary there are annular marks. The lower expansion serves as a reservoir where the fluid flows during the determination of viscosity. It is extended to the point that the height of the column of liquid under the action of which the outflow takes place remains approximately constant. In the upper part of the high elbow there is a branch pipe, which serves to 29 attach a rubber pear. On the upper extensions, the number of the viscometer and the nominal diameter of the capillary are plotted. For each specimen of the viscometer, a passport must be present, in which the constant of the viscosimeter "C" in mm2 / s2 is indicated. To fill the viscometer with fuel on the side branch, it is put on a rubber tube with a pear, turned over 180 ° and immersed a narrow knee in a glass with the test fuel. Closing a wide-knee eye with a finger, the fuel is sucked into the narrow knee of the viscose meter to the mark between the capillary and the expansion with the help of a pear. After that, the viscometer is turned to the normal position and carefully wiped the narrow knee from the fuel. Attention: - Used in work viscometers are very fragile and expensive devices. In this regard, when working with them, you need to exercise the maximum of caution and, in particular, to keep and fix them should only be for one knee. Most often, the breakdown of viscometers occurs when you put on and remove the rubber tube, so in this operation, you need to keep them precisely for the knee on which the rubber tube is put on or removed. - It should be taken into account that when it gets into the internal cavity of the viscose meter of water or even its vapors, it becomes inoperable. Then the viscometer is immersed in a thermostat (bath) so that the bead of the viscometer is completely in the thermostatic liquid (Figure 2.2). Extract the viscometer in a thermostat for at least 15 minutes at a temperature of 20 ° C. When filling and maintaining the viscometer, it should not form ruptures and air bubbles. Then, without removing the viscometer from the thermostat, a vacuum is created by a rubber bulb in the tube 7 (see Figure 2.1), slowly picking up the fuel (from expansion 6) slightly higher than the mark A in the ball 3. Lifting the fuel above the mark A, turn off the rubber bulb and observe the fuel flow through the capillary 5 and the expansion 6. At the time of reaching the fuel level, the mark A is started by the stopwatch, and at the moment of passing the level of the mark B, it is stopped. Measure time is accurate to 0.1 s. With the same portion of fuel, the test is carried out several times. It is necessary to obtain five results of fuel expiration time, the maximum difference between which would not exceed 1% of the absolute value of one of them. To fill the thermostat, the following liquids are used: at a temperature of 100 ° C, an oil-transparent oil or glycerine, at 50 ° C water, at 0 ° C there is a mixture of water with ice, at lower temperatures, ethyl alcohol with solid carbon dioxide. 2.1.3 Equipment: capillary viscometer (set of viscometers); a thermoresistant glass with a capacity of 2000ml (a device for determining kinematic viscosity); rubber tube with a pear; stopwatch; a glass with a capacity of 50-100 ml; distilled water; thermometer with a scale division price of 0.1 ° C. 2.1.4 The order of the work: When using a set of viscometers, select a viscometer with a required diameter of the capillary. If you choose, proceed from the fact that the time of fuel expiration is within not less than 200 seconds (GOST 33-2000). With a shorter 30 time of expiration, the accuracy of measuring the time with a stopwatch decreases, and with a longer one, the analysis time is extended. Depending on the test temperature and the viscosity of the fuel, capillaries with the following diameters in mm are recommended: Temperature + 50 ° + 20 ° 0 ° Diameter of the capillary 0,4-0,6 0,8-1,0 1,0-1,2 1. In a glass with a capacity of 50-100 ml pour 30-40 ml of the test sample, which does not contain water and mechanical impurities. 2. Wearing a rubber tube 15-20 cm long, remove the viscometer by 180 ° and immerse its narrow knee in the test fuel container. 3. Tighten the wide knee with the thumb of the right hand and suck up the diesel oil with pears and so that it fills without bubbles and ruptures the entire internal cavity from the end of the knee to the mark B (Figure 2.2). Рис. 2.1. Вискозиметры для Рис. 2.2. Прибор для определения определения вязкости кинематической вязкости: а нефтепродуктов: 1 - заполнение жидкостью термометр; 2 - мешалка; 3, вискозиметра типа ВПЖ-2; 4, 6 расширения б - заполнение жидкостью вискозиметра; 5 вискозиметра типа капилляр вискозиметра; 7 Пинкевича; 1 - широкое - термостат (баня); 8 колено; 2 - узкое колено; 3, электроподогреватель 4, 6 - расширительные емкости; 5 – капилляр вискозиметра; 7 – резиновый полый отросток; А - верхняя метка; Б нижняя метка At the moment when the fuel level (when sucking) reaches the mark B, turn the viscometer to its normal position, release the wide knee from grasping the finger, and wipe the narrow knee 2 (Figure 2.1) from the fuel. Put the rubber tube on a narrow elbow, immerse the viscometer (the upper mark should be below the water level) into the water poured into a 2,000-ml glass and fix it in the tripod bracket, paying attention to the viscometer assuming a strictly vertical position. 31 Install and maintain in the thermostat the temperature required for the test 20 ± 0.1 ° C. When the liquid is heated in the thermostat to the set temperature, it is necessary to avoid overheating it, which is achieved by slowly heating the glass, from the moment when the temperature is 3-5 ° C below the set temperature. The temperature of the thermostat during operation is kept constant. The deviation is not more than 0.1 ° С.6. Withstand a viscometer with diesel fuel in a thermostat at a temperature of 20 ° C for 15-20 min. Squeezing the pear to overtake the fuel into the narrow knee slightly above the annular mark between the extensions (slightly above the mark A), making sure that no bubbles of air and fluid ruptures form in the capillary and expansion. At the same time, the viscometer is in the thermostat, and its wide knee is closed with a finger. Remove the finger from the wide knee and weight-watching the flow of fuel in the expansion, when the fuel level reaches the upper mark A (see figure 2.1), turn the stopwatch on and off when the fuel level passes the bottom mark B. Having written down the time of the test, marked stopwatch with an accuracy of 0.2 s, repeat the experiment at least three to five times (differences in the results should not exceed 0.5%). 8. Calculate the kinematic viscosity of the diesel fuel under test at the test temperature according to formula (2.2). Constant viscometer, take from the passport to the viscometer. The value of τ is taken as the arithmetic mean of the three measurements of the expiration time of the test fuel. Calculate the results of the calculation in cSt (mm2 / s) and round off three significant digits. 9. The results of the work should be recorded in the report on the work. 2.1.3 Determination Of The Pour Point The main violations in the fuel supply system at low temperatures are associated with the turbidity and pour point of the fuel. Unlike benzine, there may be quite a lot of hydrocarbons in diesel fuels with a high melting point, primarily paraffin (al-cane) and aromatic hydrocarbons. When the temperature is lowered, the most high-melting hydrocarbons emerge from the fuel in the form of crystals of various shapes, the fuel becomes turbid. The highest temperature, at which fuel loses its transparency, is called the cloud point. At the same time, fuel does not lose the flow property. The viscosity value increases with an increase in temperature slightly, but the crystals, penetrating through the coarse filter, form a film impermeable to the fuel on the fine filter, which leads to a stopping of the fuel supply. The cloud point, as a rule, should be 3-5 ° C below the ambient temperature. With the further cooling of the DT, the individual crystals join the frame, which permeates all the fuel, binding it. Fuel loses fluidity. With further cooling of the fuel, the crystals of high-melting hydrocarbons begin to unite, forming a lattice in which liquid hydrocarbons remain in the cells. Then the resulting structure is so strengthened that the fuel loses fluidity - freezes. The highest temperature at which fuel loses fluidity is called the pour point. It should be 8-12 ° C lower than the ambient temperature. The pour point is the temperature at which the diesel fuel poured into the test tube does not change the 32 position of the meniscus under certain conditions for 1 minute when the test tube tilts at an angle of 45 ° from the vertical (GOST 20287-91). The pour point of diesel fuel is a conditional quantity and serves as a guide only for determining the conditions for the use of fuel. Equipment: a device for detecting the temperature of turbidity of fuel; a laboratory stand; reagents for cooling mixtures (salt-ice for temperatures up to minus 20 ° C, alcohol and carbon dioxide for dry ice for temperatures below minus 20 ° C); test tube; fuel sample; sulfuric acid. Fig. 2.3. The device for determining the temperature of turbidity and solidification of fuel: 1 - an external tube; 2 - internal tube; 3 - a stopper; 4 thermometer; 5 - agitator The order of the work: The essence of determining the turbidity of the fuel lies in its deep cooling and visual observation of the change in its state. The essence of determining the pour point is the deep cooling of the fuel to the state of loss of mobility. 1. Test the fuel thoroughly and pour into the inner tube until the mark (40 mm from the bottom labeled). Close the tube with a cork stopper with a thermometer. The thermometer is inserted so that its mercury ball is in the test tube at a distance of 15 mm from the bottom and equal to the distance from the walls. 2. Pour the test fuel into another test tube, which is used as a reference standard. 3. Fill the vessel vessel with a cooling mixture, the level of which is maintained at 30-40 mm above the fuel level in the test tube. The temperature of the cooling mixture during the test at all times should be 15 ± 2 ° C below the temperature of the test fuel. 33 4. Strengthen the internal test tube with fuel and thermometer in an external test tube. To prevent fogging of internal walls between test tubes, sulfuric acid is poured in an amount of 0.5-1.0 ml. 5. Place the collected instrument in a cooling mixture. Fuel during the cooling all the time stir. 6. For 5 ° С to the expected cloud point, remove the tube from the cooling mixture, quickly wipe with cotton wool soaked with alcohol, and compare it with the standard. The duration of the comparison is not more than 12 s. 7. If the fuel has not changed in comparison with the transparent standard, the tube is again lowered into the vessel of the device and further observation is performed through each degree, lowering the temperature of the fuel. These comparative observations with a transparent standard are made until the fuel becomes different from the standard, i.e., when the turbidity appears in it. When determining the cloud point of an unknown fuel sample, the values of these temperatures are first set approximately by observing the state of the fuel every 5 ° C. 8. To determine the pour point of the fuel, in accordance with paragraphs 1 and 2, prepare the device with the dehydrated dewatered (with the help of freshly calcined calcium chloride) fuel. The prepared device should be placed in a vessel with a cooling liquid. The temperature of the cooling mixture should be 5 ° C below the expected temperature of the fuel ingress. 9. Without taking out of the cooling mixture, tilt the device at an angle of 45 ° and keep it in this position for one minute, until the test fuel in the tube takes a temperature corresponding to its pour point. 10. Remove the tube from the cooling mixture, wipe the walls of the wa LABORATORY WORK № 3 DETERMINATION OF THE MAIN INDICATORS OF QUALITY AND THE MARK OF ENGINE OIL The purpose of the work: to familiarize and consolidate knowledge of the quality of the main macro-motor oils, with the normative and technical documentation on the quality of motor oils (GOSTs for quality indicators and methods for their determination), familiarize yourself with and study methods for carrying out a control analysis of motor oil assessment of its quality), as well as acquire skills in the calculation of viscosity values of petroleum products with the help of nomograms, monitoring and evaluation of the quality of motor oils, and to determine their suitability for use in internal combustion engines abundance. 3.1 As a result of performing laboratory work, preparing and protecting the report, students must: know: 34 - the main brands of motor oils used in road transport, their properties and features; - Basic normative and technical documents on the quality of motor oils (GOSTs on quality indicators and methods for their determination); - the main methods for conducting a control analysis of motor oils, the methodology for calculating the viscous properties of petroleum products using nomograms. be able to: - give a description of certain types of automotive motor oils; - use normative and technical documents on the quality of motor oils (GOSTs on quality indicators and methods for their determination); - to apply the basic methods of conducting control analysis of motor oils, skills in the calculation of viscous oil products by nomograms; - apply skills to control, evaluate the quality of motor oils and establish the conditions for their use for internal combustion engines in road transport. 3.2 The order of performance of work 1. Consider the quality requirements, properties, indicators, the main brands of motor oils and their application. 2. To evaluate the test sample of engine oil according to external characteristics: transparency, color, odor, the presence of water and visible to the naked eye of mechanical impurities. To get acquainted with the collection of standard engine oils available in the laboratory, and then compare them with the external signs of the test sample and give a preliminary conclusion about the adequacy of the sample to one or another brand of motor oil. 3. Determine the kinematic viscosity of the sample at 50 ° C, 70 ° C, and 100 ° C. 4. Determine the viscosity index of the engine oil according to the nomogram. 5. To establish, according to the available standard parameters, the brand of the engine oil being examined, its compliance with the GOST and to solve the problem of its application for automobiles as a motor oil for internal combustion engines, indicating the necessary limitations and, in particular, the quantity extremely low temperature, to which it is possible to start the engine without using the means of heating. 6. Perform the necessary work specified in the assignment. 7. To issue a report, to make a technical conclusion. Answer the control questions. 3.3 Brief theoretical information, composition and sequence of the work. Evaluation of engine oil by external characteristics The presence in the oil of mechanical impurities and water will certainly reduce the lubricating properties of oils, increases the abrasive wear of parts. Evaluation of lubricating oils by external characteristics should be carried out by 35 the same methods, which are considered for gasoline and diesel fuels (in laboratory works 1 and 2). Mechanical impurities can be identified in three ways. The first and most simple is to look at the light of a thin layer of oil, applied to the glass. Dregs, streaks and grains will indicate the presence of mehanic impurities in the oil. If they are absent, the oil layer will look completely transparent. In the second method, the oil is shaken and heated to 40-50 ° C. Then 25-50 ml of oil is mixed with a two-, four-fold amount of filtered gasoline. The solution is filtered through a paper filter, after which the filter is viewed through a magnifying glass. Dark dots and crumbs on the filter indicate the presence of mechanical impurities in the oil. In a third method, an oil in an amount of 50-100 ml is diluted in a beaker with a two- and three-fold amount of gasoline. The mixture is stirred and allowed to settle for 5-10 minutes. Then the mixture is given a rotational motion. If there are impurities, they will gather in the center at the bottom of the glass. To detect impurities, the glass is viewed in the light that passes from the bottom to the top. The presence of water in the oil is determined according to GOST 1547-84. The meaning of the determination is to heat the oil placed in a test tube to a temperature of 130 ° C. If water is available, the oil will foam, a crackle will be heard, and the oil layer on the test tube walls will become cloudy. Modern motor and transmission oils contain significantly more resins than diesel fuels, so compared to the latter, they have a more intense coloration, up to the point that they become opaque in a layer 40-55 mm thick. In this regard, for liquid oils, in addition to the color in transmitted light, it is still necessary to additionally fix the color and hue in reflected light. 3.4 Equipment: glass cylinder with a diameter of 40-55 mm; sample tested of my oil; two pieces of clean dry glass with a size of 100x150 mm; filtered unleaded gasoline; a glass cylinder with a prick-in tube with a capacity of 250 ml; paper filter; magnifier 2-, 3-fold magnification; a beaker for 250-300 ml; artificial light source; electric stove; thermometer up to 200 ° С; glycerol; a chemical glass made of thermo-resistant glass with a height of 100 mm; test tube; Fume cup. Order of work: 1 variant1. Apply a few drops of the test oil to the piece of glass. The second section of the glass is carried out on the first to form a thin oil film. Both segments of the glass to view the light. Record the result of the observation in the report.2 option1. Warm the oil to 40-50 OC. Measure in a beaker 25-50 ml of preheated oil and mix with a two-, four-fold amount of filtered gasoline. Filter the solution through a paper filter. Inspect the filter using a magnifying glass. Record the result of the observation in the report.3 option1. Oil in an amount of 50-100 ml dilute in a beaker with two, three times the amount of gasoline. Stir the mixture and let stand for 5-10 min. Give the mixture a rotational motion. To detect impurities, inspect the glass in the light from the bottom to the top. The result is recorded in the report.4 option - to determine the presence of water in the oil1. In a glass of heat-resistant glass, heat glycerin to a temperature of 175 + 5 ° C. Pour the test oil into a clean and dry test tube to a height of 85 ± 3 mm. 3. Insert the 36 thermometer into the tube in such a way that the ball of the thermometer is at equal distances from the walls of the tube, and also at a distance of 25 ± 5 mm from the bottom of the tube. The test tube with oil and a thermometer should be placed in a beaker with heated glycerine and watch the oil until the temperature reaches 130 ° C. The result of the observation is recorded in the report. Determination of the kinematic viscosity is carried out in accordance with GOST 33-2000. This GOST applies to all liquids obtained on the basis of oil refining, therefore the viscosity is determined similar to the determination of the viscosity of diesel fuel, which was considered in laboratory work No. 2. It must be borne in mind that when determining the viscosity of oils, a viscometer with a diameter capillary so that the time of oil flowing at a given temperature was not less than 200 s. The recommended diameter of the capillaries when determining the viscosity of various oils is given in Table. Table 3.1. Data for choosing a viscometerNaming of oils Diameter of a capillary in mm. at the test temperature 100 ° C 50 ° C 0 ° C Oviscosity class 8 and 10 mm2 / s 0.8 1.2-1.5 3.0 Oil viscosity class 16 mm2 / s 1.01.2 1.5-2, 0-If the time of the oil flow from the viscometer is from 200 to 300 s, five measurements are taken, if it is 300-600 s, then four measurements are sufficient. The viscosity is determined at three temperatures: +50, +70, + 100 ° FROM. To determine the viscosity at + 100 ° C, the water in the beaker is brought to a boil (the boiling point of water due to the barometric pressure in the laboratory, which differs from 760 mm Hg, is usually somewhat lower, rarely above 100 ° C, but this has practically no effect on the results of determining the viscosity of the oil). The results of measuring the oil flow time should not differ from each other by more than 1.5%. According to the data obtained, a curve for the viscosity versus temperature (viscosity-temperature characteristic - BTX) is constructed. An example of the change in the viscosity of two motor oils as a function of temperature is shown in Fig. 3.1. Fig. 3 1 Effect of temperature on the viscosity of the oil: 1 - steep viscosity-temperature characteristic; 2 - flat viscoustemperature characteristic Fig. 3 1 Effect of temperature on oil viscosity: 1 - steep viscosity-temperature characteristic; 2 - flat viscous-temperature characteristic Fig. 3. 1 Effect of temperature on the viscosity of oil: 1 - steep viscosity-temperature characteristic; 2 - flat viscous-temperature characteristic Equipment: - stopwatch; a set of viscometers; chemical glasses; distilled water, glycerin; flask; thermometer; water bath. The order of the work: It is carried out by the same methods as discussed in work No. 2. However, since oils have a higher viscosity than fuels, they must be preheated to a temperature of 40-50 ° C, lowering the flask with oil in a water bath. 3.3 Determination Of The Viscosity Index One of the important properties of oils, characterizing their performance properties, is the degree of change in viscosity of oils as a function of temperature, which is usually determined either by the ratio of the viscosity at two extreme temperatures, ummin / umax, or by the viscosity index. 37 The viscosity index is calculated on the basis of GOST 25371-97 and, according to its definition, the viscosity index (VI) is the design value that characterizes the change in the viscosity of oil products as a function of temperature. In Fig. 3.1 shows the change in viscosity of two engine oils as a function of temperature. The viscosity ratio at 50 ° C to the viscosity at 100 ° C for automotive oils is 4 to 9. The smaller the ratio, the more the viscosity-temperature curve, the better the viscosity-temperature properties of the oil. The evaluation of the viscosity index is based on a comparison of the viscosity-temperature properties of the test and two reference oils. One reference oil has a slippery viscosity-temperature curve, and its viscosity index is taken as 100 units; the other has a steep viscosity-temperature curve, and its viscosity index is considered to be 0. The viscous-temperature curve of the test oil will be located between the reference oil curves and its position is judged on the viscosity index. Practically, the viscosity index according to GOST 25371-97 is determined by calculation. If the expected viscosity index is in the range from 0 to 100, then it is calculated as the ratio of the viscosities determined at 40 ° C and 100 ° C according to the formulas: If the viscosity index is more than 100, then it is found by formulas using logarithms and GOST tables. A simpler way to determine the oil viscosity index (but less precise) is to use a nomogram (Figure 3.2) based on the kinematic viscosity of the oil at 100 ° C and 50 ° C. To do this, the lines from the points corresponding to the oil viscosity values at 100 ° C and 50 ° C are drawn vertically and horizontally and the viscosity index is found at the intersection site. The value of the viscosity index of the order of 90-100 and higher is characterized by good, and below 50-60 - poor visco-temperature properties of the oil. 3.3.1 Equipment: nomogram for determining the viscosity index. 3.3.2 The order of the work: 1. From the obtained value of the kinematic viscosity at 100 ° C on the noogram (Fig. 3.2), draw a vertical line from the horizontal axis. 2. From the obtained value of the kinematic viscosity at 50 ° C on the nopulse, draw a horizontal line from the vertical axis. 3. Find the viscosity index of the oil at the intersection of the lines. 4. Record the result in the report. 38 Establishment of the brand of oil and the solution of its application After obtaining all the parameters of the oil under investigation, it is necessary to establish the brand of the test sample and its compliance with GOST. To do this, the actual data available for the sample are compared with the corresponding standards. When establishing the brand of oils should be guided by the same methodology, which was set out in work 1. Preparation of the report. After completing the work, the student performs a report in which the following should be written: 5) the theme and purpose of the work; 6) the results of an experimental study of engine oil. Sample report: Task: Analyze the engine oil, determine its brand, comply with the standard and set the application conditions with the indication of the extremely low temperature at which the engine can be started without heating. 1. Evaluation of the sample by external characteristics: color in transmitted light ______________________________________ color in reflected light _______________________________________ presence of water and mechanical impurities _________________________ 2. Determination of the kinematic viscosity Viscometer No. ______________________________________________ The constant of the viscosimeter C ___________________________________ Time of oil expiration τ (accurate to the tenth of a second): at 50 ° C: І) ______________ 2) _______________ 3) ___________________ Average :_________________________ at 70 ° C: I) ________________ 2) _________________ 3) ___________________ Average:__________________________ 39 at 100 ° C: 1) ________________ 2) _________________ 3) ___________________ Kinematic viscosity: at 50 ° C υ50 = _____________________ mm2 / s at 70 ° C υ70 = _____________________ mm2 / s at 100 ° C υI00 = _____________________ mm2 / s at 0 ° C, υ0 = ______________________ mm2 / s 3. Construct a curve for the dependence of the viscosity of the oil on temperature (BTX) 4. The brand of the sample and the compliance of its main indicators with the technical requirements of the standard (summary table). Table 3.2 Final test table for the sample of motor oil Main indicators Sample The value of the basic indicators according to the standard Actual deviations of indicators from the parameters of the standard Viscosity, mm2 / s υI00 υ0 Viscosity index Pour point, OS Conclusion on work: ________________________________________ 3.3.3 Control questions. 1. What are the ways to clean the oils? Give them a comparative assessment. Enumerate the additives to the oils. What is their purpose? 3. What does the viscosity of the oil affect when using the engine? 4. What are the working conditions of motor oils? 5. For what temperatures is the viscosity of motor and transmission oils normalized? 6. What is the oil viscosity index? 7. What are the ways of lowering the pour point of the oil. 8. What is an alkali number? 9. What are the causes of engine oil aging? 10. List the requirements for engine oils. 11. What is attributed to the performance properties of oils? 12. What are the types of additives to oils, their purpose? 13. How are motor oils classified according to GOST? 14. How are SAE and API engine oils classified? 15. What are the advantages of synthetic oils in front of mineral oils? 16. What is the dynamic and kinematic viscosity? 17. What is the viscosity-temperature properties of oils and what are they estimated by what indicators? 18. How does viscosity affect the performance of oils? 19. What are the viscosity characteristics of oils used in cars in winter and summer? 20. List the brands of motor and transmission oils and their application. 21. What is the viscosity index? 40 LABORATORY WORK № 4 DETERMINATION OF THE MAIN INDICATORS OF THE QUALITY OF PLASTIC LUBRICANTS 4.1 The purpose of the work: to familiarize and consolidate knowledge on the quality of the main macro-plastic greases, with the normative and technical documentation on the quality of greases (GOSTs on quality indicators and methods of their determination), to familiarize and study the methods of conducting a control analysis of plastic lubricants, as well as acquire skills to monitor and evaluate the quality of greases, and to determine their suitability for use in cars. 4.2 As a result of performing laboratory work, preparing and protecting the report, students must: know: - the main brands of greases used in road transport, their properties and features; - Basic normative and technical documents on the quality of plastic lubricants (GOSTs on quality indicators and methods for their determination); - the main methods of conducting a control analysis of grease. be able to: - give a description of certain types of automotive plastic lubricants; - use normative and technical documents on the quality of plastic lubricants (GOSTs on quality indicators and methods for their determination); - apply the basic methods of conducting control analysis of plastic lubricants; - Apply skills to control, evaluate the quality of greases and determine the conditions for their use in road transport. 4.3 The order of performance of work 1. To consider the requirements for quality, properties, indicators, the main brands of greases and their application. 2. Evaluate the test sample of grease according to external characteristics: color, odor, structure. To get acquainted with the available in the laboratory collection of standard greases, and then compare with them by external characteristics of the test sample and give a preliminary conclusion about the belonging of the sample to this or that brand of grease. 3. Determine the homogeneity of the sample 4. Determine the solubility of the lubricant in water and in gasoline. 5. Determine the dropping temperature of the proposed lubricant samples. 6. To establish on the available standard parameters the brand of the investigated plastic grease, its conformity to the standard and to decide the question of its application on cars. 7. Perform the necessary work specified in the assignment. 41 8. To issue a report, to make a technical conclusion. Answer the control questions. 4.4 Brief theoretical information, composition and sequence of the work. Evaluation of grease by external characteristics Plastic lubricants are used for such friction parts of mechanisms, where the design features can not be maintained or regularly supplied with liquid oils, i.e. when the use of mineral oils is impossible or irrational. As an example of such units used on cars, you can call wheel bearings, hinges of various kinds of drives, etc. The operational requirements for the quality of lubricants are as follows: lubricants must be uniform; possess certain mechanical properties; to have a minimum corrosive effect on metals; should not contain water and mechanical impurities. When assessing lubrication by external characteristics, attention is drawn to its color, the state of its surface layer and its uniformity. Almost all lubricants are opaque, so their color must be fixed in reflected light. The color depends on the coloring of the components that are part of the lubricants and used for cars, the technology of its production and preserves the color of the oils contained in them during the production process. Therefore, the lighter the grease, the deeper the oil is used for its preparation. Lubricants, which do not contain special additives (solidols, kon-steels, etc.), have a color from light yellow to dark brown. The most pronounced color is graphite grease and No. 158. The first is black, the second is blue. Lubricants with hydrocarbon thickeners (technical petrolatum, etc.) have a faint smell of petroleum products. Fat greases of universal purpose (for example, solidolines of series US) can smell with laundry soap. All mass synthetic lubricants (solidol C, etc.) have a peculiar, slightly aromatic odor, which after the first acquaintance with it is quickly and unmistakably recognized. The dispersed phase forms an openwork crystalline skeleton in lubricants composed of particles of microscopic or submicroscopic dimensions. The size of the particles and the resulting originality of the skeleton are manifested not only in the mechanical properties of the lubricants, but also in their appearance. With particles of dispersed and submicroscopic size, the surface of the lubricant looks smooth and shiny, like that of solidolines, with lubricants TsIATIM-20I. If in the process of preparation crystalline formations of larger sizes (microscopic) are obtained, then, however carefully the surface of such a lubricant may be smooth, it will still look grainy and even fibrous (for example, fatty kostalin). After intensive mechanical action (in particular, after a long work in the mechanisms) we see With a simple eye, the structure of all smears is smooth. Equipment: a glass plate; putty knife; sample tested lubricant. Order of work: 1. Using a putty knife, apply a layer of 1-2 mm on the glass plate. In this case, the formation of air bubbles. Inspect the lubricant layer in transmitted light and determine whether there are or are no drops of oil, thickener clots, foreign solid 42 inclusions. Evaluation results should be recorded in the report. Evaluation of homogeneity of greases Homogeneity is one of the most important requirements for plastic greases. Compliance with this requirement should be checked first by inspecting the lubricant in a container or directly in the friction unit. In either case, there should be no noticeable separation from the lubricant of the liquid phase (oil). At the second stage of the homogeneity assessment, a glass plate should be used to apply the test sample 1-2 mm thick. When examining this layer in transmitted light, do not disclose a droplet of oil, thickener lumps, foreign solid inclusions (not to be confused with air bubbles) in the unguided eye. If the lubricant is a mechanical impurity, then it must be rubbed between the fingers. In the presence of sand, the use of lubricants is unacceptable. 4.5 Equipment: glass plate; putty knife; sample tested lubricant. Order of work: 1. Using a putty knife, apply a layer of 1-2 mm on the glass plate. 4.6 Determination In this case, the formation of air bubbles. Inspect the grease layer in the transmitted light and determine the uniformity of the lubricant, i. E. presence or absence of oil droplets, thickeners in the thickener, foreign solid inclusions. Determination of the solubility of lubricant in water and gasoline Testing of grease for solubility in water and gasoline allows to determine the thickener of this lubricant, since it is known that sodium lubricants have a weak water resistance, and calcium and lithium are insoluble in water and gasoline , although with gasoline they form viscous, but non-transparent systems. Therefore, they can only be distinguished from each other by the dropping point. A complete dissolution of the grease is possible in water heated to boiling point. In this case, a muddy (soap) solution will be formed with a layer of liquid oil floating on its surface, indicating that this sample belongs to sodium lubricants. However, if after cooling water becomes transparent or slightly turbid and there is a layer of lubricant on its surface, then this lubricant is considered insoluble in water. To check the lubricity for solubility in gasoline, it must be mixed with it in a ratio of 1: 4 at a temperature 60 ° C. If in this case a completely transparent solution is formed which has the color of the test sample when viewed, the lubricant is considered to be soluble in gasoline. In gasoline, lubricants with hydrocarbon thickeners are dissolved. The fat spot allows even more accurate determination of the composition of lubricants. The main grades of greases give characteristic fatty spots. In this way, we can distinguish not only the solidol from konstallin, but also fatty salts from synthetic ones, to detect technical petroleum jelly, etc. Equipment: test tubes; a glass rod; distilled water; unleaded petrol; gas-burner; water bath, filter paper. A sample of lubricant in an amount of approximately 1 gram is placed on the bottom of the two test tubes with the help of a glass rod, trying not to touch the walls. Add 4 times the amount of distilled water to one of the tubes. In the second test tube add four times the amount of gasoline. Being careful, bring the water in the first test tube to the boiling point on the gas burner. At the same time, the heating is carried out gradually, inserting the tube into the flame of the burner repeatedly for 2-3 seconds with simultaneous rotation around its axis. The complete dissolution of the 43 thickener and the formation of a muddy (soapy) solution with a floating layer of liquid oil on its surface testifies to the belonging of the test sample to sodium lubricants. 5. Determine the solubility of the lubricant in water and record the result in the report. Warm the second test tube to 60 ° C (heat determine by touch) .7. Determine the solubility of the lubricant in gasoline and record the result in the report. Only lubricants with thickeners from solid hydrocarbons (technical petrolatum, lubricant GOI-54, etc.) possess the ability to dissolve. A sample of a lubricant in the form of a small lump or ball with a diameter of about 5 mm is placed on a filter paper and gently heated the paper over the tile. At the same time, easily melting parts of the lubricant are absorbed by the paper, and the rest remains in the form of a dense residue. The technical Vaseline VN melts and absorbs completely, leaving an even and bright spot. Solidolide synthetic CSS forms a spot with a small residue in the middle. The color of the residue usually differs little from the color of the rest of the stain. During the heating, bubbles are noted. Konstantin UT-I, as well as lubrication of UTV remain on paper in In its original form, but with a small oil halo at the edges. With a strong heating, the bu-mage is charred, and the lubricant does not completely melt. Bubbles are not observed when heated. Graphite lubricant USs-A leaves a dark grease stain with clearly different inclusions of graphite particles. Cardan grease A15- slightly brownishyellow, halo yellow. Uniol 1-grease is brown-yellow, halo is light yellow. Litol-24 - grease brownish-yellow, halo light. 4.7 Determination Of The Dropping Temperature Of The Lubricant One of the reasons for the transition of a grease to a liquid state is excessive heating. Incorrect choice of lubricants for the friction unit leads to serious disruptions to its operation, and often causes a car accident. For example, if you put the same lubricant in the wheel hub, lubricated by the friction parts of the running gear (that is, the mid-melting grease "Solidol C"), when the car moves and the hub bearings heats, this grease flows out of the hub cavity, gets on the brake drums, breaking the system of braking the car with all the ensuing consequences. To determine the dropping temperature of the lubricant, use a special device (GOST 6793-74), the scheme of which is shown in Fig. 4.1. To the lower part of the thermometer is attached a metal sleeve 2 in which, through friction, a glass cup 1 is kept with a calibrated bottom hole. The cup filled with grease is inserted into the sleeve, and the device (calyx, sleeve and thermometer) is inserted into the glass sleeve so that the distance from its bottom to the bottom of the cup is 25 mm. The coupling is immersed in a glass with water or glycerin and fixed in the staff. The depth of immersion should be 150 mm. Then the liquid is heated in two stages. At the first stage, the heating rate is not normalized and it is conducted to temperatures: 30 ° C for low melting lubricants, 60 ° C for medium melts, 110 ° for sodium and 150 ° for lithium. In the second stage, the heating rate should be 1 ° C per minute. At both stages, the liquid in the glass should be stirred periodically. 44 The temperature at which the first drop of the lubricant under test falls from the cup during heating is the dropping point. If the lubricant does not form a drop, but is drawn from the cup in the form of a cylinder, then the dropping temperature is taken to be the one at which the outgoing grease bar touches the bottom of the coupling. Fig. 4.1. Device for determining the temperature of dropping grease: 1 - cup; 2 - sleeve; 3 - a glass with a liquid; 4 - glass coupling; 5 - cork; 6 - thermometer Practically established that the lubricant can be used in friction units, the operating temperature of which is not less than 15-20 ° C lower than the dropping temperature of this lubricant. The dropping point depends mainly on the kind of thickener: for lubricants on calcium soaps 70 ... 90 ° С, on complex calcium soaps up to 200 ° С, on sodium soap up to 120 ... 150 ° С, on lithium soap - 170 ... 210 ... FROM. 4.8 Equipment: device for determining the dropping point of lubricants; putty knife; stopwatch; glass heat-resistant glass; glycerol or water; annular metal stirrer. 4.9 The order of performance of work 1. Remove cup 1 (see figure 4.1) from the device and fill it with a spatula with a lubricant that is to be tested, preventing the formation of air bubbles in the lubricant. 2. Insert the cup back into the metal sleeve 2 as far as it will go and remove the lubricant flush with thermometer 6 with a spatula with the lower edge of the cup. 3. Assemble the assembled device with a stopper 5 in the glass sleeve 4 so that the distance from its bottom to the bottom of the cup is 25 mm. 4. Place the coupling together with the device in a glass 4 with water or glycerin and fix it in a tripod so that the depth of immersion is 150 mm. 5. Stir the liquid with a mixer, heat the glass on the gas burner to temperatures: 45 - 30 ° C for low melting lubricants; - 60 ° C for medium melting points; - 110 ° C for sodium; - 150 ° C for lithium. 6. After passing through these temperatures, the further heating rate is maintained at 1 ° C per minute. 7. Lock the temperature at which the first grease drops from the cup or its creeping column touches the bottom of the coupling. 8. The result is rounded up to integer units and written to the report. LABORATORY WORK № 5 DETERMINATION OF FLASHPOINT AND IGNITION OF PETROLEUM PRODUCTS Most of the oils have a flash point of vapor below 00C. For example, the flashpoint of the Ust-Balyk and Samotlor oil is -300C and below -350C, respectively. The natural bitumen of the Mordovo-Karmalskoe deposit, extracted by the method of in-situ combustion, has a flashpoint of 590C. Fractions 1202300C and 180-3500C of Mordovian-Karmal natural bitumen have a flash point of respectively 32 and 910 ° C. According to the flash point, petroleum products are divided into flammable and combustible. To flammable refers to petroleum products having a flash point of vapor not more than 610С in a closed crucible (not more than 660С in an open crucible). The combustible class includes petroleum products with a flash temperature exceeding 610С in a closed crucible (more than 660С in an open crucible). Flammable petroleum products are mono-fuel fuels. So, automobile gasoline has a flash point in a closed crucible -500С, aviation -300С. Fuels for jet engines, depending on the grade, should have a flash-point of at least 28-600C, and topspeed for high-speed diesel engines 35-610C. The ignition temperature of diesel fuels is in the range of 57-1190 ° C. The ignition temperature is always higher than the flash point. The self-ignition temperature of the petroleum product increases with its molecular weight: if the gasoline self-ignites at temperatures above 5000 ° C, diesel fuels at 300-3300 ° C. On the flare, ignition and self-ignition temperatures, the fire and explosion hazard of oil and oil products are assessed. The flash point of oil, light petroleum fractions and motor fuels is determined in a closed and open crucible. Determination in an open crucible is used for oils and dark oil products. Determination of flash and ignition temperatures in an open crucible by the Brenken method Devices, reagents, materials Oil product, iron crucible, sand bath, electric heating device, thermometer up to 360 0С, beams, protective mask. 46 Preparation for analysis. To determine the flash point and ignition take anhydrous oil. The crucible is washed with gasoline, then, in the presence of carbonaceous deposits, it is cleaned with a metal brush, rinsed with distilled water and dried. The device for determining the flashpoint and ignition temperature is set in a place where there is no appreciable air movement and daylight on the surface of the crucible, and protects against air movement by a shield or screen. To carry out the analysis, the crucible is cooled to 15-250C and placed in the outer crucible of the apparatus with calcined sand. In this case, the sand should be about 12 mm from the upper edge of the inner crucible, and between the bottom of this crucible and the outer crucible, the sand thickness should be 5-8 mm. Analyzed oil is poured into the inner crucible so that its level is below the edge of the crucible by 12 mm for petroleum products with flash up to 210 ° C inclusive and at 18 mm for petroleum products with a flash above 210 ° C. Attention! Do not fill the oil product above the level marked on the inside of the crucible and spray oil. The thermometer is placed in the inner crucible with the oil product in a strictly vertical position, so that the mercury ball is in the center of the crucible approximately at the same distance from the bottom of the crucible and the level of the oil product. Carrying out the analysis. In the analysis, the outer crucible of the apparatus is heated on an electric stove. For 400C to the expected flash point, the heating rate is limited to 40C / min. For 100 ° C to the expected temperature, flashes are conducted slowly along the edge of the crucible at a distance of 10-14 mm from the surface of the oil product being analyzed and parallel to this surface by the flame of the ray. The flame length should be 3-4 mm, the time of the flame advance from one side of the crucible to the other 2-3 seconds. The determination is repeated after 20C of temperature rise. The flash temperature is taken to be the temperature that the thermometer shows when the first blue flame appears above the part or over the entire surface of the oil product being analyzed. In this case, one should not mix a true flash with a reflection from the flame of a ray. In the case of the appearance of an unclear flash, it must be confirmed by a subsequent flash at 2 ° C. After the flash point of the petroleum product is determined, if it is required to determine its ignition temperature, continue heating the outer crucible so that the analyzed oil is heated at a rate of 40C / min. After every 20C of the temperature rise, the flame of the ray is brought to the oil product. The temperature of the ignition is taken to be the temperature indicated by the thermometer at the time during which the oil product being analyzed ignites a flame and continues to burn for at least 5 seconds. The discrepancy between two consecutive determinations of the flash point should not exceed the flash temperature up to 1500C - 40C, above 1500C - 60C. The discrepancy between two successive definitions of the ignition temperature is 47 not up to must exceed 60 ° C. Attention! This work should be carried out only in protective masks. 48 СПИСОК ЛИТЕРАТУРЫ 1. Автомобильные материалы: Справочник / Г.В.Мотовилин, М.А.Масино, О.М.Суворов. – М.: Транспорт, 1989. – 464с. 2. 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Автомобильные эксплуатационные материалы: Лабораторный практикум. – М.: ФОРУМ: ИНФРА-М, 2002.-208с. 24. Терентьев Г.А., Тюков В.М., Смаль Ф.В. Моторные топлива из альтернативных сырьевых ресурсов. - М.: Химия, 1989. - 272с. 25. Химики – автолюбителям / Б.Б.Бобович, Г.В.Бровак, Б.М.Бунаков и др. - Л.: Химия, 1990. – 320с. 26. Шкаликова В.П., Патрахальцев Н.Н. Применение нетрадиционных топлив в дизелях. – М.: Изд-во УДН, 1986. – 56с. 50 51 Iztleuov G.M., Tanashev S.T., Mamitova G., Sataeva L.M. METHODICAL INSTRUCTIONS FOR LABORATORY WORK on the discipline « CHEMOTOLOGY » Подписано в печать __________________________ (число.месяц.год) Формат бумаги XxY 1/16 Бумага типографская. Печать офсетная. Объем ……п.л. Тираж …….экз. Заказ № …….* © Издание Южно-Казахстанского государственного университета им. М.Ауезова Издательский центр ЮКГУ им. М.Ауэзова, г. Шымкент, пр. Тауке хана, 5 52