Cours project by discipline «basic technological processes and devices» content
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Cours project by discipline « BASIC TECHNOLOGICAL PROCESSES AND DEVICES» CONTENT 1. Introduction 2. Description of supplied products 3 Description of the technological scheme 4. Technological calculation 5. Hydraulic calculation 6. Basic device statement 7. Environmental protection 8. Summary 9. References INTRODUCTION. On February 24, the President of the Republic of Uzbekistan Shavkat Mirziyoyev held a meeting dedicated to the discussion of future plans for the reform of the chemical industry and the main tasks to be implemented this year. In recent years, many measures have been taken to modernize the industry, to improve its financial and economic health, and to expand the nomenclature of chemical products with high added value. In order to increase the profitability of network enterprises, market mechanisms were introduced, and the price formation procedure was completely revised. As a result, the chemical network ended last year with 2.3 times more profit than in 2018. Polyvinyl chloride, caustic soda and methanol production complex was put into operation at "Navoiyaazot" joint-stock company. Synthetic liquid fuel is being built in the Sho'rtan gas-chemical complex, and nitric acid, ammonia and urea production plants are being built in the "Navoiyaazot" joint-stock company. In January of this year, the head of our state paid special attention to the chemical sector in his address to the parliament and at the joint session of the supreme assembly chambers, and set a number of tasks for the government to modernize it, to widely introduce science and innovation[8]. This means that the chemical industry has an important place in the economy of the Republic of Uzbekistan, and its development is one of the priority goals. The discipline “Basics technological processes and devices” studies the physical and chemical nature and theory of processes characteristic of all branches of chemical technology, as well as the principles of design and engineering methods for calculating apparatus intended for carrying out chemical and technological processes. The purpose of studying the subject is to teach the theory of basic processes and apparatuses, the principles of arrangement of machines and apparatuses that perform these processes and methods for their calculation. Depending on the regularities characterizing the processes, the last can be divided into the following groups: Mechanical processes. Hydromechanical processes. Thermal processes. Mass transfer processes. Chemical processes. Mechanical processes. These processes used for processing solid materials are obeyed to the laws of solid body mechanics. These processes are applied mainly for the preparation of initial solid materials and the processing of final products, as well as for the transportation of lumpy bulk materials. Mechanical processes included: -grinding -transportation -classification (sorting) of material by degree of grainity -their dosing -mixing A special group of mechanical processes is the processes of processing chemical products into products: -pressing -casting -extrusion Hydromechanical processes. These processes are used in the processing of liquids and fine solid particles suspended in the liquid and these processes included: -movement of liquid -compression and movement of gases Separation of liquid and gases heterogeneous system in the field of gravity forces (settling) -separation of liquid and gas heterogeneous system in the field of centrifugal forces -mixing of liquids Thermal processes. Heat processes are associated with heat transfer of heat from one substance to another. Such processes are: -heating -cooling -evaporation -vapor condensation Mass transfer processes. Mass exchange processes, also called diffusion processes, are characterized by the transfer of one or several components of the initial mixture from one phase to another through the phase. Example: -absorbtion -adsorbtion -desorbtion -extraction -rectification -drying Chemical processes. Chemical processes, also called reactional processes, process with a speed determined by the laws of chemical kinetics. According to the method of organization, the main processes of chemical engineering are divided into: -periodic -continuous. During boiling of solutions of solid, non-volatile or poorly volatile substances, remove the solvent and the resulting vapors the sending process is called evaporation. Usually in industry evaporation process is a way of boiling solutions is done. The purpose of evaporating solutions is to increase their concentration, that is, to thicken solutions. If the solvent is removed from the solutions, solids begin to crystallize di and crystals separated comes out. Evaporation process to increase the concentration of dilute solutions or extract dissolved substances from them by crystallization method is used. It is widely used in the evaporation process in chemical, food and other industries used in scale. For example, aqueous solutions of substances such as salt, alkali, mineral and organic acids, polyatomic alcohols, sugar and imagine a technology without this process of concentrating tomatoes, milk and juices in the production technology of canned goods will not happen. Also, this process is used to produce a clean solvent can be used. It should be noted that if the evaporation process occurs on the surface of the solution at any temperature lower than the boiling temperature, and evaporation at a temperature above the boiling point of the solution occurs in the entire volume. These processes are carried out in devices known as evaporators is done. It is known that continuous and continuous evaporation processes can be organized. Continuous working devices, usually in small quantities used in product manufacturing technologies. In large industrial enterprises, continuous evaporation equipment is used, and their heat exchange surfaces are 600... 1000 m2 will be the main factor determining the cost-effectiveness of such devices is the consumption of electricity and water in the house. Evaporation is carried out under vacuum, atmosphere and high pressure possible. During evaporation under vacuum, the secondary steam is in a special condenser a vacuum is created in the device by condensation and the pump is on where non-condensable gases are absorbed. If the process is carried out in this way, it is possible to lower the boiling temperature of the solution. As a result preserving the quality of products that are highly sensitive to high temperatures opportunity is taken. In addition, the application of vacuum in the process, to action Increases the amount of driving force and the vaporizer heat al allows to reduce the machining surface and metal consumption. Another advantage of evaporation under vacuum is the low temperature direct and pressure heat conductors can be used. In this way when vaporized, the secondary vapor formed, the primary vapor in the next case can be used as Of course, this method also has its disadvantages: vacuum ash in the process increases its price; few additional devices except the evaporator and devices must be used. Atmospheric pressure a secondary vapor formed during the evaporation process released into the environment. Although this method is considered the simplest, but it is the least economical. Secondary steam produced during high pressure evaporation during repackaging and use for other purposes possible in this method, since the process is carried out at high pressure, the boiling temperature of the solutions increases significantly. Secondary steam used for other purposes is called extra steam is called two separated in the process of evaporation under high pressure Reuse of steam allows full utilization of heat compared to vacuum evaporation. Thus, this the method is used only for evaporation of heat-resistant solutions. It except for the high temperature for the evaporation process under high pressure it is necessary to use heated conductors. This case is definitely its most important is a disadvantage. The process is carried out under atmospheric pressure, in some cases vacuum when is used, single-body evaporators are used. But on an industrial scale mostly in multi-body evaporation plants assembled from several plants it is common to carry out the process. In such devices, page 1 is the first primary steam is used in the casing. In the second, third and subsequent cases however, if the secondary steam released in the front casing is used, it will cause the conveyor to slow down and lead to a reduction in steam consumption. Primary steam consumption, even in single-body evaporator can be washed. For this, the secondary steam coming out of the device is pressure to the pressure corresponding to the temperature of the primary steam by means of a vacuum pump and again to the unit for evaporation of the solution will be directed. Download 53.87 Kb. Do'stlaringiz bilan baham: |
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