Министерство науки и высшего образования республики казахстан
«СОВРЕМЕННЫЕ ДОСТИЖЕНИЯ И ТЕНДЕНЦИИ ХИМИИ И ХИМИЧЕСКОЙ ТЕХНОЛОГИИ В XXI ВЕКЕ»
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XXI ҒАСЫРДАҒЫ ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯНЫҢ ЗАМАНАУИ ЖЕТІСТІКТЕРІ МЕН ТЕНДЕНЦИЯЛАРЫ-ХИМИЯ-2023-06-05 14 54 57pm
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| «СОВРЕМЕННЫЕ ДОСТИЖЕНИЯ И ТЕНДЕНЦИИ ХИМИИ И ХИМИЧЕСКОЙ ТЕХНОЛОГИИ В XXI ВЕКЕ»
«XXI ҒАСЫРДАҒЫ ХИМИЯ ЖӘ НЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯНЫҢ ЗАМАНАУИ ЖЕТІСТІКТЕРІ МЕН ТЕНДЕНЦИЯЛА РЫ» - equipping the vacuum column with a regular nozzle with low hydraulic resistance; -preliminary mechanical activation of crude oil; - by installing an additional column. Using a regular nozzle with low hydraulic resistance. Initially, plates with low mass transfer efficiency and high hydraulic resistance were used as contact devices of vacuum columns in the blocks of vacuum distillation of fuel oil. This led to an increase in energy consumption for distillation, the amount of decomposition gases formed and a decrease in the quality of the vacuum distillates obtained [1]. In the global oil refining industry, regular-type nozzle contact devices are widely used for vacuum distillation of fuel oil, which have significantly lower hydraulic resistance per unit of theoretical plate, compared with poppet contact devices. The currently used vacuum columns with regular packing devices can be divided into two types according to the method of organizing the mutual movement of contacting liquid and steam flows: counter-current and cross-current [2]. Countercurrent nozzles are made of perforated corrugated sheets, which are then bonded together into finished sections. The main distinguishing features of countercurrent nozzles from poppet contact devices: - significantly lower hydraulic resistance; -high separation capacity. However, regular attachment devices also have a number of disadvantages, such as: - high cost and complexity of manufacturing; - the complexity of organizing an even distribution of irrigation over the entire area of the nozzle. Distillation of fuel oil in industrial conditions is usually accompanied by the introduction of water vapor in the amount of up to 1.5% of the mass of fuel oil into the vacuum column cube. Along with the positive effect (improvement of the stripping of hydrocarbons), there are also negative effects: the need to increase the cross-sectional area of the column, dilution of hydrocarbon vapors and, due to this, a decrease in the efficiency of the distillation column plates, an increase in the load on the vacuum creation system. A partial solution to this problem is the reconstruction of the vacuum column with equipping it with regular nozzles with low hydraulic resistance. The hydraulic resistance of the column directly affects the selection of vacuum gas oil according to the following basic pattern: the hydraulic resistance increases in proportion to the square of the increase in the selection of vacuum gas oil. So regular nozzles with low hydraulic resistance of the company « Koch - Glitsch » , with steam and liquid distributors, allow to increase the total output of vacuum distillates and improve their quality. In addition to the Koch - Glitsch nozzles, there are many other regular countercurrent nozzles with low hydraulic resistance per theoretical plate. Russian and foreign refineries mainly use regular countercurrent nozzle devices developed by such companies as Glitsch (Jam Pack), Zulzer (Mellapak), Cedar-89 (VAKUPAK) [3]. The main advantage of the cross-flow nozzle over the counter-flow is that the counter-flow nozzle occupies the entire cross-section of the column, and steam and liquid move towards each other, and the cross- flow nozzle occupies only part of the cross-section of the column (in the form of various geometric shapes: ring, triangle, quadrilateral, polygon, etc.) and the flow of liquid is carried out from top to bottom, while the vapor phase goes across the direction of the liquid flow. A representative of this type of nozzles is the « PETON » nozzle [4]. The developed regular cross-flow nozzle « PETON » , in contrast to the known types of contact devices, such as a high-flow nozzle, direct-flow devices, cross-flow plate, allows you to combine the advantages of these devices and substantially eliminate their disadvantages. The cross-flow regular nozzle « PETON » has the ability to independently adjust the section for the passage of steam in the nozzle from the section for the passage of liquid when designing the column. This property of the cross current in the nozzle makes it possible to solve the problem of organizing effective contact with unequal flow rates of steam and liquid in the column. Bench tests of the PETON nozzle, confirmed by industrial tests of columns in various processes with unequal steam and liquid loads, showed: - choking of the column occurs, on average, at loads 2.5 times greater than with the counterflow of phases on regular nozzles; - the efficiency of one section of the column with the « PETON » nozzle is from 60% to 99% with the height of the sections commensurate with the inter-tube distance in the column equipped with plates; - special partitioning and redistribution of steam and liquid flows increases efficiency, on average, by 1.5 times; - The WATT of the column with the « PETON » nozzle is 400 - 1000 mm. Preliminary mechanical activation of crude oil The method of mechanical activation of crude oil, which allows to increase the yield of vacuum gas oil during distillation under vacuum, is currently very ambiguous, but quite promising. |