CC BY
11COMPARATIVE ANALYSIS OF DEVICES FOR WET CLEANING OF
INDUSTRIAL GASES
Rasuljon Jumabayevich Tojiev Abduraxmon Maxamadovich
Sulaymonov
Ferghana Polytechnic Institute ABSTRACT
In the article, an analysis of equipment for wet treatment of industrial secondary exhaust gases, the principle and types of operation of devices, construction, basic operating parameters and performance, hydraulic resistance in the working bodies, gas velocities is given.
Keywords: hydraulic resistance, guide pipe, gas velocity, resistance coefficient, exhaust gas, gas flow force, drop holder, injectors, turbulence.
Introduction: Today, at a time when machinery and technology are evolving, the demand and supply of production capacity is also increasing. As a result, the quality of products is improving and its volume is increasing in line with modern requirements. Until the raw material becomes a finished product, the secondary waste dust and gases from the existing processes are released into the atmosphere. This, in turn, leads to environmental degradation.
Research methods: Emissions emitted by industrial enterprises can be divided into two groups. The first group includes "unorganized discounts". They are formed as a result of incomplete provision of enterprises with treatment facilities, improper organization of transportation of materials, insufficient compliance with the rules of storage of raw materials. The second group includes "organized discounts". Such emissions are reduced by the organization of special smoke pipes, hoods, ventilation systems, etc. Emissions from enterprises in the chemical, metallurgical, oil refining and construction materials industries are particularly dangerous.
Among the gases polluting the atmosphere of foreign countries, industrial gas, hydrocarbons and nitrogen oxides account for 60-70% of all aggressive gases, in our country this figure is 35%, and in some cities (Andijan, Bukhara, Samarkand, Tashkent) 80% [1,11].
A lot of scientific research is currently being done on the neutralization of toxic gases emitted into the atmosphere. Industrial toxic gas purification devices come in different forms, depending on the structure and dispersion of dust gases, the necessary equipment is selected.
There are dry and wet methods of secondary gas purification in the industry, these types of devices are considered to have low hydraulic resistance and high operating efficiency. However, the dry cleaning level is much lower than the wet cleaning
level. Therefore, today in the world there is a growing trend of using the wet method in the purification of industrial dust and secondary gases. The wet method is effective in trapping particles with a high dispersion composition (particle size less than 5 ^m) in a liquid medium . For example, 95-96% of the fuel smoke generated in the boilers of thermal power plants, secondary toxic gases released during the reaction in the chemical industry, and paraffin smoke released during the refining process in the oil and gas plant [6].
The principle of operation of wet dust collection devices is based on the use of events that occur when the liquid flow is directed to the dust gas stream or when the gas passes through the liquid layer, in which the liquid flow is fed to the dust gas flow path through the injector. In this case, liquid droplets sprayed through the nozzle and particles of different sizes in the gas stream collide with each other and are surrounded by a liquid, in which the dust particles that absorb moisture become heavier and are forced to move away from the general flow. ladi [2].
Research results: Dust particles colliding with liquid droplets can sink under the influence of inertia, collision, gravitational forces.
Wet dust collectors, called scrubbers, depending on the direction of gas flow relative to the liquid:
- Opposite movement,
- Moving in parallel in one direction,
- Divided into transverse movements.
According to the method of contact of gas with liquid:
- Liquid dropper,
- bubbling
- Foamy,
The gas passes through the liquid
- Filmy - the particles settle in the liquid layer (film).
According to the gas flow rate:
- Fast or
- Turbulent,
The gas passes through the Venturi pipe at a speed of u = 100 - 150m / s, the contact of gas and liquid droplets is accompanied by turbulent pulsations.layer
- Slow-moving gas appliances - hollow and nozzle scrubbers;
According to the method of spraying the liquid and the method of forming a liquid film:
- Liquid spray using a nozzle,
- Sprinkler with gas flow (ejector dust collectors),
- Dynamic gas washers or mechanical scrubbers that mechanically spray liquid (using rotors or rotating blades of various shapes).
Depending on whether there is a device to catch splashes or liquid droplets coming out of the device:
- Drop holder or
- Divided into devices without a drop holder [3].
A number of data on the principle, methods and types of operation of wet dust collection devices are given. From this we can conclude that the scientific research we are conducting will be to determine how and in what construction the toxic gases should be carried out. Based on the above information, it is important that we choose the optimal option of construction.
Therefore, it is advisable to study the design of wet dust collection devices.
Rotational and centrifugal dust collectors
Centrifugal scrubbers can be of two types according to their design:
1) devices for turning the gas flow using a central shovel turning element
2) devices in which the gas flow is transmitted tangentially by the side.
In this case, the liquid is transmitted through a nozzle mounted on the central part of the device, in addition, the liquid that flows along the surface of the inner wall of the device forms a film.
Such devices are used to trap dust particles of any appearance that do not solidify. To form a film of water along the surface of the inner wall, it is introduced into the device in a tangential state through a series of pipes located above. [3].
Barbed and foam dust collectors
In such devices, the contact between the gas and the liquid occurs on horizontally placed plates. When the velocity of the gas is small (around 1 m / s), bubbles form as the gas passes through the liquid layer, a process known as bubbling. If the velocity of the gas is large - a turbulent foam layer is formed. For this reason, plate scrubbers are divided into two types: foam and bubble.
Figure 1 shows two types of foam-washing plate gas washers: a) overturning plate; b) pouring plate. Rotary plate scrubbers use perforated and slotted grills. The diameter of the holes is 4 - 8 mm, the width of the holes is 4 - 5 mm.
The free part of the plate (the proportion of holes relative to the total section) is 0.2 - 0.5 m . Casting devices use caps, S-shaped, perforated plates with collectors and other types of plates.
In this type of device, the number of perforated plates can be several, in which case the degree of cleaning increases (up to 99%). The hydraulic resistance of a single plate is approximately 600 Pa. Plate scrubbers with a device that stabilizes the foam layer are widely used in industry. The stabilizing device (stabilizer) significantly expands the speed range of the foam mode (up to 4 m / s) and increases the height of the foam layer. The gas efficiency of such a device is standardized and can vary from 3 to 90
"5
thousand m / h. The optimal velocity of the gas in the plates is 2.5 - 4.5 m / s, the
"5
specific flow rate of the liquid is 0.05 - 0.1 l / m . Foam devices are effective in the chemical and metal processing industries, especially in the production of mineral fertilizers in the purification of gases from fluorine, sulfur, phosphorus dust [4].
purified gas purified gas
i
Figure 1. Foam-forming plate gas washer
a) overturned plate; b) pouring plate.
Forging - inertial dust traps.
In this device, the contact of the gases with the liquid is due to the collision of the gas stream with the surface of the liquid. The gas-liquid mixture is then passed through holes of various shapes. As a result of this interaction, droplets with a diameter of 300400 ^m are formed [10]..
Forging is the simplest device in the design of inertial devices. The gas enters the column at high speed. As the gas flow is rotated 180 inertial deposition of dust particles into liquid droplets occurs. At the heart of this sinking process lies a
phenomenon known as the 'shock mechanism. There are other designs of this type of device.
Cones are mounted on the bottom of the pipe to increase the gas flow rate. The gas flow rate between the holes is 35 - 55 m / s. The gas hits the surface of the liquid and forms a layer of droplets. The hydraulic resistance of this device ranges from 500 to
"5
4000 Pa, and the specific flow rate of the fluid is 0.13 l / m [4].
Doyle scrubber (Fig. 2) - This type of device is used in industry for the treatment of aggressive and high-temperature secondary gases. Since the work productivity is not
very high, it has to be installed in series.
The principle of operation of the device is as follows: The purified secondary gas is directed to the body of the device (1) through a pipe (2) mounted vertically. A conical nozzle (3) is installed in the outlet of the pipe (2), which serves to increase the speed of gas flow and even distribution of the working fluid (4) filled to a certain level of the device. The gas to be cleaned is in direct contact with the working fluid and is purified in a liquid medium. The purified gas is discharged from the unit through the pipe (5). Droplet barriers (6) are installed on the body of the device in order to trap the liquid droplets that come out with the gas. The working fluid is constantly poured into the device through the pipe (7). A siphon (8) is used to adjust the working fluid level and remove the sludge from the device. In this type of device, the cleaning rate is higher than 99% [7].
Figure 2. Construction of Doyle Scrubber Dust Cleaners.
Venturi scrubbers.
Such a device consists of a liquid spray pipe (Venturi pipe) and a separator that separates the liquid droplets from the gas stream (Figure 3). The venturi tube consists of 1 constricting part (confuser), a short cylindrical part (throat) and an expanding part (diffuser). The liquid is fed to the confusor (or throat) using a special spray device or mechanical injector. The characteristics of the pipe can vary as follows: the angle of inclination of the confuser is 25 - 28°; the angle of inclination of the diffuser is 6 -7°; 0.15 to 0.5 percent of the diameter of the length of the throat; the diameter of the throat is 0.4 to 0.5 percent of the diameter of the pipe. To reduce pressure loss, the inner surface of the Venturi pipe is sanded by mechanical machining [9].
The gas-liquid stream passes from the throat to the diffuser, where it expands into additional fine droplets during expansion. Here, the liquid droplets carry the dust particles with it. The separation of the droplets from the gas stream takes place in the cyclone-droplet holder 2.
The velocity of the gas in the throat reaches 60-150 m / s. The liquid is supplied with excess pressure (0.03 - 0.1 Pa). The flow rate in the diffuser is reduced to 20 - 25 m / s. The velocity of gas-liquid flow in a cyclone is 4-5 m / s.
Figure 3. Venturi scrubbers:
1 liquid spray tube; 2 cyclone drop holder
In the venturi scrubber, a greater velocity of the gas is achieved relative to the liquid droplets trapping the dust particles. For this reason, the Venturi device has the ability to capture solid particles smaller than 1 ^m in gas content. The degree of purification reaches 99%, but the hydraulic resistance of the device is very high (2200 -12800 Pa) [5].
Conclusion: As a result of studying the design of wet dust collection devices, the principle of operation of the devices is based on the use of phenomena that occur by increasing the contact surfaces in directing liquid flows to the dust gas flow (liquid and dust gas - parallel, liquid and dust gas - opposite). It has been found that even very small particles can be trapped and a very high degree of purification can be achieved by trapping toxic and dusty gases released into the environment.
Offer: In our research work, the main goal is to clean gases from fluorine, sulfur, phosphorus dust, mainly in the chemical industry, especially in the production of mineral fertilizers. Therefore, the dust collector to be selected must fully meet these
requirements. The use of mechanical injectors and plates with a simple structure, low cost and low energy consumption for the use of wet dust collection devices in the production of mineral fertilizers for the capture of toxic gases. Analysis of the structure, operation and performance of wet dust collectors shows that the ability to capture toxic gases using devices equipped with Scrubber dust collectors is high.
REFERENCES
[1] Вилесов Н.Г., Костюковская А.А. Очистка выбросных газов. Киев: 2001. -312с
[2] UNEP. Окружаюшая среда в Центральной Азии - 2000 год. Узбекистон Республикаси ЭКОСАН халкаро жамгармаси такдим этган лазер диск маълумотлари.
[3] Садуллаев Х.М. Атроф мухофазаловчи техника. -Фаргона: "Классик", 2020., 172 б.
[4] Нурмухамедов Х,.С., Темиров О.Ш., Туробжонов С.М., Юсупбеков Н.Р., Зокиров С.Г., Таджихужаев З.А. Газларни кайта ишлаш технологияси, жараён ва курулмалари. - Тошкент: Шарк, 2016. - 856 б.
[5] Юсупбеков Н.Р., Нурмухдмедов Х,.С., Зокиров С.Г. Кимёвий технология асосий жараён ва курилмалари. - Тошкент: Фан ва технология-лар, 2015. - 848 б.
[6] Р.Ж. Тожиев, А.С. Исомидинов, А.М. Сулаймонов. Газларни суюклик мухити оркали утказиш усулида тозаловчи инерцияли скруббер гидродинамикаси // Фаргона политехника институтининг илмий-техника журнали, - Фаргона, 2020. Том 24 . спец. вып. № 1. 263-268.
[7] Валдберг А.Ю., Николайкина Н.Е. Процесси и аппараты зашиты окружающей среды. - Москва: Дрофа, 2008. -239 с.
[8] Тожиев, Р. Ж., Исомиддинов, А. С., Ахроров, А. А. У., & Сулаймонов, А. М. (2021). ВЫБОР ОПТИМАЛЬНОГО АБСОРБЕНТА ДЛЯ ОЧИСТКИ ВОДОРОДНО-ФТОРИСТОГО ГАЗА В РОТОРНО-ФИЛЬТРОВАЛЬНОМ АППАРАТЕ И ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ АППАРАТА. Universum: технические науки, (3-4 (84)), 44-51.
[9] Rasuljon, T., Azizbek, I., & Abdurakhmon, S. (2021). RESEARCH OF THE HYDRAULIC RESISTANCE OF THE INERTIAL SCRUBBER. Universum: технические науки, (7-3 (88)), 44-51.
[10] Муминов, Ж. А., Умаров, Э. С., & Ортикалиев, Б. С. (2019). Чангларни комбинацион тозалаш технологияси. Журнал Технических исследований, (2).
[11] Rasuljon, Tojiev, Isomiddinov Azizbek, and Ortiqaliyev Bobojon. "STUDYING THE EFFECT OF ROTOR-FILTER CONTACT ELEMENT ON CLEANING EFFICIENCY." Universum: технические науки 6-5 (87) (2021): 28-32.
[12] Хакимов, А. А., Салиханова, Д. С., & Каримов, И. Т. (2019). Кумир кукунидан брикетлар тайёрлашнинг долзарблиги. Фаргона политехника институти илмий техника журнали.-2019.-№, 23(2), 226-229.
[13] Хакимов, А. А. (2020). Связующее для угольного брикета и влияние его на дисперсный состав. Universum: химия и биология, (6 (72)), 81-84.
[14] Хакимов, А. А., Салиханова, Д. С., & Каримов, И. Т. (2018). Кумир кукунини брикетловчи курилма. Фаргона политехника институти илмий техника журнали.-2018.-№ спец, 2, 169-171.
[15] Алиматов, Б. А., Эргашев, Н. А., & Каримов, И. Т. (2019). Мокрый пылеулавливающий аппарат с прямоточно-вихревыми контактными элементами. Научно-техн. журнал Ферганск. политехн. ин-та, 23(2), 152.
[16] Алиматов, Б. А., Садуллаев, Х. М., Каримов, И. Т., & Хурсанов, Б. Ж. (2008). Методы расчета и конструирования жидкостных экстракторов с пневмоперемешиванием.
[17] Хурсанов, Б. Ж., & Алиматов, Б. А. (2020). ЭКСТРАКЦИОННОЕ ИЗВЛЕЧЕНИЕ РЕДКИХ МЕТАЛЛОВ ИЗ ОТВАЛОВ ГОК. Universum: технические науки, (6-1 (75)).
[18] Мирзахонов, Ю. У., Хурсанов, Б. Ж., Ахроров, А. А., & Сулаймонов, А. (2019). ПРИМЕНЕНИЕ ПАРАМЕТРОВ НАТЯЖНОГО РОЛИКА ПРИ ТЕОРЕТИЧЕСКОМ ИЗУЧЕНИИ ДИНАМИКИ ТРАНСПОРТИРУЮЩИХ ЛЕНТ.
In Энерго-ресурсосберегающие технологии и оборудование в дорожной и строительной отраслях (pp. 134-138).
[19] Ализафаров, Б. М. (2020). ECOLOGICAL DRYING OF FINE DISPERSED MATERIALS IN A CONTACT DRYER. Экономика и социум, (11), 433-437.
[20] Ахунбаев, А. А., & Ражабова, Н. Р. (2021). ВЫСУШИВАНИЕ ДИСПЕРСНЫХ МАТЕРИАЛОВ В АППАРАТЕ С БЫСТРО ВРАЩАЮЩИМСЯ РОТОРОМ. Universum: технические науки, (7-1 (88)), 49-52.
[21] Sadullaev, X., Alimatov, B., & Mamarizaev, I. (2021). DEVELOPMENT AND RESEARCH OF A HIGH-EFFICIENT EXTRACTION PLANT AND PROSPECTS FOR INDUSTRIAL APPLICATION OF EXTRACTORS WITH PNEUMATIC MIXING OF LIQUIDS. Баркарорлик ва Етакчи Тадкикотлар онлайн илмий журнали, 1(5), 107-115.
[22] Tojiev, R. J., & Sadullaev, X. M. (2018). DETERMINATION OF THE ANGLE OF CAPTURE OF THE CRUSHING CHAMBER OF A CONE CRUSHER, TAKING INTO ACCOUNT THE KINEMATICS OF THE ROLLING CONE. Scientific-technical journal, 22(3), 55-60.
[23] Хакимов, А. А., Вохидова, Н. Х., & Нажимов, К КУМИР БРИКЕТИ ИШЛАБ ЧИКАРИШНИНГ ЯНГИ ТЕХНОЛОГИЯСИНИ ЯРАТИШ. УЗБЕКИСТОНРЕСПУБЛИКАСИ ОЛИЙ ВА УРТА МАХСУС ТАЪЛИМ
ВАЗИРЛИГИ Зауириддин Мууаммад Бобур номидаги Андижон давлат университети, 264.
[24] Мухамадсадиков, К. Д., & Давронбеков, А. А. (2021). ИССЛЕДОВАНИЕ ВЛИЯНИЯ ГИДРОДИНАМИЧЕСКИХ РЕЖИМОВ СФЕРИЧЕСКОЙ НИЖНЕЙ ТРУБЫ НА ПРОЦЕСС ТЕПЛООБМЕНА. Universum: технические науки, (7-1 (88)), 38-41.
[25] Ergashev, N., & Halilov, I. (2021). EXPERIMENTAL DETERMINATION LENGTH OF LIQUID FILM IN DUSTY GAS CLEANER. Innovative Technologica: Methodical Research Journal, 2(10), 29-33.
[26] Sadullaev, X., Muydinov, A., Xoshimov, A., & Mamarizaev, I. (2021). ECOLOGICAL ENVIRONMENT AND ITS IMPROVEMENTS IN THE FERGANA VALLEY. Баркарорлик ва Етакчи Тадкикотлар онлайн илмий журнали, 1(5), 100106.
[27] Karimov, I., & Halilov, I. (2021). Modernization of the main working shovels of the construction mixing device. АКТУАЛЬНЫЕ ПРОБЛЕМЫ ВНЕДРЕНИЯ ИННОВАЦИОННОЙ ТЕХНИКИ И ТЕХНОЛОГИЙ НА ПРЕДПРИЯТИЯХ ПО ПРОИЗВОДСТВУ СТРОИТЕЛЬНЫХ МАТЕРИАЛОВ, ХИМИЧЕСКОЙ ПРОМЫШЛЕННОСТИ И В СМЕЖНЫХ ОТРАСЛЯХ, 1(1), 293-295
[28] Rasuljon, T., Akmaljon, A., & Ilkhomjon, M. (2021). SELECTION OF FILTER MATERIAL AND ANALYSIS OF CALCULATION EQUATIONS OF MASS EXCHANGE PROCESS IN ROTARY FILTER APPARATUS. Universum: технические науки, (5-6 (86)), 22-25.
[29] Isomiddinov, A., Аxrorov, А., Karimov, I., & Tojiyev, R. (2019). Application of rotor-filter dusty gas cleaner in industry and identifying its efficiency. Austrian Journal of Technical and Natural Sciences, (9-10).
[30] Тожиев, Р. Ж., Ахунбаев, А. А., & Миршарипов, Р. Х. (2018). Сушка тонкодисперсных материалов в безуносной роторно-барабанном аппарате. Научно-технический журнал ФерПИ,-Фергана, (2), 116-119.
