RU96025U1 - MODULE OF DRAWING DUST-AND-GAS-ASO-DUST COLLECTION FROM SMOKE AND AGGRESSIVE GASES - Google Patents

Abstract

 1. The module dust and gas collection from flue and aggressive gases, comprising a large diameter housing with inlet and outlet pipes, silos for removing dust and sludge, devices for increasing the efficiency of capture and regulation of gas velocity, characterized in that the housing is made in the form of pick-up sections, such as dust collecting chamber, catalytic gas neutralization chamber, multifunctional absorption chamber and draft unit, at the base of which there is a gravity chamber for trapping condensate, the complete set of sections is dependent on operational needs and the source data cleaned gases. ! 2. The module according to claim 1, characterized in that in the dust-collecting chamber the inlet pipe is located in its upper part at an angle of 30 ° to the horizontal and is made with a bend in its lower part located inside the chamber. ! 3. The module according to claim 1, characterized in that the catalytic gas neutralization chamber is equipped with a catalyst dispenser and cassettes made in the form of diamond-shaped cells with two opposite impermeable walls, as well as a pneumatic transport assembly. ! 4. The module according to claim 1, characterized in that the multifunctional absorption chamber consists of a chamber equipped with hydrodynamic accelerators, absorbent dispensers, connected to pressureless containers for absorbents and mounted above the chamber, a separator is installed at the outlet of the multifunctional absorption chamber. ! 5. The module according to claim 1, characterized in that the draft unit has a vortex cone, on the basis of which a distribution belt is mounted for supplying compressed

Description

The utility model relates to the field of combating atmospheric air pollution, namely to devices for dust and gas ash collection.

It is known that dust and gas ash collection during dry inertial cleaning of gases is carried out by imparting a swirling or rotational movement to the dusty stream within the boundaries of a dust precipitation apparatus (cyclone) with vertical walls - an inertial force (centrifugal force) acts on particles suspended in the flow inside the cyclone, which displaces particles to the wall of the housing. Since the inertial force is proportional to the mass, large particles are released from the stream within 80-95% (cyclones, dust collectors, dust removal, gas purification, htto: //mahp.ustu.ru/cn SCN40, html. 05/01/2010).

The main disadvantage of the known designs of cyclones is the low capture efficiency of particles smaller than 5 microns. Especially with large diameters of cyclones reaching 1000-1200 mm and a height of more than 4000 mm. Small particles do not reach the walls of the apparatus, continue to move along curved currents and are carried out of the cyclone by a gas current. An increase in the efficiency of particle deposition due to a decrease in the diameter of the cyclone and an increase in the flow rate is possible up to certain limits, further limited by technical and economic factors, especially an increase in metal consumption by a factor of ten and an increase in aerodynamic drag to 1000-2000 Pa.

It is also known that with "wet dust collection" the cleaning mechanism is based on the contact of a dusty gas stream with a film or drops of liquid that trap suspended particles and carry them away from the apparatus in the form of sludge.

“Wet dust collection” is carried out in scrubbers with a body in the form of a vertical column, hollow or with a nozzle into which a swirling stream of purified gas and irrigation liquid are introduced. Scrubbers are effectively used in cases where dry devices are usually not used, for example, at high temperature and high humidity of gases, in case of danger of fire and explosions of purified gases. Most wet dust collectors are used to capture dust particles less than 5 microns. The capture efficiency of such particles is 99% and is close to the efficiency of bag and electrostatic precipitators.

Devices for "wet cleaning" allow you to jointly solve the issues of dust collection and chemical cleaning of flue gases. In this case, the choice of irrigation fluid (absorbent) is determined by the conditions of the absorption process.

The main disadvantage of scrubbers is that with large volumes of gas to be cleaned and installation dimensions, water droplets and dust particles do not have time to reach the walls at given gas flow rates before the gas stream leaves the apparatus. In order for the entrainment of liquid from the contact zone to be insignificant, the size of the droplets should be at least 500 μm, and the gas flow velocity should not exceed 0.8-1.2 m / s.

For large flows of purified gas, for example, a VTI scrubber with a diameter of 3416 and a height of 12860 mm was used. (M.I. Birger, A.Yu. Waldberg, B.I. Myagkov and others. A guide to dust and ash collection. Under the general editorship of A.A. Rusanov, 2nd ed. - M.: Energoatomizdat, 1983 - P.109).

It is known that many production processes and dust and gas collection systems are organized on the basis of a modular principle using a set of standardized equipment. (www.rae.ru/use/pdf/2005/06/ BekRer-2.pdf - a copy is attached).

One of such modern dust and gas collection modules can be considered the use of standard equipment for Vanyukov furnaces, which included: a waste heat boiler, cyclones, a dry electrostatic precipitator, a smoke exhauster, a scrubber, a wet electrostatic precipitator, an exhaust pipe. This whole system almost occupies 2/3 of the volume of production itself. And only such a set of equipment allowed to provide a standard degree of purification of waste gas flows.

The disadvantage of such a system for cleaning equipment is the large overall dimensions of the devices, the low individual performance of dust and gas traps, the small pre-set gas flow rates in the apparatus, especially when cleaning large volumes of flue and aggressive gases (“Plants for the processing of municipal solid waste and industrial waste in barbated slag melt using Vanyukov’s furnaces ”consortium of institutes of Giprotsvetmet 2009, a copy is attached).

The closest in technical essence are dust precipitation chambers, which have input outlet pipes, a large-diameter housing and silos for the deposition of trapped dust. The main advantage of these devices is the simplicity of the design, which determines the possibility of their manufacture at non-specialized enterprises, as well as the minimum aerodynamic drag in the gas path compared to known constructions (less than 100-200 Pa). However, the efficiency of gas purification is achieved in gravity apparatus no more than 50-60%. In order to obtain an acceptable cleaning efficiency, it is necessary that the particles are in the chamber volume for as long as possible. Therefore, dust precipitation chambers are considered bulky structures and are mainly used as the first stage of gas purification of relatively large particles (more than 100 microns). To increase the efficiency of collecting finer dust in many camera samples, additional devices were introduced according to a modular scheme. For uniform gas distribution over the cross section of the dust chamber, they are equipped with diffusers and gas distribution grids, and horizontal and inclined shelves are used to reduce the particle deposition height. In some designs, chain or wire curtains and deflectable partitions are provided to increase dust collection efficiency. This allows, in addition to the gravitational one, to use the effect of inertial deposition of particles when a stream of gases flows around various obstacles, even at low speeds. The disadvantage is the inability to clean gases at high speeds and temperatures, high humidity and from chemical impurities. (M.I. Birger, A.Yu. Waldberg, B.I. Myagkov and others. A guide to dust and ash collection. Under the general editorship of A.A. Rusanov, 2nd ed. - M.: Energoatomizdat, 1983 - p. 52).

The utility model is aimed at improving the efficiency of purification of flue and aggressive gases by means of integrated dust and gas separation in devices assembled according to a modular scheme while reducing metal consumption and energy costs as a whole for a multi-stage installation-module.

The result is achieved in that in the module for dust and gas ash collection from flue and aggressive gases, containing a large-diameter case with inlet and outlet pipes, bunkers for removing dust and sludge, devices for increasing the efficiency of capture and regulation of gas velocities, according to a utility model, the case is made in the form of sections, such as a dust collection chamber, a catalytic gas neutralization chamber, a multifunctional absorption chamber and a blower unit, at the base of which a gravity chamber for trapping condensate, while the configuration of the sections depends on the production need and the source data of the purified gases.

The result is also achieved by the fact that in the dust collecting chamber the inlet pipe is located in its upper part at an angle of 30 to the horizontal and is made with a bend in its lower part located inside the chamber.

The result is also achieved by the fact that the catalytic gas neutralization chamber is equipped with a catalyst dispenser and cartridges made in the form of diamond-shaped cells with two opposite impermeable walls, as well as a pneumatic transport unit.

The result is also achieved by the fact that the multifunctional absorption chamber consists of a chamber equipped with hydrodynamic accelerators, absorbent dispensers connected to pressureless absorbent containers mounted above the chamber; a separator is installed at the outlet of the multifunctional absorption chamber.

The result is also achieved by the fact that the draft unit has a vortex cone, on the basis of which a distribution belt for supplying compressed air is mounted, the top of the vortex cone covers a pocket cone with a collection cone mounted on it, passing into a discharge pipe.

The drawing schematically shows a module of a draft dust and gas ash collector from flue and aggressive gases (Figure 1). The device includes a cylindrical case of large diameter, divided into picking sections (I, II, III, IV). Each section performs a specific function as a stage of gas separation and purification and can be equipped with a module depending on production needs.

Section I - dust precipitation chamber - consists of an inlet pipe 1, with a bend and introduced at an angle of 30 ° to the housing 2 of the dust precipitation chamber, a baffle plate 3, a collecting hopper 4 and a pneumatic conveying pipe 5.

Section II - the chamber for catalytic gas neutralization - consists of the chamber 6 itself, cassettes 7, made in the form of diamond-shaped cells with two opposite impermeable walls, two other permeable, made, for example, porous or mesh. The catalytic gas neutralization chamber is equipped with a dispenser 8 located in the upper part of the chamber 6 and a pneumatic transport unit 9, the purpose of which is to return the adsorbent-catalyst.

Section III - a multifunctional absorption chamber - consists of a chamber 10, hydrodynamic accelerators 11, liquid dispensers 12, pressure tanks 13 for absorbents mounted above the chamber 10, a separator 14 (section II) located at the outlet of the chamber, receiving hoppers 15, pneumatic conveying pipes 16.

Section IV - draft installation. It has at its base a gravity chamber for trapping condensate and sludge 17, a collection hopper 18, an injector assembly 19, designed to transport condensate and sludge through pneumatic conveying pipes 16. Above the gravity chamber 17 there is an outlet pipe 20, on which a blower unit 21 with a vortex cone is mounted 22, at the base of which a distribution belt 23 for supplying compressed air is installed, the top of the vortex cone 22 covers a cone-pocket 24. A cone 25 is mounted on the cone-pocket 24, passing into the discharge pipe 26. In the lower part of the pocket-cone 24 inserted pipe 27 for discharge of condensate and sludge into the chamber 17 through manifold 28.

The module works as follows. High-temperature flue gases enter sector I through a pipe 1 into a dust-collecting chamber 2, the flow sharply loses its initial speed and direction, hits the side wall-membrane 3 of a chamber 2. Gravitational forces drag large dust particles into a dry bunker 4.

The gas stream initially cleaned by gravity is directed to sector II — to cassettes 7, made in the form of diamond-shaped cells with two opposite impermeable (guiding) walls, two - permeable - porous, for example. The catalyst enters into the cartridges dosed from the hopper 8. The catalyst is in the cartridges 7 in a suspended state and is selected depending on the gas contaminants polluting the flow. The interaction of the gas stream with the catalyst is carried out countercurrent through the porous walls of the cassettes 7. The return of the catalyst to the dispenser 8 is carried out by a pneumatic conveying unit 9.

Cleaned from certain chemical components, the waste gas enters sector III. A horizontal high-temperature gas flow at a speed of 1.5-2.5 m / s moves into the zone of action of hydrodynamic accelerators 11, where high-speed flows of compressed air are introduced into the flue and aggressive gases tangentially at an angle of 20-25 ° to the vertical. The total flow acquires a translational-rotational motion. In this case, intense inertial forces arise, affecting the dust particles that separate them from the stream. To increase the efficiency of inertial deposition of fine particles and to additionally neutralize gaseous impurities, a metered amount of water or chemical solutions is injected from pressure tanks 13 through dispensers 12. The presence of several tanks 13 allows the flow of smoke and aggressive gases to be treated with various absorbents, depending on the available chemical impurities in the stream of purified gas or smoke. As a result of the intensive rotation of the total gas flow at a speed exceeding 25-40 m / s, fine dust particles and atomized absorbents create a dense boundary layer in the internal cavity of the housing 10. When the total flow rotates over the hoppers due to the inhibition of the boundary layer by inertial forces, the compacted mass is discharged into hoppers 15. At the exit of section III, all gas passes through a separator 14 and is transferred to the next section.

The gas purified from impurities and chemical harmful components through the separator tube 14 enters section IV into the gravity chamber 17, loses the speed acquired when passing through the separator 14. Coagulated particles and condensate fall into the hopper 18. From the chamber 17, the gas flow is directed to the bladeless draft device 21. Compressed air is tangentially supplied to the base of the vortex cone 22 through the distribution belt 23, which creates an upward vortex flow with rotation speeds of up to 80 m / s. In the center of the vortex, the masses of gases moved from the chamber 17 are carried away. Energy exchange between streams with different temperatures changes the dew point of the total stream, which leads to a new process of condensate formation. Due to the centrifugal forces of the vortex, the condensate and the smallest dust particles are discharged into the lower part of the cone pocket 24. The cleaned and correspondingly cooled gas stream through the collecting cone 25 is sent through the chimney 26 to the atmosphere.

The collected condensate and sludge through the pipe 27 is discharged into the receiving hopper 18 of the chamber 17 through the collector 28.

Sludge from bins 18, 15 and 4 by pneumatic transport through pipes 16 and 5 are sent to containers.

Thus, in the proposed multisection dust-gas ash collection module, gas is separated and purified using high-speed flows of compressed air at high centrifugal speeds at the separation level. High-speed flows of compressed air introduce hydrodynamic accelerators installed tangentially at an angle of 20-25 ° to the vertical into the internal cavity of the cylindrical body and create a vortex (swirling) flow, forming additional rarefaction (traction), reducing the overall aerodynamic resistance of the installation. The use of dry catalytic neutralization of chemical impurities through the selection of adsorbents expands the versatility of the module, especially in the capture of dioxins and polyaromatic hydrocarbons.

The possibility of dosed dispersion of water or absorbents allows you to combine the processes of dry, condensation and wet dust and gas separation by selecting the best adsorbents and absorbents depending on the composition of flue and aggressive gases.

The last stage of gas purification is organized in a fanless draft unit, in addition to gas purification and cooling, it is provided with draft in the entire cavity of the module before being discharged into the atmosphere, which allows the module to work autonomously without a smoke exhauster.

The complete set of devices of the same type in the module, as dust and gas collection systems, allows you to create a universal multi-stage installation, which ensures the complete capture of dust, ash and gas neutralization.

The sectional scheme of equipment configuration allows to reduce the metal consumption, the cost of the device and maintenance. The simplicity of the design of the module allows their manufacture in non-specialized production conditions.

The implementation of the module as an integrated installation will increase the efficiency of separation and purification of flue and aggressive gases over a wide range of dispersion of dust and gaseous pollutants while reducing energy consumption, metal consumption, significantly reduce the degree of air pollution, the cost of construction and maintenance of treatment facilities.

Claims (5)

1. Module dust and gas collection from flue and aggressive gases, comprising a large diameter housing with inlet and outlet pipes, silos for removing dust and sludge, devices for increasing the efficiency of capture and regulation of gas velocity, characterized in that the housing is made in the form of pick-up sections, such as dust collecting chamber, catalytic gas neutralization chamber, multifunctional absorption chamber and draft unit, at the base of which there is a gravity chamber for trapping condensate, the complete set of sections is dependent on operational needs and the source data cleaned gases. 2. The module according to claim 1, characterized in that in the dust-collecting chamber the inlet pipe is located in its upper part at an angle of 30 ° to the horizontal and is made with a bend in its lower part located inside the chamber. 3. The module according to claim 1, characterized in that the catalytic gas neutralization chamber is equipped with a catalyst dispenser and cassettes made in the form of diamond-shaped cells with two opposite impermeable walls, as well as a pneumatic transport assembly. 4. The module according to claim 1, characterized in that the multifunctional absorption chamber consists of a chamber equipped with hydrodynamic accelerators, absorbent dispensers, connected to pressureless containers for absorbents and mounted above the chamber, a separator is installed at the outlet of the multifunctional absorption chamber. 5. The module according to claim 1, characterized in that the draft unit has a vortex cone, on the basis of which a distribution belt for supplying compressed air is mounted, the top of the vortex cone covers a pocket cone with a collection cone mounted on it, passing into a discharge pipe.