LT6479B - Multi-channel cyclone-filter for cleaning aggressive gas from particulate matter - Google Patents

Abstract

The invention relates to a multi-channel cyclone-filter for cleaning aggressive gas flow from sticky particles. The goal is achieved by using four inlets (1, 3) of the contaminated gas stream into the multi-channel cyclone-filter; the elements (6) of the quarter-ring shaped channels arranged uniformly at 90° angle to the perimeter of the cyclone and connected by a common air/gas inlet duct (1); a convex bottom (5) of the cyclone–filter extending from the centre axis of the cyclone towards its peripheral edges by an angle ?; an outer continuous circular space (8) that separates the bottom (5) from the periphery of the separation chamber wall; the segmental inner overlapping spaces (9) of the central channel arranged spirally and 10 mm apart from the concave surface of a quarter-ring shaped element (6), wherein the spaces (8, 9) are designed to remove particulate matter from the all channels of multi–channel cyclone into the hopper or to changeable collection vessel (10) for particulate matter. The internal metal surfaces of the cyclone-filter housing (4), the convex separation chamber bottom (5), curved curvilinear elements (6) and the hopper (10) are polished or coated with a friction-resistant film.

Description

The invention relates to inert gas scrubbing units, e.g. high humidity and temperature gases are cleaned of particulate matter, resulting in increased particle adhesive and autohesive forces, and the separation of particulates from the gas stream by centrifugal force and air flow filtration.

TECHNICAL LEVEL

Multichannel cyclones are increasingly used in air purifiers to purify air (gas) by removing particulates (PM). According to the purification method, these units are classified as dry gas purifiers and can be used in various areas of the economy that are associated with the release of common and sticky particulates into the atmosphere in the presence of aggressive gases.

An analog of the present invention is a multichannel cyclone (LT5912B, B04C) for particulate air and gas prototype and a multilayer multichannel cylindrical cyclone filter (LT6225, B04C).

This type of equipment can be used to clean aggressive (elevated temperature and high humidity) gas from particulate matter. By cleaning the flow of aggressive gas from sticky solids at high humidity, elevated temperature, and chemical factors in the gas stream, the cyclone system becomes clogged in a short period of time and the cleaning process stops. It is practically impossible to regenerate the unit. Therefore, operation to purify such gas requires additional design solutions to prevent system clogging and to effectively purify the gas stream from fine-dispersed particles smaller than 20 µm.

The main disadvantage of the prototype is that the incoming gas stream is fed to the cyclone through a common duct, which results in large particulate deposits at the start of the cyclone's first channel. Particulate matter flow in cyclone channels is a descending trajectory resulting from the interaction of gravitational force and peripheral / transit flows, and no additional guides are provided to direct the deposited pollutants into the outer continuous annular slot and the segmented inner central channel slots. In the case of a multichannel cyclone and a multilayer multichannel cylindrical filter, solid particles accumulate on the bottom of the separation chamber, both in the outer and inner center passages, which block the outer continuous annular gap, thereby rendering subsequent separation impossible.

The high purification efficiency of the multichannel cyclone described in the patent LT5912B is achieved when the gas from the particulate is purged by centrifugal force, filtration and regulation of the curvilinear channel spacing. The efficiency of this device depends not only on the number of semicircles of different radii present in the cylindrical separation chamber, but also on the size of their adjustable gaps. Experimental studies have found that the smaller the curvilinear channel spacing, the higher the cleaning efficiency. This results in an increase in dynamic pressure and centrifugal force in the circulating flow in the cyclone channels. Most of the larger diameter particles having a higher gravity force are subjected to stronger centrifugal forces, separating them into lower curvature channels, and escaping from the first and second channels into the cyclone conical hopper. In addition, the channel spacing and half-ring spacing can be changed thanks to a built-in locking device in the cyclone cover. The regulator also optimizes the efficiency of dust separation from the air stream and the aerodynamic drag. A baffle is provided at the tangential air flow opening to direct airflow to the first duct only. The height of the bulkhead is equal to the height of the separation chamber and the width is the width of the inlet. This multi-channel cyclone design allows for different types of dust to individually adjust the unit system for maximum particulate separation from the air stream.

The principle of multilayer multichannel cyclone filter described in LT6225B is based on the fact that biphasic air (gas) flow, i. air contaminated with particulate matter enters tangentially into the cyclone (to all levels of cyclones), all cyclone channels where particulate matter is separated from the air stream by centrifugal forces and filtration processes in all channels. While centrifugal forces separate relatively large solids from 20 µm and larger, the filtering process produces small and even very small particles less than 20 µm and even particles of 1 + 10 µm.

Experimental studies have determined the cyclone aerodynamic parameters (velocity and pressure) and air purification efficiencies, depending on the ratio of the gas (air) flows of the peripheral (flow returning to the previous channel) and the transit (flow moving further to the next channel), i.e. 75:25%, 50:50%, 25:75%. The peripheral airflow entering the previous duct forms an air curtain that filters the incoming dusty airflow, thereby trapping small 1 + 10 pm particles and directing them to the hopper.

The dusty air (biphasic flow) entering the first channel is directed by centrifugal force to the segmental annular slits and enters the hopper, while further moving the dusty air moves through other channels and enters the cleaned air removal duct, which passes to the next level (in the multilevel cyclone). for construction) and is finally removed through the cyclone outlet duct. The openings in the walls of the quarter-ring members allow the solids to return to the previous passage and pass through the outer segmental slits into the hopper, which increases the cleaning efficiency. Such openings are provided at each level and in each quarter annular member with a flanged plate that directs the dusty stream to the previous channel. The biphasic flow of air (gas) in all the channels is driven by a centrifugal force that directs the particles towards the outer wall of the channels and passes through the openings therein to the previous channel. Multiple filtration takes place, and the contaminant particles entering the first channel are finally removed from the flow through the segmental slits into the hopper.

Adjustable slits are provided on the cyclone axes between the ends of a quarter of the ring-shaped elements, and the amount of peripheral and transit air flows can be varied, e.g. 75:25%, 50:50%, 25:75%, which allows you to adjust the air purification efficiency depending on the particle density and dispersion. The higher the peripheral (return) flow rate (the greater the amount of air), the more stable, stronger the filtration curtain, resulting in a more stable filtration process. The solids are more effectively trapped by the air curtain and directed more reliably towards the outer duct wall and pass through all ducts through the duct wall openings and enter the hopper through segmental slits.

Each quarter of the annular member has a cut-out aperture that is one-third of the area of the annular annular member, and the plate of the cut-out aperture is inclined at an angle of 5 + 30 ° and directed toward the movement of dusty air. This allows you to adjust the cross-sectional area of the duct, which affects the speed of air movement and the increase in centrifugal force, which increases the efficiency of air cleaning.

Cyclone resistance increases with increasing number of channels. Four, six and eight channel cyclones were investigated. The higher the number of channels, the higher the cyclone air purification efficiency, but also the higher the resistance (Table 1).

table. Aerodynamic resistance of a four-channel cyclone as a function of average gas flow rate in the cyclone channels at 50/50% flow distribution ratio

Average gas flow rate in cyclone channels 8 m / s 12 m / s 16 m / s Aerodynamic Resistance, Pa 190 345 615

At a gas flow rate of 8 m / s in cyclone channels, the aerodynamic drag is equal to 190 Pa. Meanwhile, at 12 m / s, the aerodynamic drag increases by 1.82 times to 345 Pa. At the highest of 16 m / s, the value reaches 615 Pa, i.e. 3.24 and 1.78 times more than at 8 and 12 m / s respectively.

Using quarter-ring elements instead of half-ring elements, at the ends of the elements (ie, four locations along the axes), newly formed contaminated and partially cleaned peripheral (return) gas flow interaction zones (filtering gas curtains) are added to separate solids from the dusty gas stream. , thus increasing the efficiency of gas cleaning.

Experimental studies of the prototype determined the aerodynamic parameters (velocity and pressure) of the cyclone and the air purification efficiency. It was concluded that the optimum aerodynamic characteristics of the unit and the highest cleaning efficiency were obtained at a uniform (50:50%) ratio of peripheral to transit gas flow.

THE SUBSTANCE OF THE INVENTION

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device for cleaning aggressive gas stream from sticky solids at gas humidity up to 100% and at temperature up to 200 ° C and to create increased adhesive and autohesive forces of the particles. The goal is achieved by employing a total of four inlets to a multichannel cyclone, one of which is primary and three secondary streams of contaminated gas, channel-configured curvilinear quarter-ring elements, not only the outer continuous annular slot, but also segmented internal central channel slits sloping bottom toward cracks.

Secondary flow inlets are located at the beginning of each quarter annular member. In proportion to the cross-sections, the flow of gas from each secondary inlet passes into the corresponding cyclone channel, complementing the flow flow therein. The gas flow leakage and flow rate is reduced at each quarter annular overlap of two adjacent elements as a transit flow. Therefore, the newly flowing through each secondary inlet stream complements and smoothes the gas flow in the respective cyclone channel. The secondary inlet openings provide an evenly dispersed aerodisperse stream diluted into partial streams, with the total particulate concentration divided by four separate inlets. Such flow distribution reduces the build-up of sticky particles on the inner surfaces of the cyclone during adhesion and autohydration and avoids blocking of the cyclone system.

DESCRIPTION OF DRAWING FIGURES

The figures show images of a multichannel cyclone-filter for cleaning particulate aggressors, where:

Fig. is a schematic cross-sectional view of the multichannel cyclone filter of the present invention through FIG. line A-A image;

Fig. is a schematic cross-sectional view of the multichannel cyclone filter of the present invention through FIG. line B-B image using a hopper;

Fig. is a schematic cross-sectional view of the multichannel cyclone filter of the present invention through FIG. line B-B image using a storage container (bag);

Fig. is an axonometric view of a multichannel cyclone filter of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The multichannel cyclone filter for the removal of aggressive gases from particulates consists of four (and more) air supply ducts arranged at equal (e.g. 90 °) angles divided into primary 2 and secondary 3, connected by a common tangential duct 1, cleaned gas vent duct 11, multichannel cyclone body 4, comprising spaced-out quarter-ring circular elements 6 of equal radius and length, with apertures 14 and hinged plates 15. The cyclone separation chamber is provided with a convex downward direction from the cyclone axis to the periphery bottom 5, with a slope angle α of 20-30 ° with the horizontal plane. The convex bottom 5 of the cyclone separation chamber is separated from the peripheral wall of the separation chamber by an outer continuous annular slot 8, and the bottom 5 has internal segmental overlapping slots 9 for removing particulates from all multichannel cyclone channels and collecting them in a hopper or bag. ).

Principle of device operation

The principle of a multi-channel cyclone-filter is based on the fact that the multiphase gas stream (air-gas-vapor mixture contaminated with particulate matter) is distributed in parallel to the primary stream passing through the cyclone sequentially tangentially and to the secondary streams fed to the cyclone in this way. that every successive {flow with the previous made 90 °. The primary gas stream flows into the first channel, the secondary stream first flows into the second and 1.1, resulting in the secondary flows moving along the trajectory lines 17.

The flow of aggressive gas-vapor and particulate matter enters the contaminated gas flow duct 1 through primary 2 and secondary 3. The cyclone body 4 is provided with a curved, quarter-quarter annular ring element 6 on the sloping bottom 5. These elements form cyclone channels 7, the first to fourth elements having equal radii. The first one is mounted at the primary flow {2} and the second one at 90 ° in the direction of the gas flow.

Under centrifugal force, the particulates are directed to the outer continuous annular slot 8 and to the inner segmental overlapping slots 9 of the central duct 18 and enter the hopper or accumulator 10, while further moving dust air enters the purified gas evacuation duct. 11. The moving gas stream, having reached the edge of a quarter annular member, divides into two streams of peripheral 12 and transit 13. The newly introduced contaminated stream of aggressive gas encounters a peripheral partially cleaned stream from the previous channel and additionally separates existing solids and directs them to segmental overlaps. 9. Quarter-ring members 6 are of uniform radius and length and are arranged within the cyclone's internal structure to provide even channels of uniform cross-sectional area. The openings 14 in the walls of the latter elements allow the particulate matter to return to the previous passage and enter through the segmental overlapping slots 9 into the hopper or storage bag 10 and increase the cleaning efficiency. These openings are provided in each quarter annular member with a flap plate 15 which directs the dusty stream to the previous channel. As an optimal prototype case, a uniform 50:50% ratio of peripheral to transit gas flow distribution and a corresponding arrangement of one-fourth of the ring-shaped elements with flanged plates are accepted.

The bottom of the separation chamber is convex downward from the cyclone axis to the periphery. The sloping bottom 5 is arranged in such a way that the accumulated particles can move more easily into the hopper or storage vessel 10 and not accumulate on the bottom surface, but slide towards the peripheral annular slot 8.

By using secondary jets, the flow of aggressive gas fed to the cyclone is distributed evenly across all secondary inlets 3 in proportion to their cross sections, moving along the secondary flow trajectory lines 17. Thus, some of the dusty stream is diverted to downstream channels and reduces adhesion, autohes clogging of the internal elements of the cyclone in the first channel, adhesion and autohesion in the latter occurs most. The distributed total gas flow enters the outer (first to fourth) channels through the primary and secondary inlets, so that the gas flow rate is maintained at an average across all ducts at 90 ° angles in the peripheral wall.

The solids separated from the aggressive gas stream slide down the peripheral wall under the action of gravity and pass through a continuous slit 8 with bottom anchors into a hopper or storage bag 10. The advantage of a continuous slit 8 with anchors in a multichannel cyclone is that During this time, particulate matter in the aggressive gas does not accumulate in the gaps between segments, as in the case of segmental cracks. To ensure rigidity, the bottom of the separation chamber is mounted by attaching it to the holding members 16, which are 5 mm wide and very small in relation to the length of the outer continuous slot 8.

The openings 14 and the hinged plates 15 in the quarter-ring members direct the gas flow towards the outer continuous annular slot 8 and the inner segmental overlapping slits 9 of the inner central duct 18, the particulates passing through these openings into the hopper or the container 10 where they are. accumulated. Circulating through the openings in the inner central channel 18, the gas stream can enter and re-filter the outer channels, which increases the efficiency of the multichannel cyclone cleaning.

The convex bottom 5 of the separation chamber has cut-out internal segmental overlapping slots 9 which are located 10 mm away from a quarter of the concave surface of the annular member 6. The finer solids in the gas stream moving in the inner central channel 18 are deposited by passing through the inner central channel segment overlapping slits 9, thereby preventing their adherence to the inner surfaces of the inner central channel 18, accumulating particles on the bottom of the separation chamber. .

During the process of aggressive scrubbing of particulates with a prototype, problems arise due to the entrapment of the structure due to particle adhesion and autohesion. In order to avoid these phenomena, the inner surfaces of the multichannel cyclone are treated: polishing (polishing) or coating (painting) with friction reducing agents. The inner walls of the cyclone body and the surfaces of the one-fourth ring-shaped elements 6 forming the channels are specially treated, i. sanded and polished or antifriction coated, eg. heat-resistant varnish. These operations reduce the roughness of the surfaces, the friction of particles to the surface and their accumulation in unevenness are reduced to a slip surface, and the adhesion forces (adhesion and coating) between the particles in the gas stream and the specially prepared surfaces are reduced. Coating the surface with a thin layer of active agent fills the pores on the metal surface to give the surface a smooth appearance and forms a friction-resistant film (increases gloss). This method can be applied at temperatures up to 400 ° C, the active substance being hydrophobic, purifying the gas stream from low density and hardness solids such as wood, lignin, gypsum, graphite and the like.

When operating a multichannel cyclone filter for aggressive gas purification, pollutant particles absorb moisture as they move through the channels and, due to the increased mass, fall and accumulate on the bottom of the separation chamber. Through the peripheral annular slot 8, the particles can enter the hopper or the storage container 10 from the outer channels 7, i.e. of the first fourth. The particles are deposited in the inner central passageway 18, enter the hopper or in the collecting container 10 through inner central channel passageways 9 located at the bottom of the separation chamber at a distance of 10 mm from the lower edge of each quarter annular member 6. A multichannel cyclone filter to clean aggressive gases from particulates may be provided with a hopper 10 or a storage bag (10). When using the hopper, the inside walls are sanded or abrasion resistant. In the gas stream, in the presence of particularly sticky and damp particles, a non-watertight container (bag) 10 may be used which is suspended from the bottom of the multichannel cyclone separator chamber to prevent the hopper from clogging and regularly interrupting its cleaning. When the container (bag) 10 is full, it is replaced by a new one.

Claims (3)

DEFINITION OF INVENTION 1. Multichannel cyclone filter for aggressive particulate purification, comprising a gas tangential inlet, a curved quarter-ring element with partially slit openings in its walls, and a slit plate for the removal of particulate matter in the hopper, hopper particle a clean air duct with four particulate air / gas inlet channels, primary (2) and secondary (3) spaced at 90 ° around the cyclone circumference and connected by a common air / gas supply duct (1) with a convex cyclone bottom (5) ) descending from the central axis of the cyclone to its peripheral edges at an angle α, an outer continuous annular slot (8) separating the bottom (5) from the peripheral separating chamber wall for directing the particulates to the hopper or to the exchangeable particulate storage vessel (10) ring p with overlapping slits (9) disposed helically and spaced 10 mm from the concave surface of a quarter of the annular member (6) for removing particulates from all channels of the multichannel cyclone, guiding them to a hopper or replaceable particulate storage vessel (10); in that the inner metal surfaces of the cyclone body (4), the convex bottom of the separation chamber (5), the curved curvilinear elements (6) and the hopper (10) are treated with antifriction means. Multi-channel cyclone filter according to claim 1, characterized in that the inclination angle α of the bottom (5) is 20-30 ° with the horizontal plane. 3. A multichannel cyclone filter according to claim 1, characterized in that the inner metal surfaces of the cyclone body (4), the convex separation chamber bottom (5), the curved curvilinear elements (6) and the hopper (10) are polished or covered with abrasion resistant film.