RU2179879C1 - Bag-type filter - Google Patents

Abstract

FIELD: cleaning gases from solid admixtures; metallurgy, chemical and food-processing industries, construction engineering, etc. SUBSTANCE: bag- type filter has housing with filter sections located symmetrically inside it; dust-laden gas manifold between filter sections horizontally in lower portion and cleaned gas manifold runs in upper portion. Each filter section includes dust-laden gas chamber with set of filter bags oriented vertically; cleaned gas chamber is located at the top and dust collecting bin is located at the bottom; dust collecting bin is communicated with dust-laden gas manifold through slotted passage located between them. Besides that, provision is made for filter bag regeneration system. Side partitions between dust-laden gas manifold and dust-laden gas chambers are perforated. Ratio of passage area of holes in partitions of dust-laden gas manifolds and section of slotted passage in each filter section is about 1:1. Filter bag regeneration system includes one compressed gas receiver connected with purging pipes through electrically-driven diaphragm valve; purging pipes are provided with nozzles. Flow sections of regeneration system are made at definite rations. EFFECT: enhanced intensification and efficiency of gas cleaning procedure; enhanced reliability of bag-type filter. 4 cl, 1 dwg

Description

 The invention relates to the field of gas purification from solid impurities and can be used in various technological processes of metallurgical, chemical, food, construction and other industries.

 From the sources of scientific, technical and patent information, a large number of various filter designs are known that are used for purification from solid impurities, in which air or gas is cleaned by settling particles on the outer surface of the sleeves with the introduction of contaminated gas outside the sleeves and passing inside the sleeves when exiting of which gas is purified.

 So, from DE 2329192, 08/05/1976, B 01 D 46/02, a bag filter for gas purification is known, comprising a housing with filter bags, cleaned and dusty gas chambers, a dusty gas supply manifold located below in the hopper, a clean gas exhaust manifold located on top and a filter bag regeneration system.

 This arrangement of the bag filter leads to an increase in the vertical dimensions of the filter. In addition, the presence of a supply duct located along the entire length of the hopper and having a longitudinal outlet upper and lower slots does not ensure uniform distribution of the dust and gas stream both over the cross section and along its length. Due to the uneven distribution of speeds in the supply duct, as shown by the practice of operating such devices, significant dust deposits appear inside the duct. These deposits clog the lower longitudinal slit and the entire gas flow is directed through the upper slit, i.e., dust is practically not removed to the hopper through the lower slit.

 Closest to the claimed solution by technical nature and by the number of common essential features is the "Filter bag for air purification from mechanical impurities" according to patent RU 2144415, 01.20.2000, B 01 D 46/02, containing a housing with symmetrically filtering sections located in it between which in the lower part horizontally passes the collector of dusty gas, and in the upper part - the collector of purified gas. Each of the filter sections includes a dusty gas chamber with a set of vertically oriented filter bags with a purified gas chamber located on top and a dust collection bin located on top of it, which communicates with the dusty gas collector through the slotted passage located between them. There is also a filter bag regeneration system.

 Such a filter has a significant drawback: when passing a dust and gas stream from a dusty gas collector through a bunker space and further onto the filter bags, a partial entrainment of dust already settled in the bunker occurs. In addition, the bulk of the dust entering the filter with gas is deposited on the bottom of the sleeves. This leads to inefficient use of the entire filtering surface area and, due to an increase in the regeneration frequency, to a decrease in reliability.

 The technical problem and the technical result achieved by solving it are to increase the intensity and efficiency of the gas cleaning process, as well as to reduce the size and increase the reliability of the bag filter.

где ∑Fc. - суммарная площадь сечений проходных отверстий сопел продувочной трубы;
F пр.тр. - площадь сечения продувочной трубы;
F м.кл. - площадь сечения проходного отверстия мембранного клапана.The specified technical result is achieved in that the bag filter comprises a housing with symmetrically filtering sections located in it, between which a dusty gas collector horizontally passes in the lower part, and a purified gas collector in the upper part. Each of the filter sections includes a dusty gas chamber with a set of vertically oriented filter bags with a purified gas chamber located on top and a dust collection bin located on top of it, which communicates with the dusty gas collector through the slotted passage located between them. In addition, there is a regeneration system for filter bags. In this case, the side walls between the dust collector collector and the dusty gas chambers are perforated to enter the last parts of the dusty gas, bypassing the hopper. The ratio of the orifice of the holes (perforations) in the walls of the dusty gas collector and the section of the slotted passage into the hopper in each filter section is approximately 1: 1. The filter bag regeneration system includes at least one compressed air receiver connected through at least one electrically actuated diaphragm valve to purge pipes containing nozzles, each of which is directed to the open end part of the filter bag from the cleaned collector side gas. Each filter section is equipped with a pneumatic drive kinematically connected with a shut-off rotary damper to isolate the purified gas chamber from the purified gas manifold during the regeneration of the filter bags. The flow sections of the regeneration system are made in the following ratios:

where ∑Fc. - the total cross-sectional area of the through holes of the nozzles of the purge pipe;
F pr. - cross-sectional area of the purge pipe;
F mcl - the cross-sectional area of the bore of the membrane valve.

In addition, in special cases of the implementation of the claimed bag filter:
- to reduce the dimensions of the filter while maintaining the filtering surface in cross section, the filter bags are staggered;
- filter sections are arranged in two rows, in each of which up to ten sections;
- the membrane valve is made with a through hole, the diameter of which is 150 mm.

 These features are significant and interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

 This design solution provides for the separation of the contaminated gas entering the filter into two components: half of the flow through the openings of the perforated side walls of the collector enters directly into the contaminated gas chamber, bypassing the filter hopper. In this case, the perforated walls of the collector play the role of distribution grids and ensure uniform distribution of dust and gas flow along the height of the sleeves. The second half of the flow through the slotted passages in the lower wall of the collector enters the filter hopper and then to the filter bags. At the same time, due to a decrease in the gas flow rate in the hopper part of the filter, dust removal from the hopper is eliminated, and at the same time, dust is more efficiently deposited from the dust and gas stream entering the hopper.

 The indicated ratios of the flow areas of the regeneration system increase the intensity and efficiency of cleaning bag filters and, accordingly, cleaning dusty gas.

 The drawing shows the proposed bag filter.

 The bag filter consists of a housing 1, in which symmetrically filtering sections are located.

 Each section has a dusty gas chamber 2 and a purified gas chamber 3, which are separated by a hole plate 4. Filter sleeves 5 are attached to the openings of the sleeve plate 4. The filter sleeve 5 is a composite wire frame covered with filter material. Below the chamber 2 of dusty gas is a hopper 8 with a dust discharge opening 9.

 In the filter housing 1, between the rows of sections, a dusty gas collector 6 is located in the lower part and a purified gas collector 7 in the upper part, separated by a horizontal partition. Between the collector 6 of the dusty gas and the hoppers 8 there is a slotted passage for entering from the collector 6 of the dusty gas into the hoppers 8 and further into the chambers 2 of the dusty gas, or rather a part thereof. The side walls 10 between the collector 6 of the dusty gas and the chambers 2 of the dusty gas are perforated to enter the last other parts of the dusty gas, bypassing the hopper.

 Between the purified gas collector 7 and the purified gas chambers 3 are located on-off shut-off rotary valves 11 with pneumatic actuators 12 located outside the housing 1.

 In the chambers 3 of the purified gas are purging pipes 13 with nozzles 14. The purging pipes 13 are connected to the compressed air receivers 16 through diaphragm valves with electric drive 15.

 Bag filter works as follows. Dusty flow from the collector 6 of dusty gas through the lateral perforated partitions 10 and slotted passageways into the hoppers enters the chambers 2 of dusty gas in approximately equal proportions. In this case, due to the separation of the flow, the gas velocity in the hoppers 8 is reduced by about half compared with the known filter, which eliminates the entrainment of dust that has already settled on the hopper.

 Due to the uniform distribution of the flow using the perforated septum 10, the dusty gas is evenly distributed over the height of the sleeves 5, which leads to an increase in the efficiency of using the filtering surface area.

 From the dusty gas chamber 2, the dusty gas flow passes through the filter bags 5 from the outside to the inside, with the lower ends of the sleeves closed and the upper open. Thus, the dusty gas is cleaned of dust and then through the upper open holes of the sleeves enters the chamber 3 of the purified gas. Then, through the open shut-off rotary damper 11, the purified gas enters the manifold 7 of the purified gas and then through the fan and the pipe comes out.

 Dust particles settle on the outer surface of the sleeves 5. Periodically, as dust accumulates on the surface of the sleeves 5, they are regenerated (cleaned).

 For this, first, the clean gas chamber 3 of one of the sections, the sleeves 5 of which is to be regenerated, is isolated from the purified gas manifold 7 by means of a shut-off rotary valve 11. Then, after a time interval (after closing the shut-off rotary valve 11), during which the gas calms down flow, automatically turns on (opens) the diaphragm valve with electric actuator 15 and compressed air from the receiver 16 "instantly" through the nozzle 14 of the purge pipe 13 enters through the holes in the sleeve plate 4 in the sleeve 5. In this case um sudden deformation (inflating) of the filter material sleeves 5 with its simultaneous purge air flow in the direction opposite to the flow of gas into the filtration time. A sort of shaking of the filter material of the sleeves 5 takes place.

 Dust shaken from the filter bags 5 settles in the hopper 8 and is discharged through the dust discharge opening 9. Upon completion of the regeneration of the filter bags 5 in one of the sections, the shut-off rotary valve 11 of this section opens, reconnecting the purified gas chamber 3 to the purified gas manifold 7, and the dusty gas filtration process continues.

 The presence of perforated walls in the dirty gas manifold in combination with slotted passages in the filter hopper reduces the flow rate of contaminated gas into the hopper and thereby reduces the likelihood of picking up deposited dust from the hopper, thereby increasing the efficiency of filtering polluted air. In addition, due to the presence of perforated walls, dusty gas is more evenly distributed over the filter bags, which reduces the time for regeneration of the filter bags and, consequently, increases the gas cleaning intensity and the reliability of the bag filter.

 Due to the staggered arrangement of the sleeves, the dimensions of the bag filter are reduced.

 The regeneration of the filter bags is controlled by the control unit.

 Such regeneration of filter bags is carried out sequentially in each section of the filter at a time interval specified by a timer or differential pressure sensor on the filter bags.

 The present invention is industrially applicable, since its manufacture does not require special equipment and new technology.

 The design of the bag filter described in this example and shown in the drawing is not the only one possible to achieve the above technical result and does not exclude other variants of its manufacture containing a combination of features included in an independent claim.

Claims (4)

1. A bag filter comprising a housing with symmetrically filtering sections located in it, between which a dusty gas collector horizontally passes in the lower part and a purified gas collector in the upper part, each of the filtering sections includes a dusty gas chamber with a set of vertically oriented filtering of sleeves with a purified gas chamber located on top, and on the bottom, a dust collection bin, communicating with the mentioned dusty gas collector through a slot passage located between them, a system regeneration of filter bags, characterized in that the side walls between said dust collector and dust gas chambers are perforated to enter the last parts of the dusty gas, bypassing the hopper, while the ratio of the passage section of the openings in the walls of the dusty gas manifold and the slot passage in the hopper in each filter section is approximately 1: 1, the regeneration system of the filter bags includes at least one receiver of compressed air, with united through at least one diaphragm valve with electric drive with purge pipes containing nozzles, each of which is directed to the open end part of the filter sleeve from the side of the cleaned gas manifold, and each filter section is equipped with a pneumatic actuator kinematically connected to the shut-off rotary damper, for isolation of the purified gas chamber from the purified gas manifold during the regeneration of the filter bags, and the passage sections of the regeneration system are made in the following ratios:

where ∑ F _c. - the total cross-sectional area of the through holes of the nozzles of the purge pipe;
F pr. Tr. - cross-sectional area of the purge pipe;
F m C. - the cross-sectional area of the bore of the membrane valve.  2. The bag filter according to claim 1, characterized in that in the cross section the filter bags are staggered.  3. A bag filter according to claim 1 or 2, characterized in that the filter sections are arranged in two rows, in each of which up to ten sections.  4. Bag filter according to one of paragraphs. 1-3, characterized in that the membrane valve is made with a through hole, the diameter of which is 150 mm