JPH04503475A - Equipment for separating granular materials from hot gases - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Apparatus and method for separating particulate material from hot gas Field of the invention The present invention relates to an apparatus and method for separating particulate material from hot gases. In particular, the present invention including a gas permeable filter element and means for periodically cleaning the filter element. Related to high temperature gas filtration equipment.

Background of the invention Modern combustion and gasification methods extract particulate materials from hot combustion or product gases. This has created a demand for particle separators that can separate particles efficiently and stably. ing. In circulating fluidized bed combustion or gasification processes, e.g. Large quantities such as carcasses, ash, unburned fuel, and even reactive absorbents for capture. Dust is continuously mixed with and separated from the hot gas discharged from the combustion chamber After that, it is circulated back to the combustion chamber. The separation equipment used has a high separation efficiency and stability. Must withstand high temperatures and corrosive conditions in solid circuits without degrading There is. Effective separation equipment makes the circulating fluidized bed process itself effective. Additionally, removing particulate material prevents fouling of heat exchange surfaces in subsequent gas passages. Minimize.

In modern combined cycle power plants, hot combustion gases are expanded in gas turbines. In this case, an efficient cleaning device for hot gases can extend the life and operating time of gas turbines. It has been greatly extended. Particulate material in hot gases erodes turbine blades and greatly increase dirt.

On the other hand, today's concern about air pollution is due to the need to handle hot gases and This has created a demand for efficient dust collectors that increase the amount of dust collected.

Meeting the requirements for stable separation of solid particles from gases at high temperatures and often high pressures. Various types of granule separators have been proposed for gas cleaning processes to achieve has been configured. Recently, gas-permeable high-temperature filters have been used to separate the aforementioned particulate materials. It has become an interesting alternative to traditional vertical cyclones for Conventional A vertical cyclone has a significant impact on both the cyclone itself and the cyclone support structure. Requires new space. On the other hand, filter separators are significantly more compact; and can be incorporated into a simple system. Porous superalloy or °ceramic Filters made from carbon fibers can withstand high temperature conditions and are They do not need to be protected by cooling surfaces or refractory linings, as was the case with other engines.

Filter separators in pressurized processes are extremely easy to use in pressurized systems. can be integrated into.

In filter separators, dust gradually accumulates on the surface of porous materials; Filters need to be cleaned regularly. If a large amount of dust accumulates on the filter surface, If possible, there would be a large pressure difference between the two sides of the filter, making it difficult for gas to pass through. A large amount of pressure or energy is required.

Filters such as bag filters for cold gases should not be shaken, agitated, vibrated or Remove dust build-up on the filter media by brushing or scraping. Cleaning has been done by loosening the parts. For example, a long thin tube filter Rigid ceramic filters for high temperatures such as may be damaged by rough handling.

Cleaning rigid ceramic filters is typically done by backflowing clean gas through the filter media. This is done as a backwashing process. During backwashing, the main The separation process must be stopped in order to allow the clean gas to flow back through the filter. There is. This not only disturbs the continuous process and releases large amounts of gas. Ru.

filter tubes by periodically injecting compressed air pulses into the tubes. It has also been suggested to clean the area. Compressed air acts in a pulsed manner and filters Release dust from the surface of the tube. Each filter tube connects all filter tubes. has its own compressed air injector to ensure cleaning of the Or it is necessary to have a common movable injector for several tubes. rice National Patent No. 4,468,240 discloses a filter having a filter cleaning device according to the above technology. The filter separator is shown. Separator has space for dust-containing gas and space for clean gas It has a housing divided into spaces.

The filter tube is arranged in the space for the dust-containing gas. clean gas is For clean gas flowing into the filter tube from the outside and through the wall of the filter tube Enter the space. Clean the filter tube when it is placed in the clean gas space. From the injector in the reciprocating chamber to the filter tube to be cleaned This is achieved by supplying compressed air. This structure is extremely complex and eat a lot of food.

U.S. Pat. Filter housing divided into several compartments with filter tube supports A filter separator is disclosed. The dust-containing gas is flushed at the top. The separated particles are introduced into the filter tube and discharged from the lower end. clean moth The gas is passed through the porous tube wall to create a clean gas space surrounding the tube. flows into. Each clean gas space has one clean gas outlet. There is. The filter separator is compact and simple in construction. The aforementioned filter separator A cleaning method for this purpose is disclosed in Japanese Patent Application No. 61-268330. centre A diffuser is placed on the outside of the filter housing for each clean gas outlet vibe. has been done. Gas from the high pressure compressor is routed through the throat of the diffuser and clean gas. is introduced into the clean gas space via the gas outlet vibrator. Also, throat Due to the injector effect, the circumferentially clean gas from the gas outlet conduit is A pressurized gas jet is generated, generating a large backwashing gas flow. During the backwash stage, the main The separation process does not need to be stopped.

When filtering gases at high temperatures and pressures, use the diffuser in the clean gas outlet vibrator. The space is extremely space consuming.

The diffuser itself is relatively large and has a large splash to one side of the filter separator. It forms a protrusion. Backwash gas is filtered to eliminate thermal shock to the filter. The diffuser and purifier must be at approximately the same temperature as the hot gas in the filter. The gas outlet vibrator must be extremely well insulated, and this means that the filter housing Significantly increases the size of elements that protrude from the ding. For this reason, otherwise This makes compact filter housings less attractive from a structural point of view. Ru.

Purpose of invention The aim of the invention is to minimize the drawbacks of known filter surface cleaning systems.

Another object of the invention is to provide a vine filter cleaning system that can be used without disturbing separation operations. It is to provide. Yet another object of the present invention is to provide a compact device for cleaning hot gases. The objective is to provide a simple filter separator. Yet another object of the invention is to It is an object of the present invention to provide an easily adjustable hanging device for separating particulate material from a liquid.

Summary of the invention According to the present invention, a plurality of parallel open ends for separating particulate material from hot gases A filter housing is provided that includes a hollow, gas-permeable filter element. centre The filter housing divides the filter housing into at least three sections. and at least one pair of through openings for supporting the filter element. Includes a cross-sectional support plate. The support plate has contaminated the filter housing. a first end section having an inlet for the gas and a discharge for the separated granular material; It is divided into a second end section associated with the mouth and an intermediate filtration chamber therebetween.

A filter element is provided in an intermediate filtration chamber extending from the first support plate to the second support plate. The elements are arranged. The end portion of the hollow gas-permeable filter element is and fixed in the opening. Gas-permeable filter elements allow clean gas to filter The clean gas in the intermediate filtration chamber is removed from the hollow space inside the filter through the gas-permeable side parts. space. The inlet opening of the filter element allows contaminated gas to in communication with the first end section of the filter housing to lead to the filter element. It is located. The outlet opening of the filter element allows the separated granular material to pass through the filter element. in communication with the second end section for discharge from the second end section. Outlet conduit for clean gas clean gas in the intermediate filtration chamber so that the clean gas is exhausted from the filter housing. It communicates with the space for use. An important feature of the invention is to clean porous filter media. The means for supplying a reverse flow high pressure pulse of high energy gas to the filtration chamber to It is located inside the filter housing. Backflow high pressure pulse is compressed It may be supplied via a relatively small pipe connected to the sensor.

The invention is particularly suitable for filter separators in pressurized systems. This cleaning The removal system is vertically cylindrical and can be advantageously integrated into a pressure-tight filter housing. Can be done.

The cleaning gas pulse injector is arranged in communication with the clean gas outlet conduit at its inlet end. It is preferable that the The cleaning gas is coaxial with the inlet end of the clean gas outlet conduit. It can be delivered through gas nozzles arranged in alignment in relation to each other. For high pressure cleaning Clean gas outlet to prevent gas pulses from entering the clean gas outlet conduit. Ejector means is disposed within the conduit entrance means. The cleaning gas pulse is As the gas is blown into the Zecta throat, a gas plug is formed in the throat and the clean gas is blown into the throat. prevent leakage of water. The gas pulse is extremely short and disrupts the entire separation process It's not a thing.

The inlet end of the clean gas outlet conduit containing the ejector is connected to the clean gas outlet of the filtration chamber. It may be placed so that it extends into the pace. According to one embodiment of the invention, a clean gas The outlet for the filter is arranged parallel to the longitudinal direction of the filter element. clean gas The outlet may be in either the upper first end section or the lower second end section. through the filtration chamber and then out of the filter housing through the end wall. Just place it like that.

According to the invention, a separate An intermediate cross-sectional support plate can be provided in the filtration chamber. Each compartment is its own There may be an outlet conduit for body cleansing gas and a cleaning gas nozzle.

The clean gas conduits from the individual compartments are routed through the walls of the filter housing into individual Exit boats can be grown or the gas can be exhausted through one common gas outlet boat. It is preferable to combine them so that they are served. In a pressurized system, Boats that penetrate the wall of the pressure vessel should be as small and as few as possible. It is survival.

According to another embodiment of the invention, the outlet conduit for clean gas supplies one clean gas to the other. from one compartment to the next adjacent clean gas compartment and finally to either end compartment. from the section and the corresponding end wall to the outside.

According to a further embodiment of the invention, a separate clean gas outlet is provided adjacent to the filtration chamber. There is a room. Common outlet conduit for clean gas from each clean gas compartment It is arranged so that it is connected to a clean gas discharge chamber. In that case, the surrounding frame There only needs to be one clean gas outlet boat in the filter housing. pure The gas discharge chamber is parallel to the upright filtration chamber and is connected to the upper filter tube support plate. The pressure vessel is placed in a vertical, cylindrical pressure vessel extending from the top to the support plate below.

In that case, only one clean gas outlet boat is required in the cylindrical side wall of the pressure vessel. It is only said that

The filter elements used in the device according to the invention form filtration channels between them. Any filter tube or filter element may be used. The filter element is a porous cell. It can be made from ramic materials or superalloys.

The present invention uses a large protruding (bulky) insulated exit boat or diffuser. To provide a smaller and more compact particle separation system that does not require a particle separation device. Therefore, before Allocate the necessary space for any protruding elements or support structures on the outside of the filter container. There is no need to leave it there. The filter housing itself is slightly larger; Easy to take into account when configuring filter systems and easily adjust filter systems and can be more easily dimensioned and designed in advance. .

Thus, the present invention provides an improved design of a filter module. This is it The design had multiple outlets for the pressure vessel emanating from the side of the vessel. present invention According to It can be designed with only one. Especially for pressurized systems and high temperature systems. In the stem, everything between the main filter housing and either exit boat The expansion joint is the weak point in the system and therefore the outlet or inlet The number of ports should be kept to a minimum.

The only outlet at the bottom of the container is the filtration chamber, which arranges the filter tube in a circular manner. A clean gas outlet conduit including a cleaning ejector is located in the center of the filtration chamber. Accomplished by vine. Central outlet from multiple compartments delimits outlet conduit for clean gas Divide into as many branches as there are chambers, with all branches placed in the lowest section at the bottom of the filter housing. This is accomplished by threading the compartment or lower end section. So In the case of I am guided in this way.

Collect fly ash in multiple hoppers in the bottom end section, each hopper Can be discharged through the vibrator at the bottom of the body.

This way, a more compact device and a single outlet for clean hot flue gases are possible. It is possible to achieve this connection. In addition, assembly and inspection of filter housings are also carried out. much easier.

Brief description of the drawing FIG. 1 is a schematic vertical sectional view of a filter separator according to the invention; Figure 2 is a cross-sectional view along line A-A; 3, 5, 7 and 9 show other embodiments of the invention similar to FIG. The schematic vertical cross-sectional views shown in Figures 4, 6, 8 and 1O are taken along line A-A. FIG.

Detailed description of preferred embodiments Referring now to the drawings, identical parts in all embodiments are designated by the same reference numerals. are doing.

In FIG. 1, a filter separation consisting of a generally vertical cylindrical filter housing 2 is shown. Vessel 1 is shown. The filter housing has insulated side walls 3 and upper and lower end walls 4. , 5. The filter housing consists of two support plates or tubes. ports 6 and 7 form three sections: a first upper end section 8, a second upper end section 8; It is divided into a lower end section 9 and an intermediate section or filtration chamber IO. .

A hollow filter tube 11 with an open end is disposed in the filtration chamber 10 and is mounted on an upper support plate. It extends from the base to the lower support plate. The filter tube is supported above and below is fixed in the aperture 12 of the plate and connects the space in the upper end section to the lower end section. Connect with other spaces. In the upper end section there is an inlet 13 for contaminated gas. is arranged, and the gas containing particulate matter is transferred to the filter separator through the inlet. can be introduced. Clean gas flows through the tube wall into the hollow filter tube. It flows from the inside of the tube 11 into the clean gas space of the filtration chamber 10. Granules are filters Trapped inside the tube. The lower end section hopper 14 includes a filter filter. An opening connected to the tube is located below. Hopper to filter tube Collect the particulate material separated from the contaminated gas at the The hopper is attached to its bottom. It has a discharging vibrator 15 connected to it, and the collected particles are disposed on the lower end wall 5. out of the filter through a small opening 16.

A clean gas outlet conduit 17 is disposed in the center of the lower support plate 7 and is connected to the filtration chamber l. It extends to O. The outlet conduit for clean gas furthermore has a lower end section 9 and a lower end. It is arranged to pass through an opening 18 in the wall 5.

The inlet end 19 of the clean gas outlet conduit 17 is connected to an ejector 20 having a throat 21. It is formed as follows. A relatively small vibrator 22 is placed in the clean gas outlet conduit. and supplies pulses of high pressure gas to the filtration chamber via the ejector 20. High pressure gas jet The irradiation causes the gas to flow back through the wall of the filter tube and inside the filter tube. Loosen the dust that has accumulated on the wall.

FIG. 2 shows a cross-sectional view of the separator described above, taken along line A--A. Clean gas outlet A conduit 17 is arranged in the middle part of the housing 2, and a filter tube 11 is connected to said conduit. arranged in a ring around the

3 and 4 show another embodiment of the invention. The intermediate support plate 23 fills It is arranged in the filtration chamber IO to support the tube. Support plate is filtered The chamber IO is divided into two separate clean gas compartments 24,25. Each compartment is a separate clean gas supply extending downwardly into the lower end section 9 of the filter housing. There are outlet conduits 26 and 27 for use. Conduits 26,27 are one common outlet conduit 2 Combined with 8. In combination with a clean gas outlet conduit, the filter Only one outlet opening for clean gas is required in the wall of the housing; This significantly simplifies the structure.

5 and 6 show yet another embodiment of the invention.

The filtration chamber is divided into three separate compartments 29, 30, 31 by two intermediate support plates. divided, each compartment having its own outlet conduit 32, 33, 34 for clean gas. There is.

A clean gas conduit 34 from the compartment 31 directs the gas to the adjacent compartment 30 for clean gas. A clean gas conduit 33 leads gas from compartment 30 to compartment 29 . Clean gas is It exits the filtration chamber via a tube 32 and passes through the upper end wall 4 via an opening 35 .

7 and 8 show that the filtration chamber 10 is divided into compartments by a support plate, and each compartment A filter housing having a separate clean gas outlet conduit 37,38 in the chamber. show.

According to this embodiment, the outlet conduit extends from the filter housing into a separate opening in the upper end wall. is passing through. In the upper end wall the exit boat is smaller than in the cylindrical side wall 3. Easy to place.

Figure 9 and Figure 1O are arranged vertically parallel to the clean gas chamber 39 or the filtration chamber 10. An example of the present invention is shown below. The filtration chamber is divided into separate sections by the support plate 40. It is divided into 41 and 42 compartments. Both compartments send gas to clean gas room 39 It has an outlet conduit 43,44 for clean gas arranged for discharge. cylinder An outlet boat 45 for clean gas is arranged in the side wall 3 . In this example, clean There is space at the top and bottom of the filter housing for arranging gas outlets. Ikuuri is when there are few or no children around. Still clean gas There is only one outlet for water and no space-consuming diffuser is used. stomach.

FIGI F+ (32 FI33 FI34 "The scope of the claims 1. a device for separating particulate material from hot gas (9); and at least Divided into one intermediate filtration chamber (10, 24, 25, 29, 30, 40, 41) a pair of cross-sectional support plates (6°7); an inlet (13) for a gas containing particulate material; a discharge boat (16) for separated material; Both ends of the 7ifE opening (12) passing through the 7fiHa support plate (6, 7) The gas-permeable side parts are fixed at the filtration chamber (10, 24, 25°2 9.30, 40, 41.42) hollow elongated filters with multiple open ends an element (11) comprising an inlet opening (12) or said upper end section (18); in communication, and the outlet opening communicates with the granule ejection element (14, 15) of said lower end section. through the gas-permeable side part from the hollow space inside the filter element. a filter element that allows the filter element to flow into the filter chamber; A clean gas outlet conduit (17, 26, 27, 32, 33, 34,37°38.43.44) and The filter chamber (10, 24, 25, 29, 30 , 31, 41° 42) into the housing. Claim 1, characterized in that the container (2) is a pressure-resistant upright cylindrical container. Apparatus for separating particulate materials as described in .

The grains according to claim 1, wherein the grains are arranged so as to be blown into the grains. equipment for separating shaped materials.

4. The gas outlet conduit (17, 26, 27, 32, 33, 34, 37, 38 ) is arranged parallel to the filter tube (11) in the filtration chamber. An apparatus for separating particulate material according to claim 3, characterized in that:

5. The filter chamber has at least one intermediate section having an opening for a filter element. At least two separate cleaning plates (23, 36, 40) clean gas compartments (24, 25, 29°6, each clean gas outlet conduit (26, 27°37.38) or a separate clean gas compartment (24°25.29.30) Claim extension characterized in that the claim is arranged to exhaust clean gas from the Granular material according to claim 1, characterized in that it comprises a tube (11) containing A device that separates

8. An upright cylindrical pressure vessel (12) and a granule-containing gas introduced into said pressure vessel. entrance board) (13), an outlet boat (28) for clean gas in the pressure vessel; The pressure vessel is divided into an upper gas inlet chamber (8), a lower end chamber (9), and the upper and lower chambers. a pair of cross-sectional tube sheets (6, 7) dividing into a filtration chamber (10) between the and, disposed between the pair of cross-sectional tubesheets and connecting the gas inlet chamber to the lower end a plurality of filter tubes (11) arranged to be associated with the chamber; disposed between the pair of cross-sectional tubesheets and supporting the filter tube; and supplying clean gas to the filtration chamber through the gas-permeable filter tube. One medium cross-sectional tube sheet (23) adapted to receive and a clean gas outlet conduit projecting into each clean gas compartment (24, 25). (26, 27), where all cleaning gas conduits are connected to the cleaning gas from each compartment. to one common clean gas outlet port (28) in the pressure vessel. an inlet end of an outlet conduit for clean gas; A venturi (19, 20) located at the inlet end of each clean gas outlet conduit ) and placed at said inlet end of said clean gas outlet conduit and pulsed with high pressure gas. The filter shown in the nozzle is arranged to guide the air to the throat part (21) of the venturi. device. j international search report international search report PCT/FI90100179

Claims (20)

[Claims] 1. In an apparatus for separating particulate material from hot gas, a housing (2); a through opening (12), which connects said housing to a first end section (8) and a second end section (8); an end section (9) and at least one intermediate filtration chamber (10, 24, 25, 29, 30, 40, 41) and a pair of cross-sectional support plates ( 6,7) and an inlet (13) for a gas containing particulate material in said first end section; an evacuation port (16) for separated material in said second end section; fixed at both end portions to the openings (12) passing through the support plates (6, 7); The gas-permeable side portions are connected to the filtration chambers (10, 24, 25, 29, 30, 31, 4). 1, 42) with a plurality of open-ended hollow elongated filter elements (11). an inlet opening (12) communicates with said first end section (18) and an outlet opening (12) communicates with said first end section (18); in communication with the granule evacuation element (14, 15) of said second end section and in which gas is blown. Flow from the inner hollow space of the filter element through the gas-permeable side part to said filtration chamber. a filter element that allows A clean gas outlet conduit (17, 26, 27, 32, 33, 34, 37, 38, 43, 44) and The filter chamber (10, 24, 25, 29, 30 ．． 31, 41, 42) for supplying pressurized pulses of backflow of cleaning gas to means (22) in said housing; device to do. 2. Claim characterized in that said housing (2) is a pressure-resistant upright cylindrical container. A device for separating particulate material according to item 1. 3. Said means (22) for supplying a countercurrent high pressure pulse of high energy cleaning gas disposed in said housing in communication with the inlet end (19) of a clean gas outlet conduit (17); An apparatus for separating particulate material according to claim 1, characterized in that: 4. A backflow pulsed cleaning gas nozzle (22) connects said clean gas outlet conduit (17) to said clean gas outlet conduit (17). ) is arranged in coaxial alignment with the inlet end (19) of the An apparatus for separating particulate material according to claim 3. 5. The inlet end (19) of the clean gas outlet conduit extends inside the filtration chamber. and includes a venturi device (20, 21), and a cleaning gas nozzle (22). ) is arranged to blow cleaning gas into the throat part (21) of the ejector. 5. Apparatus for separating particulate material according to claim 4, characterized in that: 6. The gas outlet conduit (17, 26, 27, 32, 33, 34, 37, 38) is arranged parallel to the filter tube (11) in the filtration chamber. An apparatus for separating particulate material according to claim 5. 7. Clean gas outlet conduits (17, 26, 27) are connected to the filtration chamber (10, 24, 25) and the second end section (9) from each other. (7). An apparatus for separating particulate material according to item 1. 8. A clean gas outlet conduit (32, 37, 38) connects the filtration chamber (29, 30) to the first said cross-sectional support plate (6) separating from each other an end section (8) of as claimed in claim 1, characterized in that it is arranged so as to pass through one of the Equipment for separating granular materials. 9. the filtration chamber has at least one intermediate cross-section having an opening for a filter element; Directional support plates (23, 36, 40) provide at least two separate clean Divided into gas compartments (24, 25, 29, 30, 31, 41, 42) An apparatus for separating particulate material according to claim 1. 10. A clean gas outlet conduit is located in each clean gas compartment. 10. A device for separating particulate material according to claim 9. 11. Each clean gas outlet conduit (26, 27, 37, 38) has a separate clean Arranged to exhaust clean gas from the gas compartments (24, 25, 2930). A device for separating particulate material according to claim 10, characterized in that: . 12. At least two clean gas outlet conduits (26, 27, 43, 44) are common. It is characterized by being combined with a regular clean gas discharge line (28, 45). An apparatus for separating particulate material according to claim 10. 13. The clean gas outlet conduit (33) from the clean gas compartment (30) is clean. Clean gas outlet conduit (32) for discharging clean gas from the filtration chamber ) is arranged so as to lead to an adjacent clean gas compartment (29) having 11. A device for separating particulate material according to claim 10. 14. A clean gas discharge chamber (39) is a filter that is divided into compartments (41, 42). an outlet conduit (43) for said clean gas in said compartment, which is arranged parallel to said compartment; , 44) leads the clean gas to the clean gas discharge chamber and connects the common clean gas outlet. A port conduit (45) connects said clean gas to exhaust said clean gas from said housing. Claim 10, characterized in that the gas discharge chamber is connected to a clean gas discharge chamber. Equipment for separating granular materials. 15. A clean gas outlet conduit (32, 37, 38) is provided in the upper end wall of said housing. The granular material according to claim 1, wherein the granular material is arranged so as to pass through the granular material. A device that separates materials. 16. A clean gas outlet conduit (17, 28) passes through the lower end wall of said housing. The granular material according to claim 1, characterized in that the granular material is arranged so as to Separating device. 17. A clean gas outlet conduit (45) is arranged through the side wall of said housing. A device for separating particulate material according to claim 1, characterized in that: . 18. The filter element includes a tube (11) extending between the support plates. Apparatus for separating particulate material according to claim 1, characterized in that: 19. the filter element includes a channel extending between the support plates; An apparatus for separating particulate material according to claim 1, characterized in that: 20. an upright cylindrical pressure vessel (12) and a granule-containing gas introduced into said pressure vessel; an inlet port (13); an outlet boat (28) for clean gas in the pressure vessel; The pressure vessel is divided into an upper gas inlet chamber (8), a lower end chamber (9), and the upper and lower chambers. a pair of cross-sectional tube sheets (6, 7) dividing into a filtration chamber (10) between the and are disposed between said pair of cross-sectional tubesheets, said gas inlet chamber being connected to said gas inlet chamber. a plurality of filter tubes (11) arranged to be combined with the lower end chamber; , disposed between the pair of cross-sectional tubesheets, the filter tube supporting and supplying the filtration chamber with clean gas through the gas permeable filter tube. at least one intermediate cross-sectional tubesheet (23 )and, A clean gas outlet conduit (2) projects into each clean gas compartment (24, 25). 6, 27), where all cleaning gas conduits are connected to clean gas from each compartment. a common clean gas outlet port (28) in the pressure vessel. located at the inlet end of each clean gas outlet conduit and at the inlet end of each clean gas outlet conduit. Venturi (19, 20) and located at said inlet end of said clean gas outlet conduit for venting pulses of high pressure gas. A nozzle (22) arranged to lead to the throat part (21) of the churi. A filtration device according to claim 1, characterized in that the filtration device comprises: