WO1991009662A1 - A method and an arrangement for introducing gas into a particle filter - Google Patents

A method and an arrangement for introducing gas into a particle filter Download PDF

Info

Publication number
WO1991009662A1
WO1991009662A1 PCT/FI1990/000296 FI9000296W WO9109662A1 WO 1991009662 A1 WO1991009662 A1 WO 1991009662A1 FI 9000296 W FI9000296 W FI 9000296W WO 9109662 A1 WO9109662 A1 WO 9109662A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter elements
gas
feed conduit
filter
openings
Prior art date
Application number
PCT/FI1990/000296
Other languages
French (fr)
Inventor
Kai Salo
Original Assignee
Tampella Power Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tampella Power Inc. filed Critical Tampella Power Inc.
Publication of WO1991009662A1 publication Critical patent/WO1991009662A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B01D46/2407—Filter candles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/0039—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with flow guiding by feed or discharge devices
    • B01D46/0041—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with flow guiding by feed or discharge devices for feeding
    • B01D46/0043—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with flow guiding by feed or discharge devices for feeding containing fixed gas displacement elements or cores

Definitions

  • the invention relates to a method of intro- ducing gas into a particle filter comprising tubular filter elements, wherein the gas is passed through a feed conduit outside the filter elements of the particle filter into a space between the filter elements.
  • the invention is further concerned with an arrangement for realizing the method, comprising a feed conduit positioned substantially centrally in a space between filter elements in a particle filter in parallel with said filter elements, said feed conduit being provided with at least one feed opening for introducing gas outside the filter elements.
  • Particle filters are used widely for purifying various process gases from particulate matter con ⁇ tained in- them.
  • gas is introduced into the filter unit, from where it flows through separate filter elements to the discharge side while the particles remain on the surface of the filter elements.
  • DE publication 3709671 discloses a solution in which gas is introduced into the filter unit through the upper end of a pipe positioned within the filter unit in parallel with the tubular filter elements, so that the gas to be purified flows from the upper end of the pipe downwards along the filter elements.
  • the gas-entrained im- purities, which remain on the filter elements are not distributed evenly on the surfaces of the elements of the filter but may form solid local deposits.
  • the purification of this kind of filter elements is usually carried out by momentarily intro- ducing pressurized air or gas into the element so as to push off the dust gathered on the surface of the element so that it would drop on the bottom of the filter unit. If solid local deposits are formed on the surface of the element, the air is not able to detach them but it flows through the filter at points where there are no deposits, as a result of which the filter elements will not be purified properly.
  • the object of the present invention is to provide a method and an arrangement for introducing gas to be purified into the purification chamber of the filter unit in such a way that the above dis ⁇ advantages are avoided and the obtained filter both filters more evenly and purifies more reliably.
  • the method of the invention is characterized in that the gas to be purified is introduced into the space be ⁇ tween the filter elements in such a way that the flow of gas from the feed conduit towards the filter elements is substantially constant in the axial direction of the filter elements over the length of the filter elements.
  • the arrangement of the invention is characterized in that the feed conduit is closed at the top, that the feed conduit is provided with several feed openings substantially symmetrically around its longitudinal axis and over the length of the filter elements for passing gas out of the feed conduit in its transverse direction, and that the diameter of the openings increases in the direction of flow of the gas to keep the gas flow directed to ⁇ wards the filter elements substantially constant over the length of the filter elements.
  • the essential idea of the invention is that the gas to be purified is passed in the longitudinal direction of the elements of the filter unit as a substantially even flow, whereby the dust is gathered evenly on the surface of the elements without forming any local deposits.
  • This is effected especially in such a way that flow openings increasing in cross- sectional area in the longitudinal direction of the elements and positioned symmetrically in the peripheral direction of the feed pipe lead from the feed pipe into the filter chamber.
  • the flow openings may be formed by successive openings increasing in diameter in the direction of flow, or a slit in ⁇ creasing in width in the direction of flow of the gas can be formed in the pipe.
  • the feed pipe includes several such rows of holes or slits so that the distribution of the incoming gas in the peripheral direction of the feed pipe is also as even as possible.
  • Figure 1 is a cross-sectional view of one embodiment of the invention
  • Figure 2 is a cross-sectional view of the feed pipe of the filter of Figure 1 at point A-A;
  • Figure 3 is a cross-sectional view of another embodiment of the invention.
  • Figure 4 is a cross-sectional view of the feed pipe of the filter of Figure 3 at point B-B.
  • FIG. 1 shows a particle filter comprising a filter chamber 1 and a discharge chamber 2 for the purified gas.
  • the gas to be purified is fed into the filter chamber through a gas feed pipe 3.
  • the feed pipe 3 is closed at the top and provided with openings 4 which are positioned over the length of per se known ceramic filter elements 5 at uniform intervals.
  • the ceramic filters, the inner space 6 of which communicates with the discharge chamber 2 are fastened at the upper end in a manner known per se to a partition wall between the filter chamber 1 and the discharge chamber 2.
  • the gas introduction openings in the feed pipe 3 are positioned symmetrically with respect to the central axis of the feed pipe 3, whereby their number may vary, depending on the number of the ceramic filter elements 5.
  • the diameter of the holes 4 is at smallest at the lower ends of the filter elements 5, that is, in the direction of entry of the gas, and it increases in the direction of the feed pipe 3 in such a way that the openings closest to the end of the feed pipe are large.
  • the pressure and the flow of the gas from the feed pipe can be adjusted in such a way that the gas flows substantially evenly over the whole length of the filter element 5 through its surface within it.
  • the dust particles contained in the gas are gathered evenly on the surface of the filter elements 5 without forming any separate local deposits.
  • the gas flowing from the inner space of the filter elements 5 into the discharge chamber 2 is further removed from the discharge chamber through a discharge conduit 7.
  • Figure 2 shows the cross-section of the feed pipe 3 of Figure 1 at point A-A indicated in Figure 1.
  • the gas introduction openings 4 are positioned symmetrically with respect to the central axis of the feed pipe 3, whereby the gas flows evenly through all the openings in the direction of each opening and thus substantially equally evenly on to the different filter elements 5.
  • the filter shown in Figure 3 corresponds in structure to that of Figure 1, the same parts being indicated with the same reference numerals.
  • the feed pipe in the filter of Figure 3 comprises gas introduction grooves 14 which widen in the direction of flow of the gas in such a way that the groove is at narrowest at the lower end of the filter elements 5 and widens evenly towards the. upper end of the filter elements, that is, in the direction of flow of the gas.
  • the strip-like wall portions of the feed pipe are supported to each other by means of annular support elements 15 which keep them stationary with respect to each other. Even in this case, the pipe 3 is closed at the top to prevent the escape of gas and to guide it through the flow grooves 14.
  • a desired number of flow openings can be provided so that the gas flow from the feed pipe 3 is distributed evenly with respect to the filter elements 5.
  • fasteners or welds extending over the feed grooves 14. The presence of such fas- teners or welds does not substantially affect the evenness of the gas flow.
  • Figure 4 shows the cross-section of the feed pipe 3 of the filter of Figure 3 at point B-B. Also in this case, the gas introduction grooves 14 are formed symmetrically with respect to the axis of the feed pipe 3, in order that the gas flow could be passed as evenly as possible around the feed pipe and thus with respect to the filter elements 5.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)

Abstract

A method and an arrangement for introducing gas to be purified into a particle filter. The gas to be purified is passed into the filter unit through feed openings (4) formed in the surface of a feed pipe (3) extending in parallel with filter elements (5) in such a manner that the flow of gas longitudinally of the feed pipe (3) is substantially even.

Description

A method and an arrangement for introducing gas into a particle filter
The invention relates to a method of intro- ducing gas into a particle filter comprising tubular filter elements, wherein the gas is passed through a feed conduit outside the filter elements of the particle filter into a space between the filter elements. The invention is further concerned with an arrangement for realizing the method, comprising a feed conduit positioned substantially centrally in a space between filter elements in a particle filter in parallel with said filter elements, said feed conduit being provided with at least one feed opening for introducing gas outside the filter elements.
Particle filters are used widely for purifying various process gases from particulate matter con¬ tained in- them. In such filters, gas is introduced into the filter unit, from where it flows through separate filter elements to the discharge side while the particles remain on the surface of the filter elements. DE publication 3709671 discloses a solution in which gas is introduced into the filter unit through the upper end of a pipe positioned within the filter unit in parallel with the tubular filter elements, so that the gas to be purified flows from the upper end of the pipe downwards along the filter elements. In this solution the gas-entrained im- purities, which remain on the filter elements, are not distributed evenly on the surfaces of the elements of the filter but may form solid local deposits.
The purification of this kind of filter elements is usually carried out by momentarily intro- ducing pressurized air or gas into the element so as to push off the dust gathered on the surface of the element so that it would drop on the bottom of the filter unit. If solid local deposits are formed on the surface of the element, the air is not able to detach them but it flows through the filter at points where there are no deposits, as a result of which the filter elements will not be purified properly.
The object of the present invention is to provide a method and an arrangement for introducing gas to be purified into the purification chamber of the filter unit in such a way that the above dis¬ advantages are avoided and the obtained filter both filters more evenly and purifies more reliably. The method of the invention is characterized in that the gas to be purified is introduced into the space be¬ tween the filter elements in such a way that the flow of gas from the feed conduit towards the filter elements is substantially constant in the axial direction of the filter elements over the length of the filter elements.
The arrangement of the invention, in turn, is characterized in that the feed conduit is closed at the top, that the feed conduit is provided with several feed openings substantially symmetrically around its longitudinal axis and over the length of the filter elements for passing gas out of the feed conduit in its transverse direction, and that the diameter of the openings increases in the direction of flow of the gas to keep the gas flow directed to¬ wards the filter elements substantially constant over the length of the filter elements.
The essential idea of the invention is that the gas to be purified is passed in the longitudinal direction of the elements of the filter unit as a substantially even flow, whereby the dust is gathered evenly on the surface of the elements without forming any local deposits. This is effected especially in such a way that flow openings increasing in cross- sectional area in the longitudinal direction of the elements and positioned symmetrically in the peripheral direction of the feed pipe lead from the feed pipe into the filter chamber. The flow openings may be formed by successive openings increasing in diameter in the direction of flow, or a slit in¬ creasing in width in the direction of flow of the gas can be formed in the pipe. The feed pipe includes several such rows of holes or slits so that the distribution of the incoming gas in the peripheral direction of the feed pipe is also as even as possible.
The invention will be described in more detail in the attached drawings, wherein
Figure 1 is a cross-sectional view of one embodiment of the invention;
Figure 2 is a cross-sectional view of the feed pipe of the filter of Figure 1 at point A-A;
Figure 3 is a cross-sectional view of another embodiment of the invention; and Figure 4 is a cross-sectional view of the feed pipe of the filter of Figure 3 at point B-B.
Figure 1 shows a particle filter comprising a filter chamber 1 and a discharge chamber 2 for the purified gas. The gas to be purified is fed into the filter chamber through a gas feed pipe 3. The feed pipe 3 is closed at the top and provided with openings 4 which are positioned over the length of per se known ceramic filter elements 5 at uniform intervals. The ceramic filters, the inner space 6 of which communicates with the discharge chamber 2, are fastened at the upper end in a manner known per se to a partition wall between the filter chamber 1 and the discharge chamber 2. The gas introduction openings in the feed pipe 3 are positioned symmetrically with respect to the central axis of the feed pipe 3, whereby their number may vary, depending on the number of the ceramic filter elements 5. The diameter of the holes 4 is at smallest at the lower ends of the filter elements 5, that is, in the direction of entry of the gas, and it increases in the direction of the feed pipe 3 in such a way that the openings closest to the end of the feed pipe are large. In this way the pressure and the flow of the gas from the feed pipe can be adjusted in such a way that the gas flows substantially evenly over the whole length of the filter element 5 through its surface within it. Thereby the dust particles contained in the gas are gathered evenly on the surface of the filter elements 5 without forming any separate local deposits. The gas flowing from the inner space of the filter elements 5 into the discharge chamber 2 is further removed from the discharge chamber through a discharge conduit 7.
Figure 2 shows the cross-section of the feed pipe 3 of Figure 1 at point A-A indicated in Figure 1. As shown in Figure 2, the gas introduction openings 4 are positioned symmetrically with respect to the central axis of the feed pipe 3, whereby the gas flows evenly through all the openings in the direction of each opening and thus substantially equally evenly on to the different filter elements 5.
The filter shown in Figure 3 corresponds in structure to that of Figure 1, the same parts being indicated with the same reference numerals. The feed pipe in the filter of Figure 3, however, comprises gas introduction grooves 14 which widen in the direction of flow of the gas in such a way that the groove is at narrowest at the lower end of the filter elements 5 and widens evenly towards the. upper end of the filter elements, that is, in the direction of flow of the gas. In this case, the strip-like wall portions of the feed pipe are supported to each other by means of annular support elements 15 which keep them stationary with respect to each other. Even in this case, the pipe 3 is closed at the top to prevent the escape of gas and to guide it through the flow grooves 14. Similarly as in the case of Figure 1, a desired number of flow openings can be provided so that the gas flow from the feed pipe 3 is distributed evenly with respect to the filter elements 5. In place of the separate support rings 15, it is also possible to fasten the wall strips of the feed pipe together by means of fasteners or welds extending over the feed grooves 14. The presence of such fas- teners or welds does not substantially affect the evenness of the gas flow.
Figure 4 shows the cross-section of the feed pipe 3 of the filter of Figure 3 at point B-B. Also in this case, the gas introduction grooves 14 are formed symmetrically with respect to the axis of the feed pipe 3, in order that the gas flow could be passed as evenly as possible around the feed pipe and thus with respect to the filter elements 5.

Claims

Claims :
1. A method of introducing gas into a particle filter comprising tubular filter elements (5), where- in the gas is passed through a feed conduit (3) out¬ side the filter elements (5) of the particle filter into a space between the filter elements, c h a r ¬ a c t e r i z e d in that the gas to be purified is passed into the space between the filter elements (5) in such a way that the gas flow from the feed conduit (3) towards the filter elements (5) is substantially constant in the axial direction of the filter elements (5) over the length of the filter elements.
2. A method according to claim 1, c h a r a c - t e r i z e d in that the gas to be purified is passed into the space between the filter elements (5) through the feed conduit (3) positioned substantially centrally in the space, and that the feed conduit (3) is provided with openings (4) increasing in diameter in the direction of flow of the gas to keep the gas flow from the feed conduit (3) substantially constant over the length of that portion of the conduit (3 ) which contains the openings (4) .
3. An arrangement for realizing the method of claim 1, comprising a feed conduit (3) positioned substantially centrally in a space between filter elements (5) in a particle filter in parallel with said filter elements (5), said feed conduit (3) being provided with at least one feed opening (4) for introducing gas outside the filter elements ( 5 ) , c h a r a c t e r i z e d in that the feed conduit (3) is closed at the top, that the feed conduit (3) is provided with several feed openings (4) substan¬ tially symmetrically around its longitudinal axis and over the length of the filter elements (5) for passing gas out of the feed conduit (3) in its trans¬ verse direction, and that the diameter of the openings (4) increases in the direction of flow of the gas to keep the gas flow directed towards the filter elements (5) substantially constant over the length of the filter elements (5) .
4. An arrangement according to claim 3, c h a r a c t e r i z e d in that the feed conduit (3) comprises rows of openings formed by openings (4) positioned axially in succession, said rows being positioned substantially symmetrically with respect to the periphery of the feed conduit (3).
5. An arrangement according to claim 3, c h a r a c t e r i z e d in that the feed conduit (3) comprises several openings (14) substantially continuous over the length of the filter elements (5) and increasing in width in the direction of flow of the gas.
PCT/FI1990/000296 1989-12-22 1990-12-13 A method and an arrangement for introducing gas into a particle filter WO1991009662A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI896252 1989-12-22
FI896252A FI87540C (en) 1989-12-22 1989-12-22 FOERFARANDE OCH ANORDNING FOER MATNING AV GAS TILL PARTIKELFILTER

Publications (1)

Publication Number Publication Date
WO1991009662A1 true WO1991009662A1 (en) 1991-07-11

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ID=8529586

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1990/000296 WO1991009662A1 (en) 1989-12-22 1990-12-13 A method and an arrangement for introducing gas into a particle filter

Country Status (3)

Country Link
FI (1) FI87540C (en)
PT (1) PT96300A (en)
WO (1) WO1991009662A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995018662A1 (en) * 1994-01-10 1995-07-13 Lurgi (Australia) Pty Limited Fabric filter
DE19523417C1 (en) * 1995-06-28 1996-11-14 Metallgesellschaft Ag Process for dedusting a raw gas stream and / or sorption of gaseous substances from the raw gas stream and device for carrying out the process
EP2058044A1 (en) * 2006-11-06 2009-05-13 Mitsubishi Heavy Industries, Ltd. Dust collector

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3519560A (en) * 1967-08-21 1970-07-07 Filters Inc Method and apparatus for removing water from fluids
DE2835913A1 (en) * 1977-08-23 1979-03-29 Alfa Laval Ab Tubular filter with liq. distributor - has pipe inside or outside filter medium with graded flow passages to give uniform flow across filter surface
US4259095A (en) * 1979-09-26 1981-03-31 Johnson Jr Allen S Bag-type filter apparatus with combination bag support and air diffuser
DE3709671A1 (en) * 1987-03-24 1988-10-06 Man Technologie Gmbh Particle filter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3519560A (en) * 1967-08-21 1970-07-07 Filters Inc Method and apparatus for removing water from fluids
DE2835913A1 (en) * 1977-08-23 1979-03-29 Alfa Laval Ab Tubular filter with liq. distributor - has pipe inside or outside filter medium with graded flow passages to give uniform flow across filter surface
US4259095A (en) * 1979-09-26 1981-03-31 Johnson Jr Allen S Bag-type filter apparatus with combination bag support and air diffuser
DE3709671A1 (en) * 1987-03-24 1988-10-06 Man Technologie Gmbh Particle filter

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995018662A1 (en) * 1994-01-10 1995-07-13 Lurgi (Australia) Pty Limited Fabric filter
AU691851B2 (en) * 1994-01-10 1998-05-28 Lurgi Pacific Pty Ltd Fabric filter
US5846300A (en) * 1994-01-10 1998-12-08 Lurgi (Australia) Pty Limited Fabric filter with gas inlet geometry and method
DE19523417C1 (en) * 1995-06-28 1996-11-14 Metallgesellschaft Ag Process for dedusting a raw gas stream and / or sorption of gaseous substances from the raw gas stream and device for carrying out the process
EP2058044A1 (en) * 2006-11-06 2009-05-13 Mitsubishi Heavy Industries, Ltd. Dust collector
EP2058044A4 (en) * 2006-11-06 2010-01-06 Mitsubishi Heavy Ind Ltd Dust collector
US8551204B2 (en) 2006-11-06 2013-10-08 Mitsubishi Heavy Industries, Ltd. Dust collector

Also Published As

Publication number Publication date
FI87540C (en) 1993-01-25
FI896252A0 (en) 1989-12-22
FI896252A (en) 1991-06-23
FI87540B (en) 1992-10-15
PT96300A (en) 1992-08-31

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