US20050103727A1 - Sequential swinging precoat removal and renewal system, filter so equipped, and method - Google Patents
Sequential swinging precoat removal and renewal system, filter so equipped, and method Download PDFInfo
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- US20050103727A1 US20050103727A1 US11/022,004 US2200404A US2005103727A1 US 20050103727 A1 US20050103727 A1 US 20050103727A1 US 2200404 A US2200404 A US 2200404A US 2005103727 A1 US2005103727 A1 US 2005103727A1
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- filter
- precoat
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- disc
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Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
- B01D35/12—Devices for taking out of action one or more units of multi- unit filters, e.g. for regeneration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/15—Filters with filtering elements which move during the filtering operation with rotary plane filtering surfaces
- B01D33/21—Filters with filtering elements which move during the filtering operation with rotary plane filtering surfaces with hollow filtering discs transversely mounted on a hollow rotary shaft
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/44—Regenerating the filter material in the filter
- B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
- B01D33/463—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element nozzles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/44—Regenerating the filter material in the filter
- B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
- B01D33/466—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element scrapers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/58—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element
- B01D33/60—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for washing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D33/00—Filters with filtering elements which move during the filtering operation
- B01D33/80—Accessories
- B01D33/804—Accessories integrally combined with devices for controlling the filtration
Definitions
- the present invention relates generally to precoat filters such as disc filters having a layer of precoat thereon and, more particularly, to the washing and renewal of a precoat layer on such filters.
- Filtration equipment such as disc or drum filters are known in the art for their use in separating solid particles from a liquid in which they are suspended.
- Such filters typically pass the particle-containing liquid through a selected filter media which allows the passage of liquid therethrough while retaining the particles on a surface of the filter media for subsequent collection.
- the liquid passing through the filter media is typically referred to as filtrate while the particles on the surface of the filter media are typically referred to as cake.
- the filter media used in such a process may be formed from a variety of different materials but is often of a cloth- or fabric-type material, including, for example, wire mesh, formed of natural or synthetic materials. Additionally, filter media may include a built-up layer of cake on the filtration surface of a drum, disc, or other filter element. This layer of cake is referred to as a precoat. It is noted that, depending on the type of material being processed, the precoat layer may be formed from a material that is the same as or similar to the material being filtered. For example, if lime mud is being filtered and removed from a liquid, lime mud may also be used as the precoat. However, the precoat does not have to be formed of the same material as that which is being filtered.
- the precoat layer is typically formed on top of a filter cloth, with the two elements working in conjunction to separate filtrate from the process cake.
- the precoat layer is a permeable layer which allows filtrate to pass through while capturing additional particles on a surface of the precoat layer.
- the filtered particles are typically removed, often by a scraping device, while the precoat layer remains on the filter media for continued filtering.
- the precoat layer After a precoat layer has been in use for an extended amount of time, the precoat layer becomes less permeable and thus reduces the efficiency of the filtering operation by allowing less filtrate to pass therethrough.
- the precoat layer When the precoat layer is in such a condition, it becomes desirable to remove and regenerate the precoat layer by removing the existing precoat layer of material in its entirety and forming a new precoat layer in its place.
- FIGS. 1 and 2 hereof are representative of the apparatus disclosed in the Larsson patent.
- FIGS. 1 and 2 show a disc filter 10 including a plurality of hollow discs 12 having sidewalls 14 of a filter material 16 .
- the hollow discs 12 are coupled to a hollow axle 18 and are in fluid communication therewith via holes 20 formed along the hollow axle 18 .
- the hollow discs 12 are positioned within a container 22 , such as a tank, which includes an inlet 24 for introducing a slurry 26 (i.e., a particle-containing liquid) into the container 22 .
- a slurry 26 i.e., a particle-containing liquid
- a vacuum 28 draws the filtrate through filter material 16 with particles from the drawn liquid accumulating on the surface of the filter material 16 to form a cake.
- the container 22 is filled slightly less than halfway with the slurry.
- the discs 12 are configured to rotate counterclockwise through the slurry 26 . In operation, a portion of the discs 12 enters into the slurry 26 to draw filtrate from the slurry 26 and then emerge with a cake formed of accumulated particles.
- a scraper 30 is used to remove the accumulated cake from the discs 12 while leaving a specified thickness of precoat material. The cake removed from the discs 12 is collected in a chute or bin 32 and transferred from the filter 10 for further processing or disposal, as the case may be.
- an oscillating spray pipe 34 having a spray nozzle 36 coupled thereto moves between the periphery and center of the disc 12 removing the precoat layer by spraying the precoat layer with a pressurized fluid.
- the Larsson patent describes such removal and regeneration as taking place in two steps with half of the discs being stripped of the their precoat layer followed by replacement of such layer, while the precoat layers of the other half of the discs are not sprayed.
- U.S. Pat. No. 5,897,788 to Ketolainen et al. discloses the use of a spray nozzle oriented at an acute angle to the surface of a filter drum of a drum-type filter to remove an outer, more porous and softer portion of the precoat layer on a substantially continuous basis between removals of the precoat layer in its entirety down to the filter wire.
- the washing shower includes a spray pipe and one or more nozzles directed at the filtering surface of a given filter (i.e., the filtering surface of a drum or a disc).
- a given filter i.e., the filtering surface of a drum or a disc.
- the wash assembly sprays water on the precoat surface of a given disc segment subsequent to the disc segment being rotated through the pool of slurry.
- the wash water flows through the filter media, including the precoat, forcing any filtrate potentially remaining in the cake and precoat layers to be drawn through the filter by the vacuum. Without the washing apparatus, some filtrate liquid might potentially be discharged with the cake layer, thus causing some inefficiency with the operation.
- washing shower provides some increased efficiency in production of filtrate
- shower assemblies require piping and valving in addition to that required for the precoat removal system.
- inclusion of a washing shower may add constraints to the overall design of the filter as the shower heads take up additional space and must be designed so as to not interfere with any moving components of the filter.
- precoat removal apparatus and system which allows for maximum efficiency in replacing the precoat layer on filter media of filter discs of a disc-type filter without losing the vacuum (or pressure differential) formed across the filter media. Additionally, it would be advantageous to provide a precoat removal apparatus and system which also incorporates a precoat renewal feature in a disc-type filter to minimize the necessity to remove and regenerate the precoat layer and to potentially reduce the frequency of repair of the filter media.
- the present invention comprises a precoat renewal system for a filter such as a disc filter.
- the precoat renewal system includes a plurality of nozzles coupled to spray piping and valving with each nozzle being positioned for spraying an area of one side of a disc.
- the nozzles and at least a portion of the spray piping may be movable such that the nozzles may be displaced relative to the discs.
- the nozzles and piping may be arranged in groups or zones with each zone covering a specified percentage of the discs in the filter. Each zone may represent about 40% or less of the total surface area of the filter media of the plurality of filter discs in the filter. It may be preferred that each zone be configured to effect fluid impingement on between about 15 and 25% of the total surface area of the filter media of the plurality of filter discs.
- Each zone may be configured such that high pressure fluid may be supplied to that particular zone for removal of a precoat layer on the disc.
- the precoat renewal system may be configured so that other zones may be concurrently washed with a lower pressure fluid.
- the zones may be sequentially or otherwise segmentally provided with high pressure fluid until the precoat layers of each respective zone have been removed and renewed.
- a disc-type filter system incorporating the precoat renewal system as well as a method of treating a precoat layer on a disc-type filter including a plurality of filter discs are also encompassed by the present invention.
- FIG. 1 is a cross-sectional side view of a prior art disc filter
- FIG. 2 is a cross-sectional end view of the prior art disc filter shown in FIG. 1 ;
- FIG. 3 is a cross-sectional end view of a filter and precoat renewal apparatus according to one embodiment of the invention.
- FIG. 4 is a cross-sectional end view of the filter and precoat renewal apparatus shown in FIG. 1 ;
- FIG. 5 is an enlarged detail of a portion of the precoat renewal apparatus as indicated in FIG. 4 ;
- FIG. 6 is an enlarged detail of a portion of the precoat renewal apparatus as indicated in FIG. 4 ;
- FIG. 7 is an enlarged cross-sectional detail of the precoat renewal apparatus at section line 7 - 7 as indicated in FIG. 4 ;
- FIG. 8 is a schematic showing valving and piping of the precoat renewal apparatus according to one embodiment of the invention.
- FIG. 9 is a cross-sectional end view of a filter according to a further embodiment of the invention.
- a disc filter 100 which is generally constructed in a manner similar to the filter shown in FIGS. 1 and 2 .
- the disc filter 100 includes a plurality of discs 102 coupled to a hollow shaft 104 allowing for fluid communication therebetween.
- the discs 102 are formed of sidewalls 106 having a filter media 108 thereon which may include a filter cloth made, for example, of a wire mesh as well as a layer of precoat material thereover.
- the discs 102 are housed in a vessel or container 110 , which may include a tank portion 112 and a hood or lid portion 114 .
- the vessel 110 may or may not be pressurized depending on specific applications and processing requirements.
- a drive system 116 is coupled to one end of the hollow shaft 104 to rotate the discs 102 and a vacuum source 118 is coupled to the other end of the hollow shaft 104 .
- the vacuum source 118 may not be required if the vessel 110 enclosing the discs 102 is pressurized at a sufficient level.
- a plurality of sections 120 formed on the disc 102 each individually rotate downward into a slurry 122 and upward out of the slurry 122 .
- a pressure differential between the interior of the vessel 110 and the interior of the hollow shaft 104 causes the slurry 122 to flow through the sidewalls 106 of the disc 102 with filtrate passing through the filter media 108 and particulates being formed as a cake on the surface of the filter media 108 (i.e., on the surface of the precoat layer).
- a scraper assembly 124 is positioned adjacent the falling side of each disc 102 (i.e., adjacent the portion of the disc 102 rotating down toward the slurry 122 ) along with a chute or bin 126 for collection of the cake scraped from the filter media 108 .
- the collection bins 126 may be in communication with a conveyor system, such as a screw conveyor or the like (not shown), for transportation of the discharged cake as is known in the art.
- the disc filter 100 further includes a regenerative shower system 128 which is used to remove and regenerate or, alternatively, renew the precoat layers of the discs 102 in a sequential or other segmented fashion.
- the regenerative shower system 128 includes a plurality of spray pipes 130 , each extending along at least one side of a disc 102 and having a nozzle 132 at the distal end thereof.
- Each nozzle 132 is positioned and configured to spray a portion of an adjacent sidewall 106 of a disc 102 and the filter media 108 associated therewith and either remove a portion of the thickness of the layer of precoat material from filter media 108 or, in the alternative, strip the precoat material in its entirety from its associated filter media 108 on sidewall 106 and clean the filter media 108 .
- spray pipes 130 are configured to spray the sidewalls 106 of two independent but adjacent discs 102 while the spray pipes 130 on the ends of the disc filter 100 are configured to only spray one sidewall 106 of one disc 102 each.
- This arrangement may be seen in FIG. 5 , where an end spray pipe 130 ′ includes a single nozzle 132 while an interior spray pipe 130 ′′ includes two nozzles 132 , each oriented toward the sidewall 106 of a separate disc 102 .
- the spray pipes 130 are coupled to a support 134 which may be formed from a structural member such as an I-beam and which is, in turn, coupled to bearings 136 at either end of the vessel 110 .
- the bearings 136 allow the support 134 and associated spray pipes 130 to oscillate through a predetermined arc which extends from the outer edge of the discs 102 to the inner edge of the discs 102 , as is best seen in FIG. 3 .
- the oscillating pattern of the spray pipes 130 allows renewal or regeneration of the precoat layers to take place at one small section of filter media at a time.
- the support 134 and spray pipes 130 are motivated through the oscillating pattern by a drive 135 such as a servo motor coupled to the support 134 .
- a displacement mechanism of another configuration may also be used to move the nozzles 132 relative to the discs 102 .
- the nozzles 132 and spray pipes 130 may be coupled to a linear or curvilinear track positioned between the discs 102 .
- Such a mechanism would allow displacement of the nozzles 132 and might be desirable if overhead space was limited within the vessel 110 . In such a case, it might be desirable to form at least a portion of the spray pipe 130 from flexible material.
- fixed spray pipes each with a plurality of spray nozzles disposed along its length and appropriately sized to distribute liquid flow, may be placed between each of the discs 102 and longitudinally outboard of the end discs 102 to renew and regenerate the precoat layers thereon, as further described below with respect to FIG. 9 .
- an auxiliary wash shower assembly 138 for adding liquid to process material on the precoat layer may be installed on the disc filter 100 and may include one or more spray headers 140 having a plurality of spray nozzles 142 installed therein. Such a wash shower, if desirable for given process parameters and if design constraints allow, may enhance the recovery of filtrate as discussed above.
- the regenerative shower assembly 128 is arranged in sections or zones 144 A- 144 E with each zone representing a percentage of total disc filter media surface area within a predetermined range.
- the disc filter 100 shown includes a total of ten (10) discs 102 , or twenty (20) sidewalls 106 .
- Each sidewall 106 has an associated spray pipe 130 and nozzle 132 .
- the vacuum formed within hollow shaft 104 or the pressure differential formed between the vessel 110 and hollow shaft 104
- only a portion of the discs 102 may have their associated precoat layers removed and regenerated on filter media 108 at a given time.
- each zone 144 A- 144 E represents a zone in which removal and regeneration of the precoat layer may be performed at a given time.
- the precoat layers in zone 144 A which includes three (3) different spray pipes 130 and five (5) different disc sidewalls 106 , might be removed and generated at a given time while the precoat layers in each of the other zones 144 B- 144 E were not being renewed.
- zone 144 A might first be subjected to precoat removal and regeneration, followed sequentially by zones 144 B, 144 C, 144 D and finally 144 E. It is noted, however, that by monitoring the production of the disc filter 100 , it may be possible to select a particular zone for precoat removal and regeneration without the need to sequentially remove and regenerate the precoat layer in the remaining zones.
- the regenerative shower system 128 When the regenerative shower system 128 is not being used to remove and regenerate the precoat layers in a given zone, it may be used to renew the precoat layers in every zone 144 A- 144 E. Alternatively, when a given zone, for example 144 A, has the precoat layers being removed and regenerated, the remaining zones 144 B- 144 E may be renewed using the regenerative shower system 128 . This is accomplished by selectively communicating the spray pipes 130 of each zone 144 A- 144 E to separate supply sources for removal and regeneration of precoat layers (with associated cleaning of the underlying filter media 108 ) and for renewal of the precoat layers. For example, referring to FIGS.
- separate feed piping 146 A- 146 E extends to the spray pipes 130 of each zone 144 A- 144 E.
- Each zone is thus connected to a high pressure source 148 with a valve 150 being coupled therebetween.
- the high pressure source may include, for example, water at a pressure of approximately 300 to 1000 psi for removal of precoat layers of a given zone 144 A- 144 E and cleaning of the filter media 108 therein.
- a second source 152 is also coupled to the feed piping 146 which may be, for example, plant water at a pressure of approximately 60 psi.
- a second valve 154 may be coupled between the second source 152 and the feed piping 146 if so desired.
- valves 150 and 154 The piping extending downstream from valves 150 and 154 meets at a common connection, for example, a “T” connection 156 as shown, communicating with feed piping 146 .
- the valves 150 and 154 may comprise, for example, solenoid-actuated full port ball valves.
- the second valve 154 may open, allowing the second source 152 to supply a particular zone with relatively low pressure water for the renewal of precoat layers thereof by removing only a partial thickness of the outer portion or layer of the precoat, such outer layer being the first to clog with particulates and compromise filtration efficiency.
- the precoat is renewed and efficiency restored without stripping the precoat layer completely.
- the second valve 154 (if so equipped) will shut off the second supply 152 from the piping and the first valve 150 will open, allowing the high pressure source 148 to supply the feed piping 146 with relatively higher pressure water to remove the precoat layers of the associated zone.
- different sections of feed piping 146 A- 146 E are separately valved and may thus be utilized to selectively direct fluid to each zone 144 A- 144 E respectively.
- disc filter I 00 may operate in a mode wherein neither renewal nor removal and regeneration of a precoat layer is being effected on any of the discs 102 , the frequency of need for renewal of the precoat layer as well as for the removal and regeneration thereof being dependent on a number of operational parameters of disc filter 100 which may vary according to the filtration operation for which disc filter 100 is employed.
- the spray zones 144 A- 144 E and their arrangement are designed to allow for efficient removal and regeneration of precoat layers without losing the vacuum (or other pressure differential) required for filter operation.
- the first zone 144 A represents five (5) sidewalls 106 of the filtering surface area. This is equivalent to about 25% of the total filter media surface area for the depicted disc filter 100 .
- no zone represents more than about 25% of the total filter media surface area or less than about 15% (zone 144 E) of the filter media surface area.
- Most of the zones shown ( 144 B- 144 D) represent about 20% of the total filter media surface area.
- zones of a given filter may be designed to work with greater than about 25% of the total filter media surface area, it is believed that a zone representing about 50% of the total filter media surface area would allow the vacuum (or pressure differential) to be lost. Thus, a zone representing about 35 to 40% of total filter media surface area may represent the upper limit of efficiency for complete removal of precoat down to and including washing of the filter media 108 without an endangering loss of vacuum or pressure differential.
- FIG. 9 of the drawings illustrates a further exemplary embodiment of the disc filter 200 of the present invention wherein previously described components and features now depicted in FIG. 9 are identified by reference numerals having the same numbers as with respect to disc filter 100 .
- the disc filter 200 includes a plurality of discs 102 coupled to a hollow shaft 104 allowing for fluid communication therebetween.
- the discs 102 are formed of sidewalls 106 having a filter media 108 thereon which may include a filter cloth made, for example, of a wire mesh as well as a layer of precoat material thereover.
- the discs 102 are housed in a vessel or container, which may include a tank portion and a hood or lid portion.
- the vessel may or may not be pressurized depending on specific applications and processing requirements.
- a drive system is coupled to one end of the hollow shaft 104 to rotate the discs 102 and a vacuum source is coupled to the other end of the hollow shaft 104 .
- the vacuum source may not be required if the vessel enclosing the discs 102 is pressurized at a sufficient level.
- a plurality of sections 120 formed on the disc 102 each individually rotate downward into a slurry 122 and upward out of the slurry 122 .
- a pressure differential between the interior of the vessel and the interior of the hollow shaft 104 causes the slurry 122 to flow through the sidewalls 106 of the disc 102 with filtrate passing through the filter media 108 and particulates being formed as a cake on the surface of the filter media 108 (i.e., on the surface of the precoat layer).
- a scraper assembly 124 is positioned adjacent the falling side of each disc 102 (i.e., adjacent the portion of the disc 102 rotating down toward the slurry 122 ) along with a chute or bin (not shown in FIG. 9 ) for collection of the cake scraped from the filter media 108 .
- the collection bins may be in communication with a conveyor system, such as a screw conveyor or the like (not shown) for transportation of the discharged cake as is known in the art.
- a regenerative shower assembly 128 which may comprise fixed or movable spray pipes 130 bearing spray nozzles 132 , is placed below scraper assembly 124 and above the surface of slurry 122 .
- the regenerative shower system 128 may be used to periodically renew the precoat layers on the filter media 108 of filter discs 102 by removing outer portions of the precoat layers using a relatively lower pressure fluid, or remove the precoat layers in their entirety and clean the underlying filter media 106 using a relatively higher pressure fluid.
- regenerative shower system 128 is placed on a rising side of a filter disc 102 (as filter media 108 moves upwardly out of slurry 122 ), as much as about 40% of a given filter disc's total filter media surface area may be exposed during precoat layer removal, causing an unacceptable loss of pressure differential.
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- Chemical Kinetics & Catalysis (AREA)
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Abstract
A precoat renewal system for a filter, such as a disc filter is provided. The renewal system includes a plurality of nozzles coupled to spray piping and valving with each nozzle being positioned for spraying an area of one side of a disc. The nozzles and at least a portion of the spray piping are movable such that the nozzles may be displaced relative to the discs. The nozzles and piping are arranged in groups or zones with each zone covering a specified percentage of the discs in the filter and each zone representing about 40% or less of the surface area of the filter media of the discs in the filter. Each zone is configured such that high pressure fluid may be supplied to that particular zone for removal of a precoat layer on the disc. The system may be configured so that other zones may be concurrently washed with a lower pressure fluid. The zones may be sequentially or otherwise segmentally provided with high pressure fluid until the precoat layers of each respective zone have been removed and renewed. A filter system and a method of treating a precoat layer on a disc-type filter including a plurality of filter discs are also disclosed.
Description
- This application is a continuation of application Ser. No. 10/126,864, filed Apr. 19, 2002, now U.S. Pat. No. 6,833,077, issued Dec. 21, 2004, which claims the benefit of U.S. provisional patent application, Ser. No. 60/285,858 filed Apr. 23, 2001, and U.S. provisional patent application, Ser. No. 60/302,724 filed Jul. 3, 2001.
- 1. Field of the Invention
- The present invention relates generally to precoat filters such as disc filters having a layer of precoat thereon and, more particularly, to the washing and renewal of a precoat layer on such filters.
- State of the Art: Filtration equipment such as disc or drum filters are known in the art for their use in separating solid particles from a liquid in which they are suspended. Such filters typically pass the particle-containing liquid through a selected filter media which allows the passage of liquid therethrough while retaining the particles on a surface of the filter media for subsequent collection. The liquid passing through the filter media is typically referred to as filtrate while the particles on the surface of the filter media are typically referred to as cake.
- The filter media used in such a process may be formed from a variety of different materials but is often of a cloth- or fabric-type material, including, for example, wire mesh, formed of natural or synthetic materials. Additionally, filter media may include a built-up layer of cake on the filtration surface of a drum, disc, or other filter element. This layer of cake is referred to as a precoat. It is noted that, depending on the type of material being processed, the precoat layer may be formed from a material that is the same as or similar to the material being filtered. For example, if lime mud is being filtered and removed from a liquid, lime mud may also be used as the precoat. However, the precoat does not have to be formed of the same material as that which is being filtered.
- The precoat layer is typically formed on top of a filter cloth, with the two elements working in conjunction to separate filtrate from the process cake. The precoat layer is a permeable layer which allows filtrate to pass through while capturing additional particles on a surface of the precoat layer. The filtered particles are typically removed, often by a scraping device, while the precoat layer remains on the filter media for continued filtering.
- After a precoat layer has been in use for an extended amount of time, the precoat layer becomes less permeable and thus reduces the efficiency of the filtering operation by allowing less filtrate to pass therethrough. When the precoat layer is in such a condition, it becomes desirable to remove and regenerate the precoat layer by removing the existing precoat layer of material in its entirety and forming a new precoat layer in its place.
- One type of apparatus used in removing and regenerating precoat layers on a filter is disclosed in U.S. Pat. No. 5,759,397 to Larsson et al. (issued Jun. 2, 1998), the disclosure of which is hereby incorporated herein by reference.
FIGS. 1 and 2 hereof are representative of the apparatus disclosed in the Larsson patent.FIGS. 1 and 2 show adisc filter 10 including a plurality ofhollow discs 12 having sidewalls 14 of a filter material 16. Thehollow discs 12 are coupled to ahollow axle 18 and are in fluid communication therewith viaholes 20 formed along thehollow axle 18. - The
hollow discs 12 are positioned within acontainer 22, such as a tank, which includes aninlet 24 for introducing a slurry 26 (i.e., a particle-containing liquid) into thecontainer 22. Avacuum 28 draws the filtrate through filter material 16 with particles from the drawn liquid accumulating on the surface of the filter material 16 to form a cake. - As shown in
FIG. 2 , thecontainer 22 is filled slightly less than halfway with the slurry. Thediscs 12 are configured to rotate counterclockwise through theslurry 26. In operation, a portion of thediscs 12 enters into theslurry 26 to draw filtrate from theslurry 26 and then emerge with a cake formed of accumulated particles. Ascraper 30 is used to remove the accumulated cake from thediscs 12 while leaving a specified thickness of precoat material. The cake removed from thediscs 12 is collected in a chute orbin 32 and transferred from thefilter 10 for further processing or disposal, as the case may be. - When it is desired to remove and regenerate the precoat, an oscillating
spray pipe 34 having aspray nozzle 36 coupled thereto moves between the periphery and center of thedisc 12 removing the precoat layer by spraying the precoat layer with a pressurized fluid. The Larsson patent describes such removal and regeneration as taking place in two steps with half of the discs being stripped of the their precoat layer followed by replacement of such layer, while the precoat layers of the other half of the discs are not sprayed. - It is believed that such an arrangement may expose too much surface area of the fabric filter media by removal of the precoat layer therefrom, thus resulting in the loss of vacuum crucial to operation of the filter. If the vacuum is broken, it is likely that the precoat layers remaining on the additional discs (i.e., those not having the precoat layers renewed) will drop their precoat layers, causing a serious and expensive interruption in the operation of the filter.
- In addition to potential loss of vacuum, removal of the precoat layer using high pressure fluid may cause damage to the underlying filter media, particularly over time. Thus, while it may be desirable to remove and regenerate precoat at fairly frequent intervals, such frequency may necessitate a consequent undesirable frequency of downtime of the filter system for replacement of the filter media.
- U.S. Pat. No. 5,897,788 to Ketolainen et al. (issued Apr. 27, 1999) discloses the use of a spray nozzle oriented at an acute angle to the surface of a filter drum of a drum-type filter to remove an outer, more porous and softer portion of the precoat layer on a substantially continuous basis between removals of the precoat layer in its entirety down to the filter wire.
- Other filters have likewise used swinging spray showers to assist in washing of process material on precoat layers such as that disclosed in U.S. Pat. No. 6,063,294 to Martensson et al. (issued May 16, 2000), the disclosure of which is hereby incorporated herein by reference. The Martensson patent discloses a spray assembly having multiple nozzles in each spray pipe and wherein the speed at which the spray pipe traverses the face of a disc is varied according to its radial position relative to the disc. An additional feature disclosed in the Martensson patent is an independent washing shower which is optionally used to soak process material on the exterior of the precoat and thus increase the efficiency of cake removal using the scraper. In essence, the washing shower includes a spray pipe and one or more nozzles directed at the filtering surface of a given filter (i.e., the filtering surface of a drum or a disc). Using a disc as an example, and considering the disc to be divided into a plurality of segments, the wash assembly sprays water on the precoat surface of a given disc segment subsequent to the disc segment being rotated through the pool of slurry. The wash water flows through the filter media, including the precoat, forcing any filtrate potentially remaining in the cake and precoat layers to be drawn through the filter by the vacuum. Without the washing apparatus, some filtrate liquid might potentially be discharged with the cake layer, thus causing some inefficiency with the operation.
- While the washing shower provides some increased efficiency in production of filtrate, such shower assemblies require piping and valving in addition to that required for the precoat removal system. Additionally, the inclusion of a washing shower may add constraints to the overall design of the filter as the shower heads take up additional space and must be designed so as to not interfere with any moving components of the filter.
- Accordingly, it would be advantageous to provide a precoat removal apparatus and system which allows for maximum efficiency in replacing the precoat layer on filter media of filter discs of a disc-type filter without losing the vacuum (or pressure differential) formed across the filter media. Additionally, it would be advantageous to provide a precoat removal apparatus and system which also incorporates a precoat renewal feature in a disc-type filter to minimize the necessity to remove and regenerate the precoat layer and to potentially reduce the frequency of repair of the filter media.
- The present invention comprises a precoat renewal system for a filter such as a disc filter. The precoat renewal system includes a plurality of nozzles coupled to spray piping and valving with each nozzle being positioned for spraying an area of one side of a disc. The nozzles and at least a portion of the spray piping may be movable such that the nozzles may be displaced relative to the discs. The nozzles and piping may be arranged in groups or zones with each zone covering a specified percentage of the discs in the filter. Each zone may represent about 40% or less of the total surface area of the filter media of the plurality of filter discs in the filter. It may be preferred that each zone be configured to effect fluid impingement on between about 15 and 25% of the total surface area of the filter media of the plurality of filter discs.
- Each zone may be configured such that high pressure fluid may be supplied to that particular zone for removal of a precoat layer on the disc. The precoat renewal system may be configured so that other zones may be concurrently washed with a lower pressure fluid. The zones may be sequentially or otherwise segmentally provided with high pressure fluid until the precoat layers of each respective zone have been removed and renewed.
- A disc-type filter system incorporating the precoat renewal system as well as a method of treating a precoat layer on a disc-type filter including a plurality of filter discs are also encompassed by the present invention.
- The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
-
FIG. 1 is a cross-sectional side view of a prior art disc filter; -
FIG. 2 is a cross-sectional end view of the prior art disc filter shown inFIG. 1 ; -
FIG. 3 is a cross-sectional end view of a filter and precoat renewal apparatus according to one embodiment of the invention; -
FIG. 4 is a cross-sectional end view of the filter and precoat renewal apparatus shown inFIG. 1 ; -
FIG. 5 is an enlarged detail of a portion of the precoat renewal apparatus as indicated inFIG. 4 ; -
FIG. 6 is an enlarged detail of a portion of the precoat renewal apparatus as indicated inFIG. 4 ; -
FIG. 7 is an enlarged cross-sectional detail of the precoat renewal apparatus at section line 7-7 as indicated inFIG. 4 ; -
FIG. 8 is a schematic showing valving and piping of the precoat renewal apparatus according to one embodiment of the invention; and -
FIG. 9 is a cross-sectional end view of a filter according to a further embodiment of the invention. - Referring to
FIGS. 3 and 4 , adisc filter 100 is shown which is generally constructed in a manner similar to the filter shown inFIGS. 1 and 2 . Thedisc filter 100 includes a plurality ofdiscs 102 coupled to ahollow shaft 104 allowing for fluid communication therebetween. Thediscs 102 are formed of sidewalls 106 having a filter media 108 thereon which may include a filter cloth made, for example, of a wire mesh as well as a layer of precoat material thereover. Thediscs 102 are housed in a vessel orcontainer 110, which may include atank portion 112 and a hood orlid portion 114. Thevessel 110 may or may not be pressurized depending on specific applications and processing requirements. Adrive system 116 is coupled to one end of thehollow shaft 104 to rotate thediscs 102 and avacuum source 118 is coupled to the other end of thehollow shaft 104. Thevacuum source 118 may not be required if thevessel 110 enclosing thediscs 102 is pressurized at a sufficient level. - As seen in
FIG. 3 , with thediscs 102 rotating counterclockwise, a plurality ofsections 120 formed on thedisc 102 each individually rotate downward into aslurry 122 and upward out of theslurry 122. As thesections 120 rotate into theslurry 122, a pressure differential between the interior of thevessel 110 and the interior of the hollow shaft 104 (such as may be produced by the vacuum source 118) causes theslurry 122 to flow through the sidewalls 106 of thedisc 102 with filtrate passing through the filter media 108 and particulates being formed as a cake on the surface of the filter media 108 (i.e., on the surface of the precoat layer). - A
scraper assembly 124 is positioned adjacent the falling side of each disc 102 (i.e., adjacent the portion of thedisc 102 rotating down toward the slurry 122) along with a chute orbin 126 for collection of the cake scraped from the filter media 108. Thecollection bins 126 may be in communication with a conveyor system, such as a screw conveyor or the like (not shown), for transportation of the discharged cake as is known in the art. - The
disc filter 100 further includes aregenerative shower system 128 which is used to remove and regenerate or, alternatively, renew the precoat layers of thediscs 102 in a sequential or other segmented fashion. Theregenerative shower system 128 includes a plurality ofspray pipes 130, each extending along at least one side of adisc 102 and having anozzle 132 at the distal end thereof. Eachnozzle 132 is positioned and configured to spray a portion of an adjacent sidewall 106 of adisc 102 and the filter media 108 associated therewith and either remove a portion of the thickness of the layer of precoat material from filter media 108 or, in the alternative, strip the precoat material in its entirety from its associated filter media 108 on sidewall 106 and clean the filter media 108. It is noted that most of thespray pipes 130 are configured to spray the sidewalls 106 of two independent butadjacent discs 102 while thespray pipes 130 on the ends of thedisc filter 100 are configured to only spray one sidewall 106 of onedisc 102 each. This arrangement may be seen inFIG. 5 , where anend spray pipe 130′ includes asingle nozzle 132 while aninterior spray pipe 130″ includes twonozzles 132, each oriented toward the sidewall 106 of aseparate disc 102. - Referring again to
FIGS. 3 and 4 , thespray pipes 130 are coupled to asupport 134 which may be formed from a structural member such as an I-beam and which is, in turn, coupled tobearings 136 at either end of thevessel 110. Thebearings 136 allow thesupport 134 and associatedspray pipes 130 to oscillate through a predetermined arc which extends from the outer edge of thediscs 102 to the inner edge of thediscs 102, as is best seen inFIG. 3 . The oscillating pattern of thespray pipes 130 allows renewal or regeneration of the precoat layers to take place at one small section of filter media at a time. Thesupport 134 andspray pipes 130 are motivated through the oscillating pattern by adrive 135 such as a servo motor coupled to thesupport 134. It is noted that a displacement mechanism of another configuration may also be used to move thenozzles 132 relative to thediscs 102. For example, thenozzles 132 andspray pipes 130 may be coupled to a linear or curvilinear track positioned between thediscs 102. Such a mechanism would allow displacement of thenozzles 132 and might be desirable if overhead space was limited within thevessel 110. In such a case, it might be desirable to form at least a portion of thespray pipe 130 from flexible material. In addition, it is contemplated that fixed spray pipes, each with a plurality of spray nozzles disposed along its length and appropriately sized to distribute liquid flow, may be placed between each of thediscs 102 and longitudinally outboard of theend discs 102 to renew and regenerate the precoat layers thereon, as further described below with respect toFIG. 9 . - While not required, an auxiliary
wash shower assembly 138 for adding liquid to process material on the precoat layer may be installed on thedisc filter 100 and may include one ormore spray headers 140 having a plurality ofspray nozzles 142 installed therein. Such a wash shower, if desirable for given process parameters and if design constraints allow, may enhance the recovery of filtrate as discussed above. - The
regenerative shower assembly 128 is arranged in sections orzones 144A-144E with each zone representing a percentage of total disc filter media surface area within a predetermined range. For example, thedisc filter 100 shown includes a total of ten (10)discs 102, or twenty (20) sidewalls 106. Each sidewall 106 has an associatedspray pipe 130 andnozzle 132. However, if each of thespray pipes 130 were operated such that the precoat layers were being simultaneously stripped off of each sidewall 106, it is likely that the vacuum formed within hollow shaft 104 (or the pressure differential formed between thevessel 110 and hollow shaft 104) might be lost, resulting in the loss of all precoat layers and cake layers formed on the sidewalls 106 of thediscs 102. Thus, only a portion of thediscs 102 may have their associated precoat layers removed and regenerated on filter media 108 at a given time. - In the
disc filter 100 shown inFIG. 4 , eachzone 144A-144E represents a zone in which removal and regeneration of the precoat layer may be performed at a given time. For example, the precoat layers inzone 144A, which includes three (3)different spray pipes 130 and five (5) different disc sidewalls 106, might be removed and generated at a given time while the precoat layers in each of theother zones 144B-144E were not being renewed. Thus, in operation,zone 144A might first be subjected to precoat removal and regeneration, followed sequentially byzones disc filter 100, it may be possible to select a particular zone for precoat removal and regeneration without the need to sequentially remove and regenerate the precoat layer in the remaining zones. - When the
regenerative shower system 128 is not being used to remove and regenerate the precoat layers in a given zone, it may be used to renew the precoat layers in everyzone 144A-144E. Alternatively, when a given zone, for example 144A, has the precoat layers being removed and regenerated, the remainingzones 144B-144E may be renewed using theregenerative shower system 128. This is accomplished by selectively communicating thespray pipes 130 of eachzone 144A-144E to separate supply sources for removal and regeneration of precoat layers (with associated cleaning of the underlying filter media 108) and for renewal of the precoat layers. For example, referring toFIGS. 4 and 6 -8, separate feed piping 146A-146E extends to thespray pipes 130 of eachzone 144A-144E. Each zone is thus connected to ahigh pressure source 148 with avalve 150 being coupled therebetween. The high pressure source may include, for example, water at a pressure of approximately 300 to 1000 psi for removal of precoat layers of a givenzone 144A-144E and cleaning of the filter media 108 therein. Asecond source 152 is also coupled to the feed piping 146 which may be, for example, plant water at a pressure of approximately 60 psi. Asecond valve 154 may be coupled between thesecond source 152 and the feed piping 146 if so desired. The piping extending downstream fromvalves connection 156 as shown, communicating with feed piping 146. Thevalves - Thus, in operation, the
second valve 154 may open, allowing thesecond source 152 to supply a particular zone with relatively low pressure water for the renewal of precoat layers thereof by removing only a partial thickness of the outer portion or layer of the precoat, such outer layer being the first to clog with particulates and compromise filtration efficiency. By removing only an outer portion of the precoat, the precoat is renewed and efficiency restored without stripping the precoat layer completely. However, when it is desired to remove and regenerate the precoat layers in a particular zone, either by operator decision or by virtue of control logic through sensing of various filtering parameters, the second valve 154 (if so equipped) will shut off thesecond supply 152 from the piping and thefirst valve 150 will open, allowing thehigh pressure source 148 to supply the feed piping 146 with relatively higher pressure water to remove the precoat layers of the associated zone. As can be seen inFIG. 7 , different sections of feed piping 146A-146E are separately valved and may thus be utilized to selectively direct fluid to eachzone 144A-144E respectively. It is, of course, also contemplated that disc filter I 00 may operate in a mode wherein neither renewal nor removal and regeneration of a precoat layer is being effected on any of thediscs 102, the frequency of need for renewal of the precoat layer as well as for the removal and regeneration thereof being dependent on a number of operational parameters ofdisc filter 100 which may vary according to the filtration operation for whichdisc filter 100 is employed. - Referring back to
FIGS. 3 and 4 , and particularlyFIG. 4 , thespray zones 144A-144E and their arrangement are designed to allow for efficient removal and regeneration of precoat layers without losing the vacuum (or other pressure differential) required for filter operation. For example, as noted above, thefirst zone 144A represents five (5) sidewalls 106 of the filtering surface area. This is equivalent to about 25% of the total filter media surface area for the depicteddisc filter 100. For the configuration shown, no zone represents more than about 25% of the total filter media surface area or less than about 15% (zone 144E) of the filter media surface area. Most of the zones shown (144B-144D) represent about 20% of the total filter media surface area. While the zones of a given filter may be designed to work with greater than about 25% of the total filter media surface area, it is believed that a zone representing about 50% of the total filter media surface area would allow the vacuum (or pressure differential) to be lost. Thus, a zone representing about 35 to 40% of total filter media surface area may represent the upper limit of efficiency for complete removal of precoat down to and including washing of the filter media 108 without an endangering loss of vacuum or pressure differential. -
FIG. 9 of the drawings illustrates a further exemplary embodiment of thedisc filter 200 of the present invention wherein previously described components and features now depicted inFIG. 9 are identified by reference numerals having the same numbers as with respect todisc filter 100. Thedisc filter 200 includes a plurality ofdiscs 102 coupled to ahollow shaft 104 allowing for fluid communication therebetween. Thediscs 102 are formed of sidewalls 106 having a filter media 108 thereon which may include a filter cloth made, for example, of a wire mesh as well as a layer of precoat material thereover. Thediscs 102 are housed in a vessel or container, which may include a tank portion and a hood or lid portion. The vessel may or may not be pressurized depending on specific applications and processing requirements. A drive system is coupled to one end of thehollow shaft 104 to rotate thediscs 102 and a vacuum source is coupled to the other end of thehollow shaft 104. The vacuum source may not be required if the vessel enclosing thediscs 102 is pressurized at a sufficient level. - With the
discs 102 rotating clockwise, a plurality ofsections 120 formed on thedisc 102 each individually rotate downward into aslurry 122 and upward out of theslurry 122. As thesections 120 rotate into theslurry 122, a pressure differential between the interior of the vessel and the interior of the hollow shaft 104 (such as may be produced by the vacuum source) causes theslurry 122 to flow through the sidewalls 106 of thedisc 102 with filtrate passing through the filter media 108 and particulates being formed as a cake on the surface of the filter media 108 (i.e., on the surface of the precoat layer). - A
scraper assembly 124 is positioned adjacent the falling side of each disc 102 (i.e., adjacent the portion of thedisc 102 rotating down toward the slurry 122) along with a chute or bin (not shown inFIG. 9 ) for collection of the cake scraped from the filter media 108. The collection bins may be in communication with a conveyor system, such as a screw conveyor or the like (not shown) for transportation of the discharged cake as is known in the art. Aregenerative shower assembly 128, which may comprise fixed ormovable spray pipes 130 bearingspray nozzles 132, is placed belowscraper assembly 124 and above the surface ofslurry 122. As previously described with respect todisc filter 100, theregenerative shower system 128 may be used to periodically renew the precoat layers on the filter media 108 offilter discs 102 by removing outer portions of the precoat layers using a relatively lower pressure fluid, or remove the precoat layers in their entirety and clean the underlying filter media 106 using a relatively higher pressure fluid. - It will be appreciated that such an arrangement, with
regenerative shower assembly 128 on the falling side of eachdisc 102, will expose a relatively small portion of the surface area of filter media 108 of eachdisc 102 during removal of the precoat layer for regeneration. Thus, it may not be necessary to divide thediscs 102 into a plurality of zones for removal of the precoat layer, as the total filter media surface area exposed at any one time is insufficient to cause a detrimental loss of pressure differential between the interiors and exteriors offilter discs 102, since a maximum of only about 30° of arc out of 360° on eachfilter disc 102 may be exposed before being resubmerged inslurry 122. In contrast, ifregenerative shower system 128 is placed on a rising side of a filter disc 102 (as filter media 108 moves upwardly out of slurry 122), as much as about 40% of a given filter disc's total filter media surface area may be exposed during precoat layer removal, causing an unacceptable loss of pressure differential. - While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
Claims (20)
1. A precoat removal, regeneration and renewal system for a precoat filter having a plurality of filter discs, each disc having a first side and a second side, both sides bearing filter media, the system comprising:
a plurality of spray nozzles, each first side and second side of each disc of the plurality having at least one spray nozzle positioned to spray a fluid and effect removal of at least a portion of a layer of precoat material formed on a surface thereof, the plurality of spray nozzles being located on a rising side of the plurality of filter discs as the filter discs rotate about a defined axis, the plurality of nozzles being grouped in a plurality of zones, and
spray piping and at least one valve coupled to the spray nozzles of the plurality and configured for selectively providing fluid to each zone of the plurality of zones.
2. The precoat removal, regeneration and renewal system of claim 1 , wherein the at least one valve includes a separate valve associated with each zone.
3. The precoat removal, regeneration and renewal system of claim 1 , further including at least one additional valve coupled with the feed piping, wherein the at least one additional valve, in combination with the feed piping, is configured to permit selection between a first flow of a relatively lower pressure fluid and a second flow of a relatively higher pressure fluid to be conveyed to the at least one spray nozzle of an associated zone through the feed piping.
4. The precoat removal, regeneration and renewal system of claim 3 , wherein the at least one additional valve includes an additional separate valve associated with each zone.
5. The precoat removal, regeneration and renewal system of claim 3 , wherein the feed piping and the at least one additional valve are configured, in combination such that the second flow of a relatively higher pressure fluid may be conveyed to the at least one spray nozzle of at least one zone of the plurality of zones while the first flow of a relatively lower pressure fluid may substantially concurrently be conveyed to at least another zone of the plurality of zones.
6. The precoat removal, regeneration and renewal system of claim 3 , wherein the second flow of a relatively higher pressure fluid may be provided at a sufficient pressure to substantially remove a layer of precoat material in its entirety from the first and second sides of the discs, and wherein the first flow of a relatively lower pressure fluid may be provided at a pressure allowing for removal of only an outer portion of the layer of precoat material.
7. The precoat removal, regeneration and renewal system of claim 1 , wherein each of the plurality of zones includes a number of spray nozzles sufficient to effect fluid impingement on a predetermined number of first and second sides of the filter discs of the plurality and wherein no zone includes a number of spray nozzles sufficient to effect fluid impingement on more than about 40% of the total surface area of the filter media of the plurality of filter discs.
8. The precoat removal, regeneration and renewal system of claim 7 , wherein each of the plurality of zones includes a number of spray nozzles sufficient to effect fluid impingement on between about 15% and 25% of the total surface area of the plurality of filter discs.
9. The precoat removal, regeneration and renewal system of claim 1 , wherein the disc filter is configured to provide a pressure differential between interiors of the plurality of filter discs and a space exterior to the filter discs and wherein each zone is configured such that the precoat layer may be removed substantially in its entirety from a predetermined percentage of the surface area of the filter media of the plurality of filter discs without substantially diminishing the pressure differential.
10. The precoat removal, regeneration and renewal system of claim 1 , wherein at least a portion of the spray piping is movable and further including a displacement mechanism to move the plurality of spray nozzles and the at least a portion of the spray piping relative to the filter discs.
11. A precoat filter system comprising:
a plurality of filter discs, each disc having a first side and a second side, both sides bearing filter media;
a plurality of spray nozzles, each first side and second side of each disc of the plurality having at least one spray nozzle positioned to spray a fluid and effect removal of at least a portion of a layer of precoat material formed on a surface thereof, the plurality of spray nozzles being located on a rising side of the plurality of filter discs as the filter discs rotate about a defined axis, the plurality of nozzles being grouped in a plurality of zones, and
spray piping and at least one valve coupled to the spray nozzles of the plurality and configured for selectively providing fluid to each zone of the plurality of zones.
12. The precoat filter system of claim 11 , wherein the at least one valve includes a separate valve associated with each zone.
13. The precoat filter system of claim 1 1, wherein each of the plurality of zones includes a number of spray nozzles sufficient to effect fluid impingement on a predetermined number of first and second sides of the filter discs of the plurality and wherein no zone includes a number of spray nozzles sufficient to effect fluid impingement on more than about 40% of the total surface area of the filter media of the plurality of filter discs.
14. The precoat filter system of claim 13 , wherein each of the plurality of zones includes a number of spray nozzles sufficient to effect fluid impingement on between about 15% and 25% of the total surface area of the plurality of filter discs.
15. The precoat filter system of claim 11 , further including at least one additional valve coupled with the feed piping, wherein the at least one additional valve, in combination with the feed piping, is configured to permit selection between a first flow of a relatively lower pressure fluid and a second flow of a relatively higher pressure fluid to be conveyed to the at least one spray nozzle of an associated zone through the feed piping.
16. A method for treating a precoat layer on a disc-type filter including a plurality of filter discs, the method comprising:
substantially completely removing at least a segment the precoat layer from filter media of the filter discs to substantially expose at least a section of the filter media, wherein the substantially completely removing is performed on the rising side of the filter discs as the filter discs are rotated about a defined axis and, wherein the substantially completely removing is performed on no more than about 40% of the total surface area of the filter media of the filter discs of the plurality; and
when not substantially completely removing the precoat layer in its entirety from filter media of a filter disc of the plurality, optionally removing an outer portion of the precoat layer.
17. The method of claim 16 , wherein the optional removing of an outer portion of the precoat layer is performed on a substantially continuous basis.
18. The method of claim 16 , wherein the optional removing of an outer portion of the precoat layer is performed on a discontinuous basis.
19. The method of claim 16 , wherein the optional removing of an outer portion of the precoat layer is performed on a substantially regular, cyclical basis.
20. The method of claim 16 , wherein the substantially completely removing is performed on approximately 15% to 25% of the total surface area of the filter media discs of the plurality.
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US11/022,004 US20050103727A1 (en) | 2001-04-23 | 2004-12-21 | Sequential swinging precoat removal and renewal system, filter so equipped, and method |
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US30272401P | 2001-07-03 | 2001-07-03 | |
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US11/022,004 US20050103727A1 (en) | 2001-04-23 | 2004-12-21 | Sequential swinging precoat removal and renewal system, filter so equipped, and method |
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US10/126,864 Continuation US6833077B2 (en) | 2001-04-23 | 2002-04-19 | Sequential swinging precoat removal and renewal system, filter so equipped and method |
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US11/022,004 Abandoned US20050103727A1 (en) | 2001-04-23 | 2004-12-21 | Sequential swinging precoat removal and renewal system, filter so equipped, and method |
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Citations (47)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1804934A (en) * | 1927-09-09 | 1931-05-12 | Oliver United Filters Inc | Fluid pressure discharge for continuous filters |
US2655265A (en) * | 1949-01-31 | 1953-10-13 | Goslin Birmingham Mfg Company | Continuous rotary pressure or vacuum filter |
US2839194A (en) * | 1957-01-08 | 1958-06-17 | Olin Mathieson | Continuous filtration process and apparatus therefor |
US2899066A (en) * | 1959-08-11 | Rotary vacuum | ||
US2932402A (en) * | 1954-11-15 | 1960-04-12 | Denver Equip Co | Disc type filter |
US3075646A (en) * | 1959-10-01 | 1963-01-29 | Ametek Inc | Filter |
US3080064A (en) * | 1959-08-14 | 1963-03-05 | Ametek Inc | Filter scraper |
US3096278A (en) * | 1959-03-09 | 1963-07-02 | Eimco Corp | Scraper assembly for filters |
US3193105A (en) * | 1961-02-06 | 1965-07-06 | Improved Machinery Inc | Continuous disc filter |
US3331512A (en) * | 1965-06-01 | 1967-07-18 | Improved Machinery Inc | Filter screen |
US3471026A (en) * | 1966-12-09 | 1969-10-07 | Dorr Oliver Inc | Continuous rotary disc filters |
US3521751A (en) * | 1967-12-15 | 1970-07-28 | Theodorus H Holthuis | Filtering method and apparatus |
US3591009A (en) * | 1969-08-22 | 1971-07-06 | Oscar Luthi | Disc filter having filtrate directing means |
US4017399A (en) * | 1969-03-11 | 1977-04-12 | Pullman Incorporated | Method and apparatus for filtration of slurries |
US4056473A (en) * | 1976-05-25 | 1977-11-01 | Bjarne Ivar Nilsson | Rotary filter for concentrating fiber suspensions |
US4136028A (en) * | 1976-09-13 | 1979-01-23 | Rauma-Rapola Oy | Method for filtering a fibrous material by means of a disc filter as well as a disc filter for performing the method |
US4332680A (en) * | 1980-04-14 | 1982-06-01 | United States Filter Fluid Systems Corporation | Filter sluicing apparatus |
US4528103A (en) * | 1984-04-06 | 1985-07-09 | Dorr-Oliver Incorporated | Pressure filter |
US4639315A (en) * | 1984-10-18 | 1987-01-27 | Mecapec S.A. | Apparatus for mechanical purification of waste water |
US4704206A (en) * | 1984-05-14 | 1987-11-03 | Aluminium Pechiney | Apparatus for continuous flow feed to disc-type rotary filters |
US4929355A (en) * | 1985-02-05 | 1990-05-29 | Ab Hedemora Verkstader | Method and apparatus for the separation of caustic liquor, lime sludge and sludge in a causticizing process |
US4943372A (en) * | 1987-11-02 | 1990-07-24 | A. Ahlstrom Corporation | Method and apparatus of discharging a disc filter |
US4975189A (en) * | 1988-12-09 | 1990-12-04 | Liszka John A | Cleaning sprays for disc filters |
US4995991A (en) * | 1988-03-22 | 1991-02-26 | Ahlstrom Corporation | Method and apparatus for improving the operation of a disc filter |
US5149448A (en) * | 1990-04-25 | 1992-09-22 | A. Ahlstrom Corporation | Method and apparatus for thickening lime sludge |
US5374360A (en) * | 1993-12-14 | 1994-12-20 | Aqua-Aerobic Systems, Inc. | Method and apparatus for cleaning a filter apparatus |
US5407587A (en) * | 1993-08-17 | 1995-04-18 | International Paper Company | Travelling doctor blade with nozzle |
US5423977A (en) * | 1992-08-06 | 1995-06-13 | Nippon Yusen Kaisha | Rotary filter with automatic spray cleaning device for cleaning same |
US5470472A (en) * | 1994-05-16 | 1995-11-28 | Dorr-Oliver Incorporated | Rotary drum filter with reciprocating nozzle means |
US5692619A (en) * | 1992-12-14 | 1997-12-02 | Beloit Technologies, Inc. | Apparatus for filtering suspensions |
US5759397A (en) * | 1992-05-15 | 1998-06-02 | Caustec Ab | Filter with spray cake removal means |
US5849202A (en) * | 1992-11-06 | 1998-12-15 | Andritz-Patentverwaltungs-Gesellschaft M.B.H. | Rotary disc filtration process having means to prevent settlement of solids |
US5851392A (en) * | 1996-11-08 | 1998-12-22 | Brady, Jr.; C. Lamar | Process and apparatus for doctoring solids from a rotary filter |
US5897788A (en) * | 1993-04-08 | 1999-04-27 | Ahlstrom Machinery Oy | Method and apparatus for cleaning a filter drum used for thickening lime mud |
US5900158A (en) * | 1993-07-15 | 1999-05-04 | A. Ahlstrom Corporation | Method and apparatus for thickening lime mud with a disc filter |
US5968372A (en) * | 1996-12-16 | 1999-10-19 | Baker Hughes Incorporated | Logic controlled traversing shower |
US6063294A (en) * | 1996-10-15 | 2000-05-16 | Baker Hughes Incorporated | Uniform area shower for disc filter |
US6258282B1 (en) * | 1997-08-21 | 2001-07-10 | Kvaerner Pulping Ab | Rotatable filter system for filtration of a flowing substance |
US6283306B1 (en) * | 1998-02-18 | 2001-09-04 | Harry Nilsson | Rotating filter |
US20020166821A1 (en) * | 2001-04-23 | 2002-11-14 | Flanagan Peter J. | Disc filters with shower systems and methods of use |
US20020166822A1 (en) * | 2001-04-23 | 2002-11-14 | Flanagan Peter J. | Sequential swinging precoat removal and renewal system, filter so equipped and method |
US6596166B1 (en) * | 1998-12-22 | 2003-07-22 | Hydrotech Nils-Ake Persson Ab | Apparatus for cleaning a filter cloth in a filtering device |
US20040045913A1 (en) * | 2000-12-12 | 2004-03-11 | Flanagan Peter J. | Disc-type filtration apparatus including discharge collector internal to pressure vessel and method of filtration |
US20040069721A1 (en) * | 2001-02-07 | 2004-04-15 | Magnus Ingelman | Pipe system for receiving and transporting lime sludge from a white liquor filter |
US6800197B1 (en) * | 2000-10-12 | 2004-10-05 | Genencor International, Inc. | Continuously operable rotating drum pressure differential filter, method and systems |
US20070221345A1 (en) * | 2004-04-16 | 2007-09-27 | Patrik Lownertz | Method and Device for Washing of Lime Mud |
US20070251891A1 (en) * | 2004-05-26 | 2007-11-01 | Patrik Lownertz | Method and Device for Cleaning of Filter |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1148950B (en) | 1958-11-07 | 1963-05-16 | Gaudfrin Guy | Continuously working disc filter for the sugar industry |
DE3047539A1 (en) | 1980-12-17 | 1982-07-22 | Klöckner-Humboldt-Deutz AG, 5000 Köln | Vacuum drum filter - with internal blow-off shoes for lifting off filter cake and removing remnants from filter cloth |
-
2002
- 2002-04-19 US US10/126,864 patent/US6833077B2/en not_active Expired - Lifetime
-
2004
- 2004-12-21 US US11/022,004 patent/US20050103727A1/en not_active Abandoned
Patent Citations (50)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2899066A (en) * | 1959-08-11 | Rotary vacuum | ||
US1804934A (en) * | 1927-09-09 | 1931-05-12 | Oliver United Filters Inc | Fluid pressure discharge for continuous filters |
US2655265A (en) * | 1949-01-31 | 1953-10-13 | Goslin Birmingham Mfg Company | Continuous rotary pressure or vacuum filter |
US2932402A (en) * | 1954-11-15 | 1960-04-12 | Denver Equip Co | Disc type filter |
US2839194A (en) * | 1957-01-08 | 1958-06-17 | Olin Mathieson | Continuous filtration process and apparatus therefor |
US3096278A (en) * | 1959-03-09 | 1963-07-02 | Eimco Corp | Scraper assembly for filters |
US3080064A (en) * | 1959-08-14 | 1963-03-05 | Ametek Inc | Filter scraper |
US3075646A (en) * | 1959-10-01 | 1963-01-29 | Ametek Inc | Filter |
US3193105A (en) * | 1961-02-06 | 1965-07-06 | Improved Machinery Inc | Continuous disc filter |
US3331512A (en) * | 1965-06-01 | 1967-07-18 | Improved Machinery Inc | Filter screen |
US3471026A (en) * | 1966-12-09 | 1969-10-07 | Dorr Oliver Inc | Continuous rotary disc filters |
US3521751A (en) * | 1967-12-15 | 1970-07-28 | Theodorus H Holthuis | Filtering method and apparatus |
US4017399A (en) * | 1969-03-11 | 1977-04-12 | Pullman Incorporated | Method and apparatus for filtration of slurries |
US3591009A (en) * | 1969-08-22 | 1971-07-06 | Oscar Luthi | Disc filter having filtrate directing means |
US4056473A (en) * | 1976-05-25 | 1977-11-01 | Bjarne Ivar Nilsson | Rotary filter for concentrating fiber suspensions |
US4136028A (en) * | 1976-09-13 | 1979-01-23 | Rauma-Rapola Oy | Method for filtering a fibrous material by means of a disc filter as well as a disc filter for performing the method |
US4332680A (en) * | 1980-04-14 | 1982-06-01 | United States Filter Fluid Systems Corporation | Filter sluicing apparatus |
US4528103A (en) * | 1984-04-06 | 1985-07-09 | Dorr-Oliver Incorporated | Pressure filter |
US4704206A (en) * | 1984-05-14 | 1987-11-03 | Aluminium Pechiney | Apparatus for continuous flow feed to disc-type rotary filters |
US4639315A (en) * | 1984-10-18 | 1987-01-27 | Mecapec S.A. | Apparatus for mechanical purification of waste water |
US4929355A (en) * | 1985-02-05 | 1990-05-29 | Ab Hedemora Verkstader | Method and apparatus for the separation of caustic liquor, lime sludge and sludge in a causticizing process |
US4943372A (en) * | 1987-11-02 | 1990-07-24 | A. Ahlstrom Corporation | Method and apparatus of discharging a disc filter |
US4995991A (en) * | 1988-03-22 | 1991-02-26 | Ahlstrom Corporation | Method and apparatus for improving the operation of a disc filter |
US4975189A (en) * | 1988-12-09 | 1990-12-04 | Liszka John A | Cleaning sprays for disc filters |
US5149448A (en) * | 1990-04-25 | 1992-09-22 | A. Ahlstrom Corporation | Method and apparatus for thickening lime sludge |
US5759397A (en) * | 1992-05-15 | 1998-06-02 | Caustec Ab | Filter with spray cake removal means |
US5423977A (en) * | 1992-08-06 | 1995-06-13 | Nippon Yusen Kaisha | Rotary filter with automatic spray cleaning device for cleaning same |
US5849202A (en) * | 1992-11-06 | 1998-12-15 | Andritz-Patentverwaltungs-Gesellschaft M.B.H. | Rotary disc filtration process having means to prevent settlement of solids |
US5692619A (en) * | 1992-12-14 | 1997-12-02 | Beloit Technologies, Inc. | Apparatus for filtering suspensions |
US5897788A (en) * | 1993-04-08 | 1999-04-27 | Ahlstrom Machinery Oy | Method and apparatus for cleaning a filter drum used for thickening lime mud |
US5900158A (en) * | 1993-07-15 | 1999-05-04 | A. Ahlstrom Corporation | Method and apparatus for thickening lime mud with a disc filter |
US5407587A (en) * | 1993-08-17 | 1995-04-18 | International Paper Company | Travelling doctor blade with nozzle |
US5374360A (en) * | 1993-12-14 | 1994-12-20 | Aqua-Aerobic Systems, Inc. | Method and apparatus for cleaning a filter apparatus |
US5470472A (en) * | 1994-05-16 | 1995-11-28 | Dorr-Oliver Incorporated | Rotary drum filter with reciprocating nozzle means |
US6063294A (en) * | 1996-10-15 | 2000-05-16 | Baker Hughes Incorporated | Uniform area shower for disc filter |
US5851392A (en) * | 1996-11-08 | 1998-12-22 | Brady, Jr.; C. Lamar | Process and apparatus for doctoring solids from a rotary filter |
US5968372A (en) * | 1996-12-16 | 1999-10-19 | Baker Hughes Incorporated | Logic controlled traversing shower |
US6258282B1 (en) * | 1997-08-21 | 2001-07-10 | Kvaerner Pulping Ab | Rotatable filter system for filtration of a flowing substance |
US6283306B1 (en) * | 1998-02-18 | 2001-09-04 | Harry Nilsson | Rotating filter |
US6596166B1 (en) * | 1998-12-22 | 2003-07-22 | Hydrotech Nils-Ake Persson Ab | Apparatus for cleaning a filter cloth in a filtering device |
US6800197B1 (en) * | 2000-10-12 | 2004-10-05 | Genencor International, Inc. | Continuously operable rotating drum pressure differential filter, method and systems |
US20040045913A1 (en) * | 2000-12-12 | 2004-03-11 | Flanagan Peter J. | Disc-type filtration apparatus including discharge collector internal to pressure vessel and method of filtration |
US7005067B2 (en) * | 2000-12-12 | 2006-02-28 | Gl&V Management Hungary Kft | Disc-type filtration apparatus including discharge collector internal to pressure vessel and method filtration |
US20040069721A1 (en) * | 2001-02-07 | 2004-04-15 | Magnus Ingelman | Pipe system for receiving and transporting lime sludge from a white liquor filter |
US6793809B2 (en) * | 2001-02-07 | 2004-09-21 | Kvaerner Pulping Ab | Pipe system for receiving and transporting lime sludge from a white liquor filter |
US20020166821A1 (en) * | 2001-04-23 | 2002-11-14 | Flanagan Peter J. | Disc filters with shower systems and methods of use |
US20020166822A1 (en) * | 2001-04-23 | 2002-11-14 | Flanagan Peter J. | Sequential swinging precoat removal and renewal system, filter so equipped and method |
US6833077B2 (en) * | 2001-04-23 | 2004-12-21 | Gl&V Management Hungary Kft. | Sequential swinging precoat removal and renewal system, filter so equipped and method |
US20070221345A1 (en) * | 2004-04-16 | 2007-09-27 | Patrik Lownertz | Method and Device for Washing of Lime Mud |
US20070251891A1 (en) * | 2004-05-26 | 2007-11-01 | Patrik Lownertz | Method and Device for Cleaning of Filter |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070221345A1 (en) * | 2004-04-16 | 2007-09-27 | Patrik Lownertz | Method and Device for Washing of Lime Mud |
US7686964B2 (en) * | 2004-04-16 | 2010-03-30 | Metso Fiber Karlstad Ab | Method and device for washing of lime mud |
US20080164222A1 (en) * | 2004-11-25 | 2008-07-10 | Andritz Oy | Method and Apparatus for Thickening Lime Mud in a Disc Filter |
US8002994B2 (en) * | 2004-11-25 | 2011-08-23 | Andritz Oy | Method and apparatus for thickening lime mud in a disc filter |
US20100032388A1 (en) * | 2007-02-21 | 2010-02-11 | Hydrotech Veolia Water Systems Aktiebolag | Device and Method for Cleaning a Filter Cloth |
US8101090B2 (en) * | 2007-02-21 | 2012-01-24 | Veolia Water Solutions & Technologies Support | Device and method for cleaning a filter cloth |
US8444862B2 (en) | 2007-02-21 | 2013-05-21 | Veolia Water Solutions & Technologies Support | Device and method for cleaning a filter cloth |
US20140374363A1 (en) * | 2012-02-06 | 2014-12-25 | Andritz Oy | Method and apparatus for reducing the thickness of a precoat layer of a disc filter |
US9259674B2 (en) * | 2012-02-06 | 2016-02-16 | Andritz Oy | Method and apparatus for reducing the thickness of a precoat layer of a disc filter |
US20210387114A1 (en) * | 2018-11-05 | 2021-12-16 | Ishigaki Company Limited | Filter cloth cleaning method of filter press |
US11000791B2 (en) * | 2019-03-06 | 2021-05-11 | Veolia Water Solutions & Technologies Support | Rotary disc filter having backwash guides |
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US20020166822A1 (en) | 2002-11-14 |
US6833077B2 (en) | 2004-12-21 |
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