CA1223216A - Drum filter assembly for extracting filtrate from a fiber suspension - Google Patents
Drum filter assembly for extracting filtrate from a fiber suspensionInfo
- Publication number
- CA1223216A CA1223216A CA000438748A CA438748A CA1223216A CA 1223216 A CA1223216 A CA 1223216A CA 000438748 A CA000438748 A CA 000438748A CA 438748 A CA438748 A CA 438748A CA 1223216 A CA1223216 A CA 1223216A
- Authority
- CA
- Canada
- Prior art keywords
- filtrate
- fiber suspension
- mixture
- filter
- drum filter
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
Links
- 239000000835 fiber Substances 0.000 title claims abstract description 32
- 239000000725 suspension Substances 0.000 title claims abstract description 31
- 239000000706 filtrate Substances 0.000 title claims description 34
- 239000000203 mixture Substances 0.000 claims description 14
- 238000001914 filtration Methods 0.000 abstract description 11
- 238000007789 sealing Methods 0.000 abstract description 8
- 238000000034 method Methods 0.000 description 3
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 239000013049 sediment Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 241000644027 Perideridia lemmonii Species 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
- D21C9/06—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents in filters ; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces
-
- 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
- B01D33/70—Filters with filtering elements which move during the filtering operation having feed or discharge devices
- B01D33/72—Filters with filtering elements which move during the filtering operation having feed or discharge devices for feeding
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Sealing Devices (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Abstract of the Disclosure Mode of eliminating the drawbacks caused by the sealing and by leakages of sealing in filter wishers or sedimenters or equivalent, in which the fibre suspension is fed from a feeder box (4) or feeder component onto the filtering member (5), which moves in relation to the feeder box or feeder component.
The suspension leaking through the sealing between the filtering member (5) and the feeder box (4) or feeder component is passed back to the supply flow of the filter washer or sedimentary or equivalent.
The suspension leaking through the sealing between the filtering member (5) and the feeder box (4) or feeder component is passed back to the supply flow of the filter washer or sedimentary or equivalent.
Description
~L2~23~
The present invention is concerned with an assembly which eliminates the drawbacks caused by the sealing and by leakages of sealing in filter washers or sedimenters or equiva-fonts, in which the fibre suspension is fed from a feeder box or feeder component onto the filtering member, which moves in relation to the feeder box or feeder component.
For filtering or thickening and washing of fibre sup-pensions, in particular of cellulose fibre suspensions or pulp stock, filters are used in which the fibre suspension is semi-minted either on various revolving drums or on other filtering members, such as, for example, a wire or equivalent.
The fibre suspension is passed into the filter feeder box, basin or equivalent diluted to the appropriate consist Tunis. The fibre suspension is sediment Ed by means of a differ-once in pressure onto the filtering face, which moves relative to the stationary feeder component and carries the sediment Ed suspension further. In the prior art, the problem of sealing the slot between the mobile filtering member and the edge of the stationary feeder component has been resolved by using some dragging members or a small play. Dragging members cause Abram soon of the filtering member, and the small play is readily blocked, causing damage on the filtering member. Nor is it posy sidle to make the play so little that no leakages at all should occur.
An object of the present invention is to eliminate the above problem of sealing. The invention is characterized in that the suspension leaking through the sealing between -the filtering member and the feeder box or feeder component is passed back to the supply flow of the filter washer or semi-mentor or equivalent. Thus, according to the invention, it is not even attempted to make the said zone leak-proof, but a fee-son able leakage is permitted and the leaking fibre suspension ~2~3;~
is returned under control in the process upstream to the point of the process at which the fibre suspension is diluted before being fed onto the filter. The leaking suspension is not mixed together with all of the filtrate, but only with the part of the Filtrate what is used for diluting the fibre suspension Burr the cementer.
In accordance with one embodiment of the present invention, there is provided a drum filter assembly for extract-in filtrate from a fiber suspension comprising a cylindrical rotary drum filter, feeding means adjacent the filter, an enclo-sure surrounding the filter, a first portion of the enclosure being a basin adjacent the filter, a second portion of the enclosure having an opening for receiving the feeding means and a third portion providing an outlet for the fiber suspension from which filtrate has been extracted, non leakproof means between the feeding means and the rotary drum filter to permit an amount of mixture of filtrate and fiber suspension to pass directly from the feeding means to the basin without passing through the rotary drum filter so as to allow the absence of leakproof seals between the rotary drum filter and the feeding means, means for maintaining a portion of the filtrate in a hollow interior of the rotary drum filter free of fires, a lit-irate collecting tank conduit means connected between the interior of the rotary drum filter and the collecting tank for removing filtrate from the filter to the collecting tank, a first valved conduit means for removing filtrate from the got-looting tank, an inlet feed conduit for feeding the mixture of filtrate and fiber suspension to the feeding means, a drain con dull for draining the mixture of filtrate and fiber suspension from -the basin, and a second valved conduit means connected between the collection tank and the feed conduit for returning a portion of the filtrate to the inlet feed conduit, the drain ~,~
~.~223~
conduit being connected to the second valved conduit means to return the mixture of filtrate and fiber suspension to the inlet feed conduit.
In a preferred embodiment of the present invention, the drum filter assembly further comprises means for maintain-in the basin and the interior of the drum at a substantially equal pressure and means for maintaining the area above the Crimea at a pressure higher than the pressure in the basin and the interior of the drum.
Preferably the mixture of filtrate and fiber suspend soon in the supply line is in the range of 0.5 to 8% fiber sup-pension, more preferably in the range of 1 -to I fiber suspend soon.
The invention will now be described in more detail in the following, as applied to a drum washer and with reference to the attached drawings, wherein:
FIGURE 1 shows a flow diagram in accordance with an embodiment of the present invention;
FIGURE 2 is a sectional view of the principle of implementation of the mode described above, in a sedimentary-washer; and FIGURE 3 shows a section taken along the line A-A in Figure 2.
According to Fig. 1, the fibre suspension, e.g. pulp stock, is introduced, e.g., from a blow-off tank at a higher consistency (e.g., 5%) than the consistency of feeding onto the washer-filter (e.g. I The pulp stock is diluted in the feeder pipe system between points 1 and 2 before the pulp reaches the feeder box 4. In the feeder box, the pulp stock is pressed, by means of the difference in pressure between the interior of the drum and the outside as well as by means of the liquid pressure, against the filtering wire-faced drum 5, whereat the filtrate ends up inside the drum. The pressure I
prevailing outside the upper portion of the drum is higher than the pressure in the interior of the drum. On the other hand, the pressure prevailing in the basin 6 outside the lower port lion of the drum is equal to the pressure inside the drum. The S direction of rotation of the drum 5 in the figure is clockwise.
Through the slot 12 between the feeder component 4 and the drum 5, part of the pulp to be fed leaks into -the basin portion it. The width of -the slot may be, e.g., 1 to 30 mm. The leak-in pulp stock and the filtrate required for the dilution, come in into the basin 6 out of -the drum 5 interior r are mixed in the basin, and the mixture is passed via pipe 7 to the inlet side of the pump 8 and further through -the dilution pipe 9 so as to dilute the pulp to be fed in. The filtrate free from fires is passed by means of a separate pipe 10 from inside the drum into a filtrate tank 11, from which it can be also pumped further to any such position of the process at which a fibre content in the filtrate is detrimental, e.g., to the evaporate in plant, to the washing jets of the preceding washer-filtex, or to any other, equivalent purposes.
The interior of the drum and the basin 6 are isolated from each other in a way known in the prior art by means of interlaced seals 13, whereat -the filtrate can flow through the wire backwards into -the basin, but the fires have no access into the drum.
The present invention is concerned with an assembly which eliminates the drawbacks caused by the sealing and by leakages of sealing in filter washers or sedimenters or equiva-fonts, in which the fibre suspension is fed from a feeder box or feeder component onto the filtering member, which moves in relation to the feeder box or feeder component.
For filtering or thickening and washing of fibre sup-pensions, in particular of cellulose fibre suspensions or pulp stock, filters are used in which the fibre suspension is semi-minted either on various revolving drums or on other filtering members, such as, for example, a wire or equivalent.
The fibre suspension is passed into the filter feeder box, basin or equivalent diluted to the appropriate consist Tunis. The fibre suspension is sediment Ed by means of a differ-once in pressure onto the filtering face, which moves relative to the stationary feeder component and carries the sediment Ed suspension further. In the prior art, the problem of sealing the slot between the mobile filtering member and the edge of the stationary feeder component has been resolved by using some dragging members or a small play. Dragging members cause Abram soon of the filtering member, and the small play is readily blocked, causing damage on the filtering member. Nor is it posy sidle to make the play so little that no leakages at all should occur.
An object of the present invention is to eliminate the above problem of sealing. The invention is characterized in that the suspension leaking through the sealing between -the filtering member and the feeder box or feeder component is passed back to the supply flow of the filter washer or semi-mentor or equivalent. Thus, according to the invention, it is not even attempted to make the said zone leak-proof, but a fee-son able leakage is permitted and the leaking fibre suspension ~2~3;~
is returned under control in the process upstream to the point of the process at which the fibre suspension is diluted before being fed onto the filter. The leaking suspension is not mixed together with all of the filtrate, but only with the part of the Filtrate what is used for diluting the fibre suspension Burr the cementer.
In accordance with one embodiment of the present invention, there is provided a drum filter assembly for extract-in filtrate from a fiber suspension comprising a cylindrical rotary drum filter, feeding means adjacent the filter, an enclo-sure surrounding the filter, a first portion of the enclosure being a basin adjacent the filter, a second portion of the enclosure having an opening for receiving the feeding means and a third portion providing an outlet for the fiber suspension from which filtrate has been extracted, non leakproof means between the feeding means and the rotary drum filter to permit an amount of mixture of filtrate and fiber suspension to pass directly from the feeding means to the basin without passing through the rotary drum filter so as to allow the absence of leakproof seals between the rotary drum filter and the feeding means, means for maintaining a portion of the filtrate in a hollow interior of the rotary drum filter free of fires, a lit-irate collecting tank conduit means connected between the interior of the rotary drum filter and the collecting tank for removing filtrate from the filter to the collecting tank, a first valved conduit means for removing filtrate from the got-looting tank, an inlet feed conduit for feeding the mixture of filtrate and fiber suspension to the feeding means, a drain con dull for draining the mixture of filtrate and fiber suspension from -the basin, and a second valved conduit means connected between the collection tank and the feed conduit for returning a portion of the filtrate to the inlet feed conduit, the drain ~,~
~.~223~
conduit being connected to the second valved conduit means to return the mixture of filtrate and fiber suspension to the inlet feed conduit.
In a preferred embodiment of the present invention, the drum filter assembly further comprises means for maintain-in the basin and the interior of the drum at a substantially equal pressure and means for maintaining the area above the Crimea at a pressure higher than the pressure in the basin and the interior of the drum.
Preferably the mixture of filtrate and fiber suspend soon in the supply line is in the range of 0.5 to 8% fiber sup-pension, more preferably in the range of 1 -to I fiber suspend soon.
The invention will now be described in more detail in the following, as applied to a drum washer and with reference to the attached drawings, wherein:
FIGURE 1 shows a flow diagram in accordance with an embodiment of the present invention;
FIGURE 2 is a sectional view of the principle of implementation of the mode described above, in a sedimentary-washer; and FIGURE 3 shows a section taken along the line A-A in Figure 2.
According to Fig. 1, the fibre suspension, e.g. pulp stock, is introduced, e.g., from a blow-off tank at a higher consistency (e.g., 5%) than the consistency of feeding onto the washer-filter (e.g. I The pulp stock is diluted in the feeder pipe system between points 1 and 2 before the pulp reaches the feeder box 4. In the feeder box, the pulp stock is pressed, by means of the difference in pressure between the interior of the drum and the outside as well as by means of the liquid pressure, against the filtering wire-faced drum 5, whereat the filtrate ends up inside the drum. The pressure I
prevailing outside the upper portion of the drum is higher than the pressure in the interior of the drum. On the other hand, the pressure prevailing in the basin 6 outside the lower port lion of the drum is equal to the pressure inside the drum. The S direction of rotation of the drum 5 in the figure is clockwise.
Through the slot 12 between the feeder component 4 and the drum 5, part of the pulp to be fed leaks into -the basin portion it. The width of -the slot may be, e.g., 1 to 30 mm. The leak-in pulp stock and the filtrate required for the dilution, come in into the basin 6 out of -the drum 5 interior r are mixed in the basin, and the mixture is passed via pipe 7 to the inlet side of the pump 8 and further through -the dilution pipe 9 so as to dilute the pulp to be fed in. The filtrate free from fires is passed by means of a separate pipe 10 from inside the drum into a filtrate tank 11, from which it can be also pumped further to any such position of the process at which a fibre content in the filtrate is detrimental, e.g., to the evaporate in plant, to the washing jets of the preceding washer-filtex, or to any other, equivalent purposes.
The interior of the drum and the basin 6 are isolated from each other in a way known in the prior art by means of interlaced seals 13, whereat -the filtrate can flow through the wire backwards into -the basin, but the fires have no access into the drum.
Claims (4)
1. A drum filter assembly for extracting filtrate from a fiber suspension comprising a cylindrical rotary drum filter a feed box adjacent said filter, an enclosure surrounding said filter, a first portion of the enclosure being a basin adjacent said filter, a second portion of the enclosure having an opening for receiving the feed box and a third portion providing an outlet for the fiber suspension from which filtrate has been extracted, non-leakproof means between the feed box and the rotary drum filter to permit an amount of mixture of filtrate and fiber suspension to pass directly from the feed box to the basin without passing through the rotary drum filter so as to allow the absence of leakproof seals between the rotary drum filter and the feed box, means for maintaining a portion of the filtrate in a hollow interior of the rotary drum filter free of fibers, a filtrate collecting tank, filtrate pipe means connected between the interior of the rotary drum filter and the collecting tank for removing filtrate from the filter to the collecting tank, a first pipe for removing filtrate from said collecting tank including a first valve means, an inlet feed pipe for feeding the mixture of filtrate and fiber suspension to the feed box, a drain pipe for draining the mixture of filtrate and fiber suspension from the basin, and a second pipe including a second valve means connected between the collection tank and the feed pipe for returning a portion of the filtrate to the inlet feed pipe, said drain pipe being connected to said second valved pipe to return the mixture of filtrate and fiber suspension to the inlet feed pipe.
2. A drum filter assembly as set forth in claim 1 and further comprising means for maintaining said basin and the interior of the drum at a substantially equal pressure and means for maintaining the area above said drum at a pressure higher than the pressure in said basin and the interior of the drum.
3. A drum filter assembly as set forth in claim 1, wherein said inlet feed pipe means for feeding the mixture of filtrate and fiber suspension is provided with the mixture in a range of 0.5 to 8% fiber suspension.
4. A drum filter assembly as set forth in claim 1, wherein said inlet feed pipe means for feeding the mixture of filtrate and fiber suspension is provided with the mixture in a range of 1 to 5% fiber suspension.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI82-3815 | 1982-11-08 | ||
| FI823815A FI65457C (en) | 1982-11-08 | 1982-11-08 | SAFETY REQUIREMENTS FOR PULLING PROBLEMS AND FILTER VESSELS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1223216A true CA1223216A (en) | 1987-06-23 |
Family
ID=8516272
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000438748A Expired CA1223216A (en) | 1982-11-08 | 1983-10-11 | Drum filter assembly for extracting filtrate from a fiber suspension |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1223216A (en) |
| FI (1) | FI65457C (en) |
| SE (1) | SE461281B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3942724A1 (en) * | 1988-10-13 | 1991-06-27 | Sunds Defibrator Rauma Oy | METHOD AND DEVICE FOR FILTERING SUSPENSIONS |
-
1982
- 1982-11-08 FI FI823815A patent/FI65457C/en not_active IP Right Cessation
-
1983
- 1983-10-11 CA CA000438748A patent/CA1223216A/en not_active Expired
- 1983-11-04 SE SE8306063A patent/SE461281B/en not_active IP Right Cessation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3942724A1 (en) * | 1988-10-13 | 1991-06-27 | Sunds Defibrator Rauma Oy | METHOD AND DEVICE FOR FILTERING SUSPENSIONS |
| US5051195A (en) * | 1988-10-13 | 1991-09-24 | Sunds Defibrator Rauma Oy | Method and equipment for filtration of suspension |
| DE3942724C2 (en) * | 1988-10-13 | 1998-11-12 | Sunds Defibrator Rauma Oy | Method and device for filtering suspensions |
Also Published As
| Publication number | Publication date |
|---|---|
| SE461281B (en) | 1990-01-29 |
| FI65457C (en) | 1984-05-10 |
| FI823815A0 (en) | 1982-11-08 |
| FI65457B (en) | 1984-01-31 |
| SE8306063L (en) | 1984-05-09 |
| SE8306063D0 (en) | 1983-11-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20040623 |