CA2022779A1 - Dewatering device - Google Patents
Dewatering deviceInfo
- Publication number
- CA2022779A1 CA2022779A1 CA002022779A CA2022779A CA2022779A1 CA 2022779 A1 CA2022779 A1 CA 2022779A1 CA 002022779 A CA002022779 A CA 002022779A CA 2022779 A CA2022779 A CA 2022779A CA 2022779 A1 CA2022779 A1 CA 2022779A1
- Authority
- CA
- Canada
- Prior art keywords
- dewatering
- press rolls
- drum
- dewatering drum
- radius
- 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.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F9/00—Complete machines for making continuous webs of paper
- D21F9/02—Complete machines for making continuous webs of paper of the Fourdrinier type
-
- 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
- D21C9/18—De-watering; Elimination of cooking or pulp-treating liquors from the pulp
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Filtration Of Liquid (AREA)
- Paper (AREA)
- Filtering Materials (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Confectionery (AREA)
- Medicines Containing Plant Substances (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
- Press Drives And Press Lines (AREA)
Abstract
ABSTRACT
The belt type squeeze filter has an entrance gap formed by a bow-shaped guideway. The guideway is a perforated plastic shell. This plastic has very favourable sliding properties. The bow-shaped entrance part extends approximately over a sector of 15'. Thus, the frictional stresses of the wire belt running on the low friction guideway will not be very large.
The belt type squeeze filter has an entrance gap formed by a bow-shaped guideway. The guideway is a perforated plastic shell. This plastic has very favourable sliding properties. The bow-shaped entrance part extends approximately over a sector of 15'. Thus, the frictional stresses of the wire belt running on the low friction guideway will not be very large.
Description
2Q2?~
The invention concerns a dewatering device.
Dewatering devices are used for thickening fibre suspensions in, for example, paper-making processes. one type of such device is shown in German Patent No. 21 38 072 and has a perforated dewatering drum as a first dewatering stage followed by press rolls that are parallel to one another and to the drum. Two wire belts partly loop about both the dewatering drum and the press rolls to form one less press gap than the number of press rolls.
This device has already been improved in that the headbox which supplies the suspension to the area of the wire belt which directly loops partly around the dewatering drum and is located before the dewatering drum has been coordinated with an area before the approach point of the other wire belt to this wire belt. The suspension has been fed to the former wire belt and between the first and the second wire an entrance gap has been formed immediately before the dewatering drum, by a suitable reversal of the second wire. Thus it was possible to collect liquid passing through the former wire already in the area of the applicator device and, thus, remove it from the suspension already at an early stage.
It is an object of the present invention to fashion such a device in such a way that a greater throughput may be achieved and, most of all, the entering substance density can be reduced through a greater efficacy of the initial dewatering process.
According therefore to the present invention, there is provided a dewatering device, specifically for thickening fibre suspensions, with a perforated dewatering drum as a first dewatering stage and with, following the dewatering drum, press rolls that are parallel to one another and to the dewatering drum, and two wire belts which partly loop around both the dewatering drum and the press rolls forming between the press rolls, corresponding to 20227~9 their number n, a corresponding number n-l of press gaps, characterized in that an entrance gap is formed by a bow-shaped sliding guideway for the wire belt situated radially inward on the dewatering drum, with the radius of curvature k of the bow-shaped sliding guideway amounting to at least three times the outside radius of the dewatering drum 4 and the outside radius R of the dewatering drum 4 amounting to at least twice the smallest outside radius i of the press rolls.
The amount of suspension entering the entrance gap greatly determines the throughput of the dewatering device for a given setting of a speed of rotation of the dewatering drum or a revolving speed of the wires. The bow-shaped guideway at the entrance gap provides a relatively gentle increase of the squeeze pressure of the wires that increases toward the drum. As a result, the liquid is squeezed out very well forming sort of a fleece, whereas it would otherwise be easily possible for the suspension to splash out of the entrance gap sideways. This bow-shaped sliding guideway favourably extends in the area of the entrance gap across a 15 circular sector.
The invention will be explained hereafter with the aid of an embodiment illustrated in the drawings, with the figure showing a basic cross-section of the belt type squeeze filter.
The belt type squeeze filter features two wire belts 1 and 2 which jointly and partly loop around both the peripherally perforated dewatering drum 4 and the following press rolls 9-13. The radially inner wire belt 2 proceeds additionally across reversing rolls 25 and 27 and the, relative to the dewatering drum, radially outer wire belt 1 loops around the dewatering rolls 28-31. Formed in the area of the dewatering drum 4 between the reversing roll 25 and the drum 4 is an entrance gap guideway 6. The guideway 6 is formed as an upwardly convex surface in the form of a bow 2Q29~
and located radially inward in relation to the loop of the wire belt 2 which is in direct contact with dewatering drum 4 so as to support the belt 2, which is preferably of a low friction material and partly perforated in the way of a screen. This makes it possible for the water (liquid) pressed out of the suspension int he entrance gap to drain into the collection trough 38. The suspension is applied on the wire belt 2, which is in intimate contact with the dewatering drum 4, by the headbox 40, to which the suspension is supplied by the inlet socket 41. Passing through the wire belt 2, the liquid quantity that drains already here proceeds as well to the collection box 38.
The dewatering drum 4 has a perforated circumference, with preferably a wire covering placed on a perforated cylinder. The dewatering drum is sideways sealed by plates 34 which are provided with drain openings 35O The dewatering drum is mounted with its ends in a bearing 32 each supported by the upper support beam.
Of the following press rolls 9-11 of the bottom row and 12 and 13 of the top row, two adjacent press rolls of the two rows always form among each other a press gap.
The press rolls 14 and 15 of the upper row are supported by hydraulic piston/cylinder units 14 and 15 bearing on the upper support beam 20. The centre axis of the press elements 14 and 15 are inclined at an angle of about 70 and in the running direction of the wire toward the connecting plane of the lower row of press rolls 9-11. As a result, the upper press rolls 11 and 13 are forced onto the lower press rolls 9-11 in such a way that two press gaps will be formed at the upper press rolls. In the order of the press gaps, increasing squeeze pressures between 100 and 600 N/cm are applied.
The water (liquid) squeezed out is collected in the lower collection trough 36 and removed through the drain socket 37. The entire device bears on a base plate by way of supports 45 and 46 which act on the lower crossbeam 21.
Additionally, the upper crossbeam 20 bears on the lower crossbeam 21 via lateral support columns 22 and 23. As indicated at 35,33, the reversing rolls are supported by similar bearings, except here for the reversing roll 28, which for reason of creating the wire tension is supported through a swivel arm 51 and a hydraulic pressure element 52.
the set up for the upper reversing roll 27 of the other wire belt 2 is similar, with the lever 53 and the pneumatic pressure element 54 being provided for that purpose. These pneumatic pressure elements, in turn, act on levers 54 and 56, respectively.
The radius of curvature k of the bow-shaped sliding guideway 3 amounts to at least three times the outside radius R of the dewatering drum 4, and the outside radius R of the dewatering drum 4 amounts to at least twice the smallest outside radius i of the press rolls 9-13.
Preferably the radius k is 4 times the radius R. The guide 6 extends over a sector of approximately 15-.
This belt type squeeze filter affords the additional advantage that, due to the relatively gentle, technologically very favourable dewatering process, a relatively low initial substance density can be used in the area of the entrance gap 6. Due to the good dewatering effect, nearly the same leaving substance density as with previous dewatering devices of this type is obtained nonetheless. Depending upon stock type, entrance stock densities may range here between 2.5 and 2.9%.
It is preferred that the press rolls 9-11 and 13,14 lie in a horizontal plane or are inclined to the horizontal plane at an angle of 25 or less.
The invention concerns a dewatering device.
Dewatering devices are used for thickening fibre suspensions in, for example, paper-making processes. one type of such device is shown in German Patent No. 21 38 072 and has a perforated dewatering drum as a first dewatering stage followed by press rolls that are parallel to one another and to the drum. Two wire belts partly loop about both the dewatering drum and the press rolls to form one less press gap than the number of press rolls.
This device has already been improved in that the headbox which supplies the suspension to the area of the wire belt which directly loops partly around the dewatering drum and is located before the dewatering drum has been coordinated with an area before the approach point of the other wire belt to this wire belt. The suspension has been fed to the former wire belt and between the first and the second wire an entrance gap has been formed immediately before the dewatering drum, by a suitable reversal of the second wire. Thus it was possible to collect liquid passing through the former wire already in the area of the applicator device and, thus, remove it from the suspension already at an early stage.
It is an object of the present invention to fashion such a device in such a way that a greater throughput may be achieved and, most of all, the entering substance density can be reduced through a greater efficacy of the initial dewatering process.
According therefore to the present invention, there is provided a dewatering device, specifically for thickening fibre suspensions, with a perforated dewatering drum as a first dewatering stage and with, following the dewatering drum, press rolls that are parallel to one another and to the dewatering drum, and two wire belts which partly loop around both the dewatering drum and the press rolls forming between the press rolls, corresponding to 20227~9 their number n, a corresponding number n-l of press gaps, characterized in that an entrance gap is formed by a bow-shaped sliding guideway for the wire belt situated radially inward on the dewatering drum, with the radius of curvature k of the bow-shaped sliding guideway amounting to at least three times the outside radius of the dewatering drum 4 and the outside radius R of the dewatering drum 4 amounting to at least twice the smallest outside radius i of the press rolls.
The amount of suspension entering the entrance gap greatly determines the throughput of the dewatering device for a given setting of a speed of rotation of the dewatering drum or a revolving speed of the wires. The bow-shaped guideway at the entrance gap provides a relatively gentle increase of the squeeze pressure of the wires that increases toward the drum. As a result, the liquid is squeezed out very well forming sort of a fleece, whereas it would otherwise be easily possible for the suspension to splash out of the entrance gap sideways. This bow-shaped sliding guideway favourably extends in the area of the entrance gap across a 15 circular sector.
The invention will be explained hereafter with the aid of an embodiment illustrated in the drawings, with the figure showing a basic cross-section of the belt type squeeze filter.
The belt type squeeze filter features two wire belts 1 and 2 which jointly and partly loop around both the peripherally perforated dewatering drum 4 and the following press rolls 9-13. The radially inner wire belt 2 proceeds additionally across reversing rolls 25 and 27 and the, relative to the dewatering drum, radially outer wire belt 1 loops around the dewatering rolls 28-31. Formed in the area of the dewatering drum 4 between the reversing roll 25 and the drum 4 is an entrance gap guideway 6. The guideway 6 is formed as an upwardly convex surface in the form of a bow 2Q29~
and located radially inward in relation to the loop of the wire belt 2 which is in direct contact with dewatering drum 4 so as to support the belt 2, which is preferably of a low friction material and partly perforated in the way of a screen. This makes it possible for the water (liquid) pressed out of the suspension int he entrance gap to drain into the collection trough 38. The suspension is applied on the wire belt 2, which is in intimate contact with the dewatering drum 4, by the headbox 40, to which the suspension is supplied by the inlet socket 41. Passing through the wire belt 2, the liquid quantity that drains already here proceeds as well to the collection box 38.
The dewatering drum 4 has a perforated circumference, with preferably a wire covering placed on a perforated cylinder. The dewatering drum is sideways sealed by plates 34 which are provided with drain openings 35O The dewatering drum is mounted with its ends in a bearing 32 each supported by the upper support beam.
Of the following press rolls 9-11 of the bottom row and 12 and 13 of the top row, two adjacent press rolls of the two rows always form among each other a press gap.
The press rolls 14 and 15 of the upper row are supported by hydraulic piston/cylinder units 14 and 15 bearing on the upper support beam 20. The centre axis of the press elements 14 and 15 are inclined at an angle of about 70 and in the running direction of the wire toward the connecting plane of the lower row of press rolls 9-11. As a result, the upper press rolls 11 and 13 are forced onto the lower press rolls 9-11 in such a way that two press gaps will be formed at the upper press rolls. In the order of the press gaps, increasing squeeze pressures between 100 and 600 N/cm are applied.
The water (liquid) squeezed out is collected in the lower collection trough 36 and removed through the drain socket 37. The entire device bears on a base plate by way of supports 45 and 46 which act on the lower crossbeam 21.
Additionally, the upper crossbeam 20 bears on the lower crossbeam 21 via lateral support columns 22 and 23. As indicated at 35,33, the reversing rolls are supported by similar bearings, except here for the reversing roll 28, which for reason of creating the wire tension is supported through a swivel arm 51 and a hydraulic pressure element 52.
the set up for the upper reversing roll 27 of the other wire belt 2 is similar, with the lever 53 and the pneumatic pressure element 54 being provided for that purpose. These pneumatic pressure elements, in turn, act on levers 54 and 56, respectively.
The radius of curvature k of the bow-shaped sliding guideway 3 amounts to at least three times the outside radius R of the dewatering drum 4, and the outside radius R of the dewatering drum 4 amounts to at least twice the smallest outside radius i of the press rolls 9-13.
Preferably the radius k is 4 times the radius R. The guide 6 extends over a sector of approximately 15-.
This belt type squeeze filter affords the additional advantage that, due to the relatively gentle, technologically very favourable dewatering process, a relatively low initial substance density can be used in the area of the entrance gap 6. Due to the good dewatering effect, nearly the same leaving substance density as with previous dewatering devices of this type is obtained nonetheless. Depending upon stock type, entrance stock densities may range here between 2.5 and 2.9%.
It is preferred that the press rolls 9-11 and 13,14 lie in a horizontal plane or are inclined to the horizontal plane at an angle of 25 or less.
Claims (6)
1. A dewatering device, specifically for thickening fibre suspensions, with a perforated dewatering drum as a first dewatering stage and with, following the dewatering drum, press rolls that are parallel to one another and to the dewatering drum, and two wire belts which partly loop around both the dewatering drum and the press rolls forming between the press rolls, corresponding to their number n, a corresponding number n-1 of press gaps, characterized in that an entrance gap is formed by a bow-shaped sliding guideway for the wire belt situated radially inward on the dewatering drum, with the radius of curvature k of the bow-shaped sliding guideway amounting to at least three times the outside radius of the dewatering drum, and the outside radius R of the dewatering drum amounting to at least twice the smallest outside radius i of the press rolls.
2. A dewatering device according to claim 1 characterized in that the number of press rolls is at least four and that these are arranged both radially inside and radially outside with regard to the loop of the radially inner wire belt of the watering drum essentially in a row side by side, with the press rolls of at least one of the rows provided with contact elements with centre longitudinal axes inclined against the wire running direction, at an acute angle (about 70°) to the connecting plane of the centre longitudinal axis of the other row of press rolls.
3. A dewatering device according to claim 1 or 2 characterize din that the contact elements are hydraulic or pneumatic cylinder/piston units.
4. A dewatering device according to one of the claims 1 through 3 characterized in that the contact elements are arranged radially inside with regard to the loop of the wire belt which with regard to the dewatering drum is situated radially inside.
5. A dewatering device according to one of the claims 1 through 4 characterized in that the rows of press rolls and are arranged essentially horizontally or with a maximum variation of maximally 25° from the horizontal plane.
6. A dewatering device according to one of the claims 1 through 5 characterized in that the radius of curvature k of the bow-shaped sliding guideway amounts to about four times the radius R of the dewatering drum.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3926440A DE3926440A1 (en) | 1989-08-10 | 1989-08-10 | DRAINAGE DEVICE, IN PARTICULAR BAND PRESSURE FILTERS |
| DEP3926440.8 | 1989-08-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2022779A1 true CA2022779A1 (en) | 1991-02-11 |
Family
ID=6386865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002022779A Abandoned CA2022779A1 (en) | 1989-08-10 | 1990-08-07 | Dewatering device |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0412250B1 (en) |
| JP (1) | JPH03130493A (en) |
| KR (1) | KR910004895A (en) |
| AT (1) | ATE93559T1 (en) |
| BR (1) | BR9004049A (en) |
| CA (1) | CA2022779A1 (en) |
| DE (1) | DE3926440A1 (en) |
| DK (1) | DK0412250T3 (en) |
| ES (1) | ES2045642T3 (en) |
| FI (1) | FI903948A0 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT402370B (en) * | 1991-06-13 | 1997-04-25 | Andritz Patentverwaltung | DOUBLE SCREEN DRAINAGE DEVICE |
| AT401069B (en) * | 1993-06-23 | 1996-06-25 | Leripa Kunststoff Gmbh & Co Kg | Edge seal for dewatering elements |
| US20050027006A1 (en) | 2003-07-28 | 2005-02-03 | Reuben Matalon | Methods and materials for treating conditions associated with metabolic disorders |
| WO2013077169A1 (en) | 2011-11-25 | 2013-05-30 | オリンパスメディカルシステムズ株式会社 | Endoscope |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1130329A (en) * | 1954-09-18 | 1957-02-04 | Voith Gmbh J M | Device for the concentration of fibrous suspensions |
| GB1288277A (en) * | 1969-02-03 | 1972-09-06 | ||
| DE2138072B2 (en) * | 1971-07-30 | 1973-10-31 | J.M. Voith Gmbh, 7920 Heidenheim | Band pressure filter |
| EP0197731A3 (en) * | 1985-03-29 | 1988-07-06 | The Black Clawson Company | Apparatus and method for thickening pulp and paper stock |
-
1989
- 1989-08-10 DE DE3926440A patent/DE3926440A1/en not_active Ceased
-
1990
- 1990-05-22 DK DK90109712.1T patent/DK0412250T3/en active
- 1990-05-22 AT AT90109712T patent/ATE93559T1/en not_active IP Right Cessation
- 1990-05-22 ES ES90109712T patent/ES2045642T3/en not_active Expired - Lifetime
- 1990-05-22 EP EP90109712A patent/EP0412250B1/en not_active Expired - Lifetime
- 1990-08-07 CA CA002022779A patent/CA2022779A1/en not_active Abandoned
- 1990-08-08 JP JP90211423A patent/JPH03130493A/en active Pending
- 1990-08-09 BR BR909004049A patent/BR9004049A/en unknown
- 1990-08-09 FI FI903948A patent/FI903948A0/en not_active Application Discontinuation
- 1990-08-10 KR KR1019900012280A patent/KR910004895A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| DK0412250T3 (en) | 1993-11-01 |
| EP0412250A1 (en) | 1991-02-13 |
| ATE93559T1 (en) | 1993-09-15 |
| EP0412250B1 (en) | 1993-08-25 |
| BR9004049A (en) | 1991-09-03 |
| JPH03130493A (en) | 1991-06-04 |
| DE3926440A1 (en) | 1991-02-14 |
| FI903948A0 (en) | 1990-08-09 |
| KR910004895A (en) | 1991-03-29 |
| ES2045642T3 (en) | 1994-01-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19980807 |