CA2192832A1 - Forming arrangement for the sheet-forming region of a paper or cardboard machine - Google Patents
Forming arrangement for the sheet-forming region of a paper or cardboard machineInfo
- Publication number
- CA2192832A1 CA2192832A1 CA 2192832 CA2192832A CA2192832A1 CA 2192832 A1 CA2192832 A1 CA 2192832A1 CA 2192832 CA2192832 CA 2192832 CA 2192832 A CA2192832 A CA 2192832A CA 2192832 A1 CA2192832 A1 CA 2192832A1
- Authority
- CA
- Canada
- Prior art keywords
- wire
- strip
- forming arrangement
- fact
- dewatering
- 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
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/48—Suction apparatus
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/36—Guiding mechanisms
- D21F1/38—Pads
-
- 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
- D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
Landscapes
- Paper (AREA)
Abstract
The invention concerns a forming arrangement in the sheet-forming region of a paper or cardboard machine having at least one rotating, endless wire (3) and at least one dewatering strip (4-7). The dewatering strip is inclined in the direction opposite to the direction of travel of the wire.
Description
. ~
FORNING ARRANGEMENT FOR THE 5~EET-FORMING REGION
OF A PAPER OR CARDBOARD N~CHINE
The present invention is related to a forming arrangement in accordance with the preamble to Claim 1.
Forming arrangements of this type are frequently used in twin-wire paper machines. When they are continuous and have several dewatering strips, they are also known as forming shoes. It has proven suitable to provide a forming device with one or more strips which are adjustable in such a manner that their position can be changed even during operation and can be operated with an adjustable pressure with respect to the wire. These strips re6t at their bottom against a pres6ure tubing and are thus resilient with respect to the wire, i . e. they are resiliently mounted. In connection with 6aid twin-wire former6, a forming device having one or more strips i6 al60 frequently used on the opposite side, and therefore on the opposite wire. They are then generally no longer adjustable in normal operation.
Forming shoes with adjustable strips are, however, also pos6ible in the region of endless wires, particularly in order to improve the uniformity of the removal of water.
For technical and structural reasons, individually adjustable dewatering strips take up a larger amount of space than non-displaceable ones. The reason for this resides in the additional parts and anchorings which are n~ C ru~y in order to ~s~llre a pr~ci~ guiding and fiYing of the strips .
2t 92~32 ~ .
which contact the wire. Furthermore, a device for the adjustable displacement of the strip must be installed therein . If such a f orming device is used in the vicinity of a roll, then there is np~pcsArily a distance between the place where the wire leaves the roll and the place where the wire comes downstream against the f irst displaceable strip .
This distance cannot be less than a minimum amount because of structural circumstances related to the aforementioned amount of space required by the displaceable dewatering strips. In the region of this distance, the wire or twin wire is imperfectly gulded or the amount of water to be stripped off is too great for the first strip.
The task now arises of developing a f orming device in such a manner that it has dewatering strips which are adjustable individually or in pairs, the region of action of which extends as close as possible to a roll.
This object is achieved by the features set forth in the body of Claim 1.
The following advantages, in particular, are obtained by the development of the forming device in accordance with the invention:
Since the selection of the angle of attack leads to an oblique position of the strip in the direction towards the roll, it is structurally more easily possible to bring the area of contact of the dewatering strip with the ~ 1 ~2832 . ~
corresponding paper-machine wire closer to the roll.
In this way, namely, the place upstream of the anchoring of the dewatering strip, which must naturally lie at a distance from the roll, can be more easily bridged over. Due to this shorter distance between the run-of f line of the wire from the roll and the contact area of the dewatering strip, the length over which the wire is unguided in disadvantageous manner i6 also smaller. It is furthl ~ advantageous that the forming action of the first dewatering strip is earlier and thus, with a lower consistency of the stock, is active in the stock suspension lying on the wire or between the wires.
Due to the oblique position of the strip, a better discharge of the water which has collected at the front edge of the strip, as is desired in many cases, can be assured.
The substantial load on the guides of adjustable strips as a result of the frictional forces between strip and wire is reduced. With increasing inclination, the frictional force acting in the direction of travel of the wire between the wire and the strip is divided namely into an increasingly smaller component perpendicular to the direction of ad~ustment and an increasingly larger component in the direction of adjustment. Therefore, the guides are less acted on by moments of f orce .
The invention and its advantages will be explained with reference to the drawings, in which:
. ~ 2192832 Fig. 1 shows the forming device of the invention in a twin-wire former (in part);
Fig. 2 shows it in an endless-wire arrangement, Fig. 3 shows another special development.
The forming unit in Fig. 1 belongs to a twin-wire former in which the two wires 3 and 3 ' come together on the roll 2, namely a forming roll, a jet of suspension being pumped from a headbox 12 into the wire slot formed thereby.
The upstream part of the forming device 1 of the invention is E~hown in the figure. It contains a plurality of dewatering strips 4, 5, 6 and 7, which are guided in an anchoring 10. Each of the dewatering strips 4, 5, 6 and 7 is movable in its guide in the adjustment direction, indicated by dashed line E, E', E' ' or E' ' ', relative to the anchoring lo. The force necessary for the adjustment of load can be produced, for instance, by a pneumatlc ~es:,uLe element 11.
of course, there are also other known possibilities. The adjustable dewatering strip 4 lying closest to the roll 2 has the angle of attack ~ with respect to the direction of travel of the wire 3 contacted by it, said angle being greater than go degrees. The one leg of this angle of attack therefore lies in the plane of the wire in front of the region of action of the dewatering strip 4 in question. In this connection, it is assumed that, in actual practice, the deviations in the direction of travel of the wire from a 21 928~2 . ~
straight line as a result of meandering of the wire are relatively slight.
It can also be noted that, in the form shown here, the angle of attack of the strip 5 arranged next downstream is smaller than that of the strip 4. The same is true with respect to the strips 6 and 5 as well as 7 and 6. The strips can, however, in other cases also be developed, as a whole or in groups, parallel to each other. On the upper wire 3 ' there are, in the forming region, a plurality of forming strips 9 which are not adjustable in operation. They cooperate with the adjustable strips of the lower wire. In this connection, ~r~n~;ng on the requirements, the wires are conducted in meander shape, or corresponding dewatering strips are directly opposite each other. Fre~auently it is also favorable to select the number of strips present in the lower wire less than the number present in the upper wire.
As shown in Fig. 2, the ~mh~lir~nt of a forming device of this type in accordance with the invention is possible also in the case of an endless-wire former.
There can be noted therein the endless wire 3, which is conducted here over a roll 2', developed as breast roll, in the region of a headbox 12'. A jet of suspension emerges in known manner from the headbox, it passing onto the wire 3 in the initial region of the f orming path . The layer thus deposited on the wire 3 comes in succession against the 2 ~ 92832 . ~
dewatering 6trips 4, 5, 6, 7 and further. In this connection, once again, the dewatering strip 4 located nearest the roll 2 ' is so developed that its direction of adjustment E to the wire 3 forms an angle of attack ~ of more than 90 degrees.
The corrP~pnn~9 i ng angle of the next ledge downstream is smaller and that of the following downstream strip 6 again also smaller. It is not shown, but it is readily possible that only the dewatering strip 4 lying closest to the roll 2 ' has an angle of attack ~ of more than 90 degrees, while all following downstream dewatering strips can have, for instance, the same angle of 90 degrees. As already stated, the decisive advantage of the invention is that the distance between the line on which the wire 3 runs off from the roll 2 ' and the region in which the f irst dewatering strip 4 contacts the wire is as small as possible.
In ~any cases, it is f avorable to connect the displaceable dewatering ledges to each other by, for instance, at least one yoke 13 (Fig. 3~ so that they are therefore displaceable in pairs in a common direction of adjustment E or E' to the wire. This pmhorlimPnt shown here on the endless-wire former is, of course, possible also on the twin wire. In addition to the structural simplification, the advantage is thereby obtained that the tilting moments acting on the dewatering strips can be more easily intercepted .
FORNING ARRANGEMENT FOR THE 5~EET-FORMING REGION
OF A PAPER OR CARDBOARD N~CHINE
The present invention is related to a forming arrangement in accordance with the preamble to Claim 1.
Forming arrangements of this type are frequently used in twin-wire paper machines. When they are continuous and have several dewatering strips, they are also known as forming shoes. It has proven suitable to provide a forming device with one or more strips which are adjustable in such a manner that their position can be changed even during operation and can be operated with an adjustable pressure with respect to the wire. These strips re6t at their bottom against a pres6ure tubing and are thus resilient with respect to the wire, i . e. they are resiliently mounted. In connection with 6aid twin-wire former6, a forming device having one or more strips i6 al60 frequently used on the opposite side, and therefore on the opposite wire. They are then generally no longer adjustable in normal operation.
Forming shoes with adjustable strips are, however, also pos6ible in the region of endless wires, particularly in order to improve the uniformity of the removal of water.
For technical and structural reasons, individually adjustable dewatering strips take up a larger amount of space than non-displaceable ones. The reason for this resides in the additional parts and anchorings which are n~ C ru~y in order to ~s~llre a pr~ci~ guiding and fiYing of the strips .
2t 92~32 ~ .
which contact the wire. Furthermore, a device for the adjustable displacement of the strip must be installed therein . If such a f orming device is used in the vicinity of a roll, then there is np~pcsArily a distance between the place where the wire leaves the roll and the place where the wire comes downstream against the f irst displaceable strip .
This distance cannot be less than a minimum amount because of structural circumstances related to the aforementioned amount of space required by the displaceable dewatering strips. In the region of this distance, the wire or twin wire is imperfectly gulded or the amount of water to be stripped off is too great for the first strip.
The task now arises of developing a f orming device in such a manner that it has dewatering strips which are adjustable individually or in pairs, the region of action of which extends as close as possible to a roll.
This object is achieved by the features set forth in the body of Claim 1.
The following advantages, in particular, are obtained by the development of the forming device in accordance with the invention:
Since the selection of the angle of attack leads to an oblique position of the strip in the direction towards the roll, it is structurally more easily possible to bring the area of contact of the dewatering strip with the ~ 1 ~2832 . ~
corresponding paper-machine wire closer to the roll.
In this way, namely, the place upstream of the anchoring of the dewatering strip, which must naturally lie at a distance from the roll, can be more easily bridged over. Due to this shorter distance between the run-of f line of the wire from the roll and the contact area of the dewatering strip, the length over which the wire is unguided in disadvantageous manner i6 also smaller. It is furthl ~ advantageous that the forming action of the first dewatering strip is earlier and thus, with a lower consistency of the stock, is active in the stock suspension lying on the wire or between the wires.
Due to the oblique position of the strip, a better discharge of the water which has collected at the front edge of the strip, as is desired in many cases, can be assured.
The substantial load on the guides of adjustable strips as a result of the frictional forces between strip and wire is reduced. With increasing inclination, the frictional force acting in the direction of travel of the wire between the wire and the strip is divided namely into an increasingly smaller component perpendicular to the direction of ad~ustment and an increasingly larger component in the direction of adjustment. Therefore, the guides are less acted on by moments of f orce .
The invention and its advantages will be explained with reference to the drawings, in which:
. ~ 2192832 Fig. 1 shows the forming device of the invention in a twin-wire former (in part);
Fig. 2 shows it in an endless-wire arrangement, Fig. 3 shows another special development.
The forming unit in Fig. 1 belongs to a twin-wire former in which the two wires 3 and 3 ' come together on the roll 2, namely a forming roll, a jet of suspension being pumped from a headbox 12 into the wire slot formed thereby.
The upstream part of the forming device 1 of the invention is E~hown in the figure. It contains a plurality of dewatering strips 4, 5, 6 and 7, which are guided in an anchoring 10. Each of the dewatering strips 4, 5, 6 and 7 is movable in its guide in the adjustment direction, indicated by dashed line E, E', E' ' or E' ' ', relative to the anchoring lo. The force necessary for the adjustment of load can be produced, for instance, by a pneumatlc ~es:,uLe element 11.
of course, there are also other known possibilities. The adjustable dewatering strip 4 lying closest to the roll 2 has the angle of attack ~ with respect to the direction of travel of the wire 3 contacted by it, said angle being greater than go degrees. The one leg of this angle of attack therefore lies in the plane of the wire in front of the region of action of the dewatering strip 4 in question. In this connection, it is assumed that, in actual practice, the deviations in the direction of travel of the wire from a 21 928~2 . ~
straight line as a result of meandering of the wire are relatively slight.
It can also be noted that, in the form shown here, the angle of attack of the strip 5 arranged next downstream is smaller than that of the strip 4. The same is true with respect to the strips 6 and 5 as well as 7 and 6. The strips can, however, in other cases also be developed, as a whole or in groups, parallel to each other. On the upper wire 3 ' there are, in the forming region, a plurality of forming strips 9 which are not adjustable in operation. They cooperate with the adjustable strips of the lower wire. In this connection, ~r~n~;ng on the requirements, the wires are conducted in meander shape, or corresponding dewatering strips are directly opposite each other. Fre~auently it is also favorable to select the number of strips present in the lower wire less than the number present in the upper wire.
As shown in Fig. 2, the ~mh~lir~nt of a forming device of this type in accordance with the invention is possible also in the case of an endless-wire former.
There can be noted therein the endless wire 3, which is conducted here over a roll 2', developed as breast roll, in the region of a headbox 12'. A jet of suspension emerges in known manner from the headbox, it passing onto the wire 3 in the initial region of the f orming path . The layer thus deposited on the wire 3 comes in succession against the 2 ~ 92832 . ~
dewatering 6trips 4, 5, 6, 7 and further. In this connection, once again, the dewatering strip 4 located nearest the roll 2 ' is so developed that its direction of adjustment E to the wire 3 forms an angle of attack ~ of more than 90 degrees.
The corrP~pnn~9 i ng angle of the next ledge downstream is smaller and that of the following downstream strip 6 again also smaller. It is not shown, but it is readily possible that only the dewatering strip 4 lying closest to the roll 2 ' has an angle of attack ~ of more than 90 degrees, while all following downstream dewatering strips can have, for instance, the same angle of 90 degrees. As already stated, the decisive advantage of the invention is that the distance between the line on which the wire 3 runs off from the roll 2 ' and the region in which the f irst dewatering strip 4 contacts the wire is as small as possible.
In ~any cases, it is f avorable to connect the displaceable dewatering ledges to each other by, for instance, at least one yoke 13 (Fig. 3~ so that they are therefore displaceable in pairs in a common direction of adjustment E or E' to the wire. This pmhorlimPnt shown here on the endless-wire former is, of course, possible also on the twin wire. In addition to the structural simplification, the advantage is thereby obtained that the tilting moments acting on the dewatering strips can be more easily intercepted .
Claims (11)
OF A PAPER OR CARDBOARD MACHINE
1. A forming arrangement (1, 1') for the sheet-forming region of a paper or cardboard machine having at least one rotating endless wire (3), which forming arrangement (1, 1') extends with its downstream region, as seen in the direction of travel of the wire, up into the vicinity of an upstream roll (2, 2') which is located within the same wire (3), the forming arrangement (1, 1') being provided with at least one dewatering strip (4, 5, 6, 7) extending transversely essentially over the entire width of the wire, which strip is movable and adjustable in controlled manner with respect to the wire (3), characterized by the fact that at least the dewatering strip (4) lying closest to the roll (2, 2') is movable in an adjustment direction (E) and is resiliently supported, it having an angle of attack (alpha) of more than 90 degrees with respect to the direction of travel of the wire (3).
2. A forming arrangement according to Claim 1, characterized by the fact that the dewatering strip (4, 5, 6, 7) is so pressed against the wire (3) that it changes the direction of travel thereof.
3. A forming arrangement according to Claim 1 or 2, characterized by the fact that the angle of attack (alpha) is between 110 and 160 degrees.
4. A forming arrangement with (sic) according to Claim 1, 2, or 3 having at least two dewatering strips lying one behind the other in the direction of travel of the wire, characterized by the fact that the two dewatering strips (4, 5) lying closest to the roll (2, 2) have an angle of attack (alpha) between the corresponding adjustment direction (E, E ) and the wire which is greater on the strip (4) closest to the roll (2, 2) than on the adjacent strip ( 5 ).
5. A forming arrangement according to Claim 4, characterized by the fact that each of the dewatering strips ( 4, 5, 6, 7 ) lying one behind the other in the direction of travel of the wire has an angle of attack (alpha) between the corresponding adjustment direction (E, E, E ) and the wire (3) which is greater on the strip (4, 5, 6) closer to the roll (2, 2) than on the strip (5, 6, 7) further downstream.
6. A forming arrangement according to Claim l, 2, 3, 4 or 5, characterized by the fact that the adjustable dewatering strips (4, 5, 6, 7) are guided individually in an anchoring ( 10 ) relative to which they and in the adjustment direction (E, E, E, E ) are displaceable.
7. A forming arrangement according to Claim 6, characterized by the fact that the adjustable dewatering strips (4, 5, 6, 7) are guided in pairs in an anchoring (10) relative to which they and in the adjustment direction (E, E, E, E ) are displaceable, in which connection every two adjacent strips are rigidly connected to each other by at least one yoke ( 13 ).
8. A forming arrangement according to Claim 6 or 7, characterized by the fact that the force with which the dewatering strip (4, 5, 6, 7) moves relative to the anchoring (10) and can be pressed against the wire (3) is produced by a hydraulic or pneumatic pressure element (11).
9. A forming arrangement according to Claim 8, characterized by the fact that the pressure element (11) contains a deformable tubing which is located in the anchoring (10) below the dewatering strip (4, 5, 6, 7), extends substantially over the entire width of the wire, and is connected with a device for the supplying of a pressure fluid .
10. A forming arrangement according to Claim 6 or 7, characterized by the fact that the anchorings (10) are mounted on a common table (8).
11. A forming arrangement according to Claim 10, characterized by the fact that the table (8), in its turn, is adjustably connected to the frame of the paper machine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE29506380U DE29506380U1 (en) | 1995-04-13 | 1995-04-13 | Forming shoe for the sheet formation area of a paper or board machine |
| DE29506380.7 | 1995-04-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2192832A1 true CA2192832A1 (en) | 1996-10-17 |
Family
ID=8006849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2192832 Abandoned CA2192832A1 (en) | 1995-04-13 | 1996-04-12 | Forming arrangement for the sheet-forming region of a paper or cardboard machine |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0765417A1 (en) |
| CA (1) | CA2192832A1 (en) |
| DE (1) | DE29506380U1 (en) |
| WO (1) | WO1996032533A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102018123406B3 (en) * | 2018-09-24 | 2019-12-05 | Voith Patent Gmbh | dehydrator |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB948891A (en) * | 1961-08-30 | 1964-02-05 | Dominion Eng Works Ltd | Improvements in or relating to paper-making machines |
| FR2003470A1 (en) * | 1968-03-08 | 1969-11-07 | Bellmer Kg | |
| GB1346385A (en) * | 1972-09-09 | 1974-02-06 | Valmet Oy | Dewatering wet webs in paper-making machines |
-
1995
- 1995-04-13 DE DE29506380U patent/DE29506380U1/en not_active Expired - Lifetime
-
1996
- 1996-04-12 WO PCT/EP1996/001563 patent/WO1996032533A1/en not_active Application Discontinuation
- 1996-04-12 EP EP96914909A patent/EP0765417A1/en not_active Withdrawn
- 1996-04-12 CA CA 2192832 patent/CA2192832A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0765417A1 (en) | 1997-04-02 |
| DE29506380U1 (en) | 1995-06-08 |
| WO1996032533A1 (en) | 1996-10-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2104230A1 (en) | Twin-wire former | |
| US5211814A (en) | Wire loading device in a paper machine | |
| EP0296135A2 (en) | Hydrid former for a paper machine | |
| US5061347A (en) | Adjustable ledge for the sheet forming zone of a papermaking machine | |
| CA2034993C (en) | Forming section of a papermaking machine and method of use thereof | |
| US4557802A (en) | Apparatus for affecting a web drained on a wire | |
| CA1044931A (en) | Guide shower | |
| US5480520A (en) | Applying pressure on the web at the wire end of a paper machine | |
| EP0427691A2 (en) | Gap former in a paper machine | |
| CA2050844C (en) | Twin-wire web former in a paper machine | |
| US5552021A (en) | Method, device and arrangement for regulating the control of a transverse profile of a paper web in a paper machine | |
| EP0853703A1 (en) | Roll and blade twin-wire gap former for a paper machine | |
| US3996098A (en) | Twin-wire paper machine with common wire path controls | |
| CA1051245A (en) | A head box for a paper making machine | |
| CA2109781A1 (en) | Press section for a paper machine | |
| CA2157205C (en) | Twin-wire former | |
| KR0165862B1 (en) | Paper machine twin-wire former and dewatering device therein | |
| US3432385A (en) | Water extraction devices | |
| CA2067455A1 (en) | Stationary support device for dewatering wire | |
| CA2192832A1 (en) | Forming arrangement for the sheet-forming region of a paper or cardboard machine | |
| US5565064A (en) | Paper machine wet forming section and method of operation thereof | |
| FI100542B (en) | A paper machine hybrid former equipped with an MB unit | |
| US5248392A (en) | Sheet-forming apparatus for a twin wire paper machine with positive pulse shoe blades | |
| US5759353A (en) | Web former in a paper machine | |
| CA2123821C (en) | Web former in a paper machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |