CA1233055A - Process and equipment for water discharge from fiber pulp - Google Patents
Process and equipment for water discharge from fiber pulpInfo
- Publication number
- CA1233055A CA1233055A CA000450864A CA450864A CA1233055A CA 1233055 A CA1233055 A CA 1233055A CA 000450864 A CA000450864 A CA 000450864A CA 450864 A CA450864 A CA 450864A CA 1233055 A CA1233055 A CA 1233055A
- Authority
- CA
- Canada
- Prior art keywords
- water discharge
- improvement according
- bend
- wire
- water
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 100
- 239000000835 fiber Substances 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 11
- 230000008569 process Effects 0.000 title claims abstract description 11
- 238000005086 pumping Methods 0.000 claims abstract description 6
- 230000006872 improvement Effects 0.000 claims description 26
- 238000001035 drying Methods 0.000 claims description 8
- 238000007599 discharging Methods 0.000 claims description 6
- 239000011888 foil Substances 0.000 claims description 5
- 239000000725 suspension Substances 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000010276 construction Methods 0.000 description 6
- 238000003825 pressing Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 229920001131 Pulp (paper) Polymers 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000007480 spreading Effects 0.000 description 2
- 238000003892 spreading Methods 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
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
- D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
- F26B13/24—Arrangements of devices using drying processes not involving heating
- F26B13/28—Arrangements of devices using drying processes not involving heating for applying pressure; for brushing; for wiping
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Paper (AREA)
Abstract
Abstract Process and twin-wire web former for water discharge from fiber pulp. The web former has two endless wires (2, 6), between which the fiber web is suppor-ted. The fiber web is formed by feeding fiber sus-pension onto the lower wire (2) in the pumping con-sistency of 0,3 - 3,5 %. The fiber web is led through a curved or a break-line shape S-bend formed by the water discharge units (8, 9) between the wires (2, 6). The water discharge itself is led between the upper wire (6). and the lower wire (2) by means of the wire stresses, as they are going over the surfaces of the water discharge units (8, 9). (Fig. 1).
Description
~33~S
1 (10 PROCESS AND EQUIPMENT OR WATER DISCHARGE FROM GIBER PULP
This invention relates to a process or water discharge from fiber pulp by means of a tuner web wormer provide with two endless wires between which the fiber web is supported, when the giber web is formed by feeding the fiber suspension onto the lower wire in a pumping consistency, preferably in a consistency of 0,3 - 3,5 I. The invention relates also to a twin-wire web wormer with two endless wires opposite to each other.
The twin-wire construction is known in the field ox the paper manufacture from several patent issues (US-patent issue 3 201 305 (Webster), US-patent issue 4 033 812 (Valet). In a paper machine it is always a question o* high running speeds, when the centrifugal force is of essential importance at the water discharge. The drying machines for pulp or for corresponding fiber web form a completely different type ox machine construction. or the drying ox pulp or other corresponding giber web (and also or the thickening) it is important that the formed web it relatively thick (over 500 g/m2, but under 2000 g/m2). The running speeds ox production machines are thus low, i.e. 30 - 120 mjmin. Then the centric ugly force is of no importance at the water discharge of the fiber web.
Prior to this invention the water discharge in the pulp drying machines took place mainly according to three different processes: in the ~ourdrinier part, in the hoisting cylinder construction (Kamyr-cylinder~
or between the wires approaching wedge-like each other by means of small diameter table rolls by pressing the fiber web uniformly and increasingly.
. , ~q33~
I
All these machines have great production restricting problems. us one of the production restricting factors on the Eourdrinier machine can ye mentioned the absorption of water to be discharged from the fiber pulp with low pressure. In the Kamyr-machine it is not possible to run -thin fiber webs. As a problem on the wedge-like approaching wires is a too strongly forced water discharge from the fiber web causing production increase problems on -the machine due to web breaking.
In one aspect of the present invention, there it provided a process for discharging water from fiber pulp, comprising the steps of: feeding the fiber pulp at a pumping consistency in the range of .3% to 3.5%
between two endless wires while running the wires at a low speed not higher than 120 meters per minute; forming an S-bend in the two endless wires with surfaces of at least two discharge units so to direct pressure from the two wires to the web; and independently adjusting the tension in each wire as they pass over the surfaces of the discharge units to control the amount of water being discharged.
In another aspect, this invention also provides an improvement in a pulp drying machine comprising a twin-wire web former for discharging water from fiber pulp.
The web former comprises two endless wires placed opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along the path for forming an S-bend in the path; and means for independently adjusting the stresses in each wire to control the amount of water being discharged.
In a further aspect, there is also provided a pulp drying machine comprising; two endless wires placed ~L2~3~5~
-pa-opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along the path for forming an S-bend in the path; a rubbing list positioned after each water discharge unit to collect water; a straight wire part preceding the S-bend including any one of table rolls, foil lights, suction boxes or a combination of same; means for feeding onto the straight wire part a fiber pulp at a pumping lo consistency in the range of .3% to 3.5%; and tension rollers for independently adjusting the stresses in each wire to control the amount of water being discharged from said fiber pulp.
The process indicated in this invention is characterized in that the fiber web is led between the wires through a curved or break-line shape S-bend formed by the water discharge units and the water discharge itself is controlled between the upper and lower wire by wire stresses, always when going over the water discharge unit surfaces. The twin-wire web former indicated in this invention is characterized in that the wires are going through a curved or break-line shape S bend formed by the water discharge units and that the stress of the upper and lower wire is adjustable.
m the twin-wire web former of this invention the fiber slurry, e.g., pulp mechanical wood pulp, -therm-mechanical pulp, CAMP etc., is fed between two wires and the water discharge from the web is controlled in a machine part formed by the rolls and the water discharge I lists by means of a wire stress. The fiber slurry is fed in a uniform layer onto a so called forming wire.
The indeed consistency can vary widely within the range of 0.3 - 3.5%. In a twin-wire web wormer the upper wire serves to bring hydraulic pressure mechanically onto the web. The pressure is created by wire stress r when the wires are curving above the water discharge roll or the water discharge unit.
~.~;33~
In order to make the water discharge more e~ectiv0, the tuners can make one or several bends on the discharge rolls or on the water discharge units hollowing each other.
With the web former indicated in this invention it is possible to avoid all the problem of the above mentioned, earlier known machines. The water discharge can be adjusted by the stress of both wires, which are adjustable independent of each other. Since it is a question of a free water discharge between two wires, the breaking of fiber web to restrict the increase of production cannot happen. This invention makes it possible to control the water discharge from thick fiber webs without any production restricting problems. The invention makes it possible to get free water out of the fiber web very advantageously by aid of wire stresses and forces caused by them. On the present-day fourdrinier machines much energy is used to produce underpricer, whereas for the machine of this invention the needed energy amount is much smaller.
The machine indicated in this invention can be used Ida. for the modernization of fourdrinier machines, since it gives man advantage because of it reduced energy consumption and increased reliability in running.
The water discharge in the machine indicated in the invention is usually made so that the upper wire approaches the lower wire coming from a longer distance in a small, e.g. under 25, preferably under 15 acute angle. Water of fiber slurry is pressed in a uniformly and slowly narrowing wedge both through the upper wire and the lower wire.
~-~33~
Since the upper and the lower wire are usually curving downwards, the water discharged through the wires can be transferred to a chute dragging the upper wire and to a water discharge unit forming an arch to the lower wire usually to an open roll construction. A very open roll construction has been used with a good success, since it admits water to slow out through the wire without counter pressure.
The curving of the lower wire it adjusted by selecting a curving radius (usually a roll diameter) or the water discharge unit or by positioning the next roll for the preceding roll. In the machine indicated in this invention it is advantageous to make the first curving downwards, since then it is possible to get the greatest water amount out of the fiber web by means of gravity force. In the next bends the water discharge force can be increased by the change of stress, curving radius or contact angles of wires, either each separately or all ox them together. The desired final result will be usually reached in the S-band formed by two rolls.
The important process variables are the Titan of the upper and lower wire. Upending on the fiber type the number of water discharge units and diameters ox evil. rolls can vary. By using several stages it is possible to increase the drying machine speed with no damage caused to the wire. With more S-bends between the wires even the fiber webs, which are difficult to infiltrate, will reach an adequate dryness.
In the machine indicated in the invention a conventional fourdrinier wire can be used as a front part, in which the water discharge can take place on the table rolls, the water discharge lists, on wet suction boxes or the suction boxes. A too high dryness before the twin-wire unit is of no use, since the machine of this invention is capable to increase the fiber web dryness more than 20 in the S-bend, even if the output level is under 2 I.
~L~q33q~; 5 The machine indicated in the invention it cleared up with schematic drawings.
-jig. 1 shows a usual machine indicated in the invention, in Fig. 2 one press it added to the machine indicated in the inverttior~t in Fig. a particular press roll pair is put to the machine indicated in the invention in jig. 4 are indicated various possibilities to form , a curving surface of water discharge unite and in Fig. 5 are indicated various S-bend possibilities.
jig. 1 shows a twin wire machine, which includes a pulp spreading unit or head box 1, from which the fiber pulp is spread onto the lower wire 2.
There can also be placed under the lower wire various water discharge alternatives, table rolls 3, foil list 4 and suction boxes 5. The upper wire 6 approaches the lower wire in a small angle ~.
The wire follows the water discharge unit 8 at the angle 1. The size of the angle 1 can be changed by means owe a wire guide roll 7.
The upper wire and the lower wire are curving around the open water discharge unit 8 causing the pressing of water from the giber web both upwards and down-wards. The water gone through the upper wire it discharged to the chute 12 dragging from the top of wire. The water gone through the lower wire is led into the curving water discharge unit 8 and from there further to the water circulation system.
After the first bend the following bend is formed with a new water discharge unit 9 (normally a roll).
The outgoing water it led with the dragging unit 13 out of the wire. By means of roll 14 the Sue of the angle I can be changed, at which the wire hollows the water discharge unit 9.
Lucy 6 Depending on the fiber slurry and its features it is possible to continue the water discharge with new bends as indicated more closely in Fig. 5.
The water discharge in the Spend is controlled by the tightness of the upper wire 6 and the lower wire
1 (10 PROCESS AND EQUIPMENT OR WATER DISCHARGE FROM GIBER PULP
This invention relates to a process or water discharge from fiber pulp by means of a tuner web wormer provide with two endless wires between which the fiber web is supported, when the giber web is formed by feeding the fiber suspension onto the lower wire in a pumping consistency, preferably in a consistency of 0,3 - 3,5 I. The invention relates also to a twin-wire web wormer with two endless wires opposite to each other.
The twin-wire construction is known in the field ox the paper manufacture from several patent issues (US-patent issue 3 201 305 (Webster), US-patent issue 4 033 812 (Valet). In a paper machine it is always a question o* high running speeds, when the centrifugal force is of essential importance at the water discharge. The drying machines for pulp or for corresponding fiber web form a completely different type ox machine construction. or the drying ox pulp or other corresponding giber web (and also or the thickening) it is important that the formed web it relatively thick (over 500 g/m2, but under 2000 g/m2). The running speeds ox production machines are thus low, i.e. 30 - 120 mjmin. Then the centric ugly force is of no importance at the water discharge of the fiber web.
Prior to this invention the water discharge in the pulp drying machines took place mainly according to three different processes: in the ~ourdrinier part, in the hoisting cylinder construction (Kamyr-cylinder~
or between the wires approaching wedge-like each other by means of small diameter table rolls by pressing the fiber web uniformly and increasingly.
. , ~q33~
I
All these machines have great production restricting problems. us one of the production restricting factors on the Eourdrinier machine can ye mentioned the absorption of water to be discharged from the fiber pulp with low pressure. In the Kamyr-machine it is not possible to run -thin fiber webs. As a problem on the wedge-like approaching wires is a too strongly forced water discharge from the fiber web causing production increase problems on -the machine due to web breaking.
In one aspect of the present invention, there it provided a process for discharging water from fiber pulp, comprising the steps of: feeding the fiber pulp at a pumping consistency in the range of .3% to 3.5%
between two endless wires while running the wires at a low speed not higher than 120 meters per minute; forming an S-bend in the two endless wires with surfaces of at least two discharge units so to direct pressure from the two wires to the web; and independently adjusting the tension in each wire as they pass over the surfaces of the discharge units to control the amount of water being discharged.
In another aspect, this invention also provides an improvement in a pulp drying machine comprising a twin-wire web former for discharging water from fiber pulp.
The web former comprises two endless wires placed opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along the path for forming an S-bend in the path; and means for independently adjusting the stresses in each wire to control the amount of water being discharged.
In a further aspect, there is also provided a pulp drying machine comprising; two endless wires placed ~L2~3~5~
-pa-opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along the path for forming an S-bend in the path; a rubbing list positioned after each water discharge unit to collect water; a straight wire part preceding the S-bend including any one of table rolls, foil lights, suction boxes or a combination of same; means for feeding onto the straight wire part a fiber pulp at a pumping lo consistency in the range of .3% to 3.5%; and tension rollers for independently adjusting the stresses in each wire to control the amount of water being discharged from said fiber pulp.
The process indicated in this invention is characterized in that the fiber web is led between the wires through a curved or break-line shape S-bend formed by the water discharge units and the water discharge itself is controlled between the upper and lower wire by wire stresses, always when going over the water discharge unit surfaces. The twin-wire web former indicated in this invention is characterized in that the wires are going through a curved or break-line shape S bend formed by the water discharge units and that the stress of the upper and lower wire is adjustable.
m the twin-wire web former of this invention the fiber slurry, e.g., pulp mechanical wood pulp, -therm-mechanical pulp, CAMP etc., is fed between two wires and the water discharge from the web is controlled in a machine part formed by the rolls and the water discharge I lists by means of a wire stress. The fiber slurry is fed in a uniform layer onto a so called forming wire.
The indeed consistency can vary widely within the range of 0.3 - 3.5%. In a twin-wire web wormer the upper wire serves to bring hydraulic pressure mechanically onto the web. The pressure is created by wire stress r when the wires are curving above the water discharge roll or the water discharge unit.
~.~;33~
In order to make the water discharge more e~ectiv0, the tuners can make one or several bends on the discharge rolls or on the water discharge units hollowing each other.
With the web former indicated in this invention it is possible to avoid all the problem of the above mentioned, earlier known machines. The water discharge can be adjusted by the stress of both wires, which are adjustable independent of each other. Since it is a question of a free water discharge between two wires, the breaking of fiber web to restrict the increase of production cannot happen. This invention makes it possible to control the water discharge from thick fiber webs without any production restricting problems. The invention makes it possible to get free water out of the fiber web very advantageously by aid of wire stresses and forces caused by them. On the present-day fourdrinier machines much energy is used to produce underpricer, whereas for the machine of this invention the needed energy amount is much smaller.
The machine indicated in this invention can be used Ida. for the modernization of fourdrinier machines, since it gives man advantage because of it reduced energy consumption and increased reliability in running.
The water discharge in the machine indicated in the invention is usually made so that the upper wire approaches the lower wire coming from a longer distance in a small, e.g. under 25, preferably under 15 acute angle. Water of fiber slurry is pressed in a uniformly and slowly narrowing wedge both through the upper wire and the lower wire.
~-~33~
Since the upper and the lower wire are usually curving downwards, the water discharged through the wires can be transferred to a chute dragging the upper wire and to a water discharge unit forming an arch to the lower wire usually to an open roll construction. A very open roll construction has been used with a good success, since it admits water to slow out through the wire without counter pressure.
The curving of the lower wire it adjusted by selecting a curving radius (usually a roll diameter) or the water discharge unit or by positioning the next roll for the preceding roll. In the machine indicated in this invention it is advantageous to make the first curving downwards, since then it is possible to get the greatest water amount out of the fiber web by means of gravity force. In the next bends the water discharge force can be increased by the change of stress, curving radius or contact angles of wires, either each separately or all ox them together. The desired final result will be usually reached in the S-band formed by two rolls.
The important process variables are the Titan of the upper and lower wire. Upending on the fiber type the number of water discharge units and diameters ox evil. rolls can vary. By using several stages it is possible to increase the drying machine speed with no damage caused to the wire. With more S-bends between the wires even the fiber webs, which are difficult to infiltrate, will reach an adequate dryness.
In the machine indicated in the invention a conventional fourdrinier wire can be used as a front part, in which the water discharge can take place on the table rolls, the water discharge lists, on wet suction boxes or the suction boxes. A too high dryness before the twin-wire unit is of no use, since the machine of this invention is capable to increase the fiber web dryness more than 20 in the S-bend, even if the output level is under 2 I.
~L~q33q~; 5 The machine indicated in the invention it cleared up with schematic drawings.
-jig. 1 shows a usual machine indicated in the invention, in Fig. 2 one press it added to the machine indicated in the inverttior~t in Fig. a particular press roll pair is put to the machine indicated in the invention in jig. 4 are indicated various possibilities to form , a curving surface of water discharge unite and in Fig. 5 are indicated various S-bend possibilities.
jig. 1 shows a twin wire machine, which includes a pulp spreading unit or head box 1, from which the fiber pulp is spread onto the lower wire 2.
There can also be placed under the lower wire various water discharge alternatives, table rolls 3, foil list 4 and suction boxes 5. The upper wire 6 approaches the lower wire in a small angle ~.
The wire follows the water discharge unit 8 at the angle 1. The size of the angle 1 can be changed by means owe a wire guide roll 7.
The upper wire and the lower wire are curving around the open water discharge unit 8 causing the pressing of water from the giber web both upwards and down-wards. The water gone through the upper wire it discharged to the chute 12 dragging from the top of wire. The water gone through the lower wire is led into the curving water discharge unit 8 and from there further to the water circulation system.
After the first bend the following bend is formed with a new water discharge unit 9 (normally a roll).
The outgoing water it led with the dragging unit 13 out of the wire. By means of roll 14 the Sue of the angle I can be changed, at which the wire hollows the water discharge unit 9.
Lucy 6 Depending on the fiber slurry and its features it is possible to continue the water discharge with new bends as indicated more closely in Fig. 5.
The water discharge in the Spend is controlled by the tightness of the upper wire 6 and the lower wire
2 a well;as~ib~ the curving radius of the water discharge units 8 and 9 and by the contact angle .
While the tightness ox the upper wire 6 is inquired also the pressing thus caused against the water discharge unit 8 grow. The increased tightness of the lower wire 2 will increase the pressing thus caused against the water discharge unit accordingly.
the equipment indicated in the invention can be placed into connection with the ~ourdrinier wire ox the pulp machine either together with the press 10 (Fig. 2) or without it. The press in Fig. 2 it for-mod by fitting the press roll 10 against the roll 14 guiding the S-bend. By placing the press 11 (Fig. 3) into connection with two wire the equipment indict-ted in the invention makes it possibly to increase the dryness of the fiber web much over the usual level of 22 to 27 I.
It desired the lower wire 2 can be tilted between the pulp spreading unit 1 and the water discharge unit 8 so that it is inclined to either direction.
So it is possible to get the Spend fit for the fiber type.
In Fig. 1-3 the transfer directions of tension rolls are marked with arrows. my transferring the rolls the tightness of wires can be adjusted.
Fig. 4 shows various alternative of the water disk charge units 8. Fig. pa shows a stationary fixed perforated level, in which downwards discharging water goes through the level holes under it.
While the tightness ox the upper wire 6 is inquired also the pressing thus caused against the water discharge unit 8 grow. The increased tightness of the lower wire 2 will increase the pressing thus caused against the water discharge unit accordingly.
the equipment indicated in the invention can be placed into connection with the ~ourdrinier wire ox the pulp machine either together with the press 10 (Fig. 2) or without it. The press in Fig. 2 it for-mod by fitting the press roll 10 against the roll 14 guiding the S-bend. By placing the press 11 (Fig. 3) into connection with two wire the equipment indict-ted in the invention makes it possibly to increase the dryness of the fiber web much over the usual level of 22 to 27 I.
It desired the lower wire 2 can be tilted between the pulp spreading unit 1 and the water discharge unit 8 so that it is inclined to either direction.
So it is possible to get the Spend fit for the fiber type.
In Fig. 1-3 the transfer directions of tension rolls are marked with arrows. my transferring the rolls the tightness of wires can be adjusted.
Fig. 4 shows various alternative of the water disk charge units 8. Fig. pa shows a stationary fixed perforated level, in which downwards discharging water goes through the level holes under it.
3 7 Fig. 4b shows a mounded level, which is an enclosed, break-line shape web. The level can also be slightly curved. The downward discharging water is led out mainly from the front ox the water discharge lit.
Fig. 4c shows that a smooth enclosed roll is used or this purpose As indicated in Fogged two water di~s~harge~lists are pla¢ed~underithe~wlres to lead them along the break-line. Water is discharged from the front of these water discharge lists.
Fig. ye shows a grooved roll through the transverse grooves of which water is going out.
The application shown in Fig. I is an open roll, on the surface of which there is an outwards open cell construction, through which water is led out.
Except transverse grooves the grooved roll can also have grooves going to another direction. It is also possible to use crosswise going grooves, when swooper-lo rises remain between the grooves on the roll.
Fig. 4c shows that a smooth enclosed roll is used or this purpose As indicated in Fogged two water di~s~harge~lists are pla¢ed~underithe~wlres to lead them along the break-line. Water is discharged from the front of these water discharge lists.
Fig. ye shows a grooved roll through the transverse grooves of which water is going out.
The application shown in Fig. I is an open roll, on the surface of which there is an outwards open cell construction, through which water is led out.
Except transverse grooves the grooved roll can also have grooves going to another direction. It is also possible to use crosswise going grooves, when swooper-lo rises remain between the grooves on the roll.
Claims (29)
- The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
l. In a pulp drying machine, the improvement comprising a twin-wire web former for discharging water from fiber pulp, said web former comprising: two endless wires placed opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along said path for forming an S-bend in said path; and means for independently adjusting the stresses in each wire to control the amount of water being discharged. - 2. The improvement according to claim 1, wherein the means for independently adjusting the stresses is a tension roller for each wire.
- 3. The improvement according to claim 1 wherein the curving radius of the water discharge units is within the range of 25 - 1000 mm.
- 4. The improvement according to claim 1, wherein said wires comprise upper and lower wires, with the lower wire being horizontal preceding the S bend.
- 5. The improvement according to claim 1, wherein the water discharge units are freely rotating rolls.
- 6. The improvement according to claim 1, wherein at least one of the water discharge units is a water discharge list.
- 7. The improvement according to claim 1, wherein the water discharge unit is a perforated stationary surface.
- 8. The improvement according to claim 1, wherein a rubbing list is positioned after the water discharge units to collect water.
- 9. The improvement according claim 1, wherein water discharge is provided before the S-bend on a straight wire part by a member selected from the group consisting of table rolls, foil lists, suction boxes or a combination of same.
- 10. The improvement according to claim 1, wherein a press roll pair is connected to the S-bend.
- 11. The improvement according to claim 1, wherein a press roll pair has been arranged after the S-bend.
- 12. The improvement according to claim 1, wherein there is at least one additional bend after the S-bend.
- 13. The improvement according to claim 3, wherein said wires comprise upper and lower wires, with the lower wire being horizontal preceding the S-bend.
- 14. The improvement according to claim 3, wherein the water discharge units are freely rotating rolls.
- 15. The improvement according to claim 4, wherein the water discharge units are freely rotating rolls.
- 16. The improvement according to claim 3, wherein at least one of the water discharge units is a water discharge list.
- 17. The improvement according to claim 3, wherein the water discharge unit is a perforated stationary surface.
- 18. The improvement according to claim 3, wherein a rubbing list is positioned after the water discharge units to collect water.
- 19. The improvement according to claim 3, wherein water discharge has been arranged before the S-bend on a straight wire part by a member selected from the group consisting of table rolls, foil lists, suction boxes or a combination of same.
- 20. The improvement according to claim 3, wherein a press roll pair is connected to the S-bend.
- 21. process for discharging water from fiber pulp, comprising the steps of: feeding the fiber pulp at a pumping consistency in the range of .3% to 3.5%
between two endless wires while running the wires at a low speed not higher than 120 meters per minute; forming an S-bend in the two endless wires with surfaces of at least two discharge units so to direct pressure from the two wires to the web; and independently adjusting the tension in each wire as they pass over the surfaces of the discharge units to control the amount of water being discharged. - 22. The process of claim 21, wherein said S-bend is curved.
- 23. The process of claim 21, wherein said S-bend is break-line shaped.
- 24. The improvement according to claim 5, wherein at least one of the rolls is cell-surfaced.
- 25. The improvement according to claim 5, wherein at least one of the rolls is grooved.
- 26. The improvement according to claim 5, wherein at least one of the rolls is smooth.
- 27. The improvement according to claim 6, wherein the water discharge list is slightly curving in shape.
- 28. The improvement according to claim 6, wherein the water discharge list is break-line in shape.
- 29. A pulp drying machine comprising: two endless wires placed opposite to each other along a path and driven to run at a low running speed of not higher than 120 meters per minute; water discharge units positioned along said path for forming an S-bend in said path; a rubbing list positioned after each water discharge unit to collect water; a straight wire part preceding the S-bend including any one of table rolls, foil lists, suction boxes or a combination of same; means for feeding onto said straight wire part a fiber pulp at a pumping consistency in the range of .3% to 3.5%; and tension rollers for independently adjusting the stresses in each wire to control the amount of water being discharged from said fiber pulp.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI831275A FI831275L (en) | 1983-04-15 | 1983-04-15 | FOERFARANDE OCH ANORDNING FOER AVLAEGSNING AV VAETSKA UR FIBERMASSA. |
| FI831275 | 1983-04-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1233055A true CA1233055A (en) | 1988-02-23 |
Family
ID=8517059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000450864A Expired CA1233055A (en) | 1983-04-15 | 1984-03-29 | Process and equipment for water discharge from fiber pulp |
Country Status (6)
| Country | Link |
|---|---|
| BR (1) | BR8401772A (en) |
| CA (1) | CA1233055A (en) |
| DE (1) | DE3414087A1 (en) |
| FI (1) | FI831275L (en) |
| SE (1) | SE8402019L (en) |
| ZA (1) | ZA842793B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001051703A1 (en) * | 2000-01-14 | 2001-07-19 | Valmet Corporation | Method and apparatus to improve the formation of a paper of paperboard web by pre-pressing in a twin-wire former |
| DE102007000036A1 (en) * | 2007-01-25 | 2008-07-31 | Voith Patent Gmbh | Process for dewatering pulp and dewatering machine for carrying out the process |
| CN110631331A (en) * | 2019-06-11 | 2019-12-31 | 温州乐发教育科技有限公司 | Magnetic adhesive tape adhesion water removing device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3201305A (en) * | 1962-11-05 | 1965-08-17 | David R Webster | Sheet forming method and apparatus |
| FI313874A (en) * | 1974-10-25 | 1976-04-26 | Valmet Oy | |
| AT379622B (en) * | 1980-11-26 | 1986-02-10 | Escher Wyss Gmbh | PAPER MACHINE WITH TWO MOVABLE WATERPROOF DRAINAGE BELTS, e.g. SEVEN |
-
1983
- 1983-04-15 FI FI831275A patent/FI831275L/en not_active Application Discontinuation
-
1984
- 1984-03-29 CA CA000450864A patent/CA1233055A/en not_active Expired
- 1984-04-11 SE SE8402019A patent/SE8402019L/en not_active Application Discontinuation
- 1984-04-12 BR BR8401772A patent/BR8401772A/en unknown
- 1984-04-13 ZA ZA842793A patent/ZA842793B/en unknown
- 1984-04-13 DE DE19843414087 patent/DE3414087A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| BR8401772A (en) | 1984-11-20 |
| SE8402019L (en) | 1984-10-16 |
| ZA842793B (en) | 1984-11-28 |
| FI831275A0 (en) | 1983-04-15 |
| DE3414087A1 (en) | 1984-10-18 |
| SE8402019D0 (en) | 1984-04-11 |
| FI831275L (en) | 1984-10-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20050223 |