CA2213352A1 - Press section and process for draining a watery fibrous pulp sheet - Google Patents
Press section and process for draining a watery fibrous pulp sheetInfo
- Publication number
- CA2213352A1 CA2213352A1 CA 2213352 CA2213352A CA2213352A1 CA 2213352 A1 CA2213352 A1 CA 2213352A1 CA 2213352 CA2213352 CA 2213352 CA 2213352 A CA2213352 A CA 2213352A CA 2213352 A1 CA2213352 A1 CA 2213352A1
- Authority
- CA
- Canada
- Prior art keywords
- press
- fibrous pulp
- pulp sheet
- opening
- felt belt
- 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
- 238000000034 method Methods 0.000 title claims description 16
- 230000003750 conditioning effect Effects 0.000 claims abstract description 23
- 238000009499 grossing Methods 0.000 claims description 21
- 238000001035 drying Methods 0.000 description 12
- 230000013011 mating Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003020 moisturizing effect Effects 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F3/00—Press section of machines for making continuous webs of paper
- D21F3/02—Wet presses
- D21F3/04—Arrangements thereof
- D21F3/045—Arrangements thereof including at least one extended press nip
Landscapes
- Paper (AREA)
Abstract
The press section of a paper machine dewaters a watery fibrous pulp sheet which is guided along with a continuous circulating felt belt through two sequentially-arranged press openings. The felt belt is dried by a conditioning device positioned between the two press openings, and the felt belt is again dried with the aid of another conditioning device after it exits the second press opening but before it returns to the first press opening. By quickly separating the felt belt from the watery fibrous pulp sheet after they pass through the press openings, reverse moistening of the felt belt is effectively prevented. A smooth, soft press belt preferably guides the fibrous pulp sheet between the two press openings.
Description
CA 022l33~2 l997-08-l9 ,~j P15762.SCA
PRESS SECTION AND PROCESS FOR DRAINING A WATERY FIBROUS
PULP ~H~;~; l .
CROSS-REFERENCE TO RELATED APPLICATION
The present invention claims the priority under 35 U.S.C. 119 of German ApplicationNo.196 33 422.5 filed August 20, 1996, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND INFORMATION
1. Field of the Invention The present invention relates to the press section of a paper machine which includes at least two press openings through which a watery fibrous pulp is guided, together with at least one felt belt. The invention also relates to a process for dewatering a watery fibrous pulp sheet, whereby the sheet is guided with the felt belt through at least two press openings.
PRESS SECTION AND PROCESS FOR DRAINING A WATERY FIBROUS
PULP ~H~;~; l .
CROSS-REFERENCE TO RELATED APPLICATION
The present invention claims the priority under 35 U.S.C. 119 of German ApplicationNo.196 33 422.5 filed August 20, 1996, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND INFORMATION
1. Field of the Invention The present invention relates to the press section of a paper machine which includes at least two press openings through which a watery fibrous pulp is guided, together with at least one felt belt. The invention also relates to a process for dewatering a watery fibrous pulp sheet, whereby the sheet is guided with the felt belt through at least two press openings.
2. Discussion f Background Information In the current state of the art, a watery fibrous pulp sheet, coming out of the sieve section of a press machine, is drained in several press openings in the paper machine's press section. For this, each fibrous pulp sheet is guided together with at least one felt belt through a press opening. The watery fibrous pulp sheet is dewatered due to the high pressure and force exerted in the press opening, and moisture is absorbed by the felt belt.
2 0 A separate felt belt is thereby guided for each press opening as an endless belt via a number of felt belt guide rollers, and the felt belt is conditioned (i.e., it is dewatered) in a conditioning device before le~ g to the press opening, where it once again absorbs moisture upon entering the press opening. The conditioning device generally includes a number of suction units that are operated under a high vacuum, in order to 2 5 vacuum fluid away from the felt belt to a great degree.
A disadvantage with this arrangement resides in the elaborate arrangement of thefelt belts needed for each press opening, each of which must be guided around several deflection rollers. In addition, these felt belts have to be monitored during operation, and from time to time they have to be replaced, which can be quite costly.
CA 022l33~2 l997-08-l9 P15762.SCA
SUMMARY OF THE INVENTION
An object of the present invention, therefore, is to provide an improved a presssection of a paper press machine, and to provide a process for dewatering a watery fibrous pulp sheet, wherein the construction is made as simple as possible and wherein 5 operation of the press section can occur in a simplified and cost efficient manner.
The object of the present invention is accomplished in the press section of a paper press machine by guiding a felt belt through both press openings, and by designing a conditioning device to be interposed between the two press openings that dries the felt belt as it passes between the two openings.
The object ofthe present invention also is accomplished by a process of guiding the fibrous pulp sheet together with a single felt belt through both press openings, and by conditioning (i.e., de-watering) the felt belt between the press openings.
In contrast with the current state of the art, where a felt belt is required for each press opening, the present invention utilizes a single felt belt which is guided through two or more sequential press openings. According to the present invention, after the felt belt passes through a first press opening, it is separated from the paper sheet and dewatered with the aid of a conditioning device, before it enters a second press opening.
In this manner, construction of the press section is greatly simplified, since fewer deflection rollers are required, because the number of endless circulating felt belts is reduced. Additionally, m~tçri~l costs are saved, since the total length ofthe felt belt sheet will be shortened. Moreover, the costs incurred during a felt belt exchange also are reduced, as substantially fewer felt belt exchanges have to be performed.
According to the present invention, after the felt belt exits from the second press opening, the felt belt is again dewatered, with another conditioning device.
2 5 In a particular embodiment of the present invention, the watery fibrous pulp sheet is guided between two press openings on a smooth press belt. This embodiment has the advantage of ensuring a closed sheet guidance system for the fibrous pulp sheet, whereby reverse moistening of the pulp sheet can be avoided.
In another embodiment of the invention that represents a modification of the CA 022133~2 1997-08-19 Pl 5762.SCA
above, the felt belt is separated from the fibrous pulp sheet shortly after exiting the first or the second press openings. In this manner, reverse moistening of the pulp sheet is almost completely prevented. Dewatering is particularly effective, and at the same time a closed sheet guidance system is ensured, as a result of guiding the fibrous pulp sheet between both press openings on the smooth press belt.
According to yet another embodiment of the present invention, the fibrous pulp sheet is guided through a smoothing press. In this manner, the characteristics of each side of the paper sheet can be controlled or separately modified.
According to still another embodiment of the invention, the press openings comprise shoe presses. In this way, a high degree of dehydration is achieved.
Theoretically, the shoe presses can be designed as top felt presses, or as bottom felt presses. In the case of a top felt press, a scraper can be designed on one of the deflection rollers over which the smooth press belt is guided to remove fibrous pulp residues.
Alternatively, where the shoe press is a bottom felt press, the scraper can be designed on one of the deflection rollers of the smooth press belt. However, if a smoothing press is additionally designed behind the second press opening, the scraper is preferablypositioned on the central roller of the smoothing press.
Overall, the construction of the press section according to the present invention is designed in a simple manner and can be adjusted to fit the respective requirements.
2 0 The present invention provides a press section of a paper machine that includes a first pair of press rollers having a first press opening therebetween, a second pair of press rollers having a second press opening therebetween, a felt belt which is guided with a water,v fibrous pulp sheet through the first press opening and the second press opening, and a conditioning device which is positioned between the first press opening and the second press opening to dewater the felt belt after it passes through the first press opening. Dewatering the watery fibrous pulp sheet yields a fibrous pulp sheet, as the watery fibrous pulp sheet passes through the first or second press openings. The fibrous pulp sheet may be guided between the first and second press openings on a smooth press belt. The felt belt also may be separated from the fibrous pulp sheet shortly after exiting CA 022l33~2 l997-08-l9 P1 5762.SCA
the first or second press openings. The fibrous pulp sheet may further be guided through a smoothing press, and it may be transferred to the smoothing press with the aid of a suction roller. The first and second pairs of press rollers may be constructed as shoe presses. The shoe presses may be designed as top felt belt presses or as bottom felt belt presses. If the shoe presses are designed as bottom felt presses, a scraper may be placed on the smoothing press to capture fibrous pulp residues.
The present invention also provides a process for dewatering a watery fibrous pulp sheet in a press section of a press m~t~hin~ comprising providing a first pair of press shoes having a first press opening therebetween, providing a second pair of press shoes having a first press opening therebetween, guiding a felt belt and a watery fibrous pulp sheet through the first and second press openings, and dewatering the felt belt with a conditioning device as it is guided between the first press opening and the second press opening.
It goes without saying that the aforementioned and following characteristic features can be used not only in the described combinations, but also in other combinations or alone, without leaving the scope of the invention. Further embodiments and advantages can be seen from the detailed description and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which 2 0 follows, in reference to the noted drawing by way of non-limiting examples of preferred embodiments ofthe present invention, wherein same reference numerals represent similar parts throughout the drawings, and wherein:
Figure 1 illustrates a schematic representation of a press machine's press section according to one aspect of the present invention; and 2 5 Figure 2 illustrates a schematic representation of a press machine's press section according to another aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are CA 022l33~2 l997-08-l9 P 15762.SCA
presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken 5 with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
According to the present invention, the press section in Figure 1 is referenced as a whole with the number 10. In press section 10, a watery fibrous pulp sheet 72 is passed on o sieve belt 12 from a preceding sieve section. Sieve belt 12 is guided over sieve guide rollers 14, 16. With the aid of a vacuum-assisted transfer/uptake roller 24, the watery fibrous pulp sheet 72 is transferred to an endless circulating felt belt 22 and through a first press opening 18. Press opening 18 is created by a top-mounted shoe press roller 40 and a bottom-mounted mating roller 38. Around the mating roller 38, a smooth press belt 15 52 is guided which is also guided around the mating roller 42 of a subsequent second press opening 20, with a top-mounted shoe press roller 44. The fibrous pulp sheet is guided over a number of deflection rollers 54, 56, 58.
Between the two press openings 18, 20, immediately after leaving the first pressopening 18, felt belt 22 is guided away from fibrous pulp sheet 72 with the aid of a 20 deflection roller 36. At this time, fibrous pulp sheet 72 adheres to smooth press belt 52 and reaches the following press opening 20 on the smooth press belt 52.
By immediately separating felt belt 22 from the fibrous pulp sheet 72 after leaving the first press opening 18, reverse moistening of sheet 72 is prevented.
Felt belt 22 reaches the second press opening by traveling over the deflection 25 roller 36. Felt belt 22 is dewatered by conditioning device 46 ,which is positioned between the two press openings 18, 20. The conditioning device 46 consists of two vacuum units 48, 50, by which moisture taken up in the first press opening 18, is largely vacuumed off, captured in a trough 51, and removed to the outside.
- After passing through the second press opening 20, the fibrous pulp sheet 72 CA 022133~2 1997-08-19 P15762.SCA
remains adhered to the smooth press belt 52 as it is guided down with the aid of a deflection roller 58. Felt belt 22 is immediately carried up and over felt guide roller 34, after passing through the second press opening 20, in order to prevent reverse moistening of the pulp sheet.
The felt belt 22 is guided further along over additional felt belt guide rollers 26, 28, 30, 32, and felt belt 22 is dewatered in a second conditioning device 74 with the aid of two vacuum units 76, 78, whereby the water is captured in a trough 79 and removed to the outside.
Afterwards, the fibrous pulp sheet 72 is transferred from the smooth press belt 52 with the aid of a suction roller 62. The fibrous pulp sheet 72 is guided on a drying sieve belt 66 to a subsequent drying section, of which only the first drying cylinder 64 is displayed. Drying sieve belt 66 feeds around drying cylinder 64, which then reaches the subsequent drying cylinders of the drying section in the direction of the arrow 70.
Fibrous pulp residues are removed from the smooth belt 52 in the bottom section of the press section with the aid of a scraper 60 that mounts to a deflection roller 56, and over which the smooth, soft press belt 52 is guided. The drying cylinder 64 likewise is equipped with a scraper 68 to scrape off the fibrous pulp residues.
Another embodiment of the present invention is described in Figure 2. It consists of two shoe presses 38a, 40a, 42a, 44a, but in contrast to the embodiment in Figure 1, 2 o it is constructed as a bottom-felt belt press.
In Figure 2, the fibrous pulp sheet 72 is passed on a sieve belt 12 that is guided in a preceding sieve section over sieve guide rollers 14, 16. With the aid of a smooth transfer/uptake roller 24a and moisturizing elements 84, 86, the fibrous pulp sheet 72 is transferred to an endless, smooth press belt 52a. Fibrous pulp sheet 72 passes to the first 2 5 press opening 18, that is created by a bottom-mounted shoe press roller 38a and a top-mounted mating roller 40a.
A felt belt 22a, guided by guide rollers 26a, 28a, 30a, 32a, 34a, and 36, also is guided through the first press opening 18. The felt belt subsequently passes through a second press opening 20 after being deflecting over felt belt guide roller 36.
CA 022l33~2 l997-08-l9 P 15762.SCA
After passing through the first press opening 18, the felt belt 22a is drained in a conditioning device 46a which is positioned between the first and second press openings with the aid of vacuum units 48a, 50a. The drained fluid is captured in a trough 51 a and removed. After passing through the second press opening 20, the felt belt 22a is5 deflected over felt belt guide rollers 34a, 32a, and felt belt 22a is dewatered in a second conditioning device 74a, with the aid of vacuum units 76a, 78a. The drained fluid is captured in trough 74a and removed. Before felt belt 22a returns to the first press opening 18, it is guided over additional felt belt guide rollers 30a, 28a, 26a.
By draining felt belt 22a with the aid of the first conditioning device 46a shortly 10 before enter1ng the second press opening 20, a particularly effective drying of the felt belt occurs, and therefore a high water absorption capability is achieved in the second press opening.
After passing through the first press opening 18, the fibrous pulp sheet 72 is guided to the second press opening 20 on smooth press belt 52a, while the felt belt 22a, 15 after exiting press opening 18, is immediately separated from the fibrous pulp sheet 72 in order to prevent reverse moistening.
Felt belt 22a is separated from the fibrous pulp sheet 72 immediately after exiting the second press opening 20. The fibrous pulp sheet is guided by belt 52a to smoothing press rollers 80, 82, so that reverse moistening is prevented here as well. Smoothing 2 o press rollers 80, 82 also serve to control or modify the characteristics of each side of the manufactured paper sheet, in accordance with respective requirements.
Fibrous pulp residues are taken off smoothing press roller 82 with the aid of scraper 60a. The fibrous pulp sheet 72 is transferred from smoothing press roller 82, with the aid of a suction roller 62, onto drying sieve belt 66, and it is guided over the first 25 drying cylinder 64 of a subsequent drying section. Fibrous pulp residues are again removed with the aid of a scraper 68.
According to the present invention, it is understood that the common felt belt can be guided through two or more press opening, provided that the felt belt is dewatered between each of the press openings.
CA 022133~2 1997-08-19 P1 5762.SCA
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention.
While the invention has been described with reference to a preferred embodiment, it is understood that the words which have been used herein are words of description and 5 illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described herein with reference to particular materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention 10 extends to a functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
2 0 A separate felt belt is thereby guided for each press opening as an endless belt via a number of felt belt guide rollers, and the felt belt is conditioned (i.e., it is dewatered) in a conditioning device before le~ g to the press opening, where it once again absorbs moisture upon entering the press opening. The conditioning device generally includes a number of suction units that are operated under a high vacuum, in order to 2 5 vacuum fluid away from the felt belt to a great degree.
A disadvantage with this arrangement resides in the elaborate arrangement of thefelt belts needed for each press opening, each of which must be guided around several deflection rollers. In addition, these felt belts have to be monitored during operation, and from time to time they have to be replaced, which can be quite costly.
CA 022l33~2 l997-08-l9 P15762.SCA
SUMMARY OF THE INVENTION
An object of the present invention, therefore, is to provide an improved a presssection of a paper press machine, and to provide a process for dewatering a watery fibrous pulp sheet, wherein the construction is made as simple as possible and wherein 5 operation of the press section can occur in a simplified and cost efficient manner.
The object of the present invention is accomplished in the press section of a paper press machine by guiding a felt belt through both press openings, and by designing a conditioning device to be interposed between the two press openings that dries the felt belt as it passes between the two openings.
The object ofthe present invention also is accomplished by a process of guiding the fibrous pulp sheet together with a single felt belt through both press openings, and by conditioning (i.e., de-watering) the felt belt between the press openings.
In contrast with the current state of the art, where a felt belt is required for each press opening, the present invention utilizes a single felt belt which is guided through two or more sequential press openings. According to the present invention, after the felt belt passes through a first press opening, it is separated from the paper sheet and dewatered with the aid of a conditioning device, before it enters a second press opening.
In this manner, construction of the press section is greatly simplified, since fewer deflection rollers are required, because the number of endless circulating felt belts is reduced. Additionally, m~tçri~l costs are saved, since the total length ofthe felt belt sheet will be shortened. Moreover, the costs incurred during a felt belt exchange also are reduced, as substantially fewer felt belt exchanges have to be performed.
According to the present invention, after the felt belt exits from the second press opening, the felt belt is again dewatered, with another conditioning device.
2 5 In a particular embodiment of the present invention, the watery fibrous pulp sheet is guided between two press openings on a smooth press belt. This embodiment has the advantage of ensuring a closed sheet guidance system for the fibrous pulp sheet, whereby reverse moistening of the pulp sheet can be avoided.
In another embodiment of the invention that represents a modification of the CA 022133~2 1997-08-19 Pl 5762.SCA
above, the felt belt is separated from the fibrous pulp sheet shortly after exiting the first or the second press openings. In this manner, reverse moistening of the pulp sheet is almost completely prevented. Dewatering is particularly effective, and at the same time a closed sheet guidance system is ensured, as a result of guiding the fibrous pulp sheet between both press openings on the smooth press belt.
According to yet another embodiment of the present invention, the fibrous pulp sheet is guided through a smoothing press. In this manner, the characteristics of each side of the paper sheet can be controlled or separately modified.
According to still another embodiment of the invention, the press openings comprise shoe presses. In this way, a high degree of dehydration is achieved.
Theoretically, the shoe presses can be designed as top felt presses, or as bottom felt presses. In the case of a top felt press, a scraper can be designed on one of the deflection rollers over which the smooth press belt is guided to remove fibrous pulp residues.
Alternatively, where the shoe press is a bottom felt press, the scraper can be designed on one of the deflection rollers of the smooth press belt. However, if a smoothing press is additionally designed behind the second press opening, the scraper is preferablypositioned on the central roller of the smoothing press.
Overall, the construction of the press section according to the present invention is designed in a simple manner and can be adjusted to fit the respective requirements.
2 0 The present invention provides a press section of a paper machine that includes a first pair of press rollers having a first press opening therebetween, a second pair of press rollers having a second press opening therebetween, a felt belt which is guided with a water,v fibrous pulp sheet through the first press opening and the second press opening, and a conditioning device which is positioned between the first press opening and the second press opening to dewater the felt belt after it passes through the first press opening. Dewatering the watery fibrous pulp sheet yields a fibrous pulp sheet, as the watery fibrous pulp sheet passes through the first or second press openings. The fibrous pulp sheet may be guided between the first and second press openings on a smooth press belt. The felt belt also may be separated from the fibrous pulp sheet shortly after exiting CA 022l33~2 l997-08-l9 P1 5762.SCA
the first or second press openings. The fibrous pulp sheet may further be guided through a smoothing press, and it may be transferred to the smoothing press with the aid of a suction roller. The first and second pairs of press rollers may be constructed as shoe presses. The shoe presses may be designed as top felt belt presses or as bottom felt belt presses. If the shoe presses are designed as bottom felt presses, a scraper may be placed on the smoothing press to capture fibrous pulp residues.
The present invention also provides a process for dewatering a watery fibrous pulp sheet in a press section of a press m~t~hin~ comprising providing a first pair of press shoes having a first press opening therebetween, providing a second pair of press shoes having a first press opening therebetween, guiding a felt belt and a watery fibrous pulp sheet through the first and second press openings, and dewatering the felt belt with a conditioning device as it is guided between the first press opening and the second press opening.
It goes without saying that the aforementioned and following characteristic features can be used not only in the described combinations, but also in other combinations or alone, without leaving the scope of the invention. Further embodiments and advantages can be seen from the detailed description and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which 2 0 follows, in reference to the noted drawing by way of non-limiting examples of preferred embodiments ofthe present invention, wherein same reference numerals represent similar parts throughout the drawings, and wherein:
Figure 1 illustrates a schematic representation of a press machine's press section according to one aspect of the present invention; and 2 5 Figure 2 illustrates a schematic representation of a press machine's press section according to another aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are CA 022l33~2 l997-08-l9 P 15762.SCA
presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken 5 with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
According to the present invention, the press section in Figure 1 is referenced as a whole with the number 10. In press section 10, a watery fibrous pulp sheet 72 is passed on o sieve belt 12 from a preceding sieve section. Sieve belt 12 is guided over sieve guide rollers 14, 16. With the aid of a vacuum-assisted transfer/uptake roller 24, the watery fibrous pulp sheet 72 is transferred to an endless circulating felt belt 22 and through a first press opening 18. Press opening 18 is created by a top-mounted shoe press roller 40 and a bottom-mounted mating roller 38. Around the mating roller 38, a smooth press belt 15 52 is guided which is also guided around the mating roller 42 of a subsequent second press opening 20, with a top-mounted shoe press roller 44. The fibrous pulp sheet is guided over a number of deflection rollers 54, 56, 58.
Between the two press openings 18, 20, immediately after leaving the first pressopening 18, felt belt 22 is guided away from fibrous pulp sheet 72 with the aid of a 20 deflection roller 36. At this time, fibrous pulp sheet 72 adheres to smooth press belt 52 and reaches the following press opening 20 on the smooth press belt 52.
By immediately separating felt belt 22 from the fibrous pulp sheet 72 after leaving the first press opening 18, reverse moistening of sheet 72 is prevented.
Felt belt 22 reaches the second press opening by traveling over the deflection 25 roller 36. Felt belt 22 is dewatered by conditioning device 46 ,which is positioned between the two press openings 18, 20. The conditioning device 46 consists of two vacuum units 48, 50, by which moisture taken up in the first press opening 18, is largely vacuumed off, captured in a trough 51, and removed to the outside.
- After passing through the second press opening 20, the fibrous pulp sheet 72 CA 022133~2 1997-08-19 P15762.SCA
remains adhered to the smooth press belt 52 as it is guided down with the aid of a deflection roller 58. Felt belt 22 is immediately carried up and over felt guide roller 34, after passing through the second press opening 20, in order to prevent reverse moistening of the pulp sheet.
The felt belt 22 is guided further along over additional felt belt guide rollers 26, 28, 30, 32, and felt belt 22 is dewatered in a second conditioning device 74 with the aid of two vacuum units 76, 78, whereby the water is captured in a trough 79 and removed to the outside.
Afterwards, the fibrous pulp sheet 72 is transferred from the smooth press belt 52 with the aid of a suction roller 62. The fibrous pulp sheet 72 is guided on a drying sieve belt 66 to a subsequent drying section, of which only the first drying cylinder 64 is displayed. Drying sieve belt 66 feeds around drying cylinder 64, which then reaches the subsequent drying cylinders of the drying section in the direction of the arrow 70.
Fibrous pulp residues are removed from the smooth belt 52 in the bottom section of the press section with the aid of a scraper 60 that mounts to a deflection roller 56, and over which the smooth, soft press belt 52 is guided. The drying cylinder 64 likewise is equipped with a scraper 68 to scrape off the fibrous pulp residues.
Another embodiment of the present invention is described in Figure 2. It consists of two shoe presses 38a, 40a, 42a, 44a, but in contrast to the embodiment in Figure 1, 2 o it is constructed as a bottom-felt belt press.
In Figure 2, the fibrous pulp sheet 72 is passed on a sieve belt 12 that is guided in a preceding sieve section over sieve guide rollers 14, 16. With the aid of a smooth transfer/uptake roller 24a and moisturizing elements 84, 86, the fibrous pulp sheet 72 is transferred to an endless, smooth press belt 52a. Fibrous pulp sheet 72 passes to the first 2 5 press opening 18, that is created by a bottom-mounted shoe press roller 38a and a top-mounted mating roller 40a.
A felt belt 22a, guided by guide rollers 26a, 28a, 30a, 32a, 34a, and 36, also is guided through the first press opening 18. The felt belt subsequently passes through a second press opening 20 after being deflecting over felt belt guide roller 36.
CA 022l33~2 l997-08-l9 P 15762.SCA
After passing through the first press opening 18, the felt belt 22a is drained in a conditioning device 46a which is positioned between the first and second press openings with the aid of vacuum units 48a, 50a. The drained fluid is captured in a trough 51 a and removed. After passing through the second press opening 20, the felt belt 22a is5 deflected over felt belt guide rollers 34a, 32a, and felt belt 22a is dewatered in a second conditioning device 74a, with the aid of vacuum units 76a, 78a. The drained fluid is captured in trough 74a and removed. Before felt belt 22a returns to the first press opening 18, it is guided over additional felt belt guide rollers 30a, 28a, 26a.
By draining felt belt 22a with the aid of the first conditioning device 46a shortly 10 before enter1ng the second press opening 20, a particularly effective drying of the felt belt occurs, and therefore a high water absorption capability is achieved in the second press opening.
After passing through the first press opening 18, the fibrous pulp sheet 72 is guided to the second press opening 20 on smooth press belt 52a, while the felt belt 22a, 15 after exiting press opening 18, is immediately separated from the fibrous pulp sheet 72 in order to prevent reverse moistening.
Felt belt 22a is separated from the fibrous pulp sheet 72 immediately after exiting the second press opening 20. The fibrous pulp sheet is guided by belt 52a to smoothing press rollers 80, 82, so that reverse moistening is prevented here as well. Smoothing 2 o press rollers 80, 82 also serve to control or modify the characteristics of each side of the manufactured paper sheet, in accordance with respective requirements.
Fibrous pulp residues are taken off smoothing press roller 82 with the aid of scraper 60a. The fibrous pulp sheet 72 is transferred from smoothing press roller 82, with the aid of a suction roller 62, onto drying sieve belt 66, and it is guided over the first 25 drying cylinder 64 of a subsequent drying section. Fibrous pulp residues are again removed with the aid of a scraper 68.
According to the present invention, it is understood that the common felt belt can be guided through two or more press opening, provided that the felt belt is dewatered between each of the press openings.
CA 022133~2 1997-08-19 P1 5762.SCA
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention.
While the invention has been described with reference to a preferred embodiment, it is understood that the words which have been used herein are words of description and 5 illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described herein with reference to particular materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention 10 extends to a functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
Claims (30)
1. A press section of a paper machine, comprising:
a first press opening;
a second press opening;
a felt belt which is guided through the first press opening and the second pressopening together with a watery fibrous pulp sheet; and a conditioning device which is positioned between the first press opening and the second press opening that drains the felt belt after it passes through the first press opening.
a first press opening;
a second press opening;
a felt belt which is guided through the first press opening and the second pressopening together with a watery fibrous pulp sheet; and a conditioning device which is positioned between the first press opening and the second press opening that drains the felt belt after it passes through the first press opening.
2. A press section according to claim 1, wherein the felt belt is separated from the fibrous pulp sheet shortly after exiting at least one of the first press opening and the second press opening.
3. A press section according to claim 1, wherein the fibrous pulp sheet is guided between the first press opening and the second press opening on a smooth press belt.
4. A press section according to claim 3, wherein the conditioning device includes a vacuum unit.
5. A press section according to claim 3, wherein the felt belt is separated from the fibrous pulp sheet shortly after exiting at least one of the first press opening and the second press opening.
6. A press section according to claim 5, wherein the fibrous pulp sheet is guided through a smoothing press.
7. A press section according to claim 6, wherein the fibrous pulp sheet is transferred from the smoothing press with the aid of a suction roller.
8. A press section according to claim 3, wherein the first press opening and thesecond press opening are constructed as shoe presses.
9. A press section according to claim 8, wherein the shoe presses are designed as top felt presses.
10. A press section according to claim 9, wherein the shoe presses are designed as bottom felt presses, and wherein a scraper is placed on the smoothing press to capture fibrous pulp residues.
11. A process for draining a watery fibrous pulp sheet, comprising:
providing a press section of a press machine with a first press opening and a second press opening;
guiding the fibrous pulp sheet together with a felt belt through the first pressopening and the second press opening;
dewatering the felt belt with a conditioning device between the first press opening and the second press opening.
providing a press section of a press machine with a first press opening and a second press opening;
guiding the fibrous pulp sheet together with a felt belt through the first pressopening and the second press opening;
dewatering the felt belt with a conditioning device between the first press opening and the second press opening.
12. A process for draining a watery fibrous pulp sheet according to claim 11, further comprising:
dewatering the felt belt with a conditioning device after the felt belt exits the second press opening.
dewatering the felt belt with a conditioning device after the felt belt exits the second press opening.
13. A process for draining a watery fibrous pulp sheet according to claim 12, further comprising:
separating the felt belt from the fibrous pulp sheet shortly after the felt belt exits at least one of the first press opening and the second press opening.
separating the felt belt from the fibrous pulp sheet shortly after the felt belt exits at least one of the first press opening and the second press opening.
14. A process for draining a watery fibrous pulp sheet according to claim 11, further comprising:
guiding the fibrous pulp sheet between the first press opening and the second press opening on a smooth press belt.
guiding the fibrous pulp sheet between the first press opening and the second press opening on a smooth press belt.
15. A process for draining a watery fibrous pulp sheet according to claim 14, further comprising:
guiding the fibrous pulp sheet through a smoothing press.
guiding the fibrous pulp sheet through a smoothing press.
16. A process for draining a watery fibrous pulp sheet according to claim 15, further comprising:
transferring the fibrous pulp sheet from the smoothing press with the aid of a suction roller.
transferring the fibrous pulp sheet from the smoothing press with the aid of a suction roller.
17. A process for draining a watery fibrous pulp sheet according to claim 11, wherein the first press opening and the second press opening are constructed as shoe presses.
18. A process for draining a watery fibrous pulp sheet according to claim 17, wherein the shoe presses are designed as top felt presses.
19. A process for guiding a watery fibrous pulp sheet according to claim 18, wherein the shoe presses are designed as bottom felt presses, and wherein a scraper is placed on the smoothing press to capture fibrous pulp residues.
20. A press section of a paper machine, comprising:
a first pair of press rollers having a first press opening therebetween;
a second pair of press rollers having a second press opening therebetween;
a felt belt which is guided with a watery fibrous pulp sheet through the first press opening and the second press opening, whereby the felt belt removes moisture from the watery fibrous pulp sheet to yield a fibrous pulp sheet; and a conditioning device which is positioned between the first press opening and the second press opening, whereby the conditioning device dewaters the felt belt after it passes through the first press opening.
a first pair of press rollers having a first press opening therebetween;
a second pair of press rollers having a second press opening therebetween;
a felt belt which is guided with a watery fibrous pulp sheet through the first press opening and the second press opening, whereby the felt belt removes moisture from the watery fibrous pulp sheet to yield a fibrous pulp sheet; and a conditioning device which is positioned between the first press opening and the second press opening, whereby the conditioning device dewaters the felt belt after it passes through the first press opening.
21. A press section according to claim 20, wherein the fibrous pulp sheet is guided between the first press opening and the second press opening on a smooth press belt.
22. A press section according to claim 21, wherein the conditioning device includes a vacuum unit.
23. A press section according to claim 21, wherein the felt belt is separated from the fibrous pulp sheet shortly after exiting at least one of the first press opening and the second press opening.
24. A press section according to claim 23, wherein the fibrous pulp sheet is guided through a smoothing press.
25. A press section according to claim 24, wherein the fibrous pulp sheet is transferred from the smoothing press with the aid of a suction roller
26. A press section according to claim 25, wherein the fibrous pulp sheet is guided through a smoothing press.
27. A press section according to claim 26, wherein the fibrous pulp sheet is transferred from the smoothing press with the aid of a suction roller.
28. A press section according to claim 21, wherein the first pair of press rollers and the second pair of press rollers are shoe presses.
29. A press section according to claim 28, wherein the shoe presses are designed as top felt belt presses.
30. A press section according to claim 28, wherein the shoe presses are designed as bottom felt belt presses, and wherein a scraper is placed on the smoothing press to capture fibrous pulp residues.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19633422.5 | 1996-08-20 | ||
| DE1996133422 DE19633422A1 (en) | 1996-08-20 | 1996-08-20 | Press section and method for dewatering an aqueous fibrous web |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2213352A1 true CA2213352A1 (en) | 1998-02-20 |
Family
ID=7803040
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2213352 Abandoned CA2213352A1 (en) | 1996-08-20 | 1997-08-19 | Press section and process for draining a watery fibrous pulp sheet |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0828027A3 (en) |
| CA (1) | CA2213352A1 (en) |
| DE (1) | DE19633422A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19840023A1 (en) * | 1998-09-02 | 2000-03-09 | Voith Sulzer Papiertech Patent | Press arrangement |
| DE19921205A1 (en) * | 1998-09-02 | 2000-03-09 | Voith Sulzer Papiertech Patent | Press for web of e.g. paper or card, which prevents creasing |
| DE19919085A1 (en) * | 1999-04-27 | 2000-11-02 | Voith Sulzer Papiertech Patent | Papermaking machine press section to extract water from a wet web has a separation section between the roller press gaps where the blankets and the web move on separate paths |
| DE10159115A1 (en) | 2001-12-01 | 2003-06-18 | Voith Paper Patent Gmbh | press section |
| DE10251666A1 (en) * | 2002-11-06 | 2004-06-03 | Voith Paper Patent Gmbh | Press arrangement |
| DE10252841A1 (en) * | 2002-11-13 | 2004-06-03 | Voith Paper Patent Gmbh | Press arrangement and method for dewatering a fibrous web, in particular paper web |
| DE10329675A1 (en) * | 2003-07-01 | 2005-02-03 | Voith Paper Patent Gmbh | Pressing and coating treatment for fibrous web in papermaking plant producing e.g. newsprint, coats chemical agent on wet side of dewatering nip |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3013938A (en) * | 1958-12-11 | 1961-12-19 | Beloit Iron Works | Plain press with suction felt drying means |
| FR1373102A (en) * | 1963-08-02 | 1964-09-25 | Beloit Corp | Mechanism and method for removing moisture from felt in a paper machine |
| SE314893B (en) * | 1966-06-06 | 1969-09-15 | Nordiska Maskinfilt Ab | |
| FI770542A (en) * | 1977-02-18 | 1978-08-19 | Valkama P J | PRESS RELEASE FOR THE CONSTRUCTION OF VAT ON FIBER BAN |
| FI770540A (en) * | 1977-02-18 | 1978-08-19 | Schauman Wilh Oy | FRAMEWORK FOR THE FRAMEWORK OF PAPERBOARD ELLER ANNAN DYLIK FIBERBANA MED TAENJBARHET OCH / ELLER HOEG FRIKTIONSKOEFFICIENT |
| US4483745A (en) * | 1982-09-29 | 1984-11-20 | Beloit Corporation | Method and apparatus of sheet transfer using a nonporous smooth surfaced belt |
| FI903349A (en) * | 1990-07-03 | 1992-01-04 | Tamfelt Oy Ab | MAETNINGSANORDNING FOER MAETNING AV SKICKET HOS EN FILT. |
| AT395184B (en) * | 1990-07-04 | 1992-10-12 | Andritz Ag Maschf | DEVICE FOR TREATING CELLULOSE AND OR OR MULTIPLE MIXTURES OR SUSPENSIONS |
| DE4102356C1 (en) * | 1991-01-26 | 1992-01-23 | J.M. Voith Gmbh, 7920 Heidenheim, De |
-
1996
- 1996-08-20 DE DE1996133422 patent/DE19633422A1/en not_active Withdrawn
-
1997
- 1997-07-03 EP EP97111130A patent/EP0828027A3/en not_active Withdrawn
- 1997-08-19 CA CA 2213352 patent/CA2213352A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| DE19633422A1 (en) | 1998-02-26 |
| EP0828027A2 (en) | 1998-03-11 |
| EP0828027A3 (en) | 1998-12-30 |
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| Date | Code | Title | Description |
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| FZDE | Dead |