CA1337236C - Papermaking machine in which the paper web is supported in the draw between the press and dryer sections - Google Patents
Papermaking machine in which the paper web is supported in the draw between the press and dryer sectionsInfo
- Publication number
- CA1337236C CA1337236C CA000601066A CA601066A CA1337236C CA 1337236 C CA1337236 C CA 1337236C CA 000601066 A CA000601066 A CA 000601066A CA 601066 A CA601066 A CA 601066A CA 1337236 C CA1337236 C CA 1337236C
- Authority
- CA
- Canada
- Prior art keywords
- web
- felt
- dryer
- press
- paper web
- 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 - Fee Related
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 238000000034 method Methods 0.000 claims 2
- 238000011144 upstream manufacturing Methods 0.000 claims 2
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000007665 sagging Methods 0.000 abstract description 4
- 238000009434 installation Methods 0.000 description 3
- 239000004744 fabric Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F5/00—Dryer section of machines for making continuous webs of paper
- D21F5/02—Drying on cylinders
- D21F5/04—Drying on cylinders on two or more drying cylinders
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F2/00—Transferring continuous webs from wet ends to press sections
-
- 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
Landscapes
- Paper (AREA)
- Advancing Webs (AREA)
- Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Drying Of Solid Materials (AREA)
Abstract
A papermaking machine having a press section in-cluding a pair of cooperating press rolls. A papermaker's felt is mounted for endless travel and carries a wet paper web through the hip between the press rolls. After passing through the press rolls, the felt carries the paper web across a substantial span of distance to the dryer section, thereby preventing sagging and possible breakage of the web as the web travels across this span.
Description
1 PAPERMAKING riAcHINE IN WHICH THE PAPEP~
WEB IS SUPPORTED IN THE DRAW BETWEEN
THE PRESS AND DRYER SECTIONS
Background of the Invention The conventional papermaking machine includes a press section having one or more pairs of cooperating press rolls and the wet paper web is supported on a papermaker's felt as it passes through the nip between the cooperating rollsj thereby extracting water from the web. After leaving the press section, the paper ~
web is transferred to the dryer section which can con-sist of a plurality of heated dryer rolls. The paper web passes sequentially around the dryer rolls to remove further moisture from the paper.
In some installations, there is a substantial draw or span between the press section and the dryer section. The paper web is fairly wet and heavy, so that the web can sag in this draw and possibly break.
A papermaking machine can be operating at a speed in the neighborhood of 2,000 ft. per minute, and if the web breaks, the paper web must be re-fed through the entire press and dryer sections and this not only results in a loss of product, but also results in sub-stantial downtime for the papermaking machine.
Sag in the draw between the press section and the dryer section can be minimized by increasing the tension on the paper web, but an increase in tension will correspondingly tend to stretch the paper web and increase the tendency for breakage.
Summary of the Invention The invention is directed to a papermaking machine in which the wet paper web is supported by the press section felt as it is transferred from the press section to the dryer section of the machine, thereby preventing sagging and possible breakage of the web.
WEB IS SUPPORTED IN THE DRAW BETWEEN
THE PRESS AND DRYER SECTIONS
Background of the Invention The conventional papermaking machine includes a press section having one or more pairs of cooperating press rolls and the wet paper web is supported on a papermaker's felt as it passes through the nip between the cooperating rollsj thereby extracting water from the web. After leaving the press section, the paper ~
web is transferred to the dryer section which can con-sist of a plurality of heated dryer rolls. The paper web passes sequentially around the dryer rolls to remove further moisture from the paper.
In some installations, there is a substantial draw or span between the press section and the dryer section. The paper web is fairly wet and heavy, so that the web can sag in this draw and possibly break.
A papermaking machine can be operating at a speed in the neighborhood of 2,000 ft. per minute, and if the web breaks, the paper web must be re-fed through the entire press and dryer sections and this not only results in a loss of product, but also results in sub-stantial downtime for the papermaking machine.
Sag in the draw between the press section and the dryer section can be minimized by increasing the tension on the paper web, but an increase in tension will correspondingly tend to stretch the paper web and increase the tendency for breakage.
Summary of the Invention The invention is directed to a papermaking machine in which the wet paper web is supported by the press section felt as it is transferred from the press section to the dryer section of the machine, thereby preventing sagging and possible breakage of the web.
1 The press section includes a pair of cooperating press rolls and an endless papermaker's felt supports the paper web as it passes between the press rolls to extract water from the wet web.
The papermaking machine also includes a dryer section consisting of a group of heated dryer rolls, and the press section felt travels from the press rolls of the press section and passes around at least one of the dryer rolls, so that the felt acts to support the wet paper web in the span or draw between the press section and the dryer section.
As the wet paper web is supported in the draw, sagging and possible breaking of the web is pre-vented in this area. As the tendency for breakage is minimized, product loss is minimized and downtime of the machine is correspondingly decreased.
Other objects and advantages will appear in the course of the following description.
Description of the Drawings The drawings illustrate the best mode presently contemplated of carrying out the invention.
The drawing is a schematic representation of a portion of a papermaking machine incorporating the invention.
Description of the Illustrated Embodiment The drawing is a schematic representation of a portion of a paper making machine including a press section 1 and a dryer section 2. Press section 1 includes a pair of cooperating press rolls 3 and 4 and a wet paper web S is supported by a papermaker's felt 6 as it passes between through the nip between the press rolls 3 and 4. The paper web can be any type of paper, preferably heavier weight paper, such as liner board, newsprint, writing paper, or the like.
_3_ 1 337236 1 The papermaker's felt 6 is endless in config-uration and can consist of natural fibers, synthetic fibers, or a combination thereof. The particular con-struction or co~position of the felt is not critical to the invention.
Felt 6 is supported in its endless travel by a plurality of idler rolls, indicated by 7A - 7I. In addition, the felt 6 passes arcund a tensioning or stretch roll 8, which is located between the rolls 7F
and 7G. Roll 8 operates in a conventional manner to provide the desired tension on the felt 6.
Dryer section 2 includes a plurality of con-ventional heated dryer rolls, three of which are shown in the drawing, and indicated by 9, 10 and 11. In practice, the dryer section may include up to 10 or more rolls which are steam heated to a temperature in the range of 150F to 280F. The temperature of the rolls in the group may be varied, with the highest temperature being located at the downstream end of the dryer section.
In certain installations there may be a con-siderable gap or draw between press section 1 and dryer section 2 and this draw can be in the neighborhood of 10 to 15 feet. When dealing with a heavier weight paper, such as liner board, the paper web will be fair-ly wet and heavy as it leaves the press section, with the result that the paper web has a tendecy to sag in the draw between press section 1 and dryer section 2.
If the web should break, the paper we~ from the forming section must be dropped into a disposal site and then re-fed through the press section and dryer section.
Refeeding the web may take from one-half to three-quarters of an hour and this down time results in a substantial decrease in the production rate of the papermaking machine.
_4_ 1 337236 1 To eliminate the sagging of the paper web in the draw between the press section and the dryer sec-tion and thereby prevent possible breaking of the web, the felt 6 from the press section is passed around at least one of the dryer rolls in the dryer section. As illustrated, the felt is passed around dryer roll 9 and thus supports the paper web in the draw between the press rolls 3,4 and the dryer roll 9.
As illustrated, the web 5 is located on the outside of felt 6 as it passes around dryer roll 9 and the web then travels around roll 10 and 11. A conven-tional dryer fabric 12 is mounted for endless travel in the dryer section and as shown, travels around a pair of idler rolls 13. The dryer fabric 12 operates in a conventional manner to support the paper web against the heated dryer rolls to aid in removal of moisture from the web.
I~lhile the drawing illustrates the felt 6 being located between the dryer roll 9 and the web 5, it is contemplated that in other installations the paper web may be sandwiched between the felt and the dryer roll. Similarly, the felt 6 from the press sec-tion can travel around a plurality of rolls in the dryer section.
The position and number of the idler rolls 7 in the press section is not critical and various paths of travel for the felt are contemplated depending upon the requirements of the papermaking machine.
~5~ 1 337236 Various modes of carrying out the invention are contemplated as being within the scope of the following claims particulary pointing out and distinctly claiming the subject matter which is regarded as the invention.
B
The papermaking machine also includes a dryer section consisting of a group of heated dryer rolls, and the press section felt travels from the press rolls of the press section and passes around at least one of the dryer rolls, so that the felt acts to support the wet paper web in the span or draw between the press section and the dryer section.
As the wet paper web is supported in the draw, sagging and possible breaking of the web is pre-vented in this area. As the tendency for breakage is minimized, product loss is minimized and downtime of the machine is correspondingly decreased.
Other objects and advantages will appear in the course of the following description.
Description of the Drawings The drawings illustrate the best mode presently contemplated of carrying out the invention.
The drawing is a schematic representation of a portion of a papermaking machine incorporating the invention.
Description of the Illustrated Embodiment The drawing is a schematic representation of a portion of a paper making machine including a press section 1 and a dryer section 2. Press section 1 includes a pair of cooperating press rolls 3 and 4 and a wet paper web S is supported by a papermaker's felt 6 as it passes between through the nip between the press rolls 3 and 4. The paper web can be any type of paper, preferably heavier weight paper, such as liner board, newsprint, writing paper, or the like.
_3_ 1 337236 1 The papermaker's felt 6 is endless in config-uration and can consist of natural fibers, synthetic fibers, or a combination thereof. The particular con-struction or co~position of the felt is not critical to the invention.
Felt 6 is supported in its endless travel by a plurality of idler rolls, indicated by 7A - 7I. In addition, the felt 6 passes arcund a tensioning or stretch roll 8, which is located between the rolls 7F
and 7G. Roll 8 operates in a conventional manner to provide the desired tension on the felt 6.
Dryer section 2 includes a plurality of con-ventional heated dryer rolls, three of which are shown in the drawing, and indicated by 9, 10 and 11. In practice, the dryer section may include up to 10 or more rolls which are steam heated to a temperature in the range of 150F to 280F. The temperature of the rolls in the group may be varied, with the highest temperature being located at the downstream end of the dryer section.
In certain installations there may be a con-siderable gap or draw between press section 1 and dryer section 2 and this draw can be in the neighborhood of 10 to 15 feet. When dealing with a heavier weight paper, such as liner board, the paper web will be fair-ly wet and heavy as it leaves the press section, with the result that the paper web has a tendecy to sag in the draw between press section 1 and dryer section 2.
If the web should break, the paper we~ from the forming section must be dropped into a disposal site and then re-fed through the press section and dryer section.
Refeeding the web may take from one-half to three-quarters of an hour and this down time results in a substantial decrease in the production rate of the papermaking machine.
_4_ 1 337236 1 To eliminate the sagging of the paper web in the draw between the press section and the dryer sec-tion and thereby prevent possible breaking of the web, the felt 6 from the press section is passed around at least one of the dryer rolls in the dryer section. As illustrated, the felt is passed around dryer roll 9 and thus supports the paper web in the draw between the press rolls 3,4 and the dryer roll 9.
As illustrated, the web 5 is located on the outside of felt 6 as it passes around dryer roll 9 and the web then travels around roll 10 and 11. A conven-tional dryer fabric 12 is mounted for endless travel in the dryer section and as shown, travels around a pair of idler rolls 13. The dryer fabric 12 operates in a conventional manner to support the paper web against the heated dryer rolls to aid in removal of moisture from the web.
I~lhile the drawing illustrates the felt 6 being located between the dryer roll 9 and the web 5, it is contemplated that in other installations the paper web may be sandwiched between the felt and the dryer roll. Similarly, the felt 6 from the press sec-tion can travel around a plurality of rolls in the dryer section.
The position and number of the idler rolls 7 in the press section is not critical and various paths of travel for the felt are contemplated depending upon the requirements of the papermaking machine.
~5~ 1 337236 Various modes of carrying out the invention are contemplated as being within the scope of the following claims particulary pointing out and distinctly claiming the subject matter which is regarded as the invention.
B
Claims (2)
1. In a method of papermaking, the steps of mounting a press felt for travel in an endless path, positioning a first upstream dryer roll of a series of dryer rolls within said endless path so that said felt passes in direct contact with said first dryer roll, heating said first dryer roll to an elevated temperature, supporting a wet paper web on said felt, passing the felt and the supported web through a pressure nip to thereby extract water from said web, thereafter passing said felt and said supported web around said first heated dryer roll with said felt separating said web from said heated dryer roll, exposing the outer surface of the portion of the web passing around the first dryer roll so that said outer surface is free of confinement to thereby heat said felt and said web, separating the web from the felt, passing the web around the remaining downstream dryer rolls in said series and returning the heated felt to the pressure nip in position to support said paper web.
2. The method of claim 1, wherein the step of positioning the first upstream dryer roll within said endless path comprises a step of wrapping the felt around said first dryer roll through an arc greater than 90°.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US20573688A | 1988-06-13 | 1988-06-13 | |
| US205,736 | 1988-06-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1337236C true CA1337236C (en) | 1995-10-10 |
Family
ID=22763436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000601066A Expired - Fee Related CA1337236C (en) | 1988-06-13 | 1989-05-24 | Papermaking machine in which the paper web is supported in the draw between the press and dryer sections |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0346659B1 (en) |
| JP (1) | JPH0226993A (en) |
| AT (1) | ATE92986T1 (en) |
| AU (1) | AU619302B2 (en) |
| CA (1) | CA1337236C (en) |
| DE (1) | DE68908287T2 (en) |
| ES (1) | ES2043949T3 (en) |
| FI (1) | FI92847C (en) |
| NO (1) | NO892405L (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI904699A0 (en) * | 1989-10-02 | 1990-09-25 | Appleton Mills | PAPER MASK, DAER PAPPERBANAN STOEDS MELLAN PRESS- OCK TORKSEKTIONERNA. |
| DE4004331C1 (en) * | 1990-02-13 | 1991-04-18 | J.M. Voith Gmbh, 7920 Heidenheim, De |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR359419A (en) * | 1905-01-21 | 1906-03-26 | Eugene Armengaud Aine | Further training in flat machine papermaking |
| GB481190A (en) * | 1936-05-20 | 1938-03-07 | Beloit Iron Works | Felt arrangements for horizontal press roll assemblies of paper-making machines |
| US2443352A (en) * | 1944-03-11 | 1948-06-15 | Boloit Iron Works | Suction press section for paper machines |
| US2786398A (en) * | 1952-05-01 | 1957-03-26 | Sprague Electric Co | Apparatus and process for producing an extremely thin paper web |
| FI812060L (en) * | 1980-07-02 | 1982-01-03 | Black Clawson Int | FOER REFRIGERATION FOER FRAMSTAELLNING AV PAPPER OCH KARTONG |
| US4483745A (en) * | 1982-09-29 | 1984-11-20 | Beloit Corporation | Method and apparatus of sheet transfer using a nonporous smooth surfaced belt |
-
1989
- 1989-05-24 DE DE89109322T patent/DE68908287T2/en not_active Expired - Fee Related
- 1989-05-24 EP EP89109322A patent/EP0346659B1/en not_active Expired - Lifetime
- 1989-05-24 ES ES89109322T patent/ES2043949T3/en not_active Expired - Lifetime
- 1989-05-24 CA CA000601066A patent/CA1337236C/en not_active Expired - Fee Related
- 1989-05-24 AT AT89109322T patent/ATE92986T1/en active
- 1989-05-31 JP JP1141306A patent/JPH0226993A/en active Pending
- 1989-06-07 AU AU36142/89A patent/AU619302B2/en not_active Ceased
- 1989-06-12 NO NO89892405A patent/NO892405L/en unknown
- 1989-06-12 FI FI892860A patent/FI92847C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE68908287T2 (en) | 1993-11-25 |
| FI92847C (en) | 1995-01-10 |
| AU619302B2 (en) | 1992-01-23 |
| AU3614289A (en) | 1989-12-14 |
| FI892860A (en) | 1989-12-14 |
| EP0346659A2 (en) | 1989-12-20 |
| NO892405D0 (en) | 1989-06-12 |
| DE68908287D1 (en) | 1993-09-16 |
| NO892405L (en) | 1989-12-14 |
| FI92847B (en) | 1994-09-30 |
| JPH0226993A (en) | 1990-01-29 |
| EP0346659B1 (en) | 1993-08-11 |
| ATE92986T1 (en) | 1993-08-15 |
| FI892860A0 (en) | 1989-06-12 |
| EP0346659A3 (en) | 1991-05-08 |
| ES2043949T3 (en) | 1994-01-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |