US2369674A - Couch roll arrangement for paper machines - Google Patents

Description

Feb. 20, 1945. HQRNBOSTEL 2,369,674

COUCH ROLL ARRANGEMENT FOR PAPER MACHINES Filed May 13, 1942 ZnYEZ 22:?

Patented Feb. 20, 1945 aacaou OFFICE couon non. samcrnmnr roa ram uacnmns Lloyd Hornbostel, Beloit, Wis, assignor to Belolt Iron Works, Beioit, Wis., a corporation of WI- oonsin Application May 13, 1942, sci-m No. 442,155

Claims. (01. 92-44) This invention relates to endless band type. or Fourdrinier type paper making machines and more particularly to couch roll arrangements for such machines which will eliminate rewetting of the paper with liquids extracted therefrom;

In accordance with this invention the forming wire of a paper machine is directed around a suction couch roll soas to subject the web of paper carried thereby to the suction in the roll and thereby extract water from the web; It has heretofore been customary to allow the web and forming wire to remain on a suction couch roll after the same have passed beyond the suction area of the roll. In such arrangements water or other liquid drawn into the holes of the rotating couch roll cylinder or shell will be released as soon as the holes pass beyond the suction area. Inasmuch as the cylinder or shell is rotating, the water entrained in these holes will be thrown back into the wire and web by centrifugal force. a 1

In accordance with this invention, both the web and the forming wire are directed away from the couch roll shell before the vacuum in the holes of the shell is released. In this manner, any water which is discharged out of the holes after the vacuum therein is released can be so directed as to prevent its reentry into'the wire I and web. In accordance with this invention a baflie or save-all is interposed between the wire and the shell for intercepting the water discharged from the shell before it reaches the wire.

It has heretofore been customary to permit the forming wire to follow around the under side of the couch roll for passage back to the breast roll of the machine. According to this invention, however, a wire. roll is mounted adjacent the couch roll to receive the wire from the roll before the wire starts on its path back to the breast roll. A save-all trough is disposed around the rotating shell of 'the couch roll within the loop of the wire so as to intercept any liquids discharged fromthe shell. The wire roll is positioned to separate the wire from the shell before the vacuum in the holes of the shell is released. For example the wire and web can be removed from the shell at a point immediately adjacent the offgoing seal of the couch roll so that the suction area of the roll will not be directly vented since it will be covered by the web and at the same time the holes, in passing over the seal, will have the vacuum therein retained by the seal. Thus high vacuum can be maintained in the suction area of the roll and the web can be out of the path of liquids discharged from the roll when vacuum in the holes of the roll shell is eventually released. Y

A paper roll is also provided for stripp the web 011 of; the wire as soon as the suction eiiect 5 on the web is broken.

It is, then, an object of this invention to prevent rewetting of paper webs as the same pass beyond the suction area of asuction couch roll.

A further object of the invention is to provide a directing roll within ,the loop of a Eourdrinier forming wire for guiding the wire away from a. suction couch roll at the'point where the suction eflfect on the couch roll shell is terminated.

A further object of this invention is to provide an improved couch roll arrangement for Fourdrinier type paper making machines which prevents rewetting of a web of paper onthe machine.

Another object of this invention is to intercept water discharged from the rotating shell of a suction couch roll to prevent rewetting of the web of paper passing around the couch roll.

Another object of the invention is to remove the forming wire of a paper machine from the rotating shell of a suction couch roll before the vacuum in the holes of the shell is completely broken.

Other and further objects of the invention will i be apparent to those skilled in the art from the following detailed description of the annexed sheet of drawings, which, by way of preferred examples, illustrate several embodiments of the invention.

On the drawing: 1 Figure 1 is a diagrammatic side elevational view 5 of a Fourdrinier type paper making machine having a couch roll arrangement in accordance with this invention.

Figure 2 is an enlarged fragmentary vertical cross-sectional view'of the couch roll arrangement shown in Figure 1. r Figure 3 is a fragmentary view similar to Figure 1, showing a slightly modified couch roll arrangement.

Figure 4 is a top plan view of a suction couch roll and save-all trough inaccordance with this invention.

Figure 5' is a diagrammatic fragmentary view similar to Figure 3 illustrating a couch roll arrangement according to-this invention coupled with a primary suction couch roll.

As shown on the drawing:

In Figure 1 the reference numeral ll designates generally a Fourdrlnier type paper making machine including a looped forming wire ll trained '55 betweenabreastroli I: andacouchroll II. A

plurality, of stationary suction boxes I are mounted within the loop of the wire ll under the upper run thereof between the breast and couch rolls. A head box I 5 is provided adjacent the breast roll end of the machine for discharging stock through stock inlet it onto the upper run of the wire.

In accordance with this invention a wire roll I! is provided adjacent the lastsuction box H and the upper run of the wire isdirected over this wire roll to extend in a somewhat downwardly sloping direction to the couch roll it. The wire, after passage over the couch roll l3,

- does not extend around the under side of roll but, in accordance with this invention, is

. vbeeliminated and the suction'boxessuch as N trained over a wire roll positioned somewhat beyond the couch roll l3 ata level below the roll;

The wire then travels over a tensioning roll I! and under another wire roll back to the breast r011 l2.

A save-all tank or trough 2| is disposed around the couch roll I3 and has a front end wall 2la extending vertically from the bottom Nb of the trough into closely spaced relation with the upper run of the wire at a point adjacent the wire roll H. The trough also has an arcuate rear end wall He extending from the bottom wall 2|b thereof between the roll [3 and the wire II to a point adjacent the wire so that the wire run between the rolls l3 and I! will clear the wall 210 in closely spaced relation. Front and rear side walls 2Id extend above the bottom end or .the roll l3 so that any liquid collected in the trough will discharge through a drain pipe 22 communicating with the bottom of the trough.

The :web of paper W formed on'the forming wire H is stripped fromthe wire by being directed under a roll 23 and thence over another roll 24 positioned adjacent the couch roll l3.

As best shown in Figure 2, the couch roll I3 includes a rotatin cylinder or shell 25 having holes or perforations 26 therethrough. The shell 25 rotates around a suction gland 21 which is stationarily mounted in the shell and which has seals 21a thereon defining therebetween a. localized suction area 28 on the shell.

The forming wire II is guided onto the shell 25 in advance of the suction area 28 so as to carry the web W over this suction area. However, in accordance with this invention, the wire II is removed from the shell 25 to carry the web W therewith before the vacuum in the holes 26 of the shell is completely broken by passage of the holes beyond the ofigoing seal 21a. In other words the wire roll l8 of Figure 1 directs the wire H eff of the shell 25 at a point adjacent the offgoing seal 21a so that the wire is removed fro-:1 the shell before any water in the holes 26 is released for centrifugal discharge out of the holes. As shown in Figure 2, this water will be released from the holes 26 in streams 29 extending tangentially of the shell 25 but the wire II is positioned outwardly from these streams 29 so that the streams will impinge against the wall He of the trough 2| to be collected in the trough.

can mend up to the sa've all trough 2 I;

As shown in Figure 5 a primary suction couch roll 30 can :be disposed within the loop of the wire ll between the last suction box l4 and the I couch roll l3. This primary suction couch roll 30 can have a suction area defined by a stationary suction boxr such as II for acting on the wire and web! before they reach the suction area 28 of the couch roll II. The primary couch roll 30 will have an additional dehydrating eflect upon the web W cwithout, however, imparting a frictional drag on the wire H such as occurs when stationary suction boxes H are used to dehydrate the web as much as possible. 7

I A modified save-all trough-33 can be used to collect water discharged by centrifugal force from the rotating shells of both rolls I2 and 30. The roll 30 is arranged within the loop of th wire so that the wire will be separated from the suction area thereof adjacent the ongoing seal of the suction box 3| to prevent rewetting of the web by centrifugal discharge of water out of the holes in the rotating shell of the roll. The trough 33 is similar tothe trough 2| but can have a central dividing wall 32a between the rolls I3 and 30 so that water thrown out of the roll 30 will not be impinged against the roll I3. A drain 34 can b provided for that portion of the trough housing the roll 30 while a second drain 35 can be provided for that portion of the trough housing the roll I 3.

From the above descriptions it will be understood that this invention now provides couch roll arrangements for Fourdrinier type paper making machines which eliminate rewetting of the paper web as it passes beyond the suction area of the couch roll.

It will, of course, be understood that various details of the invention may bevaried through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A Fourdrinier type paper making machine comprising a breast roll, a first wire roll in spaced lateral relation therefrom, a couch roll beyond the wire roll at a level below the top of the wire roll, said couch roll including a foraminous cylinder and a suction gland in the cylinder having spaced opposed on-coming and oil-going seals acting on the cylinder todefine a suction area, a second wire roll beyond the couch roll at a level beneath the top of the couch roll, a looped forming wire around all of said rolls and having an upper run extending substantially horizontally from the breast roll to the first wire roll and then sloping downwardly to the second wire roll, said first wire roll guiding the wire onto the cylinder of the couch roll in advance of the suction area, said second wire roll directing the wire ofi of the cylinder at the oil-going seal before suction in the holes of the cylinder is completely broken, a save-all trough in the loop of the wire receiving the cylinder therein, said trough havinga first wall extending between the cylinder and the first wire roll into closely spaced relation with said forming wire together with a second wall extending between the cylinder and second wire roll into closely spaced relation with the forming wire, and a stripping roll for stripping a web of paper from the forming wire as soon as the suction effect on the web is broken by removal of the wire from the'cylinder.

2. In a Fourdrinier paper making machine including a looped forming wire, a suction roll having a perforated cylinder receiving the wire around an area thereof, said suction roll having a suction gland in the cylinder with spaced opposed off-going and on-coming seals defining a suction area on the cylinder portion covered by the wire, and means in the loop of the wire directing the wire tangentially ofi of the cylinder at a point immediately adjacent the off-going seal where the perforations in the cylinder have vacuum retained therein by said seal and where said perforations are not in direct communication with the suction area whereby the wire is outward from tangential streams of liquid released from said perforations after these perforations pass the off-going seal.

3. A Fourdrinier type paper making machine comprising a breast roll, a couch roll spaced from the breast roll, said couch roll including a for-aminous cylinder and a suction gland in the cylinder having spaced opposed on-coming and oil-going seals acting on the cylinder to define a suction area, another roll beyond the couch roll at a level beneath the top of the couch roll, a looped forming wire around all of said rolls, said roll beyond the couch roll directing the wire off the cylinder at the off-going seal before suction in the holes of the cylinder is completely broken, a saveall trough in the loop of the wire receiving the cylinder therein, said trough having a first wall extending between the cylinder and breast roll into closely spaced relation from said forming wire together with a second wall extending between the cylinder and roll beyond the couch roll into closely spaced relation with the forming wire, and a stripping roll for removing a web of paper from the forming wire as soon as the suction effect on the web is broken by removal of the wire from the cylinder.

LLOYD HORNBOSTEL.

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