US3214328A - Method and apparatus for treating the web in a paper making machine by a lump crusher roll - Google Patents

Description

Oct. 26, 1965 G. D. MUGGLETON 3,214,328

METHOD AND APPARATUS FOR TREATING THE WEB IN A PAPER MAKING MACHINE BY A LUMP CRUSHER ROLL Filed April 25, 1963 \o M (O u E cc LZ INVENTOR.

GERALD D. MUGELETON @MQ P022071) ATTQRNi-ZY United States Patent 3,214,328 METHOD AND APPARATUS FOR TREATING THE WEB IN A PAPER MAKING MACHINE BY A LUMP CRUSHER ROLL Gerald D. Muggleton, Appleton, Wis, assignor to Combined Locks Paper Co., Combined Locks, Wis., a corpoi-ation of Wisconsin Filed Apr. 25, 1963, Ser. No. 275,738 6 Claims. (Cl. 162-205) This invention relates to improvements in the art of paper making and particularly to an improved method and means for treating the Web by a lump crusher roll.

Lump crusher rolls rotate in contact with the web and exert pressure thereon. They are located on top or immediately forward of the couch roll. The purpose of the lump crusher roll is to increase the levelness of the top of the web at this point where, due to its high moisture content, the web is susceptible to leveling action. Another purpose of the lump crusher roll is to increase the density of the sheet by the pressure exerted thereon. After passing between the lump crusher and couch rolls, the web is fully formed into a wet sheet of paper and leaves the wire to proceed to the presses and dryers in the dry end of the paper making machine.

it is necessary that the surface of the lump crusher roll be wet as it comes into contact with the traveling web, because a dry surface will tend to adhere to the web and damage the same by picking up or otherwise disturbing the compacted fibers of the web. Prior to this invention lump crusher rolls were either run wetted only by virtue of contacting the wet web, or were wetted by water delivered on top of the lump crusher roll by delivery through a perforated pipe or similar means.

This method of wetting has been unsatisfactory in that the means employed has not been able to produce a uniformly wetted roll surface at the place where the roll engages the web. In the equipment known prior to this invention, the descending side of the lump crusher roll quite frequently appeared dull thereby showing lack of sufficient wetting, or appeared to be quite obviously carrying excess water in some areas and much less in others. This unevenness in wetting caused frequent damage to the web.

I have discovered that by providing a uniform and controlled amount of liquid coating to the lump crusher, not only the heretofore mentioned damage and/or impairment of the web is remedied, but also that the levelness of the finished paper could be markedly improved.

The principal object of this invention is to improve the operation of the lump crusher roll and thereby to improve the levelness of the paper produced.

This object is attained by providing a small wetting roll on the descending side of the lump crusher roll and in nip forming relationship therewith, and by supplying the nip with a controlled amount of water or coating material to maintain a small pool therein. The wetting roll, actuated under mild pressure, permits only a uniform amount of liquid to pass through the nip and provides a uniformly wetted lump crusher roll as it comes into contact with the web. This method of wetting not only provides even and controlled amount of moisture added to the web, but also improves the action of the suction box by prompting more even moisture removal at this point, with the result that the wet web proceeding to the first press has a more even moisture content and therefore results in a more evenly controlled moisture of the sheet as it travels through the presses and into the dryers. The uniformity and consistency provided at the lump crusher roll has a marked effect upon every stage of the paper making process, and is evident in the final product by the resulting more level top surface of the paper.

A further object of this invention is to provide means for removing any loose fibers from the traveling web before it leaves the wire, thereby improving the web as well as final paper surface.

Although the lump crusher roll is wetted to eliminate adhesion between the web and the roll, the wetted roll picks up loose fibers and crumbs which at times lie on the top surface of the web. The removal of these fibers or crumbs at this stage of the paper making process is desirable since their presence impairs the web with corresponding impairment of the final paper surface. The lump crusher rolls known prior to this invention did not remove the lost fibers from the web, but merely wetted them, picked them up, and again deposited them on the surface of the web after one or more revolutions. The heretofore described wetting roll and liquid pool, in addition to the even wetting of the lump crusher roll, also removes any of the fibers adhering to the lump crusher surface, thus preventing their return to the traveling web. To avoid formation of slush in the pool, and thus eventual re-cleposition of the fibers on the web, the pool is maintained by two end pans which in combination with the two rolls confine the liquid to the nip. The water or coating in the nip is continuously relieved thereby carrying away the fibers therein. If star-ch or coating is used with the water, the liquid removed is passed through strainers to remove the fibers and returned for re-use.

The novel features, which are considered characteristic of this invention, are set forth with particularity in the appended claims. The invention, together with additional objects and advantages thereof, will be best understood from the following description when read in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic view in side elevation of the stage of the paper making process in which the web leaves the wire to pass to the dry end of the paper making machine, and

FIG. 2 is an enlarged fragmentary diagrammatic view in side elevation of the lump crusher roll and wetting roll embodying my invention and showing a simplified version of the end pans.

The web 10 is formed in the usual manner on the wire 12 of the paper making machine. The web and wire travel in the direction as indicated by the arrows. After leaving the dandy roll 14 the web is squeezed between the couch roll 16 and rubber covered lump crusher roll 18. The pressure exerted by the lump crusher roll on the top surface of the web levels it and increases its density. The moisture squeezed out by this operation is removed by the suction boxes 20 within the couch roll. At this point the web leaves the wire and proceeds to the presses and dryers of the dry end of the machine.

A wetting roll 22, having a rubber cover 24 and of smaller diameter than the lump crusher roll, engages the latter on its descending side in a nip forming relationship. The wetting roll is engaged under mild pressure with the lump crusher roll and is rotated therewith by virtue of the friction between the two rolls.

A. predetermined and controlled amount of liquid is provided from the supply line 26 and sprayed between the rolls to form a small pool in the nip. The wetting roll permits only a small and uniform amount of liquid to pass through the nip which amount may be varied by changing the pressure between the two rolls and/or by changing the amount of liquid supplied from the supply line 26. However, the particular combinations of pressure and quantity of liquid supplied to obtain a desired amount of Wetting can be determined by easy experimentation and is thought to be well within the skills of a person versed in this art when made in view of this disclosure.

End pans 28 (shown in a simplified form in FIG. 2) are provided at each side of the nip formed by the lump crusher roll and the wetting roll. As the liquid is added to the nip from supply line 26, a portion of the pool in the nip flows over the inside Wall 30 of the end pans and is removed therefrom by conduit means 32. This circulation of liquid in the nip carries away any of the loose fibers and crumbs which were picked up by the lump crusher roll from the web and which were in turn removed from the lump crusher roll at the nip.

It also may be desirable to add starches or other coating material to the water supplied to the nip between the lump crusher roll and the wetting roll. In so doing, both uniform amount of liquid is applied to the lump crusher roll, with the resulting more uniform final paper surface, and a uniform controlled amount of coating is applied to the web at this stage of the paper making process.

To prevent loss of the starches and/or other coating materials, the liquid flowing from the pool into the end pans 28 is conveyed by the conduit 32 to a strainer 34, which serves to remove the fibers and crumbs contained in the liquid and is thereafter supplied to the nip for reuse by means of pump 36 and supply line 26.

Although only one embodiment of the invention is shown and described herein, it will be understood that this application is intended to cover such changes or modifications as come within the spirit of the invention or scope of the following claims.

I claim: 1. A method of increasing the levelness of paper produced by a paper machine having a lump crusher roll which engages the traveling wire supported web as it passes over the couch roll of the machine, comprising the steps of:

providing a uniform wetting of the lump crusher roll as it comes into contact with the traveling web by providing a rotating wetting roll in nip forming relationship with the descending side of the lump crusher roll, and by providing a pool of liquid in the upwardly divergent nip formed by said rolls to thereby cause a metered amount of liquid to escape past the nip and to be uniformly applied across the face of said lump crusher as it moves toward the web,

replenishing the liquid in said pool during operation of the machine,

leveling the Web by the contact pressure between the lump crusher roll and the web and removing loose fibre and crumb material from the surface of the web by causing such loose material to adhere to the wetted surface of said lump crusher roll as it moves away from said web,

removing said material from the surface of the lump crusher roll by virtue of causing it to separate from said surface as the surface carrying said material enters said pool, and,

removing said material from said pool.

2. A method according to claim 1 wherein said material is removed from said pool by overflow means which convey a portion of the liquid containing said material away from the pool.

3. A method according to claim 2 wherein said liquid contains coating materials and wherein the liquid removed from said pool is strained to remove the fibres and crumbs therefrom and is recirculated to said pool.

4. In a paper making machine, apparatus for improving the quality of the web as it leaves the wire at the 0 couch roll, comprising:

a lump crusher roll having a nonabsorbent outer surface operable to press against and level a traveling web as it is moved over the couch roll by the wire,

a wetting roll position on the descending side of said lump crusher roll and in a relationship therewith to provide an upwardly divergent nip operable to support a pool of liquid therein and to provide a uniform application of said liquid on the surface of said lump crusher roll as said surface presses said nip,

means positioned on each end of said nip to confine said pool to said nip,

means for replenishing liquid to said pool during operation of the paper making machine, said lump crusher roll being operable by virtue of said uniform application of liquid to cause loose fibres to adhere to said surface to thereby remove them from the traveling web and to deposit the same in the pool of liquid in said nip,

and means removing said fibres from the pool.

5. The apparatus according to claim 4 wherein said means for removing said fibres comprises overflow means operable to convey a portion of said liquid together with the fibres from said pool.

6. The apparatus according to claim 5 wherein said replenishing means are positioned above the upwardly divergent end of said nip in a position to spray liquid into said nip.

References Cited by the Examiner UNITED STATES PATENTS 1,191,912 7/16 Sanburn 162-266 3,097,968 7/ 63 Schaefer 118-249 FOREIGN PATENTS 291,707 7 14 Germany. 302,848 10/ 15 Germany. 306,049 6/17 Germany.

DONALL SYLVESTER, Primary Examiner.

Claims (2)

1. A METHOD OF INCREASING THE LEVELNESS OF PAPER PRODUCED BY A PAPER MACHINE HAVING A LUMP CRUSHER ROLL WHICH ENGAGES THE TRAVELING WIRE SUPPORTED WEB AS IT PASSES OVER THE COUCH ROLL OF THE MACHINE, COMPRISING THE STEPS OF: PROVIDING A UNIFORM WETTING OF THE LUMP CRUSHER ROLL AS IT COMES INTO CONTACT WITH THE TRAVELING WEB BY PROVIDING A ROTATING WETTING ROLL IN NIP FORMING RELATIONSHIP WITH THE DESCENDING SIDE OF THE LUMP CRUSHER ROLL, AND BY PROVIDING A POOL OF LIQUID IN THE UPWARDLY DIVERGENT NIP FORMED BY SAID ROLLS TO THEREBY CAUSE A METERED AMOUNT OF LIQUID TO ESCAPE PAST THE NIP AND TO BE UNIFORMLY APPLIED ACROSS THE FACE OF SAID LUMP CRUSHER AS IT MOVES TOWARD THE WEB, REPLENSIHING THE LIQUID IN SAID POOL DURING OPERATION OF THE MACHINE, LEVELING THE WEB BY THE CONTACT PRESSURE BETWEEN THE LUMP CRUSHER ROLL AND THE WEB AND REMOVING LOOSE FIBRE AND CRUMB MATERIAL FROM THE SURFACE OF THE WEB BY CAUSING SUCH LOOSE MATERIAL TO ADHERE TO THE WETTED SURFACE OF SAID LUMP CRUSHER ROLL AS IT MOVES AWAY FROM SAID WEB, REMOVING SAID MATERIAL FROM THE SURFACE OF THE LUMP CRUSHER ROLL BY VIRTUE OF CAUSING IT TO SEPARATE FROM SAID SURFACE AS THE SURFACE CARRYING SAID MATERIAL ENTERS SAID POOL,AND REMOVING SAID MATERIAL FROM SAID POOL.

4. IN A PAPER MAKING MACHINE, APPARATUS FOR IMPROVING THE QUALITY OF THE WEB AS IT LEAVES THE WIRE AT THE COUCH ROLL, COMPRISING: A LUMP CRUSHER ROLL HAVING A NONABSORBENT OUTER SURFACE OPERABLE TO PRESS AGAINST AND LEEL A TRAVELING WEB AS IT IS MOVED OVER THE COUCH ROLL BY THE WIRE, A WETTING ROLL POSITION ON THE DESCENDING SIDE OF SAID LUMP CRUSHER ROLL AND IN A RELATIONSHIP THEREWITH TO PROVIDE AN UPWARDLY DIVERGENT NIP OPERABLE TO SUPPORT A POOL OF LIQUID THEREIN AND TO PROVIDE A UNIFORM APPLICATION OF SAID LIQUID ON THE SURFACE OF SAID LUMP CRUSHER ROLL AS SAID SURFACE PRESSES SAID NIP, MEANS POSITIONED ON EACH END OF SAID NIP TO CONFINE SAID POOL TO SAID NIP, MEANS FOR REPLENISHING LIQUID TO SAID POOL DURING OPERATION OF THE PAPER MAKING MACHINE, SAID LUMP CRUSHER ROLL BEING OPERABLE BY VIRTUE OF SAID UNIFORM APPLICATION OF LIQUID TO CAUSE LOOSE FIBERS TO ADHERE TO SAID SURFACE TO THEREBY REMOVE THEM FROM THE TRAVELING WEB AND TO DEPOSIT THE SAME IN THE POOL OF LIQUID IN SAID NIP, AND MEANS REMOVING SAID FIBRES FROM THE POOL.

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