US2209760A

US2209760A - Suction press roll assembly

Info

Publication number: US2209760A
Application number: US210705A
Authority: US
Inventors: Earl E Berry
Original assignee: Beloit Iron Works Inc
Current assignee: Beloit Iron Works Inc
Priority date: 1938-05-28
Filing date: 1938-05-28
Publication date: 1940-07-30
Anticipated expiration: 1957-07-30

Description

July 30, 1940. BERRY 2,209,760

SUCTION PRESS ROLL ASSEMBLY Filed May 28, 1938 2 Shee'ts-Sheet l July 30, 1940. E. E. BERRY SUCTION PRESS ROLL ASSEMBLY 42 Shets-Sheet 2 7 Filed May 28, 1938 Patented July .30, 1940 UNITED STATES PATENT OFFICE 2,209,760 7 SUCTION PRESS ROLL ASSEMBLY Earl E. Berry, Belolt, Wis., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wisconsin This invention relates to suction press roll assemblies wherein a wet web of paper is subjected to localized suction treatments at spaced intervals along the length of travel thereof and wherein water is prevented from re-entering the web between the localized suction areas.

More specifically the invention relates to press roll assemblies having the constituent rolls thereof in horizontal alignment and including a suction roll having a top press roll cooperating therewith for "hardening the web before it enters the first nip of the horizontal assembly of rolls.

In the dewatering of wet paper webs by suction, it is customary to pass the webs around a perforated revolving surface having a localized suction area. As the web travels beyond the localized suction area, water entrained in the perforations of the revolving surface is thrown back into the web by centrifugal action. This invention now eliminates the remoistening of suction treated webs by retaining the water entrained in the perforations of the revolving surface on which the web is supported until the web is removed from the surface. At the same time, the invention makes possible a desired long length of travel of the web around the surface and a second suction treatment of the web without being removed from the surface.

An important feature of this invention is the removal of water from a web by suction and pressure to harden the web before the same is subjected to an additional suction and pressure operation on the same supporting surface for the 35 web.

It is, then, an object of this invention to provide suction press roll assemblies for dewatering wet, fibrous webs without remoistening the webs after the suction treatment.

40 Another object of the invention is to retain water entrained in the perforations of suction roll cylinders after the suction treatment of a wet, fibrous web on the cylinder until the web is either removed from the cylinder or subjected to a second suction treatment.

Another object of the invention is to provide a horizontal press roll assembly wherein one of the constituent rolls has a separate press roll cooperating therewith to partially dewater a web 50 entering the horizontal assembly of rolls before it reaches the first nip of the assembly.

A further object of this invention is to provide suction rolls having a plurality of spaced, localized suction areas and means for retaining water entrained in the perforations of the roll cylinders during their travel between the localized suction areas.

A further object of this invention is to prevent the remoistening of paper webs traveling around suction rolls after the webs have been subjected to a suction treatment.

Another object of the invention is to provide a horizontal press roll assembly for dewatering wet paper webs with a suction roll having a plurality of localized suction areas and means for retaining water entrained in the suction roll cylinder as the web passes on the roll between the suction areas.

Other and further objects of the invention will become apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which disclose preferred embodiments of the invention.

On the drawings:

Figure 1 is a somewhat diagrammatic side elevational view of a horizontal press roll assembly, with the first roll of the assembly in vertical cross section.

Figure 2 is a somewhat diagrammatic side elevational view of another form of horizontal press roll assembly according to this invention showing the middle roll of the assembly in vertical cross section.

Figure 3 is a somewhat diagrammatic side elevational view of a horizontal press roll assembly according to this invention with the first roll of the assembly shown in vertical cross section.

Figure 4 is a somewhat diagrammatic side e1evational view of another form of horizontal press roll assembly according to this invention showing the first and third rolls of the assembly in vertical cross section.

Figure 5 is a transverse vertical cross-sectional view of a suction roll adapted to be used in the assemblies of Figures 1 to 4 inclusive in place of the suction rolls therein shown and illustrating the constituent parts of the roll somewhat diagrammatically.

Figure 6 is a longitudinal cross-sectional view, with parts in elevation, taken along the line VI-VI of Figure 4.

As shown on the drawings:

In Figure 1 the reference numeral l0 designates a Fourdrinier forming wire trained around a couch roll II as is customary on Fourdrinier paper making machines. The couch roll II can have a suction head l2 therein for removing water from a web of paper W formed on the wire III as the web is removed from the wire. The web W is directed under a guide roll l3 first roll l5 of a horizontal press roll assembly according to this invention. The horizontal press roll assembly includes rolls l5, l6 and I! having their axes in horizontal alignment and preferably lying in the same horizontal plane.

The rolls l5 and H are urged against the center roll IE to create pressures at the nips defined by the rolls.

A second felt I 8 is trained over the roll H.

A guide roll l9 laps the felt l8 against the roll I1 before the felt enters the nip between the rolls l6 and I1.

' Guide rolls 20 and 2| are mounted within the loop of the first felt |4 so that the felt will meet the web W before the web reaches the first roll |5.

The roll I5 is a suction roll comprising the usual perforated cylinder 22 having a suction conduit 23 therein. The suction conduit 23 has a pair of circumferentially spaced

heads

24 and 25 defining localized suction areas 26 and-21 respectively at the top portion of the roll l5 and at the nip defined by the rolls l5 and I6.

Since the

suction heads

24 and 25 are spaced circumferentially within the cylinder 22, a space 28 is provided between the suction heads. In

accordance with this invention this space 28 is maintained under reduced pressure to prevent water entrained in the perforations of the cylinder 22 from being thrown back by centrifugal action into the felt l4 and web W as the same pass between the localized suction areas 26 and 21.

In order to evacuate the space 28, the suction conduit 23 is formed with a slotted housing 29 adapted to receive a slotted rod 30 in rotatable relation thereto. The rod 3 0 can be rotated to produce any desired degree of communication between the space 28 and the interior of the suction conduit 23. The rod 30 thereby acts as a valve for controlling the pressure in the space 28 A rubber covered top press roll 3| is urged against the suction roll 5 opposite the suction area 26 thereof. The roll 3| is adjustable peripherally around the top portion of the roll l5 as indicated in dotted lines so as to vary the nip between the rolls l5 and 3| along the length of the suction area 26,

After the cylinder 22 of the roll l5 passes beyond the suction area 2'! the water retained in the holes of the cylinder is free to drop by gravity and by centrifugal action out of the holes. A moisture collecting pan 32 is mounted around the under portion of the cylinder 22 to receive the discharged water. A moisture collecting pan 33 can likewise be disposed under the roll IT for collecting water thrown by or draining from the periphery of the roll. The pans 32 and 33 can be emptied through drains 34 and 35 respectively.

A doctor 36 is provided at the top of the middle roll l6 for cleaning the periphery of the roll before it enters the first nip of the assembly and also for preventing water carried by the roll from entering the nip.

In operation of the assembly shown in Figure 1, the web W from the Fourdrinier wire l0 meets the felt l4 and is conveyed on the felt around the top of the suction roll |5 where it is subjected to suction at the suction area 26 and also to a light pressure treatment. This suction and pressure treatment sufilciently dewaters the web so that it can be subjected to high pressures in the first nip of the horizontal assembly of rolls without being crushed.

onto a felt l4. The felt I4 is trained around the As the web and felt leave the first suction area 26 they travel around the roll l5 to the second suction area 21. During the passage between the suction areas 26 and 21, however, water sucked into the holes of the roll cylinder 22 is retained in the holes by reduced pressure existing in the space 28 between the suction areas. The pressurein this space is regulated so as to prevent the water in the holes of the cylinder from be ing thrown back into the felt and web. As the felt and web contact the second suction area 21, they are subjected to an additional suction dewatering treatment, and, while still under the influence of suction, they are pressed between the rolls l5 and I6 for the additional pressure removal of water.

After the web and felt pass through the nip between the rolls l5 and Hi, the web is separated from the felt and travels around the center roll l6. While on the roll l6, the web enters the nip between the rolls |6 and I! and passes through this nip with the felt l8. Additional amounts of water are thus removed from the web. This water can freely drain downwardly out of the nip and away from the web. The felt |8 continues around the roll I! while the web W is directed vertically upward from the nip over a guide roll 31.

The apparatus shown in Figure 1 therefore provides an initial suction and light pressure treatment to harden" the web before it enters the nips between the horizontal press rolls. Water is retained in the perforations of the suction roll 22 along the length of travel of the web and felt between the suction areas so as to prevent the remoistening of the web and felt.

In the embodiment shown in Figure 2, parts identical with parts described in Figure 1 have been marked with the same reference numeral.

In Figure 2 the horizontal press roll assembly comprises three press rolls 40, 4| and 42 having their axes in substantially horizontal alignment with the end rolls 40 and 42 pressed against the middle roll 4| to define two nips for the assembly.

The middle roll 4| is a suction roll comprising the usual perforated cylinder 43 and a suction conduit 44 mounted within the cylinder 43. The suction conduit has two suction heads 45 and 46 defining suction areas 41 and 48 at the nips between the rolls of the assembly. There is thusprovided a space 49 in the cylinder 43 between the suction areas 41 and 48. This space 49 can be evacuated by communication with the interior of the suction conduit 44. For this purpose the conduit 44 is provided with slotted rod housing portions 50 and 5| adjacent the top sides of the suction heads 45 and 46. Slotted rods 52 and 53 are rotated in the housings 58 and 5| to act as valves for controlling the pressure in the space 49.

A felt 54 is wrapped around the bottom portion of the roll 40 by means of a guide roll 55 and is trained over the top of the roll 4|.

Doctors such as 56 and 51 act against the rolls 40 and-42 respectively to prevent moisture carried by the rolls from contacting the felt or web trained around the rolls.

A drip pan 58 is mounted beneath the middle roll 4| for collecting water draining from or thrown out of the holes in the roll cylinder 43. The drip pan can be emptied by means of a drain 59.

The web W from the Fourdrinier wire I0 is trained over a guide roll 60 and against the first roll 40 of the horizontal press assembly. The web on the roll 40 is covered by the felt 54 and the web and felt together pass through the first nip of the assembly between the rolls 48 and 4|. The web and felt are subjected to suction as they pass through the nip at the suction area 41. After leaving the suction area 41 the web is trained around the roll 4| on top of the felt 54 over the area 49 of the roll and water is prevented from re-entering the web and felt by reduced pressure in the space 49. As the web and felt enter the second nip of the assembly, the same are subjected to suction at the suction area 48. After passage through the second nip, the web is separated from the felt and travels around the third press roll 42.

In the modification shown in Figure 3, parts identical with parts described in Figure 1 are designated by the same reference numerals used in Figure 1. In the modification shown in Figure 3, however, the suction conduit 23 within the perforated cylinder 22 has a wide suction head 6| defining a suction area 62 extending from the top of the roll into the first nip of the horizontal roll assembly. The web W traveling on the felt 14 is thus continuallysubjected to suction during its complete travel between the top press roll 3| and the first nip of the horizontal roll assembly. This wide suction area prevents moisture from being thrown back into the felt or web after the initial light pressing or hardening" operation between the rolls l5 and 3|.

In the embodiment shown in Figure 4, parts corresponding with parts described in Figure 1 have been designated by the same reference numerals. In Figure 4 the felt I4 is trained directly around the roll I5 so that the web W first contacts the felt on the roll, for travel thereon over the suction areas 26 and 21 and through the first nip of the horizontal press roll assembly. The web is then removed from the felt and travels around the under side of the middle roll I6 into contact with the felt l8 for passage upwardly through the second nip of the assembly defined by the roll l6 and a second suction roll 18 receiving the felt I8 therearound. The roll I0 comprises the usual perforated cylinder ll having a suction conduit 12 therein. The suction conduit has a suction head 13 defining a suction area 14 at the nip between the rolls I6 and I0 and extending below the nip to initially dry the felt 18 before the felt contacts the web on the roll.

The suction conduit 12 has a second suction head 15 defining a suction area 16 at the top portion of the roll Ill. The space 11 between the

suction areas

14 and 16 is maintained under reduced pressure to prevent water entrained in the holes of the cylinder H frombeing thrown back into the felt l8 and web W. For the purpose of partially evacuating the space 11 the suction conduit is provided with a cylindrical housing portion 18 receiving a slotted rod 19 in rotatable relation therein. The rod 18 can act as a valve to establish a desired amount of communication between the space H and the interior of the suction conduit.

The web W is carried on the felt [8 over the suction area 16 and is then separated from the felt for passage to additional press rolls or directly into the drier section of the paper machine. The felt l8 continues around the roll 10.

If desired a drip pan can be mounted beneath the middle roll IS. The drip pan can be emptied by means of a drain 8|.

In the operation of the assembly shown in Figure 4, the web W is first subjected to a suction and a light pressure treatment at the suction area 28 of the first roll l5. This treatment hardens the web so that the same can be subjected to the higher pressures in the downward passage nip of the horizontal press roll assembly. The web is then subjected to a second suction pressure treatment in the upward passage nip of the assembly and finally to a forced suction treatment over the suction area 18.

As best shown in Figure 6,"the rolls such as 15 have end seals 82 for the suction areas such as 21 and end seals 83 for the space 28 between the suction heads 24 and 25. These end seals 82 and 83 can he slid along the suction conduit 23 to vary the width of the evacuated areas. As shown. the suction area 21 communicates with the interior. of the conduit 23 through an opening 84 in the central portion of the conduit. However, the space 28 only communicates with the interior of the suction conduit 23 through the opening provided by the slotted rod 38. The slot in the rod may be coextensive with the opening 84 while the remaining portion of the rod is solid. The rod extends through an end seal 83 and may have a head portion 30a thereon for manual turning of the rod to adjust the size of the slot opening.

As is customary, the end seals 82 and 83 are adiusted longitudinally within the cylinder 22 to define suction areas coextensive in width with the paper web being passed around the roll.

In the embodiment of the roll l5 shown in Figure 5, parts corresponding to parts described in Figure l have been designated with the'same reference numerals. In Figure 5, however, the space 28 between the suction heads 24 and 25 is maintained under reduced pressure from a separate source of vacuum than the interior of the conduit 23. Thus the space 28 can be evacuated through a pipe connected with a separate suction pump. The pipe 85 may extend through a trunnion of the suction roll and be connected to a separate suction pump.

From the above descriptions it should be understood that this invention provides for the extraction of water from wet, fibrous webs by suction and pressure and prevents water from being thrown back into the fibrous webs between suction treatments.

The horizontal press roll assemblies of this invention provide upward and downward passage nips for pressing water from. wet, fibrous webs. The upward passage nips of the assembly permit gravity drainage of water therefrom.

In order to prevent crushing of a newly formed wet, fibrous web, in a nip of the horizontal press roll assembly the web can be given a light pressure and suction-treatment to harden the same before it enters the first nip of the horizontal roll assembly.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore. do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. A press roll assembly for dewatering newly formed wet, soggy webs which comprises a perforate cylinder adapted to receive the web therearound, a pair of press rolls in peripheral pressure relation with the cylinder at peripherally spaced points thereon, a suction conduit defining spaced localized suction areas at the nips between the rolls and cylinders, and separate suction means acting from within the cylinder on that portion thereof carryingthe web between the localized suction areas for eliminating discharge of water carried by the perforations of the cylinder into the web.

2. A press roll assembly for dewatering wet, soggy webs which comprises a perforate cylinder adapted to receive the wet web therearound, a pair of rolls in peripheral pressure relation with the cylinder at peripherally spaced points therealong, a suction conduit in the cylinder having a pair of head portions defining spaced localized suction areas at the nips between the rolls and cylinder, said suction conduit defining a space in the cylinder between the suction areas, and valve means joining said space with the interior of the suction conduit whereby the space is maintained under reduced pressure for eliminating the discharge of water from the cylinder into the web carried thereon.

3. A press roll assembly comprising a suction roll having a pair of peripherally spaced localized suction areas, separate rolls cooperating with said suction roll at each of said suction areas to define therewith a pair of pressure nips in spaced relation from each other, means directing a wet web of paper around the suction roll over the suction areas and through the nips, and means acting from within the suction roll to subject to suction that portion of the suction roll conveying the web between the localized suction areas.

4. A horizontal press roll assembly comprising a plurality of rolls in peripheral pressure relation having their axes lying in the same horizontal plane to define at least one vertical passage nip therebetween, a felt lapped around part of the periphery of the first roll for guiding a wet, fibrous web through the first nip of the horizontal assembly, a press roll acting against the first ,roll and felt thereon at a point ahead of said first nip of the horizontal assembly to define with the first roll an initial pressure nip, and suction means acting from within said first roll to suck liquid from the initial pressure nip and from the first nip of the horizontal roll assembly.

5. A horizontal press roll assembly comprising a middle roll, a roll on each side of the middle roll in peripheral pressure relation therewith, said rolls having their axes lying in substantially the same horizontal plane and adapted to receive a web of paper through the vertical passage nips defined thereby, a separate press roll acting against the first roll of the horizontal assembly to'define therewith an initial pressure nip ahead of the first nip of said assembly, and means acting from within said first roll to suck water from the initial nip and from said first nip of the horizontal assembly.

6. A dewatering roll assembly adapted to receive a wet, soggy web of paper directly from its forming surface comprising three rolls in peripheral pressure relation having their axes lying in substantially the same horizontal plane, said rolls defining therebetween vertical upward and downward passage pressure nips for the web of paper, a top press roll cooperating with the first roll of the horizontally aligned rolls to define therewith an additional pressure nip ahead of the first nip of the horizontally aligned rolls, a felt for conveying the web around the first roll through the nip between the top press roll and first roll and into the downward passage nip, a second felt trained around the third roll for conveying the web through the upward passage nip, and common means acting from Within the first roll to suck liquid from the two nips partially defined by said first roll.

7. A dewatering roll assembly adapted to receive a newly formed wet, soggy web of paper directly from its forming surface comprising three horizontally aligned rolls in peripheral pressure relation, the middle roll of said three rolls having spaced localized suction areas at the nips defined by the rolls, and suction means acting from within said middle roll to subject to suction that portion of the middle roll conveying the web between the nips of the assembly.

8. A press roll assembly for dewatering wet, soggy webs comprising three horizontally aligned rolls in peripheral pressure relation, means in said first and third rolls defining localized suction areas at the nips between the rolls, said means within the first and third rolls also defining additional localized suction areas at points on said rolls spaced from said nips, and a press roll cooperating with said first roll at the additional suction area thereof for initially subjecting the web to a suction and pressure operation before it enters the first nip of the horizontally aligned rolls.

9. A press roll assembly comprising three rolls in peripheral pressure relation having their axes lying. in substantially the same horizontal plane, suction conduits in said first and third rolls defining localized suction areas at the nips between the rolls and additional localized suction areas at the tops of the rolls, said suction conduits defining spaces in the rolls between the localized suction areas, and means for evacuating said spaces to prevent remoistening of the web as it travels over the rolls between the localized suction areas thereof.

10. In a press roll assembly, a suction roll comprising a hollow perforated cylinder, a suction conduit in said cylinder having a pair of peripherally spaced suction heads defining localized suction areas on the cylinder, a passageway through said suction conduit between the suction heads, and a valve controlling the efiective size of the passageway for regulating the pressure on that portion of the cylinder between the localized suction areas.

11. A suction roll comprising a hollow perforate cylinder, a suction conduit in said cylinder having a pair of spaced suction heads defining localized suction areas at peripherally spaced sections of the cylinder, a cylindrical housing in said suction conduit between the suction heads thereof having an opening therethrough, a rod rotatably mounted in said housing having a slotted portion for venting that space in the cylinder between the suction heads to the interior of the suction conduit, and means for rotating the rod to regulate the effective communication between said space and the interior of the conduit.

12. A suction press roll assembly comprising a suction roll having a rotatable liquids-pervious cylinder, a stationary suction conduit in said cylinder having a pair of spaced suction heads defining localized high vacuum areas at peripherally spaced sections of the cylinder in direct communication with the conduit, separate press rolls cooperating with said cylinder adjacent each localized high vacuum area to define with the cylinder a pair of spaced pressure nips, said cylinder in operation receiving a paper web therearound over the high vacuum areas and through the nips, said conduit and suction heads defining a localized low vacuum space in said cylinder between said localized high vacuum areas, end seals for said space, means providing a passageway between said low vacuum space and the interior of said conduit for evacuating said space, and a valve cooperating with said means to regulate the pressure in said space and on that portion oi the cylinder between the" localized high vacuum areas for preventing remoistening oi the paper web as it travels over the cylinder between the high vacuum areas without wasting suction.

EARL E. BERRY.