US2782693A

US2782693A - Press roll assembly for paper machines

Info

Publication number: US2782693A
Application number: US464577A
Authority: US
Inventors: Stanley C Williams
Original assignee: Dominion Engineering Works Ltd
Current assignee: Dominion Engineering Works Ltd
Priority date: 1954-10-25
Filing date: 1954-10-25
Publication date: 1957-02-26
Anticipated expiration: 1974-02-26

Description

1957 s. c. WILLIAMS PRESS ROLL ASSEMBLY FOR PAPER MACHINES Filed 001:. 25. 1954 INVENTOR ATTORNEY United States Patent 2,782,693 PRESS ROLL ASSEMBLY FOR PAPER MACHINES Stanley C. Williams, Pointe Claire, Quebec, Canada, assignor to Dominion Engineering Works Limited, Montreal, Quebec, Canada Application October 25, 1954, Serial No. 464,577 1 Claim. (Cl. 92-49) This invention relates to machines for the manufacture of paper and more particularly to that part of a newsprint machine where the paper web is transferred from the Fourd-rinier wire to the pick-up felt and the first press section.

The invention lies in the rearrangement of the first press section whereby it is possible to eliminate the trans for press and the bottom felt and carry the paper web on the pick-up felt directly from the Fourdrinier wire to the first press and thence to the second press and drier sections in the usual manner.

By the elimination of the bottom felt, the paper web is taken from the Fourdrinier wire on the under side of the pick-up felt and is carried through the nip of the first press section. In this section the relationship of the suction press roll and the solid roll are reversed from the normal assembly, the suction press roll being on top with its suction box being located in the lower portion thereof. In the manufacture of newsprint fairly high line pressures are utilized in the presses and in order that the paper web may be skinned off the solid roll and carried onto the following sections, the best practice is to utilize a solid roll of natural granite. Substitute materials for natural granite have been used for this roll but none have proved entirely satisfactory. However, natural granite has a very low value of tensile strength which was of no great importance so long as the roll of this material was located on top of the suction roll. With the solid roll being located under the suction roll, as in this application, it is necessary to support the roll throughout its length in order to relieve it of the high bending stresses and to maintain a constant high line pressure in the nip. This support is accomplished by mounting a back-up roll of suitable strength under the granite roll, thereby relieving the granite roll of any undue stresses and providing a solid foundation for the press roll and the maintenance of a high and constant line pressure in the nip between the suction roll of the granite roll.

The object of the invention is to eliminate from a paper machine a section of transfer rolls. and a complete section of felt and to so arrange the press section of themachine to take up the paper web on a single felt and pass it through the nip of the press in which the suction roll is placed on top of a solid roll.

Referring to the drawings,

Figure 1 is a diagrammatic showing of first and second press sections of a Fourdrinier machine embodying the present invention.

Figure 2 is a part sectional view of the press section frame showing the mounting of the rolls of the press section.

The web of newsprint is picked up from the F ourdrinier wire 1 by the under side of the looped pick-up felt 2 by means of the suction pick-up roll 20 located within the lower loop of the felt 2 and in contact with the delivery end of the Fourdrinier wire just beyond the couch roll 21. The paper web is carried forward on the under side of the pick-up felt through the nip of the first press section 3 where it is skinned off the solid roll and thence passed onto second press and drier sections.

The first press section comprises a suction press roll located within the lower loop of the pick-up felt 2 in the bottom portion of the roll substantially in line with the nip between the rolls 10 and 11. Means 17 controls the nip pressure between these rolls 10 and 11 and can be either mechanical, pneumatic or hydraulic in nature. The granite roll 11 is also adjustably mounted on a pivoted arm 18 and rides in the vertical slots 19 in the side frames 15. The back-up roll 12 is solidly mounted and provides a solid support throughout its width for the rolls 10 and 11. This solid support is carried through the granite roll 11 which in turn provides a solid base to ensure equal high line pressure at the nip between it and the suction roll 10, with the felt 2 and the paper web on its underside being pressed therebetween; the required line pressure being developed by the pressure means 17.

With the above described press section and the single pick-up felt a substantial saving is achieved both in first cost of the machine and in running expense. Also, the web of newsprint passing through the nip of the press on the underside of the pick-up felt and between the suction roll and granite roll more readily adheres to the granite roll and is, therefore, more easily skinned off the felt than would be the case if the newsprint web were sandwiched between two felts at the press nip.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

In a paper making machine, a Fourdrinier wire, a couch roll around which the delivery end of the Wire is trained, a suction pick-up roll positioned in close proximity to said couch roll to form a nip therewith, a suction press roll spaced horizontally from the side of the pickup roll remote from the couch roll, an endless looped pick-up felt having the lower portion thereof trained around said pick-up roll and said suction press roll so that the lower run of the felt travels horizontally beneath said rolls, said suction pick-up roll serving to transfer the paper from the forming wire to the under side of the lower run of the pick-up felt, a granite press roll engaging the lower side of a portion of the lower run of the pick-up felt which is in contact with the lower portion of the suction press roll, and a backing-up roll underlying the granite press roll in supporting contact therewith, said suction press roll being provided in the lower portion thereof with a downwardly opening suction box overlying the nip formed by and between the suction press roll and the granite roll.

References Cited in the file of this patent UNITED STATES PATENTS 878,946 Escarfail Feb. 11, 1908 1,163,254 Millspaugh Dec. 7, 1915 1,959,520 Blais et al May 22, 1934 2,204,426 Millspaugh June 11, 1940 2,669,912 Goodwillie et al Feb. 23, 1954 2,694,348 Beachler Nov. 16, 1954 FOREIGN PATENTS 394,878 France Dec. 10, 1908 295,540 Germany Dec. 5, 1916 OTHER REFERENCES Leicester: Practical Studies for Paper Manufacturers, page 167 (1924), published by Charles Grifiin and Co. Ltd., London, England.