US1998046A - Cylinder paper machine and suction roll for use therein - Google Patents

Description

April 16, 1935. c. L. ELLIS 1,998,046

CYLINDER PAPER MACHINE AND SUCTION ROLL FOR USE THEREIN Filed Dec. 19, 1931 An important object of the invention is Patented Apr. 16, 1935 is or.

, practical water extraction from the pulpweb by means of a suction roll directly cooperating with the web.

It has beenproposed to employ suction rolls with cylinder paper machines for the purpose of extracting water from the felt and web and sporadic attempts have been made to employ suction rolls which directly co-operated with the pulp web. Such devices were, however, extremee ly unsatisfactory due to'the fact that a suction roll of ordinary construction co-operating di rectly with the pulp web has a tendency to draw the particles of the pulp into the openings of the suction roll, thereby clogging these openings and interfering with the action of the suction roll and, furthermore, causing the pulp web to adhere to the suction roll to an extent such that it could not be practically disengaged therefrom. Even where successfully disengaged, the surface of the sheet is rough or pimply as a result of the increased suction actionat the suction openings of the roll. Suction rolls may be employed with some slight success where they operate through a felt and the formed pulp web is extremely thin asin the case of crepe paper or tissues; When, however, such rolls are employed through a felt with board or relatively heavy papers, the suction action has been found to' be practically useless for the suction efiort is insumcient to enable the water to be drawn through the heavy paper web so that any water extraction accomplished by the roll must be accomplished by indirection;

that is to say, by removal thereof. from the felt and subsequent withdrawal by the felt of water from the web. Sinca'however, it is impossible to use a suction roll through the 'felt without employing a second felt with the pick-up felt of cylinder machines where a press roll is associated with the suction roll, no pressing action can be obtained and, accordingly, the extent of water extraction from the felt is extremely slight. It

has, therefore, been the common practice where ,sa PAPER MAC through the suction roll;

soc'rrou ngtown E ingtown, Pa, a corporation Application December 19, 1931, Sendai No. scares (CE. 9H9) suction presses is so increased that the emciency of the suction action is counteracted.

- In the prior applications above identified it has been disclosed that the felt with its attached web may be passed between a pair of pressureengaged rolls, provided the pressure-engaged roll having engagement with the web is formed with a wire face, and it has, furthermore, been proposed to dry the sheet to an extent such that it may be passeddirectly to presses by the use of a plurality of presses including such wirefaced rolls which have direct engagement with the pulp web prior to the time that it leaves the felt.

More specifically, objects of the present invention are first, the provision of a cylinder paper machine wherein the drying of the pulp web while still attached to the pick-up felt may be extended to a point such that the web may be directly delivered to the first press; and second, the provision of a suction roll of such construction that it may be mployed directly in engagement with the pulp web for the purpose of extracting water therefrom without damage to the sheet.

These and other objects I attain by the construction shown in the accompan drawing wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention and wherein:

Fig. l is a diagraatic view she a cylinder paper machine embodying my invention;

Fig. 2-is an enlarged transverse sectional view Fig. 3 is a fragmentary diagrammatic view showing a modified construction of the suction press;

Fig. t is a characwristic iraentary sectional view through the roll of Figs. 1 to 3',

Fig. 5 is a characteristic longitudinal section through the roll; and

Fig. 6 is a f g entary perspective of the press roll of one of the extractor presses.

Referring now to the drawing, and more 'particularly to Fig. 1 thereof, the numeral it generally designates vats each containing a cylinder mold it having a couch i2 cooperating therewith. i3 designates extracton prcsses each having a wire-faced press roll its directly engaging the the felt l4, and i5 designates the first main press of the machine.

In accordance with my invention, the felt I after leaving the last of the extractor presses l3, and with the web still attached thereto, is passed through a. suction press it includinga suction roll ll of special construction more clearly shown in Figs. 2, e and 5. o

Referring more particularly to Figs. 2, 4 and 5, it will be seen that the perforated roll l8 of this suction roll is longitudinally grooved to form ribs l9, the surfaces of which have spaced notches 29 receiving heavy reinforcmg wires 2| which are placed in fairly close proximity to one another. Surrounding the reinforced roll is a relatively course wire covering 22 which is in turn surmounted by a fine mesh covering of wire cloth 23. In the construction shown in Figs. 1 and 2, this wire cloth is permanently mounted upon the roll, although as will hereinafter become obvious, and as illustrated at 23a in Fig. 3 it is not essential that this covering be permanently associated with the roll in any way except in that of traveling at the same speed as .the roll. Suction roll ll operates at the same during its rotation. The suction eifort exerted by the suction box tends-to act directly upon the paper web W carried by the felt H and by its action not only to withdraw water from the paper web but likewise to loosen the web from. the feltto which it is attached and cause it to rest upon the wire covering 23.- Beyond the final packing 25, in the direction of the rotation of the roll, a blow pipe or other suitable means for producing an air blast is provided as indicated at 2? and the blast of air emitted. thereby lifts the sheet from the wire 23 so that it may be freely passed to the press iii.

Due to thefactthat the. surface of-wire 23 is very close andthe paper web has already been acted upon by the extractorpresses so that it is compacted and has little or no tendency to displacement of the fibres thereof, this web does not tend to enter into the meshes of the wire 23 so that the pimpling effect and adherence ordinarily present as a result of use of a suction'roll in direct engagement with the sheet is entirely face, great pressure can be brought to bear upon the suction roll through the associated press roll 24 with the result that the'water extraction at the'suction press It is very. considerable and the sheet is prepared so that it may receive its final pressing without any material loss in strength as a result of such pressing. "It may be here pointed out that in handling a pulp web by the ordinary constructions employed in cylinder paper machines the pulp web has its greatest strength at that time when it has just been completed by the final cylinder mold; that is to say, if the paper machine is stopped and samples are taken of the pulp web immediately following the final cylinder mold at varying stages in the preliminary pressing and after final ressing, it will be found that the web when greatest pop test in the sample taken immediately following the final cylinder mold and before any pressing. This is undoubtedly due to v the fact that the water included in the web hasits.

7 1,9 8,046 paper web formed by the cylinder molds upon causes the web when subjected to great presfsures, as in pressing, to shift as regards the lay of its fibres, for the press tends to expel water from that portion of the web held in the nip of the rolls through the web and this water acting upon the fibres of the web tends to cause them to assume positions longitudinal to the web. The actual pressing operation, when performed in the ordinary manner, has doubtless the same tendency. ,Board produced without preliminary pressing and simply by the use of extractor rolls has a much greater pop test than board produced from similar materials and under similar circumstances withpreliminary pressing. However, in order to sufliciently dry board by the use of extractor presses alone it is necessary that too great a number of extractor presses be of the wire covering or 23a overlying the suction box will be affected. This uniform dis-' tribution throughout the suction area, instead of confinement thereof to the relatively small number of openings, effectually prevents any such suction effort being exerted upon the paper as will cause the same to cling to the wire or to be deformed by being drawn into the interstices of the wire.

Sincethe construction employed is, obviously, capable of modification without departing from the spirit of my invention, I do not wish to be understood as limiting myself thereto except as hereinafter claimed. i W

I claim:

-l. In a cylinder paper machine comprising a plurality of cylinder molds, a pick-up felt associated with said molds and collecting the paper web therefrom, and means for extracting water from the web comprising a suction press through which the felt and web pass, said suction press including a suction roll having a cylindrical wire face in direct engagement with the web.

2. In a cylinder paper machine, a plurality of cylinder molds, a plurality of extractor presses and a suction press and a single felt passing sue- -cessively over said cylinder moldsthrough said extractor presses and through said suction press,

each of said extractor presses and suction press including a suction roll having a cylindrical wireface in direct engagement with the web, the suction box of the suction roll being disposed to exert its suction through the wire entirely in advance of the nip between the suction roll and its associated press roll.'

4. In -a cylinder paper machine comprising a plurality of cylinder molds, a pick-up felt associated with said molds and collecting the paper web therefrom, and means for extracting water from the web comprising a suction press throughwhich the felt and web pass, said suction press including a suction roll having a wire face in 5. In a cylinder paper machine, a plurality'of cylinder molds, a plurality of extractor presses and a suction press and a single felt passing suecessively over said'cylinder molds through said extractor presses and through said suction press,

each of said extractor presses and suction press including a -roll having a wire face directly engaging the paper web accumulated by the felt in its passage over the cylinder molds, the suction box of the suction roll being disposed to exert its suction through the'wire entirely in advance of the nip between the suction roll and its associated press roll.

6. In a suction press, a suction roll comprising a perforated shell, an interiorly arranged suction box co-operating with the shell, a cylindrical wire facing" for and attached to the shell, means spacing the shell and facing constructed and arranged to permit distribution of suction effort exerted through openings of the shell substantially uniformly through the portions of the facing overlying the suction box and a press roll co-acting with said suction roll.

7. In a suction press, a suction roll comprising a perforated shell having longitudinally-extending ribs, 9. wire facing for the shell operativelyvsupported from said ribs and a press roll co-acting with said suction roll.

8. In a suction press, a suction roll comprising a perforated shell having longitudinally-extending ribs, a heavy wire operatively supported from said ribs, a relatively light wire facing for the roll supported from said heavy wire and a press roll co-acting with said suction roll.

9. In a suction'press, a suction roll comprising a perforated shell having longitudinally-extending ribs, circumferentialiy-extending heavy reinforcing wires supported by said ribs, 9. heavy sieve wire supported by said circumferentially reinforcing wires, a relatively light sieve wire fac ing for the roll supported from said heavy sieve wire and a press roll co-acting with said suction roll.

10. In a suction press, a suction roll comprising a perforated shell having longitudinally-extending ribs, circumferentially-extending heavy reinforcing wires supported by said ribs, a heavy sieve wire supported by said circumferentially reinforcing wires, a relatively light sieve wire facing for the roll supported from said heavy sieve wire, the circumferentially-extending reinforce ing wires being engaged in notches formed in the ribs whereby to dispose the inner face of the heavy sieve wire in close proximity to the outer ends of the ribs and a press roll co-acting with said suction roll.

11. In a cylinder paper machine comprising a plurality of cylinder molds, a pick-up felt associated with said molds and collecting the paper web therefrom, means for extracting water from the web comprising a suction press through which the felt and web pass, said suction press includ ing a suction roll having a cylindrical wire face in direct engagement with the web, said suction roll comprising a perforated shell and an interiorly arranged suction box, and means supporting the wire face from said shell constructed and arranged to permit distribution of suction exerted through the perforations of the shell substantially uniformly throughout the area of the wire face aligned with the suction box.

12. In a cylinder paper machine, a cylindermold, a' pick-up felt associated with said mold and collecting apaper web therefrom, and means through said suction press, each of said extractor and suction presses including a roll having .a cylindrical wire face directly engaging thepaper web accumulated by the felt in its passage over the cylinder mold.

14. In a cylinder type of paper machine including a pick-up felt for transferring a fibrous web from the forming molds, means forextracting water from said felt and web carried thereon comprising a suction roll' having a defined suction area, a foraminous carrier passing over said suction area and means located outside of'said suction area for bringing said felt and web into direct cooperation with said carrier and suction roll for the application of suction through said carrier to said felt and web.

15. In a cylinder type of paper making machine, means for removing water from the paper web while on the pick-up felt comprising a suction roll, a foraminous carrier entrained around said suction roll. and means located outside of the suction area of said suction roll for directly contacting without pressure the fibrous web against said foraminous carrier when traveling over the suction area of said suction roll.

- l6. In'a cylinder paper machine comprising a plurality of cylinder molds, a pick-up felt as sociated with said molds and collecting the paper web therefrom, means for extracting water from the web comprising a suction roll over which the felt and web pass, said suction roll having a wire face in direct engagement with the web, the wire face being directly carried by theroll, and means to maintain the paper web in contact with the surface of the suction roll while passing over the suction box of the roll.

- CHARLES L. ELLIS.

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