US2259859A - Apparatus for making paper - Google Patents

Description

Oct. 21, 1941. c v

APPARATUS FOR MAKING PAPER Filed March 5, 1939 Patented Oct. 21, 1941 UNITED STATES APATENT OFFICE APPARATUS z'i R l zzxlNG PAPER Elzy Earl Covey, Niagara Falls, N. Y.

Application March 3, 1939, Serial No. 259,587 In Canada March 23, 1937 1 Claim.

cloth of much shorter length than that at pres-, ent used in paper making machines; with elim ination of the many supporting tube rolls now required, thereby reducing wear on the cloth to a large extent and permitting a much more rapid and convenient replacement of worn cloths. Further objects are to insure delivery to the wire of pulp in which the fibres are uniformly distributed and heterogeneously aligned, to prothrough a-pipe 4 having a valve 4', 5 a flow table for feeding the pulp onto the wire 2 at a point in its upward travel on the cylinder and somewhat above the centre thereof, 6 a suction box carried by a frame I within the cylinder I opposite the point of impingement of the pulp on the wire and-adapted immediately to extract water therefrom to form a paper web on the wire, and 8 an additional suction box also carried by frame I at a point above suction box B'within cylinder. I and adapted to extract further excess water from the paper web.

The cylinder I is mounted for rotation, by

lneans of bearing flanges 9, in semi-circular bearvide for continuous contact with the wire of a relatively small volume of flowing pulp and immediate withdrawal of water therefrom, to provide for more than one such flow of pulp to the wire and to provide for recovery of fine fibres from the white water from the wire. Another object is to provide means for readily varying the suction applied to the pulp at spaced points on the wire. e

The invention thus contemplates conveying the pulp from one or more head boxes over a flow table, which maintains the fibre thoroughly distributed, to impinge upon the wire at a point at which water is withdrawn from the pulp to form a web which isthereafter subjected to the action of suction. When more than one head box and flow table are used the water withdrawn by suction is returned with its contained fine fibres to the second head box which provides pulp for superimposing additional thickness of fibre on the web first formed.

The invention will now be described with reference to the accompanying drawing in which Figure 1 is an elevation of a machine in accordance with the invention,

Figure 2 is a plan,

Figure 3 is a diagrammatic form of the invention,

Figure 4 is an enlarged detail view in elevation of a flow table gate,

Figure5 is a plan of the view shown in Figure 4, and t Figure 6 is an enlarged plan of a battle arrangement in a flow channel.

Referring to Figures 1 and 2, I is a perforated cylinder, on which the usual endless wire cloth view of a modified 2 travels, 3 a. head box supplied with pulp stock ings I0, and is driven by means of gears II at either. end of the cylinder, chains I 2 and gears I3 on a driven shaft Id.

The flow table 5 is adapted to deliver continuously a relatively small volume of pulp to the wire 2 and includes means for uniformly distributing and heterogeneously aligning the fibres in the pulp as it flows thereon so that there is delivered to the wire at a constant rate, in uni form suspension in the water, a mass of fibre sufficient to form the desired web upon contact with the wire where the water is removed. .To this end, a series of channels l5 are provided on 'the flow table by means of a plurality of longitudinal partitions I6. The two outside partitions extend to the endof the flow table and the re maining partitions extend to within a short distance from the end whereby the pulp unites in a single stream just prior to its impingement on the wire 2. The pulp flows into each channel from head box 3 through openings I! each independently adjustable by means of gates I8 slidable in vertical members l9 and movable by means of a screw 20, which extends through a .cross member 2|, and nut 22. The independent adjustment of openings ll provides a ready and accurate means for overcoming any lack of uniformity in the formed paper web by regulation of the pulp flow atfixed points. 7 Two series of oppositelyinclined baliles 23 are provided in each channel I5 adjacent the lower end thereof to agitate the pulp just prior to its contact with the wire and thus to heterogeneously align the fibres whereby a much stronger web is formed.

A means 211s provided for shifting flow table 5 back and forth to permit access to the adjoining side of cylinder I and to provide adjustment of the table and comprises a pair of pinions 25 carried by a shaft 26 mounted in a frame 21 operable by handwheels 28 and meshing with racks 29 carried by the under surface of the table.

Owing to the substantially immediate extraction of water. from the pulp on its contact with the wire cloth, a pulp of greater density than usual is preferably used and a wire cloth of approximately fifty per cent less length than that required in ordinary paper machines may be employed. The usual number of supporting tube rolls are also eliminated and thus drag of the cloth on such rolls, with resultant wear on the cloth, is avoided. Thus, not only do such shorter cloths require more infrequent replacement, but the actual replacement is conveniently accomplished in a much less period of time than that ,required for the longer and more cumbersome cloths.

In some instances, when a thicker paper web is required or when one or more layers of pulp of a different grade or color are required in the web, one or more additional head boxes, as indicated at 33, may be provided. Pulp is supplied to head box 33 by means of inlet pipe 3| having a connection with pipe I by means of valve 32, for admission of, pulp of the same grade as that supplied to head box 3, and a connection with a second pulp supply pipe 33 by means of valve 34 for admission of pulp of a different grade, if desired. Pulp is delivered from head box 30 onto the wire 2, by means of a flow table 35 of similar construction to that of flow table 5, at a point slightly above the point of delivery of flow table 5, a corresponding suction box 36 also supported on frame I intermediate suction boxes 6 and I being provided within the cylinder I. Shifting means 31, similar to shifting means 24, is provided for table 35.

Suction boxes 6, 3 and 36 are connected to a header 33' of a vacuum pump 38 by respective pipes 33 having valves 40 whereby the suction applied to the wire at each point may be regulated as required, A relief valve 40' is provided in header 38' whereby regulation of the vacuum applied to the pipes 39 may be effected.

When pulp of the same grade is being delivered to the wire from at least two'head boxes, an im-' portant feature of the invention resides in the recovery of line fibres from the white water drawn of! by vacuum pump 33. This white water is fed into a chest 4| from whence it is pumped through a line 42 having a valve 43 into the second head box 30. Since delivery of pulp from head box 30 is made unto the outer surface of a web already formed on wire 2 the fine fibres are not again drawn through the wire and are substantially retained in the web.

While the arrangement of the wire 2 on a perforated cylinder is preferable in that frictional wear of the wire by direct pressure against suction boxes is eliminated, the invention may be readily applied to a system such as illustrated diagrammatically in Figure 3, wherein the wire 2 travels on rolls 44 with a similar arrangement of suction boxes and flow tables.

The supply of pulp to each head box is under a constant pressure, which may be substantially high, since the machine described, in view of the relatively small continuous volume of pulp delivered to the wire and the immediate withdrawal of water therefrom, is capable of a more rapid web formation than machines of the usual type.

It will be noted that the inlet pipes 4, 3| and 33 are of a. larger relative size than is usual since such pipes will accommodate the increased stock pressure without causing undesirable currents and resultant lack of uniformity in the stock on the flow tables.

I.claim:

In a paper making machine having a perforated cylinder, a travelling paper web forming member on said cylinder, a head box adjacent thereto, a flow table slightly inclined in a downward direction and leading from the top of the head box to said member on the cylinder, said table having a plurality of longitudinally extending channels thereon terminating short of the lower end thereof, independently adjustable gate means for admitting a controlled shallow stream of pulp from the head box into each of said channels, a plurality of series of pulp-engaging inclined baflles in each of said channels adjacent said lower end, said baiiles being inclined to the direction of flow of stock and the bailies in one series being oppositely inclined with respect to those in adjacent series, said streams of pulp being adapted to flow by gravity down said table and to unite in a single stream at the termination of said channels for delivery onto said member, and vacuum means within said cylinder for extracting water jfrom the pulp stream at substantially its point of contact with said member.

ELZY' EARL COVEY.

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