US2641972A

US2641972A - Cylinder mold for papermaking machines

Info

Publication number: US2641972A
Application number: US128655A
Authority: US
Inventors: George A Engert
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-21
Filing date: 1949-11-21
Publication date: 1953-06-16
Anticipated expiration: 1970-06-16

Description

June 16, 1953 ENGERT CYLINDER MOLD FOR PAPERMAKING MACHINES 2 Sheets-Sheet 1 Filed Nov. 21, 1949 June 16, 1953 e. A. ENGERT 2,641,972

CYLINDER MOLD FOR PAPERMAKING MACHINES Filed Nov. 21, 1949 2 Sheets-Sheet 2 INVENTOR 6:04 :11 Elven TTORN YS Patented June 16, 1953 CYLINDER MOLD FOR PAPERMAKING r t MACHINES George A. Engert, North Hoosick, N. Y.

' Application November 21, 1949, Serial No. 128,655

This invention relates to improvements in pape making machines and particularly relates to a new and useful cylinder mold construction for high-speed cylinder paper machines.

- In such machines, a foraminous cylinder mold having a finemesh woven wire outer surface, revolves partially submerged in a vat pond of Water and paper stock mixture.

The stock consists of vegetable fibers reduced by acid'or alkali process or by mechanical means to hair-like particles of cellulose ranging in length from one millimeter to one and a quarter millimeters. These particles or fibers of cellulose are then mixed with water, generally to form a consistency of one half of one percent solids to water. Clay, starch, resin size, coloring matter, alum and other -loading chemicals are added, the choice depending on the properties desired in the finished paper. This mixture is then flowed r pumped to the vat into which the foraminous cylinder rotates.

Usually the cylinder is from to 12 feet long with a series of internally spaced supporting :spiders. The ends of the cylinder are sealedto. the sides of the vat so that water in the paper .stock flows through the fine wire cover of the cylindrical surfaces into the inside of the cylinder. A-sheet of cellulose fibers'isthus deposited on the face of the cylinder. Water is drawn from the inside of the cylinder forming a differential head of pressure between the inside and the out- .side of the cylinder to further draw liquids from the vat and deposit solids on the cylinder face.

The speed in forming a sheet of paper by this method is limited to the rate at which water in the stock outside the cylinder can be drawn through the screen face into the cylinder. It is known that a lighter consistency of solids to water in the paper stock will make a better sheet. However, to .gainthis lighter consistency, a larger volume of water must be drawn from the stock.

Cylinders heretofore used have not been capable of drawing the larger volume of water without appreciably slowing the rate of speed.

The speed of such prior cylinder machines is limited to a sheet formation at a rate of approximately four hundred feet of paper perminute. Beyond this speed centrifugal force tends to throw the formed sheet off the wire face of a cylinder. The supporting structure of spokes and rods inside the cylinders agitate the water in the'cylinder interior at such higher speeds forcing the water outwardly through the cylinder face. Thus distortion occurs in the sheets being formed. In

addition churning of the water retards the 'angular velocity of the cylinder and interferes with the proper drainage of Water from the interior cylinder.

An object of this invention is to provide a cylinder mold construction which will form a stronger sheet of paper from a lighter consistency of paper stock and water and to do so with a minimum of grainage at a speed greatly in excess of the speeds now obtained by conventional molds for this purpose.

Another object of my invention is to provide a smooth hollow cylinder free from internal spokes,

box chamber to assist in dislodging the formed sheet more rapidly in transferring the same from the cylinder onto the under side of the usual felt conveyor belt for further drying and processing.

Other objects and advantages will be apparent from the following description and drawings, in

which:

Fig. '1 is a more or less diagrammatic view in perspective of a new cylinder as installed in a vat, with suction couch roll and traveling felt also indicated;

Fig. 2 is an elevational view showing a cylinder mold in the tank as inFig. 1 with parts broken away for, clarity; Fig. 3 is a sectional view taken on line 3-.-3 of Fig. 2; v

Fig. 4 is a fragmentary sectional view taken on line 44 of Fig. 3 to show details of the sealing ring and cylinder face construction;

Fig. 5 is across section of the cylinder with parts removed taken on line 5-5 of Fig, 2 to show suction box arrangement;

Fig. 6 is a perspective view, in broken section, of the cylinder; and

-Fig. '7 is a perspective view on reduced scale of contained in a stock vat ll having a series of adjustable making boards l2. Paper stock is fed 'into thevat as shownby the flowarrows, while terior of the cylinder.

the cylinder I is revolving, to almost totally submerge the cylinder. As stock attempts to penetrate the cylinder face, wire mesh screen l3 on the face of the cylinder l0 strains out the stock solids and the water filtrate drains into the interior of the cylinder where it is pumped off through outlet M in one side of the vat. The solid material which collects and settles on the wire mesh l3 emerges as a wet sheet on the mold at the stocl; level near the top of the vat. Across the top of the cylinder ID a felt web 15 is drawn and the wet sheet is lifted from the mold surface by the web. At the point of contact, .a couch suction roll it of the usual construction draws further water out of the wet sheet.

Cylinder it is supported by two end spiders ll (Figs. 2 and 3). Spiders I! are provided with hollow hubs l9 and 26 which extend through the sides of vat H and are supported thereby. Both hubs are journaled in the vat sides and are freely rotatable therein. A stationary pipe 2! is supported in the hubs as an axle and extends between the sides of the vat. Pipe 2| is closed at one end by a cap 22 and is connected at its other end to a vacuum pump arrangement as will be described.

Hub is of spider ll is slightly elongated and carries a spur gear 28 for driving engagement with a variable speed gear drive mechanism (not shown) so as to revolve cylinder iii aboutstationary pipe 2!. Bearing bushings 24 are interposed between each hub and the pipe 2 l.

The supporting shell of the new cylinder is formed by a cylindrical plate 25 (Fig. '6) attached to rims 26 of the two spiders. Plate 25 is perforated with large closely spaced openlugs 52! for free drainage of water into the in- Closely spaced longitudinal rods 28 are affixed as by countersinking on plate 25 and are held as by riveting.

They extend the length of the cylinder between the spider rims -26. Transversely of rods 28 and wrapped around the cylinder are a series of closely spaced wires 29. The woven cylindrical wire screen t8, covers wires 281 and is of approximately 50 or 60 mesh as maybe desired.

Inside cylinder 59, the lower half of the stationary pipe 2i is perforated (see Fig. so as to form a suction tube for drawing a vacuum in the interior of the submerged lower portion of the cylinder. Longitudinal walls or

partitioning plates

35 and 3|, extending the full length of the cylinder between the two rotating end spiders, divide the cylinder interior into upper and lower compartments. The wall plates 3t and 35 are fixed to the pipe Eland extend radially from the pipe. Gaskets 32 at their outer edges abut the inner surface of. shell plate 2-5 to provide a sealing contact. I 7

Rims 26 of the spidersare flanged and a complementary circular flange or chime ring 33 (Fig. t) extends from each side of vat ii. A liquid tight rubber ring 34 sea1s the space between these flanges and prevents any of the vat conlower half ofpipe 2i.

the rotating cylinder thus drawing water through the cylinders peripheral openings into the lower compartment 38 which water in turn is pumped out through outlet M.

The open end of pipe 2| provides a conduit for a connection to a suitable vacuum pump and suction created in pipe 2| is exerted in lower compartment 36 through the perforations in the The partial vacuum in the lower compartment 35fassists, in drawing a greater amount of water from the sheet being formed on the face of the cylinder and further helps in the rapid forming of the sheet against the face.

In the upper half of the cylinder provision is made'for three chambers or

sections

37, 38 and 39. (see Fig. 7) by two vertically disposed longitudinalwall plates t0 and Al fixed to pipe 2| and extending radially therefrom. These plates also have sealing gaskets 32 at their outer edges to abut the revolving inner surface of the shell plateZE. Semi-circular end walls in the upper half of the cylinderradjacent the spiders as at 42 in Fig. close the ends of sections 37., 32 and 3%.

A. suction tube 43 located within tube 2| is connected to section 37 by branches through the wall of tube'il adjacent section 37 so as to create a vacuum of slightly different degree in this section than is drawn in the lower compartment through. the larger suction pipe 2|. The vacuum drawn in section 31 is preferably slightly greater and is for the purpose of further sheet formationiand to eliminate wash and slippage of the formed wet sheet as it leaves the stock level in the vat at the point of emergence as will be described. At this location on the cylinder facing the inlet side of the tank the sheetisstronger and can stand somewhat more suction without aifecting its proper formation.

Section 38 is of'appreciably smaller volume, covers less cylindrical surface and provides a pressure chamber for the cylinder. It is locatedlat the top of thecylin der where the wet sheetcontacts the felt/web 15 at the nip of thefcouch roll 15.

This chamber is supplied with'pneumatic pressure from a pressure line as a tube 3 1 placed inside pipe 2!. Tube 2-6 has branches as at 45 'to section 38 so as to direct the air under pressure toward the nip of the couch it and assist in the removal of the wet sheet of paper from the web I5.

The third section 39 in the upper portion of thecylinder liesbetween plates 3%) and 4| and is blanked oil so that pipe 21 for compartment cylinder onto the felt .36 willnot have connection to the top of the cylinder on this side and the atmosphere. The wall 39 is at the mid line of the vat so that stock level in the vat can diminish to'that point without aifecting the desired vacuum pressure in lower compartment '35.

In Figs. 2 and 3 it will be noted that sealing caps dfi are providedat each endof the vat to seal the exposed part of the cylinder from the atmosphere at each end between the edge of the cylinder and, the tank.

Plate 25 with its relatively large perforations is of sufiicient strength together with the longitudinal rods '28 to be self sustaining when mounted on the end spider construction as described. The inner surface of the plate 25 being smooth creates less turbulence and permits the use of the suction boxes orchambers as described.

The speed. possible with the new cylinder is appreciably greater than that possible with usual high speed cylinder mold constructions. In operation the formation of the sheet on the mold is assisted first by suction in the lower compartment in addition to the usual differential and secondly by the slightly greater degree of suction created in the section chamber 31 Where the wet sheet emerges from the level of stock in the vat. Furthermore, the speed of sheet formation is not affected by the usual limitations of speed at which the sheet may leave the cylinder. Air pressure at the nip of the couch roll may be controlled to enable a faster take off as may be desired onto the traveling felt web.

Having described my invention, I claim:

A cylinder mold for operation in the stock vat pond of a paper making machine comprising a hollow cylindrical shell having a series of closely spaced relatively large openings in the wall thereof and a smooth inner and outer surface, supporting spiders solely at the ends of said shell, a stationary pipe of relatively small diameter throughout supporting said shell, hubs on said spiders journaled on said pipe, a plurality of spaced rods fixed longitudinally on the outer surface of the shell, closely spaced, transverse wires encircling said rods and a wire mesh screen covering over said wires in closely spaced relation to said shell, the interior of said shell-being compartmented into four chambers,.horizontally disposed flat walls extending longitudinally of 6 one of said horizontal walls and therebetween an inlet side of said cylinder shell, a second pipe longitudinally disposed within said shell supporting pipe and forming a second suction conduit, said second pipe having suction port conduits communicating through the wall of the shell supporting pipe between said latter Walls for creating a second suction chamber for the inlet side of said shell, a fiat wall closely spaced from said vertical wall and on the outlet side of the same to form therebetween a pressure chamber, a pressure conduit in said pipe and ports therein communicating with said pressure chamber, the chamber formed by said last-named wall and the horizontal wall at the outlet side of said shell being closed and preventing communicaticn at said outlet side with any of said other chambers, semi-circular end walls adjacent said spider supports closing off the ends of said chambers in the upper portion of said shell and sealing gaskets at the outer ends of the walls abutting the smooth inner surface of the shell.

GEORGE A. ENGERT.

References Cited in the file of this patent UNITED STATES PATENTS I Number Name Date 693,895 Parker Feb. 25, 1902 1,166,882 Beaumont Jan. 4, 1916 1,709,026 Kutter Apr. 16, 1929 1,991,346 Ellis Feb. 12, 1935 2,329,553 Newbold Sept. 14, 1943 2,338,465 Street Jan. 4, 1944 2,520,327 Nilson Aug. 29, 1950 FOREIGN PATENTS Number Country Date 21,597 Sweden Mar. 24, 1905 557,413

Germany Aug. 23, 1932