US2123958A

US2123958A - Paper manufacture

Info

Publication number: US2123958A
Application number: US115A
Authority: US
Inventors: Roland A Packard
Original assignee: SMITH PAPER Inc
Current assignee: SMITH PAPER Inc
Priority date: 1935-01-02
Filing date: 1935-01-02
Publication date: 1938-07-19
Anticipated expiration: 1955-07-19

Description

July 19, 1938. R. A. PACKARD PAPER MANUFACTURE Filed Jan. 2, 1935 2 Sheets-Sheet l wom .El

lNVENTOR Roland A. Pocko Vd BY ATTORNEYS July 19, 1938.

R. A. PACKARD Pffl. MANUFACTURE Fifed Jan. 2, 1935 2 Sheets-Sheet 2 INVENTOR Roond A. Packard BY ATTORNEYS Patented July 19, 193s UNITED STATES PAPER MANUFACTURE Roland A. Packard, Lee, Mass., asslgnor to Smith Paper, Inc., Lee, Mass., a corporation of Dela- Application January 2, 1935, Serial No. 115

20 Claims.

This invention relates to the manufacture of paper, and more particularly to the treatment of half stock, especially rag half stock.

In accordance with prior practice, bleached unbeatenrag stock or rag half stock is dropped into a drainer which ordinarily takes the form of a bin having perforated brick at the bottom. After the stock remains 'in the drainer for a considerable period, it must be dug out manually and conveyed to the beater. The drainage is not thorough, and retained bleaching agent has a weakening effect on the fibre.

The object of my invention is to generally improve the handlingand drainage ofI rag half stock, that is, unbeaten rag stock, and to avoid the delay and labor heretofore necessary, as well as to improve the strength of the product by thorough drainage.

To the accomplishment of the foregoing general objects and numerous more specific objects which will hereinafter appear, my invention consists in the method steps and apparatus elements and their relation one to the other, as are hereinafter more particularly described in the specication and sought to be defined in the claims.

\ The specification is accompanied by drawings in which:

Fig. 1 is a side elevation of apparatus embodying features of. my invention;

Fig. 2 is a plan view of the same;

Fig; 3 is a detail of the table lowering mechanism;

Fig. 4 is a section taken in elevation through the screen or wringer apparatus;

Fig. 5 is a section .taken in the plane of the line 5-5 of Fig. 4; and

Fig. 6 is a section taken in the plane of the line 6--6 of Fig. 4.

Referring to the drawing and more particu- 40 larly to Figs. 1 and 2, the complete apparatus comprises a bleacher B, a centrifugal pump P for delivering the stock to a spout S located over the moving screen of drainage and lmat-forming apparatus W which, for convenience, may be referred to as a wringer. The rate of feedof stock to the Wringer is controlled by bleeding a part of the stock back `into the bleacher B, as by the use of overflow sluices O. From another viewpoint, it may be said that the bleached stock is continuously circulated by the pump P, and that a. desired amount ofthe circulating stock is supl plied by spout S to the wringer W. The stock is formed into a mat or web by the wringer, and this is piled or lapped on a suitable table T by means of an apron A.

, means not shown in the drawings.

Considering Vthe arrangement in greater detail, the bleacher B may be of conventional type comprising a tank I2 provided with a paddle I4 mounted on a shaft I6 driven by appropriate Tank I24 is 5 provided with a central wall or partitlonJ which insures thorough circulation of the stock upon rotation of. paddle I4. The contents of the tank are drained. through pipe 20 the upper end of which may be stopped by an appropriate valve or 10 cover plate 22. It will be understood that with the cover plate in place, the stock may be treated in the paddle bleacher until properly bleached, at which time the cover plate is removed by a suitable hook. y l 15 In accordance with prior practice, the bleached rag half stock is drained in this manner directly into simple drainage bins-from which the stock must later be dug out. I have discovered that it is possible to handle the rag half stock by 20 flowing the samev in its liquid or bleaching vehicle, even at a consistency of, say, 4% (4 pounds of dry stock to 96 pounds of water) This was heretofore thought impossible because unbeaten rag stock or rag half stock is heavy, long-fibered, 25 stringy, and easily tangled and snarled. Despite the difficult nature of the material, I find-it possible to elevate the same by means of a suitable centrifugal pump 24 which is preferably provided with Stellite cutting blades cooperating with the 30 impeller blades of the pump, and which is further provided at its inlet end with a screw conveyor or feed 26.

The stock ascends through conduit 28 having a horizontal section 30 extending over the bleacher 35 B and terminating at spout S located directly above the end of wringer W. It should be noted that the spout is large, fully open, and preferably expanded or be1l-mouthed., Also, that

conduit

28, 30 is preferably devoid of fittings or obstruc- 40 tions which might discriminate between the liquid and solid parts of the stock. I have accordingly devised special means for controlling the rate of flow of stock to the wringer, it being undesirable to use ordinary valve or gatemeans which 45 tend to dam the solid parts of the stock. Instead of obstructing the flow of material, I bleed a. part of the ow back into the bleacher B and control the feed to the wringer by modifying the amount of stock bled back to the bleacher. For this pur- 50 pose, I provide overflow sluices O, best shown in Figs. 1,2, and 6 of the drawings. The conduit 30 is cut-"away at 32.` Troughs 34 arehsecured to the sides of conduit 30 far below the top of the conduit 'and preferably near the bottom thereof, and said 55 of the same.

troughs lead rearwardly and downwardly to a point over the bin B. 'I'he forward ends of troughs 84 are preferably closed by a wall or partition 36. It is possible to pivot the troughs 34, thereby regulating the overflow by changing the tilt or angle of the troughs, but Iflnd that satisfactory results are obtainable while xing the troughs rigidly to the conduit in the manner shown, the feed being regulated by varying the height of the mouth of discharge spout S above the wire screen of the wringer W. For this purpose, the conduit is counter-balanced by weight 38 connected to the conduit by means of an appropriate cord 40 passing over pulleys 42. The position of the conduit may be adjusted by a screw 44 threaded in block 46 mounted on the frame of wringer W. The movement of the spout is small and is accommodated by elasticity of the conduit leading to the spout.

Spout S terminates in a large open and preferably expanded mouth 48 the bottom edge of whichl is disposed parallel to the wire screen 50 of wringer W, as is best shown in Fig. .4 of the drawings. It will be understood/that much of the stock flowing through conduit 30 is at a level higher than the overflow troughs, and is simply circulated, with the stock kept constantly in motion to prevent settling and accumulation, and that the part of the stock flowing from spout S spreads out on the traveling screen. The stock is at all timeskept in motion or dynamic, and is not allowed to dwell or become static, for it then promptly settles. There is an automatic regulation of the rate of feed because the stock builds up on the wire at the spout and automatically checks the feed of stock when the supply is excessive. This, of course, encourages overflow at the sluices and increased bleeding of stock back into the bleacher. In practice it is seldom necessary to change the position or adjustment of the spout. It will be evident, however, that the elevation of the spout above the screen determines the thickness of the mat of material deposited on the screen before the checking or automatic regulation takes` effect. This in turn is a measure of the rate of feed of stock to the wringer.

The wringer W comprises a frame 52 mounted on posts 54 and supporting at one end a breast roll 56 and at the other end a couch roll 58. The wire screen 50 is in the form of an endless band passing around the breast roll 56 and couch roll 58. It will be noted that the couch roll 58 is at a higher elevation than breast roll 56, so that the screen is given a slight upward inclination. 'I'he upper or useful part of the screen is supported on a large number of closely adjacent carrier rolls '60 and also upon

maple boards

62 and 64, as is bestshown in Fig. 4. 'I'he screen may be four feet or more in width and is preferably of fine mesh, say 40 x 40. The lower part of the screen is supported on idlersl 86, while the screen is kept taut by a tensioning roll 68.

Above the screen, I provide a series of rolls spaced progressively nearer the screen for compressing the stock into a mat or web-and for wringing substantially all of the wash water out In the present example, I employ first and second rolls 10 and 12 which act primarily as forming rolls to level and form the stock into a relatively thick mat. I also provide

rolls

14 and 16 which act as press rolls to compress the mat and to eliminate most of' the liquid. The wringer terminates with a preferably rubber covered couch roll 18 which bears against couch roll 58. The upper couch roll is made extra-heavy and operates to wring any remaining free liquid from the mat or web of stock. I do not mean that the stock is absolutely dry, but it is nearly dry and much more eifectively so than was the case when using drainage bins as in the prior art.

It should be noted that the rolls are mounted on arms 80 (see Fig. l) pivoted at 82 and provided with stop bolts 84 for limiting the permissible downward movement of the rolls. Stop bolts 84 are threaded in arms 80 and are provided with lock nuts 86 to hold the same at any desired adjustment. 'I'he adjustment is made such that there is a space of, say, one inch or more between the first roll and the screen, which is reduced, however, to a matter of o nly, say, one-sixteenth of an inch at the last roll. The mass of the rolls is relied upon for downward pressure, there being nothing to positively prevent upward movement of the rolls.

The yreaction of the forming rolls 'l0 and 12 is taken by the

maple boards

62 and 64 which are provided with lateral grooves 88 and drain holes 90 to insure free discharge of liquid. The reaction of press rolls 14 and 16 is taken by the continuous series of carrier rolls heretofore referred to, while the reaction of the final pressure roller 18 is, of course, taken by couch roll 58. The upper rolls are all provided with appropriate doctor means to prevent any stockf clinging to the roll from traveling up around the roll. For this purpose, the

rolls

10, 12, 14, and 16, which may be made of brass, are fitted with doctor blades 82 preferably made of bakelite. The rubber covered roll 18 is provided with a flapper 94 having rubber blades 96 and rotated against the roll by means of a chain and sprocket drive 08.

- The stock is confined to the screen at the side edges of the screen by deckle boards |00, best shown in Figs. 4 and 5, and anend board |0| located at the breast; roll. These deckle boards are preferably fitted with rubber deckle strips |02 which bear directly against the screen 50. The rubber strips may be terminated before the end, say, between the press rolls 14 and 16 because from that point on, the mat is already fairly solid and controllable. The wash water expressed from the stock is caught by an appropriate save-all pan |04 which is preferably made co-extensive with the screen. Because of the inclination of the screen and the corresponding inclination of the save-all pan, the liquid drains toward the inlet end of the wringer where it may be discharged at one side by an outlet |08. 'Ihe floor beneath the wringer is preferably walled-in by curbs |08, and the enclosed space is provided with a suitable drain ||0.

The wringer W strengthens the fibre because it greatly shortens the drainage time, and more importantly, because it provides thorough drainage of the bleaching agent. The screen alonel with the stock spread well out on its surface, is a good drainage medium, while the rolls afford a positive compression and wringing of the stock. The absence of a breast box, reservoir or pond, is important because of the stringy tangled condition of the rag half stock, and the impossibility of suspending the same, the stock' being in gobs or clumps like handfuls of machinists waste. The screen is upwardly inclined to help retard the stock and to thereby forin a better mat. The mat formation is convenient for transfer to the beater, and wholly eliminates tedious manual digging out of stock from a pit or bin.

The wringer is driven by a motor ||2 connected through a speed reducing gear box ||4 to the shaft ||6 of couch roll 58, which, of course, drives the s'creen 50. Shaft I6 is provided with a gear H8 which meshes through a direction reversing idler |20 with a gear |22 for driving the apron A, the operation of which will be described in detail later. With respect to the wringer W, the gear meshes with a direction reversing idler |24, which is connected to press roll 16 by a chain and sprocket connection |26. Similarly, rolls 14, 12, and are connected by chain and sprocket connections |28, |30, and |32. The linear speed of the wire may be varied, but I nd a speed of 140 feet per minute to be satisfactory. I also find it helpful to so gear the earlier rolls, preferably the

rolls

10, 12, and 14, that they run at a surface speed slightly greater than the speed of the wire.

The mat or web leaving the wringer is ready to be delivered to a beater. A convenient and preferred way to handle the web is to load the same in lapped formation on a loading table. Referring to Figs. l, 2, and` 3, I provide a loading table T on which the stock is lapped" by a load# ing apron A. Apron A may be made of fabric and passes over drive roll |40 which moves at the same surface speed as the screen 50 and is geared to the couch roll of screen 50 to insure synchronous operation. As previously mentioned, this gearing comprises gear ||8, idler |20, and a gear |22 mounted on the shaft of drive roll |40. The apron passes over a carrierroll |42 and then between twin guide rolls |44 mounted on a carriage 4|48 which is horizontally reciprocable on rails |48. 'The apron is led back over carrier roll |60, and slack of the apron is preferably taken .up by weighted tensioning rolls |52 located von opposite sides of a support roll |54.

' It' will be understood that reciprocation ofthe carriage |46 over table T will cause the mat or web of stock supported on yapron A to be deposited on the table in lapped formation, as shown in Fig. 1 of the drawings. n

Although I have indicated the use of a separate motor |80, it will be understood that this mechanism may, if desired, be-operated from motor ||2, as by .extending the shaft of the motor from gear box ||4 to gear box |62. In fact, the usey of a single motor is preferable for maintaining exact synchronisrl between the linear speed of the web and the speed `at which the apron guide |46 is reciprocated.

Table T is preferably made vertically reciprocable inlorder to maintain the top of the stock at a substantially constant level. For this purpose, I mount table T on supports |80 threaded on posts |82 which are geared for simultaneous rotation by a chain and sprocket system |84. One of the posts is provided with a worm gear |86 meshing with a worm |88 mounted on a shaft |90. Shaft |90 carries a ratchet wheel |92 best shown in Fig. 3. The ratchet wheel is operated by a pawl |94 carried by an arm |96 oscillated by a link |98 connected to the crank pin of crank disc |10. The rate at which the table is lowered may be regulated by adjusting the point of connection of link |08 and pawl arm |96, thisl adjustable connection being indicated at 200. The outer end of shaft |90 is also ypreferably provided with a manually operable crank 202. This crank facilitates restoration of the table toelevated position, the pawl |94 being released while the crank is operated.

The operation of the apparatus may be summarized as follows. The stock, which is unbeaten rag stock, is preliminarily bleached in paddle bleacher B. The cover plate 22 is then removed, and the bleached stock is mechanically pumped directly from the bleacher to the moving screen 50 of the wringer W. The supply of stock is regulated by bleeding or bypassing part of the stock directly back to the bleacher. The resulting continuous circulation of the stock helps maintain the same in an active condition and at a uniform consistency. No breast box is employed, and every effort is made to prevent damming or dwelling of the stock, with consequent settling of the solid matter. The large open-mouthed spout S and overflow O form a combination practically automatic in operation. The stock is impelled outwardly from the spout and oods out on the wire screen and undergoes preliminary drainage through the screen. It is restrained at the edges by the deckle boards |00. Former rolls 10 and 12 level off the stock and causeadditional drainage. Bress rolls 14 and 16 compress and further drain the stock to form a compacted mat. This is given a final wringing between couch'roll 58 and rubber covered pressure roll 18. The discharged web, of material is fed upon and supported by apron A the discharge point of which is reciprocated over table T by carriage |46. This causes a. lapping of the web on table T. The table is lowered as stock is loaded thereon, by rotation of the supporting screws |82.

It is believed that the mode of practicing m invention, as well as the many advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described my invention in preferred form, many changes and modifications may be made without departing from the spirit of the invention, defined in the following claims.

I claim:

l. In the manufacture of paper, the method which includes bleaching rag half stock, feeding the bleached stock to moving wringer means, and bleeding or bypassing a part of the stock being fed to the wringer means in order to regulate the rate of fiow of stock thereto, the stock being handled in a continuous active state of movement,

and being given no opportunity to dwell and settle.

2. In the manufacture of paper, the method which includes bleaching rag half stock in a conventional paddle bleacher, feeding the stock to a pump,- thereby pumping the stock to wringer means located at an elevation higher than the paddle bleacher, and Without damming the stock being pumped to the wringermeans bleeding a part of the same back into the paddle bleacher in order to regulate the rate of fiow of'stock to the wringer means.

3. In the manufacture of paper, the method which includes bleaching rag half stock, feeding the stock in its bleaching vehicle and in a dynamic condition to a traveling screen, bleeding a part of the feed in order to regulate the -rate of flow of stock to the screen, and pressing the stock on the screen.

4. In the manufacture of paper, the method which includes bleaching unbeaten rag half stock in a bleacher, feeding Ithe unbeaten stock to a pump and thereby elevating the stock to a traveling screen located higher than the bleacher, bleeding a part of the unbeaten stock being pumped to the screen back into the bleacher in order to regulate the rate of flow of stock to the 5 screen, and pressing the unbeaten stock on the 1 screen.

5. Apparatus for treating unbeaten'rag half stock. comprising a bleacher and a. centrifugal pump connected to form a circulating system for continuously circulating the unbeaten stock,

wringer means, and means to feed a desired part r only of the circulating unbeaten stock to said wringer means.

6. Apparatus for treating unbeaten rag half stock, comprising a paddle bleacher and a pump connected to form a closed circulating system for continuously circulating the unbeaten stock, means to feed adesired part of the circulating unbeaten stock to a traveling drainage and wringer screen, and cooperating rolls for pressing the unbeaten stock on the screen and the same into a mat.

7. Apparatus for treating unbeaten rag half stock, comprising a bleacher and a centrifugal forming pump connected to form a closed circulating system for continuously circulating the unbeaten stock, means to feed a desired part only of the circulating unbeaten stock to a traveling drainage and wringer screen, cooperating rolls for wringing and forming the unbeaten stock into a.

mat, and means at the end of the wringer screen for piling the unbeaten stock in lapped formation on a suitable table.

8. Apparatus for drying bleached rag half stock, said apparatus comprising a frame, a

breast roll at one end of said frame, a couch roll at the other end of said frame and higher than said breast roll, an endless wire screen passing around said breast roll and couch roll, a plurality of carrier rolls located beneath and supporting said screen, a plurality of rolls located above and spaced-along said screen, a roll located above the aforesaid couch roll, the rolls being arranged successively progressively nearer the screen,A means driving some of said rolls, and doctor means for said rolls.

9. Apparatus for drying bleached rag half stock, said apparatus comprising a frame, a breast roll at one end of said frame, a couch roll Zat the other end of said frame and higher than said breast roll, an endless wire screen passing-V around said breast roll and couch roll, a plurality of carrier rolls located beneath and supporting said screen, a plurality of forming rolls spaced s; along said screen, drain boards located beneath i the screen at said forming rolls, a plurality' of Y press rolls following said forming rolls, a rubber covered pressure roll located above the aforesaid couch roll, said rolls being arranged successively do progressively nearer the screen, means driving at least some of said rolls, said means being arranged to drive the ilrst rolls ata speed somewhat greater than the speed of the screen, and doctor means for said rolls. l

10. Apparatus for treating unbeaten rag half stock, said apparatus comprising a bleacher, a wringer, means to feed the unbeaten stock from the bleacher to the wringer, and means to bleed away part of the stock being fed to the wringer 70.111 order to regulate the rate of feed of stock reaching the wringer.

1l. Apparatus for treating rag half stock, said apparatus comprising a bleacher, a traveling drainage and wringer screen, means to feed the u stock from the bleacher and to ow the same on 12. Apparatus for treating unbeaten rag half stock, said apparatus comprising a bleacher, a centrifugal pump connected thereto, a traveling wire wringer screen located at an elevation higher than said bleacher, a conduit extending from the pump outlet directly to the screen without intermediate breast box or the like, said conduit, being provided with means to bleed excess stock back into the bleacher and thence to the pump, in order to regulate the rate of feed of stock to the screen.

13. Apparatus for treating unbeaten rag half stock, said apparatus comprising a bleacher, a centrifugal pump connected thereto, a traveling wringer screen located at an elevation higher than said bleacher, a conduit extending from the pump outlet to a spout located above the screen,

overflow sluiceways located directly in the conduit and leading back to the bleacher, and means to vary the bleeding effect of the overflow sluiceways.

14. Apparatus for treating unbeaten'rag half stock, said apparatus comprising a bleacher, a centrifugal pump located therebeneath, a traveling wringer screen located at an elevation higher than said bleacher, a valved conduit connecting the bleacher and the pump inlet, another conduit extending from the pump outlet to a spout located above the screen, said spout being provided with overflow sluiceways extending to a point over the bleacher, and means to adjust the height of the spout above the screen in order to regulate the rate of feedof stock to the screen, the excess stock being returned to the bleacher and thence to the pump.

15. Apparatus for drying bleached half stock, said apparatus comprising a wringer screen to form the stock into a mat or web, and means to pile said mat, said means comprising laterally reciprocable guide `means for the mat leaving th`e screen, a vertically movable table located beneath said guide means, and means for reciprocating the guide means and for simultaneously lowering the table.

16. Apparatus for drying bleached rag half stock, said apparatus comprising a wringer screen to form the stock into a mat or web, and means to pile said mat, said means comprising an endless conveyor or apron, a drive roll for moving the same, a vertically movable table located beneath said apron, guide rolls mounted on a laterally reciprocable carriage for4 reciprocatin'g the discharge end of the apron over the table, means for taking up the slack of the apron,

and means for reciprocating the guide' rolls and nected to said bleacher and having a discharge conduit extending upwardly to a point. directly over the receiving end of the wire screen without intermediate breast box or the like, the discharge end oi' said conduit being provided with a downwardly directed expanded or bell-mouthed spout the edge of which is disposed generally,

parallel to the surface of the screen andi at a.

height thereabove such as to help regulate the discharge of the stock onto the screen.

18. Apparatus for drying bleached but unbeaten rag stock, said apparatus comprising an endless wire drainage screen, a plurality of rolls for supporting and moving said screen, one or more rolls for pressing stock owed onto said screen, and means including an enclosed supply conduit having a downwardly turned spout for so flowing the unbeaten stock directly onto the drainage screen as to initially spread and distribute the stock over the surface of the screen, said spout being an enclosed conduit forming a continuation of the supply conduit and having at its bottom end a fully open downwardly directed mouth of large area, said mouth being as large as the cross-section of the conduit and opening directly onto the top of the screen, without intermediate box or the like, the periphery or lip of said open mouth being disposed directly over and generally parallel to the screen, and sufliciently close thereto as to cause the unbeaten stock to spread out sidewardly from the spout over the surface of the screen.

19. Apparatus for drying bleached but unbeaten rag stock, said apparatus comprising a breast roll, a couch roll, an endless wire screen passing around said breast roll and couch roll, a pressure roll located above said couch roll, other pressure rolls above said screen between the couch roll and the breast roll, means driving at least some of said rolls, said means being so arranged as to drive the iirst pressure rolls at a speed higher than the last pressure rolls, and means to feed the stock in an active dynamic unsettled condition directly onto the screen, said means including an enclosed supply conduit having a downwardly turned spout for so iiowing the unbeaten stock directly onto the drainage screen as to initially spread and distribute the stock over the surface of the screen, said spout being an enclosed conduit forming a continuation of the supply conduit and having at its bottom end a fully open downwardly directed mouth of large area, said mouth beingl as large as the crosssection of the conduit and opening directly onto the top of the screen, Without intermediate box or the like, the periphery or lip of said open mouth being disposed directly over and generally parallel to the screen, and sufiiciently close thereto as to cause the unbeaten stock to spread out sidewardly from the spout over the surface of the screen.

20. Apparatus for drying bleached but unbeaten rag stock, said apparatus comprising a frame, a breast roll at one end of said frame, a couch roll at the other end of said frame, an endless wire screen passing around said breast roll and couch roll, a plurality of carrier rolls located beneath and supporting said screen without appreciably obstructing free ow of liquid therethrough, a substantial number of rolls 1ocated above and spaced along said screen, means to limit the movement of said rolls away from said screen to amounts which are successively progressively less, whereby the rolls are progressively nearer the screen and have a progressive wringing action, means driving one or more of the rolls, and means to flow the unbeaten stock directly onto the drainage screen, said means including an enclosed supply conduit having a downwardly turned spout for so owing the unbeaten stock directly onto the drainage screen as to initially spread and distribute the stock over the surface of the screen, said spout being an enclosed conduit forming a continuation of the supply conduit and having at its bottom end a fully open downwardly directed mouth of large area, said mouth being as large as the cross-section of the conduit and opening directly onto 4the top of the screen, without intermediate box or the like, the periphery or lip of said open mouth being disposed directly over and generally parallel to the screen, ciently close thereto as to cause the unbeaten stock to spread out sidewardly from the spout over the surface of the screen.

ROLAND A. PACKARD.

and suiii-