US1746708A

US1746708A - Paper-making machine

Info

Publication number: US1746708A
Application number: US247515A
Authority: US
Inventors: Everett K Mansfield
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-01-18
Filing date: 1928-01-18
Publication date: 1930-02-11
Anticipated expiration: 1947-02-11

Description

Feb. ll, 1930.

E. K. MANsFlELD 1,746,708 PAPER MAKING MACHINE Filed Jan. 18, 1928' 4 Sheets-Sheet 2 Jw en o 2'. MV

Feb ll, 1930 E. K. MANsFlELD PAPER MAKING MACHINE Filed Jan. 18, 1928 4 Sheets-Sheet Feb. ll, 1930. E. k. MANsFlELD PAPER MAKING MACHINE Filed Jan. 18, 1928 4 Sheets-Sheet 4 Iriver/ibn @gli l Patented Feb. 11, 1930 i UNITED STATES EVEBETT K. MANSFIELD, OF WHITE PLAINS, NEW YORK PAPER-MAKING MACHINE Application filed January 18, 1928. Serial No. 247,515.

This invention relates to certain improvements in that type of paper making machines in' which an endless wire screen, usually termed a wire, is so driven that it passes 5 down into and up from a vat containing the paper pulp held in suspension in water, while water is withdrawn from within the submerged portions of the wire and returned to the vat at another point, so that, as the water 19 passes thru the wire, the ulp will be deposited over the entire surface t ereof in a thin layer,

\ which will remain thereon when the wire emerges from the water in the vat and will be removed therefrom 'at or adjacent the high 15 point of its movement, usually by an endless felt operating in connection wlth a couch roll, after which it will be conducted to the dryers.

Machines of this type which are in very n general use, are known as cylinder machines, 2" the wire being mounted on a cylindrical frame which holds the same in true cylindrical form. My invention, however, comprehends use in a paper making machine in which the wire is in the form of an endless belt, similar 2, to that used in Fourdrinier machines, but in which the wire is carried beneath the liquid level in a vat to receive the deposit of a layer of pul thereon.

In t e operation of machines of this type s" the proportion of ulp to water in the vat is usually increasedpaccordin to the weight of the web to be produced. T e wire is practically always run at the highest speed which n other conditions permit and the speed of cir- 3" culation of the water in the vat is controlled according to the speed of the wire and other conditions.

Prior to my invention, however, the extent to which the speed of the wire and the speed of circulation may be increased has been very definitely limited for several reasons, aside from limitations imposed by such conditions as the centrifugal action of the cylinder, intending to throw oi pulp dei ited on its surface, and the limitations of gying capacit These reasons are due pr1- fact that, in the operatlon of marily to the all paper makin referred to, so

carrying water ar as I am aware, the pulp begins to iiow thru the wire machines of the type above immediatel after it is submergedso that the layer o pulp is fully formed on the surface of the wire within a few inches of the point where the wire passes below the surface of the pul carrying water. Consequently the layer o pulp which is formed on any portion of the wire is carried thereon thruout nearly the whole of its travel while submerged, regardless of the direction in which the wire moves with relation to the direction of the flow of the pulp in the vat.

One of the chief diiculties which has been encountered in the operation of such machines under these conditions has been in the production of a very thin web, as in the manufacture of tissue paper, or of board having very thin plys, or when it has been attempted to increase the s eed of the wire or the speed of circulation o the water, the result being that the web produced has not been uniform 70 or has been liable to have holes, or thin spots, and also to have thickened portions, or clots therein. This, I have ascertained, has been due to two primary causes-First to the washing actionon the pulg, after it has been 75 deposited on the wire, of t e waves or strong currents in the vat, caused primaril by the force with which it is necessary to discharge the circulating water into the vat, and in some instances by the contrawise flow of the circulation in the vat to the direction of movement of the wire while submerged. Second, to the action of the radial arms and longitudinal rods in cylinder machines, which support the wire in cylindrical form, by causing agitation of the water within the cylinder, which tends, by being thrown outward, to dislodge the pulp, this tendency rapidly increasing as the speed of the cylinder is increased.

On the other hand, it is very desirable, for many reasons, to be able to increase both the speed of the wire and the speed of circulatlon in the vat, and at the same time, to produce a very thin, but uniform, web.

The objects of my invention are to provide a form of paper making machine,o f the general type above referred to, with means whereby the rate of circulation in thevat, or the speed or force with which the circulated water is discharged into the vat by the circulating pump, may be increased practicall to any extent which may be found desira le, without causing displacement of pulp which has already been deposited on the wire, and, at thesame time, to permit the thickness of the web to be reduced to any extent desired, so far as danger of displacement from this cause is concerned. Also to enable the speed of the wire to be substantially increased without danger of causing dislodgment of the pulp which has been deposited on ythe wire.

I accomplish these objects by providing the vat of a paper making machine of this type with a form of shield, or deiiector which extends partly about the submerged portion of the wire and from side to side of the vat in a manner to prevent the pulp carrying water in the vat from coming in contact with the wire, or from fiowing thru the same, so as to deposit the pulp on its surface, until after the force of the discharge from the circulating pump has been dissipated, and also in a manner to prevent the agitatin action within the cylinder from causing isplacement of the pulp already deplosited on its surface, so that the flow thru t e Wire to deposit the ulp lwill be from a space in which the mixe pulp and water will be practically motionless and from which the water will pass directly thru the wire, as from a flow box. Also by the formation oi' the web on any portion of the wire until such portion is about to emerge, or pass above the liquid level, so that the pulp, after it has been (leposited will be unalected by currents in the vat, or by the agitation of the water within the cylinder, also by providing means whereby the area of the submerged portion thru which the water may pass to deposit the pulp thereon, may be varied according to the requirements of various'conditions, such as the speed of the wire, the desired thickness of web to be produced and the rapidity with which the pulp which is being used gives up its water.

For a more complete disclosure of the invention reference is made to the accompanying drawings in which:

Fig. 1 is a central longitudinal sectional view of the vat of a paper making machine of the cylinder type, provided with a preferred embodiment of my invention.

Fig. 2 is a plan view thereof.

Fig. 3 is a sectional view at line 3 3 of Fig. 1.

Fig. 4 is a longitudinal sectional view similar to Fig. 1, showing certain parts in a different position.

Figs. 5 and 6 are detail views.

Fig. 7 is a sectional view indicatin another form of paper making machine emodyinthe invention.

ig. 8 is a detail view of a portion of a form of shield which may :be employed therein.

Fig. 9 is a sectional view indicating the application of my invention to another forni by suitable rings at each end located closey to the sides of the vat, and supported on longitudinal rods and radial arms (not shown). The ends of the cylinder are open to

side chambers

14, 15, which are connected by the end chamber 40, the chamber 15 extending to the opposite end of the vat and opening to the inlet to a circulating pump 16, which p has its discharge end connected to the adjacent end of the vat by a pipe 17 having a throttle valve 18 therein. The vat is provided with various defiecting lates located at intervals thruout the len of the vat, primarily for the purpose o securing' uniform distribution of the pulp in the water. In the ordinary operation, the cylinder is rotated in the direction of the arrow in Fig. 1, and the water is drawn from the ends of the cylinder and returned to the opposite end of the vat, pulp being delivered to the vat near the point where the discharge pi e from the pum opens into the vat. As t us far describe the construction and operation is the same as that of any ordinary paper making machine of the cylinder type. That is, a layer of pul is deposited on the wire, as the water 1s circulated therethru, which is removed by the felt f ressed against the top portion of the cylindler by a couch roll, as indicated-in Fig. 1. In the operation of such a machine thefiow of mixed pulp and' water past the bale, or deflecting plate which is next to the c linder, would then be directly against tiie surface of the cylinder from which the water is constantly being drawn, and practically all of the pulp, which will be deposited on the surface of the cylinder under such conditions, will be deposited thereon during the first few inches of the downward travel of any portion, after it passes beneath the surface, so that norma ly the maximum amount of pulp will be held on the surface of the cylinder during practically the wholev of the travel of any portion while submerged, and during all of this time the pulp which 'has been deposited is liable to be dislodged by the waves or currents due both to the circulation flow caused by the pump and the agitating action within thecylinder, so that 4the web produced is liable to be uneven to an undesirable extent, as already described.

yat each edge,

According to my invention I provide a vertical partition 20 which extends entirely across the vat from the upper edge of its sides to the level of the axis of the cylinder and at points in close proximity to the cylinder at its side next that from which the pulp flows, and also in this instance, at the downwardly moving side of its cylinder. I further provide a curved sheet metal partition 22, which is connected at its upper edge to the lower portion of partition 20 and at its ends by edge flanges 23 to the sides of the vat, said partition being extended in concentric relation to the surface of the cylinder in close proximity thereto, to points directly beneath the cylinder, or points adjacent thereto. I further provide an adjustable partition or shield 24, which is also curved to correspond to the shield 22 and is arranged in concentric relation to the surface of the cylinder, so as to form a continuation of the shield 22, and to extend about the opposite portion of the cylinder from that enclosed y shield 22, the lower end portion of shield 24 resting on the lower portion of shield 22 and being slidable thereon. To provide a further support for the shield 24, the shield 22 may be provided with flanged extensions 25 lwhich are secured to the sides of the vat and extend approximately to the level of the cylinder axis. To provide means for adjustably supporting the shield 24 on the shield 22 and the extensions 25 thereof, links 26 are pivotally connected at one end to the upper end portion of said shield 24, and the opposite ends of said links each have a ball and socket connection with the lower end of a screw 28, each screw being extended vertically thru a bracket 30, having horizontally disposed arms 31 between which a nut 32 is held. Each nut 32 is c lindrically formed and has worm gear teet on its exterior, and a shaft 34 is rotatably mounted in brackets 30 and has portions thereof provided with worm sections arranged in mesh with the gear teeth of the nuts 32. The screws 28 are slidable verticall in the bracket arms 31 and are splined t erein to hold them against turning, so that, when the shaft 34 is rotated, so as to cause the nuts 32 to be rotated simultaneously, the screws 28 will be moved vertically either up or down according to the direction of rotation of the shaft. By this means the shield 24 may be vertically adjusted between a position in which its upper edge is close to the liquid level, and a position in which its upper edge is approximatel half way between the level of the cylin er axis and the. level of a horizontal tan ent at the lowest point in the cylinder sur ace. e

An apron 36, preferably consisting of a readflyilexible sheet of rubber, of suflicient weight to give it ample stability for the purpose, is attached to the shield ,24 at its upper edge and side next the cylinder, said apron being arranged to extend longitudinally thruout the length of said edge and to extend transversely upward from the edge in an oblique direction towards the cyhnder, so that the edge portion of the apron may rest on the surface thereof, and prevent downward flow of water directly from the vat over the top edge of the shield and between the latter and the cylinder.

The vat is provided with a partition 38, which extends from the bottom thereof beneath the cylinder at the lowest point of its travel, upwardly in concentric yrelation with the cylinder, to approximately the horizontal level of the cylinder axis and then vertically to provide an overflow edge 39 at the liquid level desired at this point. The space 40 between the partition 38 and the end wall of the vat opens to the

return channels

14, 15, so that overflow at edge 39 will pass to the circulating pump. The cross sectional area of the space between the shield 24 and partition 38 is suilicient to carry the entire ow of stock necessar to supply the cylinder to the extent required lVith the above described construction the partition 20,

shields

22 and 24, and apron 36 act to prevent the contents of the vat from coming in contact with the cylinder until it has passed between the shields alid partition 38 up to the level of the top edge of the apron 3G. As a result the entire flow from the vat into the cylinder will take place between the top edge of the apron 36 and the liquid level directly thereabove, which level is limited by the height of the overflow edge 39 adjacent thereto.

In operation therefore, the flow of the pulp in the vat is directed downward by the partition 20 and shield 22 and then upward between the shield 24 and end partition 38, so that it rises into the space between the upper end of the partition 38 and the cylinder, which acts as a flow box, from which the water passes thru the screen of the cylinder between the upper edge of the apron 36 and the liquid level, depositing the pulp thereon.

As the pulp is thus deposited 0n all portions of the cylinder immediately preceding the time when such portions are carried above the liquid level, the deposited pulp is removed from positions in which it might be affected by forces within the vat or the cylinder, as before described, before it can be affected thereby. Moreover, the deposit of the pulp on the cylinder takes place in a position in which it practically can not be affected by such forces. As a result a uniform sheet or web will be produced.

The screen area thru which water may flow at any one time will be varied by adjusting the shield 24 according to dierentconditions, and may be varied while the machine is in operation, so that adjustment may be made until the desired results are secured. The position to which the shield 24 will be adjusted depends on several conditions. An increase in speed of the cylinder and in the speed of circulation would ordinarily require an increase in the area of the screen on which pulp may be deposited at one time, or a lowering of the shield 24, while if a reduction in the thickness or weight of the web is desired, this area will be reduced by raising it. Also the pulp is likely to be much more thoroughly hydrated in some instances than in others, and, in consequence, gives up its water much more slowly. Consequently, it will usually be necessary to increase the area to the extent to which the pulp, in any instance, is hydrated.

lVhile the end of the shield 24 may be arranged practically in contact with the surface of Athe cylinder, this would be objectionable, as it would be likely to cause Wear and might not be entirely effective in preventing flow from the vat between the shield and the cylinder. The rubber apron 36, however, does not cause appreciable wear on the cylinder and effectively prevent such flow from the vat, so that practically no pulp will be deposited on any portion of the cylinder until after it has passed the end of the apron. The space between the cylinder and the shield will, however, be filled to the liquid level within the cylinder by water which has passed thru the screen. The liquid level within the cylinder will be varied accordin to conditions, one possible condition being illustrated i-n Fig. 1.

In Fig. 7 a modified type of paper making machine which I have devised, is indicated, in which the basic principles of the present invention are involved and in which certain features of both the cylinder and F ourdrinier machines are combined. In thisform of machine an endless wire screen 43 is provided which is arranged in the vat 41, so that it extends from side to side thereof, as in the cylinder type, said screen being su ported on two rolls 42, 44 which are located eneath the liquid level and a single roll 45, which is located above the liquid level, said rolls 42, 45 being driven to carry the screen in the di'- rection indicated by the arrow. The roll 44 is an idler, or stretch roll, and acts to keep the screen taut, and the

rolls

42 and 45 are so arranged that, as the screen is drawn from the roll 42, below the liquid level in the vat, to the roll 45, above the vat, it will be held at an inclination, approximating to 45 and its outer surface will face upward. The circulation flow will be in the same direction as in Fig. l (indicated by the arrow) and the circulation pump will be arranged to withdraw water from the space within the screen, and return it to the vat as before described. A partition 46 is fixed in the vat and extends from sidgto side thereof and from above the liquid level in the vat, downwardly, horizontally and then upwardly beneath theL screen. A shield 48 which is preferably made up of flat sections jointed together, as indicated in Fig. 8, is mounted in guideways 49 on the lower end portion of the partition, and a flexible rubber apron 50, similar to the apron 36 already described, is secured on the outer end of the shield 48 and extends into contact with the screen 43, as it extends upward at an inclination from the roll 42 to the roll 45. The upper end portion of the guide ways 49 are extended in parallelism with the upwardly inclined portion of the screen and suitable means for adjusting the shield 48 in the direction in which the screen travels are provided, the means shown comprising a link 52, which is connected at one end to the shield 48 and at the opposite end to a nut 53, in which an adjusting screw 54 is threaded, said screw having a swivel connection with a stationary support 55. By this means the flexible apron 50 may be adjusted from a osition adjacent the roll 42 nearly to the liquld level. n operation, the action is similar to that already described, the flow from the discharge'from the circulating pump encounters the partition 40 and directs the flow downward beneath the screen and then it passes upward into the space between the overflow partition 56 and the screen, and the water will then flow thru the screen above the end of the apron 50, leaving its deposit of pulp on the screen surface. The screen carries the pulp deposited thereon above the liquid level and it is removed by the felt 58 over the roll 45. In this instance therefore, the flow thru the screen from the vat only takes place adjacent the point of emergence and the area thru which the water may flow from the vat may be varied according to the requirements of the 'various conditions, as before indicated.

In Fig. 9 a common type of cylinder machine is indicated, in which the circulation flow is against the direction of rotation, instead of towards it as in Fig. l. As shown therein the vat 60 has a cylinder 62 therein, which is rotated in the direction of the arrow, the flow in the vat being towards the upwardly moving side of the cylinder. In this instance the bottom section 64 of the vat beneath the cylinder is shaped concentrically with the cylinder and normally the pulp and Water in the vat would flow over the edge 65 thereof and beneath the cylinder, so that the flow would pass thru the screen as it moved downward below the liquid level and the pulp would be deposited on the screen at this point. As the movement of the pulp thus deposited on the screen would then be in the opposite direction to the flow, the same difnculties due to the displacement of the deposited pulp, would arise as before described. To avoid these difliculties under these conditions the shield or apron may be mounted on the bottom section 64 so as to extend from the edge 65 to the cylinder, the indicated construct-ion comprising a partition 66, which is mounted for vertical adjustment in front of the bottom section 64 and flexible apron 68 which is connected thereto and extended into contact with the surface of the cylinder at its upwardly moving side.

With this arrangement the flow beneath the cylinder would be prevented and the flow thru the screen would take place above the upper end of the apron 68, so that the pulp will be deposited on each portion of the screen as it is about to emerge and will be immediately carried above the liquid level, and removed by the felt 70 as before described. Displacement of the pulp from the screen by the action of the circulating pump and other forces will thus be avoided.

The action in all the instances before described will thus be the same, the pulp being deposited on the screen as it is about to emerge, instead of as it becomes submerged, so that the generic principles involved are identical.

From the yforegoing description it will be apparent that, in all the specific types of machines described, the rate at which water may be forced into the vat and the extent to which the contents thereof may be agitated will have no effect tending to dislodge pulp already deposited on the screen. Also, the above described construction permits substantial increase in the speed of the screen without causing like results due to agitation of the lwater within the screen. The uniformity of the web produced is also substantially increased and its weight may be effectively controlled within certain limits.

I claim:

1. A paper making machine comprising a vat for containing the mixed pulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to wit-hdraw water from the space Within the screen and to discharge it into the vat, to deposit a layer of pulp on the screen surface, means arranged to prevent flow of Water from the vat thru any portion of the screen during the initial portion of the submergence thereof, and means for varying the area. of the submerged portion of the screen thru which flow will be permitted at one time.

2. A paper making machine comprising a vat for containing the mixed pulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to withdraw water from the space within the screen and to discharge it into the vat, to deposit a layer 'of pulp on the screen surface, and means arranged to prevent flow of water from the vat-:thru the screen at the downwardly side thereof and to ermit variation of the screen area thru whlch it may flow at any the submergence of one time at the upwardly moving side thereof. Y

3. A paper making machine comprising a vat for containing the mixed pulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to withdraw water from the space Within the screen and to discharge it into the vat, to deposit a layer of pulp on the screen surface, and a shield disposed adjacent one side of the screen and arranged to prevent flow of water from the vat thru the screen during the initial portion of the s ubmergence of any portion thereof, said shield being arranged for adjustment longitudinally of thepath of movement of the screen, to vary the area of the submerged portions of the screen thru which the water may flow from the vat at any one time.

4. A paper making machine comprising a vat for containing the mixed pulp and Water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to withdraw water from the space within the screen and to dischargel it into the vat, to deposit a layer of pulp on the screen surface, and a shield disposed adjacent one side of the screen and arranged to prevent flow of water from the vat thru the screen during the initial portion of the submergence of any portion thereof, said shield having its end portion extended into engagement with the surface of the screen beneath the liquid level in the vat and arranged for adjustment in the direction in which the screen travels.

5. A paper making. machine comprising a vat for containing the mixedfpulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to withdraw water from the space within the screen and to discharge it into the vat, to deposit a layer of pulp on the screen surface, and a shield disposed adjacent one side of the screen and arranged to prevent flow of water from the vat thru the screen during the initial portion of any .portion thereof, said shield having a llexibleend portion extended into contact with the surface of the screen beneath the liquid level in the vat and arranged for adjustment in the direction in which the screen travels.

6. A paper making machine comprising a vat, for containing t'he mixed pulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly from the vat, means to withdraw water from the space within the screen and discharge it into the vat, to deposit a layer of pulp on the screen surface, and a shield disposed in the vat at the downwardly moving side of the screen and extending laterally from side to side of the vat and longitudinally downward from the liquid level therein beneath the screen, said shield havin an end section mounted for adjustment in t ie direction of travel of the screen and arranged to extend into engagement with the screen surface at its upwardly moving side', to direct the How from the vatv thru the screen at points above the position of engagement thereof with the screen surface.

7. A paper making machine comprising a vat for containing the mixed pulp and water, an endless paper forming screen arranged for continuous movement downwardly into and upwardly rom the vat, means to withdraw water from the space within the screen and to discharge it int-o the vat, to deposit a layer of pulp on the screen surface, a rigid partit-ion disposed adjacent the screen and extending transversely" from side to side of the vat and longitudinally in position to in tercept the flow ot liquid in the vat to he downwardly moving side of the screen, means permitting adjustment' of said partition in the direction in which the screen travels and a fiexible apron connected to said partition and extended in said direction of travel in position to rest againstthe screen surface.

8. A paper making i'i'iachine comprising a vat for containinff the mixed pulp and water, an endless paper forming screen transversely disposed in the vat and arranged for continuous movement downwardly into.l and npwardly from the vat, means to withdraw water from within the screen and to deliver it to the vat at the downwardi moving side of the screen a partition exten ing trom side to side of the vat adjacent and in front of the downwardly moving side of the screen and from. points above the liquid level in the vat downwardly beneath the screen and op wardly1 adjacent the upwardly moving side ther-eet7 and said partition having an end ser tion reciprocally adjustable in the direct f, of movement of the screen to vary the ienrf thereof and a exible apron connected and extending upward from said section and arranged to have its end pot7 on r. on the surface of the screen beneat. ne liquid levelf a flow passage being provided beneath. and in the rear of said partition which opens 'to the screen above the upper end of said apron.

9. A paper making machine comprising a vat for containing the mixed pulp and water, a pair of guide roiis, one rnou'ntea in the vat below the normal lqu'. l level therein and the other above said liquid ei/ei.; an endless paper forming screen arranged to be. driven about said rolls, the :relative position thereof being such, that7 as the screen moves upward. from the lower roll te upper roli, it moves over the lower l1 an acute angle to the hori- Zonta?. a pe :n :an the vat arranged to prevent new r iii-om the vat through vthe aves the lower roll screen g ard therefrom, and

as it pas.

an apron extending from said partition into Contact with the screen at points between the line when the screen leaves the lower roll and the liquid level at its point of emergence therefrom.

10. A paper making machine comprising a vat for containing the mixed pulp and water, a pair of guide rolls, one mounted in the vat below the normal liquid level therein and the other above said liquid level, an endless paper forming screen arranged to be driven about said rolls,' the relative position thereof being such, that, as the screen moves upward from the lower roll to the upper roll, it moves over the lower roll at an acute angle to the horizoi' ah a partition in the vat arranged to prevent flow of water from the vat through the screen until the screen leaves the lower roll as it passes obliquely upward therefrom, an apron extending from said partition into Contact with the screen at points between the line when the screen leaves the. lower roll and liquid level at its point of emergence therefrom, and means permitting adjustment of said apron with relation to said partition in the direction el travel of the screen to vary the screen area through hh-,h water maj" dow frein the vat.

ln testimony whereof, .l have signed my naine te this Elf - LETT E. 'Mi