US2260198A - Paper stock hydrator - Google Patents

Description

C. W. SMITH Oct. 21, 1941.

FPAPER STOCK HYDRATOR Filed Feb. '21, 1936 2 Sheets-Sheet 1 INVENTOR. Charles Wmirh ATTORNEY .3

Oct. 21, 1941. SM'TH 2,260,198

PAPER STOCK HYDRATOR Filed Feb. 21, 1936 2 Sheets-Sheet 2 INVENTOR.

Charles WOmiTh EM W ATTORNEYS Patented Oct. 21, 1941 UNITED STATES PATENT OFFICE PAPER STOCK HYDRATOR Charles W. Smith, North Muskegon, Mich. Application February 21, 1936, Serial No. 65,029

(CI. 92-24) I 8 Claims.

This invention relates to improvements in paper stock hydrators.

This invention relates to paper making and primarily to an apparatus and method for beating and hydrating pulp stock which it will be understood includes all suitable fibrous raw ma terials which are beaten or hydrated for use in manufacturing paper.

Heretofore in beating or hydrating pulp stock,

Hollander or similar type beaters have been em-' circuit of the tank. The heater roll and bed plates are closely matched and the beating and hydrating action is obtained from the direct contacting-action' of the rolls and bed plates on the stock. The beater rolls are supported in suitable hearings in their closely matched relationship to the bed plates.

In employing such a beater, a batch of pulp stock is charged into the tub and is beaten or hydrated to the desired condition by the continued action of the beater roll and bed plates on the circulating stock. In most beating operations, the beater roll is set away from the bed plate to give a mild processing at the beginning of the beating operation but as the beating or hydrating progresses the roll must be moved down closer to the bed plate to give more drastic treatment. When a batch of stock has finally been beaten and hydrated to the desired state, it is removed from the tub of the beater and a new batch of pulp stock is charged in and the process is repeated.

The use of such beaters results in considerable waste of power, labor and stock. Power is wasted because most of the power is expended in circulating stock and not in beating or hydrating it, and it is essential to have the stock pass between the beater roll and bed plate many times.

Charging, discharging and re-charging the beater adds materially to the labor costs. Setting down the roll as the beating progresses requires highly skilled and experienced labor in order to produce properly beaten or hydrated stock. Even using the most highly skilled and experienced labor, much time may and probably will be consumed in getting the desired setting of the roll. I

Due to the fact that the stock is not positively fed tothe beater roll, there may and probably will be considerable damage due to overbeating of the fibres, whereas in my invention a positive feed of the stock eliminates this serious draw back.

In the old style beaters, the touching of the rolls and bed plates is relied upon to accomplish the necessary hydrating. .In many cases this results in overheating which is obviated in my invention through the suspension or floating of the rolls on a film of stock which is positively fed to the rolls.

With my invention, the difficulties above referred to, which are encountered in using the Hollander or other present day type of beater,

are obviated and a separate continuous process is employed to produce more satisfactory or hydrated stock more conveniently and at a lower cost.

The objects of this invention are:

First, to provide a new and difierent apparatus for beating and hydrating pulp stock.

Second, to provide such an apparatus in which the process of hydrating the stock may be carried on continuously, eliminating the undesirability of treating and tending individual batches with the extensive labor costs attendant thereon.

Third, to provide such an apparatus in which the beating or hydrating is accomplished with a very low power consumption and in which practically all of the power employed is devoted to the beating and hydrating of the stock rather than to the circulating of the stock through a tub as in the present day Hollander beater.

Fourth, to provide such an apparatus in which 'the stock is fed to the beater roll under pressure which assists in the hydration of the stock and materially assists in circulating the stock and feeding it between the beater roll and its bed plates.

Fifth, to provide such an apparatus in which the stock is fed positively under pressure to assure the-maintenance of a film of stock between the beater roll and bed plate to eliminate overbeating of the fibre which creates mucilage.

Sixth, to produce such an apparatus in which the beater roll floats on a film of stock positively maintained so that the beating will result from internal friction of fibre against fibre rather than from friction and contact between beater roll and bed plate. v

Seventh, to provide such an apparatus in which a higher consistency stock can be beaten "than in the present day beaters.

Eighth, to provide such an apparatus 'in which bed plates embracing a substantial arc of the roll maybe employed to multiply the beating or hydrating action of the roll for each revolution thereof.

Ninth, to provide such an apparatus in which the beater roll is enclosed in a chamber and in minimum.

Twelfth, to produce such-an apparatus which -will produce paper with a high Mullen, Elmendorf or folding and porosity test, at lower power, labor and material cost than heretofore.

, Thirteentln to produce such a machine in which the control of the amount of treatment of the stock may be easily obtained through varyingthe head at which pulp is fed to the machine and by varying the back pressure on the stock in the beater by controlling the speed of rotation of the rolls or the size or the nature of the outlet from the beater.

Fourteenth, to produce a new and improved method of beating and hydrating paper stock.

Fifteenth, .toproduce such a method which is continuous and economical.

Sixteenth, to produce such a method in which internal friction of fibre against fibre is employed to give the desired beating and hydrating effect to the pulp sto'ck.

Other objects and advantages pertaining to details and economies of construction and operation will appear from the description to follow. A preferred embodiment of my invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical sectional view through an apparatus embodying my invention taken on line l-l of Fig. 2.

Fig. 2 is a view partlyin horizontal section taken on line 2-2 of Fig. l.

' which the stock passes spirally and along the roll so that in its passage it is subject aplu- Fig. 3 is a vertical section in detail of a slightly modified form of the apparatus shown at the right hand end of Fig. l.

Fig. 4 is a detail view of the mounting for the beater rolls.

Referring to the drawings, I, 2 and 3 are a series of horizontally disposed beater rolls of conventional type arranged in vertically stepped relationship. Disposed at the periphery of each I roll is a series of conventional type bed plates 4. The rolls and bed plates illustrated are what are known as stone rolls although it will be appreciated by those skilled in the art that steel or bronze filled rolls or rolls embodying combinations of these or any other desired materials could be employed. The bed plates 4 are relatively narrow and are arranged to embrace substantially 180 degrees of the surface of the roll.

' formed It willbe understood that the exact number of degrees can be varied and that my invention can be carried out in a device in which any substantial arc of the surface of the rolls is embraced. I prefer to embrace a much greater are of the surface of the roll than is customary or possible in present day practice.

In the hydrating operation, the-paper stock passes between the revolving roll and the bed plates and it will be apparent that with this arrangement, the .action of the beater roll and bed plates upon the paper stock'is multiplied at each passage of the stock between the beater roll and bed plate.

Each of the beater rolls with its cooperating bed plates is enclosed in an individual tub or chamber 5, 6 and 1 for the rolls l, 2 and 3 respectively. The bottom of each. chamber is of a cement or concrete base 8 in which the bed plates 4 are set and the top wall 9 of .each chamber extends concentrically over the top of the roll. I have shown top wall 9 formed of planking, but it will be understood that other suitable material could bev used and since the stock is introduced under pressure, it may be desirable to reinforce the planking by. suitable metal straps or the like.

The wall 9 is curved as illustrated and extends over the top of the roll to provide a uniform space or passage between the roll and the wall 9. The advantage of this construction of providing a uniform restricted space over the top of the roll and in the portion of the-chamber not occupied by the bed plates 4 will be pointed out more fully hereafter. Each one of the chambers 5, 6 and 1 has an inlet and an outlet. The'inlet for the chamber 5 is disposed adjacent the end of the roll I and discharges into the chamber substantially tangentially to the roll. The outlet H from chamber 5 is disposed adjacent the other end of the roll and opens directly into the inlet l5 of the chamber 6 which discharges adjacent one end of the roll 2 while the outlet l6 of chamber 6 is disposed'adjacent the opposite end of the roll 2. This outlet I6 discharges into the inlet I! of the chamber 1,,which is adjacent one end of the roll 3, whereas the outlet I 8 of the chamber 1 is disposed adjacent the other end of theroll 3. As shown in the drawings, the

inlets lead into the front of the individual chambers and the outlets lead out at the back. The roll is rotated in a direction shown in the arrows in Fig. 1, so that the surface of the roll is rotating in the space between the roll and wall 9 in the direction of the inlet, thus carrying the stock from the inlet directly to the bed plates and preventing the passage of stock over the top of the roll directly to the outlet from the fillet.

The inlet I 3 of chamber 5 is connected. by a suitable conduit I9 to a head box 20. The head box has an outlet2l separated from the remainder of the box in the customary fashion by the partitions 22. An inlet 23 connected by a suitable pipe or conduit 24 to a pump 25 which is connected by pipe 26 to a chest discharges pulp stock into the head box 20. The pulp stock flows over one of the partitions 22 and fills-the space between the partitions and passes through the outlet 2|. If the pump 25 is pumping an excess of stock from the chest, which is not shown here, the excess flows over the right partition 22 and through an outlet 21 back to the chest. This arrangement provides a constant head absolutely divorced from variations in pressure due to the pump.

Ordinarily the head box will be located on a floor above my improved beater so that the pulp stock will be discharged through the inlet 13 into chamber 5. under pressure. Provision can be made for varying this pressure if so desired, either by changing the elevation of the headbox "or by some other suitable pressure controlling means. x 7

At the outlet l8 of chamber I, I may provide an adjustable gate 28 which will control the amount of stock-permitted to pass to the discharge 29.

In some situations, instead of using'a gate 28 it is possible to employ hydrostatic pressure for controlling the output of my machine. .A device such as shown in Fig. 3 may be, employed and the stock discharge from the beater passing through the outlet I8 would pass up through the conduit. 30 ovzrvthe weir or dam 3| and out through the discharge 29. The height of this weir can be varied to secure the desired back pressure. In a paper mill in which pulp stock is to be beaten and hydrated to the same degree in every instance, such an arrangement could be employed satisfactorily without the necessity for a gate such as 28, although inFig. 3 such a gate is illustrated to be used if so desired.

The rolls I, 2 and 3 are trunnioned on suitable shafts 32 running in bearings 33 and are provided with some suitable stuffing box 34 or the like. I have found in the operation of my beater that the tendency is for the rolls to float on the stock and it is necessary, instead of supporting the rolls above the bed plates 4, to hold the rolls down to the bed plate. The rolls are made adjustable by having the bearing 33 suitably supported on arms 35 which are pivoted as at 35. Means are provided at the free end 31 of the arm 35 to hold the roll down to the bed plate in operation. This may be accomplished by a weight 38 or by any other suitable adjusting mechanism.

In the operation of my beater, the stock is fed under pressure through the inlet l3 of the chamber 5. The beater rolls I, 2 and 3are driven in the direction indicated by the arrows in Fig. 1. As has been pointed out, the-top portion of the roll is rotating in such manner that in the space not occupied by the bed plates and between the outlet and inlet; the roll is exerting a force on the stock to prevent the passage directly from the inlet to the outlet. Suitable means for driving these rolls may be employed. I show the pulleys 39 which may be driven by belts and suitable variable speed motors 50 or drives to permit the speed of rotation of the individual rolls to be varied independently of one another.

As the stock is fed through the inlet l3 under pressure, it is subjected to the action of the revolving roll I and its cooperating bed plates 4. The pressure on the stock and the rotation of the roll tends to drive the stock around the roll and the passage between the top wall 9 and the roll 1 is restricted and of such dimensions that the rotation of the roll will be effective to drive the stock on around the roll, rather than permit-it to run parallel with the axis of the roll. The uniformity of the passage betweenthe wall 9 and the roll contributes to the effectiveness of the roll as a means to drive the stock in its helical path.

As the stock is fed in, it passes around and along the roll in a helical -'path and is subjected in a very short space of time to a very extensive beating and hydrating treatment. Every time the stock passes around the roll, it is subjected to the action of the roll and the cooperating bed plates and this is repeated several times in the passage of the stock through the beater, so that in a much shorter period of time than in the .conventional Hollander beater, the stock is much more completely beaten and hydrated.

In operating my beater, the introduction of the.

stock under pressure as described, results in a positive feeding of the stock and the maintenance of a film of stock between the roll and bed plates at all times. This causes the roll to float on the film of stock and the beating or hydrating is accomplished by the rubbing of fibre against fibre rather than by the contact of roll and bed plate. This prevents overbeating of the stock and gives a much more satisfactory final product.

When the chamber 5 is full, the stock discharges through the outlet l4 into the inlet 15 of the chamber 6. The introduction of stock through the opening l3, which is somewhat restricted, and the action of the revolving roll on the stock feeds it along the roll in a helical or spiral path to the discharge Hi. When the stock is discharged into the chamber 6 through the inlet l5, a similar action takes place. By controlling the speed of rotation of the roll 2, it is possible to create a back pressure on the outlet ll of chamber 5, which will control the discharge of stock from chamber 5 into chamber 6 and the rate of passage of stock through the chamber 5. It is thus possible to control the amount of beating or hydrating in chamber 5 by controlling the speed of rotation of the roll 2. Similarly, the speed of rotation of the roll 3 may be varied to vary the back pressure created on the outlet Hi from chamber 6. The gate 28 may be. employed to control the back pressure at the outlet l8 of chamber 1. i

It will thus be seen that by controlling these various factors it is possible to control the amount of beating or hydrating of the stock and the output of the beater in a simple and easy manner. It will also be appreciated that the rolls I, 2 and 3 may be independently set with relation to their cooperating bed plates so that in chamber 5 there may be a wide setting while the roll 3 in chamber 1 is given a very close setting. This allows a gentle treatment of the stock at the beginning with a very drastic beating at the end.

Thus, by making one setting of the rolls l, 2 and 3, it is possible to eliminate the operation of setting down the rolls as in an ordinary Hollander beater practice and it is posisble to provide a stock as can be produced by a great number ofordinary Hollander beaters, each of which would take up an equivalent floor space; Considerable additional floor space is saved in having a continuous process because the output of my beater can be regulated to correspond with the requirements of the paper machines in use, thus eliminating the necessity for storage chests for the beaten and hydrated stock which are necessary when-ordinary Hollander heaters are employed.

Ihave found that with my improved beater, it is not only possible to produce a continuous for rotating said rolls, and means for independalso possible to employ a high consistency stock which is practically impossible with theo'rdinary Hollander heater.

7 roll.

ently controlling the speed of. rotation of each 4. The method of hydrating and beating pulp stock comprising feeding the stock under pressure to a revolving beater roll and abed plate, caus- I have also found that-it is possible to save considerable power since my beater and process require only about 40% as much power for hydration of a given amount of stock as would be required by the old Hollander or other style heaters.

Having thus described my invention, what I claim as new anddesire to secure by Letters Patent is: I 1. In an apparatus for beating and hydrating pulp stock, the combination of a series of horizontally disposed beater rolls arranged in vertically stepped relationship, bed plates disposed at the periphery of each roll and embracinga substantial arc thereof, a closed chamber for each roll and its bed plates each of said chambers having its walls disposed concentrically about the roll therein to form a restricted space aboutsaid roll in the portion of the chamber not occupied by bed plates, said restricted space being-of such dimension that the rotation of the roll in the ing the stock to pass helically around and along the roll whereby it passes between the roll and,

I the bed plate a plurality of times, feeding the stock still under pressure directly to a second revolving beater roll and a second bed plate, causing the stock to pass helically around and along said second roll, whereby it passes between said 'secondroll and bed plates a plurality of times,

controlling the rate of passage of said stock along said first roll by controlling the rate of rotation of said second roll, and controlling the rate of passage of said stock along said second roll by creating and controlling a back pressure on said stock as it leaves said second roll.

5. The method of hydrating and beating stock comprising feeding the stock under pressure to a chamber carries the stock around the roll, each chamber having an" inlet for pulp stock adjacent one end of the roll therein and an outlet 'for pulp stock adjacent the opposite end of said a roll, means for introducing stock under pressure to the inlet of the uppermost chamber passages connecting the outlet of each chamber to the inlet of the next lower chamber, means for rotating said rolls, means for independently controlling the speed of rotation of each roll, and means for creating a back pressure at the outlet of the lowermost chamber.

2. In an apparatus for beating'and hydrating pulp stock, the combination of a series of-horizontally disposed beater rolls arranged in vertically stepped relationship, bed plates disposedat the periphery of each roll and embracing a substantial arc thereof, a closed chamber for each roll and its bed plates each of said chambers having its walls disposed concentrically about the roll therein to form a restricted space about said roll in the portion of the chamber not occupied by bed plates, said restricted space being of such dimension that the rotation of the roll in the chamber carries the stock around the roll, each .chamber having an inlet for pulp stock adjacent one end of the roll therein and an outlet for pulp stock adjacent the opposite end of said roll, means for introducing stock under pressure to r the inlet of the uppermost chamber, passages connecting the outlet of each chamber to the in- "let of the next lowerchamber, means for rotating said rolls. 3. In an apparatus for beating and hydrating pulp stock, the combination of a series ofbeater I rolls, a bed plate for each roll, a closed chamber for each roll and its bed plate each chamber having its wallsdisposedconcentrically about therevolving beater roll and a bed plate, causing the stock to pass helically around and along the roll whereby it Passes between the roll and the bed plate a-plurality of times, feeding the stock still under pressure directly to a second revolving beater roll and a second bed plate, causing the stock to pass helically around-and along said second roll whereby it passes between said second roll and bed plates a plurality of timesi'controlling the rate of passage of said stock along "said I and the bed plate first roll by controlling the rate of rotation of said second roll.

6. In an apparatus for beating and hydrating pulp stock, the combination of a beater roll with fixed stock engaging surfaces, bearings for said roll to permit rotation thereof, said bearings being'mounted for vertical movement, a bed plate embracing an arc of thebottom half only of the roll and of an area sufllcient that when high consistency stock under pressure is posistively,forced between the plate and the roll during rotation of the roll the roll will be raised from the bed plate and will float on the stock between the roll and the bed plate, a casing enclosing said roll and having an inlet at one end of the roll and an outlet at the other end thereof, said casing extending over the top of the roll inspaced relation theretoto form a restricted space free from bed plates opposite the aforesaid bed plate and of such depth that it will confine roll, means for rotating said roll, means for con-- trolling the force exerted by the roll in opposition to the floating thereof on stock between the roll and the bed plate, and means for feeding stock under pressunerto said inlet whereby stock is" fed toone end of the roll and is positively carried by rotation ofthe roll between the roll to float the roll and is fed in a spiral passage through the casing and around the roll and between the roll and the bed plate a plurality of times, said means for controlling the force exerted by is maintained on said roll and the spacing between the roll and the bed plate may be varied by controlling the flow of stock.

the roll in opposition to the floating thereof being such that a constant force ing mounted for vertical movement, a bed plate embracing an arc of the bottom half only of the roll and of an area suflicient that when high consistency stock under 'pressureis positively forced between the plate and the roll during rotation of the roll the roll will be raised from the bed plate and will float on the stock between the roll and the bed plate, a casing enclosing said roll and having an inlet at one end of the roll and an outlet at the other end thereof, said casing extending over the top of the roll in.

spaced relation thereto to forma restricted space free from bed plates opposite the aforesaid bed plate and of such depth that it will confine stock between the roll and the casing to such an extent that rotation of the roll will cause the stock to pass over the top of the roll and through the casing in a spiral passage whereby the stock is beaten and hydrated only in its passage between the roll and the bed plate and will not be injured during its passage over the top of the roll, means for rotating said roll, means for controlling the force exerted by the roll in opposition to the floating thereof on stock between the roll and the bed plate, and means for feeding stock under pressure to said inlet whereby stock is fed to one end of the .roll and is' positively carried byrotation of the roll between the roll and the bed plate to float the roll and is fed in a spiral passage through the casing and around the roll and between the roll and the bed plate. a plurality of. times.

8. In an apparatus for beating and'hydrating pulp stock, the combination of a beater roll with fixed stock engaging surfaces mounted for rotation and for vertical movement, a bed plateembracing an arc of the bottom half of the roll of an area sufl'lcient that when high consistency stock under pressure is positively forced between the plate and the roll during rotation of the roll, the roll will be raised from the bed plate and will float on the stock between the roll and the bed plate, means for rotating the roll, and means for controlling the force exerted by the roll in opposition to the floating thereof on stock between the roll and the bed plate and means for forcing a stock under pressure between said roll and said bed plate.

.' CHARLES W. SMITH.

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