US2159317A - Paper pulp consistency regulator - Google Patents

Description

May 23, 1939. E. l.. BUCHANAN PAPER PULP CONSISTENCY REGULATOR Filed July l. 1936 Hllll E Patented May 23, 1939 PATENT GFFICE PAPER PULP CONSISTENCY REGULATOR Application July 1, 1936, Serial No. 88,411

Claims.

The present invention relates to the manufacture of paper products and has particular reference to an improved device for the regulation of the consistency of stock employed in making paper, paperboard and the like.

In the manufacture of paper it is customary to subject the raw materials from which the paper is to be produced to disintegration in equipment known as beaters. The beaters prom duce a water suspension of fibrous materials which is passed into paper-making equipment for the production of a web of the desired type. The Weight of the resulting paper depends, to a considerable extent, upon the amount of paper stock contained in the slurry of fibrous materials which is passed into the paper machine. Unless special eflorts are made to control the consistency of the paper stock a considerable variation generally occurs and this variation results in a final product of uneven characteristics. ability of controlling the consistency of the paper stock long has been recognized andA a large number of devices have been suggested for this purpose. In their practical application these prior deviceshave not met with success.

A principal object of the present invention is the provision of an improved type of regulating mechanism for controlling the consistency of paper stock in such a manner that the device may be employed to great advantage in practice.

An additional object isto provide a consistency regulator having a consistency-sensitive wing valve operable to maintainy a hydraulic head under the conditions of use, the mechanism being employed in connection with an improved dilution. device .which will vrestore the desired consistency conditions.

Still another object is the'provision of a consistency regulator in which 'the stock is diluted. to the desired consistency as used, the regulator having an open consistency indicator ctnmber provided with alevel establishing overlpow connected to the intale side of a pump operable'to` 4"progress stock through a. diluting mechanism.V f These and oth?! objects wililie evidntupon,

1 a consideration' of the following spedneatims" and by reference to the acompanying drawing, in which Fig. 1 is a side view of a regulatory constructed in accordance with the invention;

Fig. 2 is an end view of the regulatory shown in Fig. 1; and n Fig. 3 is a plan view taken along line 3-3 of Fig. 1. f

The desir- As before stated, an initial step in the production of paper includes the disintegration of the material from which the paper is made to produce a slurry of bers. The operation is performed in beaters in which the raw materials are pulverized and hydrated in the presence of water. Ordinarily, a number of beaters may be employed and after the disintegration is complete the beaters may be dumped into a storage chest. The disintegration of the stock and the nal hydration generally is accomplished by one cr more Jordans. From the Jordans the carrier water which contains a suspension of individual fibers impregnated with water of hydration is 5 passed to a paper machine which may be of the well known Fourdrinier type.

As shown in the drawing, the consistency regulator is employed in connection with a head box, indicated generally at I0, which is positioned just in advance of the paper machine. Paper stock from the Jordans or other source is transferred through a line II into a dilution device, indicated generally at I3, by means of a pump I2. The dilution line is provided with a water pipe Il extending transversely thereof and hav- 25 ing longitudinally extending slots I5 through which the diluting water is forced into admixture with the paper stock. Preferably, the slots I5 are positioned to pass the diluting water downwardly against or transversely of the upwardly flowing paper stock.

The amount of water passing through line Il is determined by a motor-operated semi-balanced or balanced valve I6 and the action of the latter is controlled by a reversible motor I1 and a gear box I8 of conventional structure. 4

Positioned above the terminal portion of line Il is a. ball seat I 9 which is provided `with an opening receiving the ball 2D. As the paper stock is pumped upwardly through line I3 the ball 2B is unseated and the stock passes through the openand platform I9. To limit the upward movement of the ball Il a pin 2l is positioned transversely of line I8. Above the pin 2| is mounted u asecond ball receiving platform 22 and this platioifni'hasny central opening for receiving the ball 2 3. I'he upward movement of the ball 23 is limited by a transversely extending pin 24. The upward flow of water through line I3 causes the 50 ball 23 to be unseated and the paper stock passes through the opening of the platform 22.

Paper stock, passing through line II, generally is heavier than is desirable for use in the paper machine, so that a certain amount of dilution in 'the' line I3 is necessary. 'I'he valve I6 is of a construction such that the proper amount of dilution water is added to the stock at an intermediate position of the valve. When the stock is heavier than usual the valve I6 may be opened to add additional water and when the stock passing through line II is more dilute than usual the valve I6 may be restricted to reduce the amount of dilution water added to line I3. I

The construction of the dilution line or chamber I3 is such that a quick and very effective mixing of the paper stock and dilution water is obtained. In passing through the openings in platforms I9 and 22 themixture of paper stock and water of dilution travels at a faster rate of flow than in the line I, due to the restricted nature of the ball sea'ts Additionally, the balls 20 and 23 have an effective mixing action, so that as the diluted slurry of paper stock enters head box I0 through openirg 25 it is in a state of thorough admixture.

The head box I 0 is providedwith a transversely extending platform 26 which extends downwardly from the upper portion thereof to a point spaced from the bottom of the tank, as shown in Fig. 1, thereby dividing the box into two consecutive compartments communicating with each other only beneath the partition 26. Adjacent the vlower end ofA the partition 26 the head box; is provided with a transversely extending shaft 21 which is rotatably mounted in the sides of the box.

Rigidly attached to the shaft 2'I is a consistencysensitive wing valve or partition 28. This consistency indicator extends entirely across the head box I0 and has a normal operating position angularly disposed with respect to the bottom of the head box, as shown in Fig. 1. That is, the consistency indicator has a normal position in which its lower or free end is inclined toward the direction of flow of water in the head box.

One end of the shaft 2'I extends outwardly beyond the head box, as shown in Fig. 3, and is rigidly secured to an intermediate portion of lever 29. 'I'he lever 29 carries on one end an adjustable weight 30 which biases the indicator 28 ltoward a downward position.

An arm 3| is attached to and extends upwardly from lever 29. A second arm 32 is connected to arm 3l and operates a recording device of conventional structure, diagrammatically indicated at 33.

Iiluctuations inthe consistency of a paper stock,

as indicated by the wing valve 28, thereby are recorded as they occur.

The opposite end of lever 29 carries an upward contact 34 and allower contact 35. When the` indicator 28 moves downwardly toward a vertical f position upon a decrease in consistency of the paper s'tock the contact 34 touches contact 36 positioned thereabove and establishes a circuit of conventional structure for operating'the motorV I'I-v l``torestrict valve I6.v Likewise, when the consistency of the stockinreases to such an extent that the indicator l28 is raised or movedtoward a hurl-y Zonta] position the lowerA contact 35 touches a' contact 3I'which positioned therebelow. `When 5 the contacts 35'and 3'I'tou'ch, the motor' IIfis operout of engagement with cont'acts'36 and 31, and' thevalve I6is at'its normal position. The ciry f 4 ated in a reverse mannerfto open valve I 6 and to v` added to the paper stock. When the indicator 28 allowlarger quantities .of water dilution to be is in normal positionthe contacts 34 and 35 are kcuits for operating motor I'Iin the manner de` The paper stock into a third compartment andis transferred scribed are conventional and for the sake of clarity have not been shown in the drawing.

The head box I0 likewise is provided with a forward darn or weir which includes a lower stationary partition 38 extending transversely of the head box andan upper adjustable partition 39. Partition 39 is maintained adjacent partition 38 by means 'of guides 40. To adjust the height of this forward dam the partition 39 is secured to an upwardly extending rod 4I which is threaded through a hand wheel 42, thelatter being carried by a frame member 43. Rotation of the hand wheel 42 causes the partition 39 to be raised or lowered, as desired, to establish the proper head in the forward end of the head box.

The head box I8 is open to the atmosphere and the paper stock is pumped through the dilution line on the rear or upstream side of the indicating wing member 28. The stock establishes a head in this firstcompartment on the upstream side of the wing member, this head being limited by an overflow line 44. Any paperstock which rises above the opening of overflow line 44 passes downwardly through the latter into the line II on the suction side of the pump I2 and is recirculated through the dilution chamber, thereby providing inthe initial compartment of head box I0 to a somewhat definite maximum level.

The dam 39 is ata lower level than overflow line 44 and provides an outlet for paper stock passing into the second compartment of the head box on the downstream side of the consistency indicator 28. The wing valve 28 is mounted in the path of flow of paper stock from the inlet and outlet of the head box and limits the ow between the two compartments to beneath its free end. Changes in the consistency of the paper stock are more effectively indicated from the practical standpoint by this type of device than by the devices known heretofore.

'Ihe stock pumped into the head box passes beneath the indicator 28 and then flows over the topof the partition 39 constituting the forward dam, the indicator establishing a differential head on the upstream side of the indicator 28. Changes in consistency of the paper stock are followed by movement ofthe counterweighted wing valve. An increase in consistency of the stock results in movement of the valve upwardly, thereby opening the dilution valve I6.` If the consistency falls Vbelow normal the wing valve falls sufficiently to establish connection between contacts 35 and 31, thereby energizing motor I'I to restrict valve I6. vThe limit. of the head on the vupstream side of wing valve 28 will be the positionof the4 overflow pipe I44, and; on the discharge or downstream side of the ,indicator 28 the head will be limited by thedpo'sition of the dam39. v

passes'vover forward dam from .the latter through line Q45 to thepapermaking machine.vl'I"he-amount of stock.` taken through line 451s controlledby agate valve 46 which is vertically inici/)sible'in'A guidesJI. The position of the gate valve is" controlledy by opera- ''aonx yof menage wheel 4a, Aniiswmei -being threaded aboutrod 49 extending upwardly from the gate valve.

A 1 A frame lmember v5I) forms a base for thehand wheel. The fpaperzmachine Y supply compartmentkbetween't'he forward dam andthe opening thro'ixgh which line 45.com municatesvv with the head box is provided with an overflow-line'SI which communicates with the cthe order of 3 per cent.

supply line II on the suction side of pump I2. 'I'he elevation at which overflow line 5I communicates with the forward compartment of the head box is at a lower level than the forward dam 39.

In operation of the device there is a continuous flow of stock through line II, pump I2 and the dilution and mixing line I3. In the head box to which the stock is pumped there is provided a three-stage gravity flow in which the initial or primary head on the supply side of the consist-4 ency indicator 2d may be as high as the level of the overflow line t4. The secondary head on dam 39, this head being sufficiently lower than the initial head to create a flow of stock through the device. The third head exists in the supply compartment for the paper machine and its upper limit may be determined by the overow line 5I. By employing a separate supply compartment for the paper machine the function of the consistency indicator is relieved of the effect which will be produced by the withdrawal of the paper machine supply from the head box on the discharge side of the indicator 28.

f Paper stock generally consists of a slurry in which the percentage of paper stock may be of Oi?l course, in practice the percentages vary widely from this amount but for any particular purpose a definite percentage is desirable. In actual practice I have found that the type of consistency indicator def scribed herein is of particular utility in maintaining the stock supply to the paper machines in uniform predetermined condition with respect to consistency. 'I'he wing 28 extends completely across the head box I0 and offers suilicient resistance to flow of the stock to create a differential head. The weight 30 is adjusted on arm 29 for any particular condition in consistency that it is desired to maintain. All of the stock flowing over the dam 39 must pass beneath the member 28, this ow tending to raise the consistency indicator in accordance with the consistency of the stock. The partition 26 divides the consistency indicating chamber into two compartments communicating only through the space below theY member 28. A true indication of changes in the consistency of the stock is obtained and the stock is diluted so as to maintain the proper equilibrium'4 conditions. The structure of the device is such that static pools of stock are prevented and the dilution occurs at a point just prior to entrance of the stock into the head box. This stock is in a thoroughly mixed condition when it enters the head box and the nature of the indicating mechanism is such that errors in the consistency indication and other effects due to unequal local flows or static surface conditions within the head box are prevented. A

The flow in the initial compartment of the head box includes a partial overflow through line 44 back to the suction side of pump I2. Return of the diluted overflow stock in this manner prevents undue dilution of the stock in the stuff chest to which line II is connected and insures that the diluted stock progressively leaves the system promptly after the dilution'step.

It will be understood that many changes in the structure described and shown herein for purposes of explanation and illustration are possible without departing from the scope of the invention defined in the appended'. claims.

I claim:

1. In a device of the type described, in combination, a paper stock supply line, means for supplying water of dilution to said supply line, a vertical mixing line, an oriced ball seat in said mixing line, a ball for said seat and adapted to bey raised by flow through said line to open said oririce, an open head box communicating with said mixing line, an overflow line extending from said box to said supply line, a pivotal counterweighted consistency-indicating wing valve extending across said head box and affording a path of travel for paper stock therebeneath, a forward dam of less height than said overflow line on the discharge side of said wing valve, a supply compartment for kreceiving paper stock from said dam, an overflow in said compartment at a lower level than said dam, means for transferring stock from said compartment to a paper machine, and means responsive to movement of said wing valve for controlling said dilution means.

2. A device of the type described, comprising a head box having three compartments provided with progressively lower overflows, means for supplying paper stock to the rst of said compartments, a transverse partition and a pivotally mounted consistency-indicating wing valve below said position between the first and second of said compartments andconning the flow of paper stock between the first and second compartments to beneath said valve, a movable dam between th'e second and third compartments providing a level of paper stock in the second compartment below that in the first compartment and providing for flow of the paper stock thereover into the third compartment, means responsive to movement of`said valve for diluting said paper stock,v

and means for transferring paper stock from the third compartment to a paper machine.

3. In a consistency regulator of the type described, a head box having a path of flow therethrough for paper stock, a partition extending across the box and downwardly therein in spaced relation to the bottom of the box to provide inflow and outflow chambers in communication below the partition, a pivotally mounted consistencyindicating wing valve below the partition tending to close the flow communication, means for supplying paper stock to the inflow chamber to maintain an initial hydrostatic head therein at one side of the valve, means providing a lower hydrostatic head of stock in the outflow chamber' and providing withdrawal of said stock at a level above saidvalve to cause flow of stock through the box, means for diluting the vstool: supplied to the inflow chamber, and means responsive to movement of said valve for controlling the diluting means. p

4. In a device of the type described, a head box having a bottom member, a partition extending across said head box and dividing the same into inflow and outflow compartments, said partition extending downwardly within said head box ,below the normal liquid levels therein but spaced from said bottom member to establish a liquid commpnication between said compartments therebenneath, a pivotally mounted consistency-indicating wing valve extending across said head box beneath said partition tending to close said liquid communication, means for supplying paper stock to said inflow chamber, means for withdrawing paper stock from said outflow chamber to cause a flow through said head box beneath said wing valve, the withdrawing means in said outflow chamber being above said wing valve, means for biasing said wing valve against said flow, means for diluting the stock in said supplying means, and means responsive to movement of said valve for controlling said diluting means.

5. A device of the type described including a head box having a bottom member, a transverse partition extending downwardly into said head box to a point spaced from said bottom member and dividing said box into two compartments having a liquid 4communication therebeneath, a consistency-indicating wing valve partition pivotally mounted beneath said partition tending to close said liquid communication, means for supplying paper stock to one of saidcompartments, means for withdrawing said paper stock EDWARD L. BUCHANAN.

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