US2577712A - Apparatus for controlling freeness of papermaking stock - Google Patents

Description

C. N. NILSON Dec. 4, 1951 APPARATUS FOR CONTROLLING FREENESS OF PAPER MAKING STOCK 2 SHEETS-SHEET l Filed May 17, 1947 C. N. NILSON Dec. 4, 1951 APPARATUS FOR CONTROLLING FREENESS OF' PAPER MAKING STOCK 2 SHEETS-SHEET 2 Filed May 17, 1947 if BY ZM M@ Patented Dec. 4, 1951 UNITED STATES PATENT IOFFICE APPARATUS FOR CONTROLLING FREENESS F PAPERMAKING STOCK Clifton N. Nilson, Springfield, Mass., assigner to Cheney Bigelow Wire Works, Springfield, Mass., a corporation of Massachusetts Application May 17, 1947, Serial No. 748,775

s claims. 1

This invention relates to paper making and is directed more particularly to improvements in apparatus for determining and controlling the freeness of stock in paper making operations.

The principal object ofv the invention is the provision of means and apparatus for determining and adjusting or controlling the freeness of paper making stock before itis delivered to the paper making machine so that stock of the desired freeness will be delivered to the paper machine.

When in the manufacture of paper at the paper machine it is evident that the degree of freeness of the stock is not as desired, the procedure is to adjust the Jordan or other ber treating apparatus in an attempt to provide stock of the desired freeness.

Not only may the freeness of stock effect the speed of production but the formation of the paper is dependent on freeness to a considerable extent and for numerous other reasons freeness is an important consideration. In any event, it is desired in paper making to provide a certain condition of freeness of stock and in an attempt to attain the desired condition the stock refining or treating apparatus used in preparing bers is and must be adjusted.

As an example, an apparatus such as a Jordan engine is used for rening or preparing fibers and this consists essentially of a rotatable tapering plug having cutter bars cooperating with cutter bars of a shell in which the plug rotates. The

plug is moved in and-out longitudinally of the shell or adjusted in order to obtain different results.

In many cases the stock from the rening apparatus flows to a stock chest and then to the paper making machine. The results of the particular condition of freeness of the stock is usually determined at the wet end of the paper machine. While the rening machine may be adjustedin an attempt to provide the desired degree of freeness, there is the time lag between the refining apparatus and the paper machine so that the results of adjustment are not known presently and is objectionable.

That is, the refining step is remote from the paper making step and while adjustments may be made to prepare or refine the stock so as to provide the desired freeness, a very considerable amount of stock lies between the refining or conditioning step and the web forming step whereby the effects of a present adjustment to affect freeness cannot be known for a considerable time and when known it is entirely possible that the adjustment has not produced the desired freeness.

According to this invention, apparatus and a method is provided whereby as the stock refining or treating operation proceeds, the degree of freeness of the stock is determined and as the freeness varies from that desired the stock treating or refining apparatus such as a Jordan or the like is adjusted. In this way stock of the desired freeness will be produced and delivered to the paper making machine. To accomplish this, the apparatus of the invention is preferably located adjacent the rening or conditioning apparatus and stock delivered to the paper machine or machines is delivered simultaneously to the apparatus hereof. Thereby the stock is continuously tested or the freeness is continuously determined and adjustments are made as and when necessary in order that stock of desired and uniform freeness is delivered to the paper making machine.

Wth the foregoing and various other novel features and advantages and other objects of my invention as will become more apparent as the description proceeds, the invention consists in certain novel features of construction and in the combination and arrangement of parts as will be hereinafter more particularly pointed out in the claims hereunto annexed and more fully described and referred to in connection with the accompanying drawings wherein:

Fig. l is a plan view of apparatus embodying the novel features of the invention and adapted for the novel method;

Fig. 2 is a combined side elevational and longitudinal sectional view through the apparatus shown in Fig. l;

Fig. 3 is a sectional elevational view on the line 3-3 of Fig. 1;

Fig. 4 is a sectional elevational view on the line 4-4 of Fig. l;

Fig. 5 is a sectional view on the line 5-5 of Fig. 1;

Fig. 6 is a diagrammatic view of the apparatus of the invention associated with a stock treating apparatus such as a Jordan; and

Fig. 7 is a wiring diagram.

Referring now to the drawings more in detail. the invention will be fully described.

A stock supply compartment is represented by 2 and a water compartment is represented by 4 and between these is a combining and delivery compartment 6 al1 of which will now be described.

The compartment 2 has a lower wall 8, end walls I0 and Il and front and rear walls I2 and I4. A wall I6 between walls l0 and H extends 3 downwardly and terminates at a point above lower wall 8. Another wall I8 between said walls and extends upwardly from lower wall I and terminates at a distance upwardly from said lower wall. A gate is slidable up and down relative to the wall I8 and a screw 22 having ita lower end secured to said gate isin engagement with a nut 24 rotatable on a support 25.

The gate 20 as well as other gates to be described are such as used in and well known in paper mill machinery and have a screw in engagement with a nut which when rotated in one direction or the other raises or lowers the gate. An inlet 28 for stock is provided at the forward wall |2 and an outlet 38 extends from the rear wall |4.

Paper making stock is delivered through inlet 28 direct from the Jordan or other fiber treating machine during its operation and as said stock is delivered to a paper making machine or machines. Gate 20 is adjusted to provide the desired stock level and the overflow iiows through the outlet 30.

Wall I| is provided with an outlet 30. see Fig. 3, and a gate 38 is slidable relative thereto which has a screw 40 secured thereto. The screw has a nut 42 engageable therewith which rests on a bearing 44 secured to wall Il.

Water compartment 4 is similar to compartment 2 and has a lower wall 48, front and rear walls 50 and 52, and end walls 54 and 55. Downwardly and upwardly extending walls 56 and 58 extend between walls 54 and 55. A gate 60 is slidable relative to wall 58 and has a screw 52 extending through a bearing 64 and a nut 60 is in engagement therewith. A water inlet 68 extends through wall 50 and an outlet 10 extends from wall 52. Wall 55 is provided with an opening l2 and a gate 'Il slidable relative thereto has a screw 14 slidable in a bearing 18 with a nut 'i8 in engagement therewith.

The combining compartment 6 has front and rear wals 80 and 82 between walls and 52 and lower walls 84 merge into a delivery conduit 85. A perforated wall 88 extends between walls 00 and 82.

s Stock delivered to compartment 2 from the stock reiining apparatus ows through opening in a predetermined volume and will be of a known consistency. The volume is controlled by adjustment of gate 38. Water ows through opening '|2 in predetermined volume and is intermixed with the stock from outlet 3B. The volume of water is controlled by gate 13. The perforated wall or baille 88 brings about a thorough intermixing of stock and water.

With the consistency of the stock being known, the relative proportion of water mixed therewith may be varied as desired, it being desirable to use more water than stock. As an example, the proportion of stock and water may be one to ten so that errors in consistency of the stock is in the mixed stock reduced according to the proportion of stock and water.

'I'hus mixed stock and water with the consistency known and with any errors in original consistency reduced, is delivered through conduit continuously while the stock treating machine is in operation and from which stock flows to compartment 2. The mixed stock and water to be called stock is delivered through conduit 80 to a mixing box 0 of the apparatus hereof. This Y apparatus will be relatively small and will prei'- erably be located adjacent the Ystock refining or treating apparatus such as a Jordan.

Front and rear walls 92 and 94 and end walls 86 and 98 secured together provide a mixing box 9 and vat A cylinder mold |09 having a foraminous surface |02 of any well known form has a shaft |05 rotatable in bearings |04 which may be driven by any suitable means such as a motor or other means which is common with paper machines.

Levers |06 pivoted at |01 to brackets |08 secured to the vat walls have a roll ||0 journalled therebetween which is preferably yieldable. Weights 2 on .the free ends of the levers |00 hold the levers and roll down and a doctor ||4 between the levers removes the mat of fibers formed on the cylinder mold. A trough I I0 receives the mat as it is removed and an outlet or discharge ||8 extends fromsaid trough. The material may be returned to the stock refining apparatus or delivered to the paper machine.

The ends of the mold 4are sealed to the side walls of the vat in the usual and well known manner as indicated by |20. A white water compartment |22 is formed at one side of the vat |I by walls |24 and |26. Gates |28 and |30 are slidable relative to transverse walls |29 and |3| of the mixing box 9 and have screws |22 and |34 secured thereto which are slidable in bearings |36 xed to supports |38. Nuts |40 in engagement with the screws are adapted on rotation to move the screws and thereby the gates up or down.

An overilow outlet |42 is provided at the lower side of the mixing box 9. 'I'he lower side ofthe mixing box and vat are connected to a conduit ,|44 which has a T |46 for clean out purposes. This facilitates washing and flushing out of the apparatus. A baille |48 extends between walls 82 and 94 and a lower wall of the vat is concaved at |50 below the said baille and then extends as at |52 downwardly and ar'ound the cylinder in the well known manner as shown in Fig. 2.

The apparatus is preferably small in size as compared to the size of a paper machine and is so connected to a stock rening machine as to receive stock therefrom as the stock is delivered to a paper making machine. The vat is generally similar to a cylinder paper making'machine vat except that it may be modified for the practice of the invention and the cylinder mold |00 is driven in any well known manner as previously stated. It is intended that the mold be in rotation simultaneously with the operation of the renner or machine to which the apparatus is connected. The various gates are constructed and operated as is customary with paper making machines.

As before stated, stock, that is water and paper making bers,--is delivered into compartment 2. Its consistency is known'and'the percentage of error is small. A predetermined ratio of Water and stock are mixed in compartment 6 and is accomplished by adjustment of the gates associated with the compartments 2, 4 and 6. There will preferably be a suili'cient ratio of water and stock to reduce any error in the consistency of the original stock.

The mixed stock flows from compartment 4 through pipe 85 to the mixing box 9 and the desired amount ows over gate` |30 to the vat. The iiow is controlled by adjustment of gate |30. Any excess flows over gate |32 and through pipe |42 to the rener, stock chest of a paper making machine or wherever desired.

As the cylinder mold rotates a mat of fibers is taken on thereby which is couched by roll III' and doctored by |I4 into trough H5. White water asusual ilows into the white water compartment |22. partment is shown at |23 in Fig. 2.

The level of stock in the vat and level of water in the white water compartment are related or have a differential dependent upon the freeness condition of the stock. According to the invention this `differential indicates the freeness of stock and is employed to control or bring about adjustment of the stock refining apparatus, such as a Jordan, in order to bring about and maintain the desired freeness conditions of the stock.

As an example, where the stock is slow the level of white water in compartment |22 is a greater distance .below the level of stock in the vat than where the stock is more free. That is the differential between white water and stock levels is greater with slow stock than with stock which is relatively more free so that the differential is a result of the condition of the stock.

A certain or desired condition of freeness has a corresponding diierential so that when that differential is attained and maintained the stock will be as desired. According to the invention, the rening apparatus is adjusted so as to bring about a differential in levels of stock and white water which is related to the freeness condition desired and as the stock ows continuously to the apparatus the varying conditions of freeness bring about variations in level differentials which are utilized to adjust the stock treating machine so as to result in a constant, uniform and predetermined freeness.

This may be accomplished by various means but for purposes of disclosure the following will suilice, see Figs. 6 and 7.

The vat I I is shown in Fig. 6 as is a stock treating machine |60. The stock treating machine may take various forms but for illustration isa Jordan engine such as shown in U. S. Letters Patent No. 1,961,808 of June 5, 1934. Such a machine has a plug which is adjustable back and forth or longitudinally in a shell. The plug and shell carry coacting blades and the adjustment of the plug brings about various conditions of freeness of the stock being treated.

'I'he discharge from'said com- The adjustment of the plug is accomplished by means of a screw |82 in threaded engagement with a worm gear |64 operatively engaging a worm |66 fixed to a shaft |68 of a motor |10. As the motor rotates in one direction or the other the plug is moved thereby to adjust the plug relative to the shell.

According to this invention, the differential of level of stock in the vat and of Water in the white water compartment is utilized to control the operation of the refining apparatus. It may be accomplished in various ways but the following is for purposes of disclosure.

A float |14 is disposed in vat and a float |16 is disposed in the white water compartment. These floats are carried by float rods '|18 and |80 which have end extensions |19 and I 8 I 'Ihe rods and their extensions are relatively swingable on a stationary pivot between the rods and extensions, as shown.

Outer ends of the extensions are pivotally con- ,nected to one end of links |84 as shown at |82 in connection with extension I8I. Opposite ends of links |84 are pivotally connected to the upper end of. a. switch lever |86, as shown.

The switch lever at its lower end is pivoted on a stationary pivot, as shown, for swinging movements to engage either one of contacts |92 and- III.

As the level of stock increases or decreases. lever |18 is swung up or down and as the level of white water increases or decreases lever is swung up or down. For a certain freeness of stock the levels of stock will have a certain relationship. A change in freeness results in a change in the relationship of the levels of stock and white Water so that accordingly relative swinging of levers |18 and |80 results.

The motor |10 is of the reversible type adapted to rotate its shaft |68 in either direction thereby to move plug in or out relative to the shell. Connections |88 and |90 extend from the motor |10 to contacts |92 and |94 which are engageable by arm |86. A power supply represented by |98 1s Vconnected to the motor and switch arm as shown.

As the differential of levels in the vat and in the white water compartment becomes greater or less than normal or such as is related to the desired freeness of the stock, the switch arm is moved in one direction or the other to bring about rotation of the motor |10 and movement of the plug of the Jordan in one direction or the other. The action of the rei-'mer then results in a different cr corrected freeness of stock so that the diierential in levels becomes normal.

Variations in the differential of levels brings about relative movements of the floats which actuate the switch arm and thereby the motor is energized for moving the plugin one direction or the other. In this way the rener is caused to produce stock of a desired condition of freeness so that the paper making machine is supplied with constant and uniform stock. Any desired condition of freeness may be maintained so tlm the paper making machine is supplied with stock of the desired freeness and any changes in freeness are atonce corrected.

The invention may be embodied in other speciiic forms without departing from the essential characteristics thereof. Hence, the present embodiments are therefore to be considered in all respects merely as being illustrative and 4not as being restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all modifications and variations as fall within the meaning and purview and range of equivalency of the appended claims are therefore intended to be embraced therein.

What it is desired to claim and secure by Le't ters Patent of the United States is:

l. The combination of stock treating apparatus for delivering stock to a paper machine and having adjustable means for varying the freeness of stock with apparatus for adjusting the means accordingly as the freeness of stock varies comprising, means to receive a portion of the stock, means to mix the stock with water in predetermined proportions and provide stock of certain consistency, a vat to receive the stock having a white water compartment and a foraminous mat forming element rotatable therein whereby a mat is formed onsad element and diierent levels of stock and Vwhite water are provided in` said vat and white water compartments, and means for operating the adjustable means actuated by the differential in the levels.

2. The combination of stock treating apparatus for delivering stock to a paper machine having-adjustable means for varying the freeness of stock accordingly as the freeness of stock varies comprising, a compartment to receive a portion of the stock and a water compartment separate therefrom, a mixing compartment for stock and water, said compartments provided with adjustable means to control the relative proportions of stock and water delivered to said mixing compartment, a vat having a foraminous element rotatable therein and provided with a white water compartment, means for conducting mixed stock and water to said vat whereby a mat of paper making fibers is formed on said element and a differential in levels of stock and white water in said vat and white water compartment is provided according to the freeness o1 the stock, and means actuating the adjustable means operated by variations in level differential.

3. .lipparatusl for controlling the freeness of stock supplied a paper making machine from an adjustable stock treating machine comprising in combination, a stock compartment for receiving a portion of the stock fromthe stock treating machine, a. separate water compartment, a mixing compartment for continually mixing stock and Water and means for controlling the relation of stock and water in said mixing compartment to provide diluted stock of predetermined consistency, a vat having a rotatable foraminous cylinder continuously rotatable therein and provided with a white water compartment and connections therefrom to said vat, connections between said mixing compartment and vat whereby diluted stock is continuously supplied said vat and a mat is formed on said cylinder and a differential oi' stock and white water levels exists according to the freeness of the stock, and means actuated by variations in the levels which is connected to and adapted to adjust the stock treat ing machine.

CLIFTON N. NILSON.

I REFERENCES CITED The following references are of record in thev ille of this patent:

UNITED STATES PATENTS OTHER REFERENCES Manufacture of Pulp 8: Paper, vol. III, 1937, McGraw-Hill Book Co., pages 27-28.

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