US2203925A - Stock regulating apparatus for paper machines - Google Patents

Description

June 11, 1940.

E. POIRIER 2,203,925

STUCK REGULATING APPARATUS FOR PAPER MACHINES Filed May 12, 1937 2 Sheets-Sheet 1 1&1

I'll

n Hu 4 ATTORNEY.

June 11, 1940.

Filed May 12, 1937 2 Sheets-Sheet 2 IIII II llll INVENTOR.

Patented June 11', 1940 's'rocx nnccm'rmc armnsrus ron rarsa moms Ernest l oirier, Watel'vill e, Maine Application May '12, 1937, Serial No. 142,141

'4 Claims.

This invention relates to steps in the process of manufacturing paper and to apparatus used in such processes. While useful in other relationships, it is more especially concerned with I the control of, or the compensation for, variations in consistency of the-stock from which the paper is to be made.

. As is well understood by those skilled in the art of manufacturing paper, the stock or pulp -10 delivered to a Fourdrinier wire, or other paper 'making surface, contains a relatively small proportion, by weight, of solid constituents such as fiber, fillers, coloring material, and the like, the remainder of the stock consisting of water. ll While the percentage of these solid constituents varies greatly in different grades of paper, it is verycommon for the proportion of these materials to run in the neighborhood of 2% to 4% of the total weight of the stock. In making most 20 papers it is important to control variations in successive portions of the sheet or web within very narrow limits, and for this purpose it is essential that the consistency of the stock delivered to the paper making wire be accurately :5 controlled. According to the prior practice the control of the weight and formation of the sheet depend very largely on the care, skill and judgment of the machine tender. He watches the web closely, takes weighings at suitable intera vals, and makes such changes in the rate of delivery of the stock to the wire or in the proportion of diluting water added to the stock as may be required to correct any variations which he discovers.

35 -A further factor closely related to that of consistency is the rate at which the water leaves the fiber as the web passes over the suction boxes and during the formation of the sheet. In a Fourdrinier machine the wire is vibrated laterally 40 during this period, such movement assisting in causing the fibers to arrange themselves uniformly and to felt together in the desired relationship. If the water leaves the stock too rapidly, stock is said to run too free. This action in- 45 terferes with the proper formation of the sheet,

tends to make it run wild, and is usually compensated for by adding more water to the stock, on the other hand, if the water does not leave the sheet rapidly enough, it will be too wet when 60 it reaches the couch rolls, and the fiber will be crushed and the web will take on an undesirable surface appearance. Such. a stock is said to be slow, and the operator attempts to compen- V sate for it by reducing the quantity of water 55 added-to the stock.

While much care is given to the beating and preparation of the stock preparatory to deliver- 3 stock of a uniform character for any great length of time. Consequently, the nature of the final sheet will depend, in a large degree, on the care, skill, judgment and experience of the machine tender. -l0 In my earlier Patent No. 1,990,501 I have shown and described an apparatus designed to compensate for the variations in the character of the stock and to deliver to the paper making surface a more uniform product, thus relieving the mal chine tender of much of the care and attention required of him and producing a better sheet of paper than can reasonably be expected from any machine tender. This apparatus has proved very satisfactory in practice, and the present invention aims further to improve it with a view especially to making the control which it exercises more accurate, enabling it to handle a wider va-' riety of stocks, simplifying adjustments, effecting economies in manufacture and installation, and generally refining and perfecting the apparatus.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawlugs, and the novel features will be particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a vertical, sectional view with some parts in elevation, of an apparatus embodying this invention;

Fig. 2 is a front elevation of the apparatus shown in Fig. 1;

Fig. 3 is an angular view showing certain details of the apparatus on a larger scale; and

Fig. 4 is a horizontal, sectional view through the discharge chute just above the control gates.

Referring first to Fig. 1, the apparatus there shown comprises a head box 2 which is partly divided by weirs 3 and 4 into three compartments, namely, a supply compartment 5, an overflow compartment 6, and a stock mixing compartment l. The paper making stock is pumped from the stuff chest, or other preparatory apparatus, through a supply pipe 8 into the compartment or chamber 5 at a slightly higher rate than the stock can be utilized so that the surplus constantly overflows the weir 3 into the chamber 6 and is conducted back to the stuff chest through the return pipe l0.. A constant level thus is maintained in the head box.

Secured to one side of this head box is a tank or container i2 provided with an intake connection I 8 which opens directly into the lower part of the mixing chamber I. Mounted in the intake fitting I3 is a restrictor I which cooperates with the curved front wall a of said fitting to provide a-somewhat tortuous inlet channel or conduit ii of approximately S-shape. These parts thus cooperate to compel the stock flowing into the container l2 to follow a crooked path which, accordingly, imposes a certain resistance to said flow. This container also is provided with an outlet spout Iii Figs. .1 and 4, equipped with two slidable gates, indicated at I! and .I8, respectively, for controlling the rate of discharge of the stock from the container.

By properly adjusting the resistances offered to the flow of stock into and out of the container, the level of the stock in said container may be made to rise and fall automatically with changes in the consistency and freen'ess of the stock. For this purpose the restrictor I4 is made adjustable backward and forward in the fitting it to vary the dimensions of the inlet channel l5 and consequently, to change the resistance which'this part of the apparatus imposes upon the inflow of the stock. This restrictor ll fits snugly between the side walls of the fitting l3, and its top is shaped to run substantially in contact with the upper inner wall of said fitting. Its lower end, however, is rounded and its surface at the right-hand side thereof is curved to correspond in general with the contour of the front wall a of the fitting.

The adjusting mechanism for the restrictor includes two rods -20, at opposite sides of the discharge chute, passing through the front wall of the inlet fitting i8 and secured to the restrictor near opposite ends thereof. At their forward ends these rods are secured to a bar or yoke 2| provided with a central boss through which a screw threaded shaft 22 passes, the 'boss being internally threaded to engage the threads of the shaft. The shaft itself is mounted in abracket structure 28 at the front of the'container so that it can revolve but cannot move axially. Near its forward end it is equipped with a gear. Consequently, by revolving this shaft the restrictor Ibis moved forward or backward.

After the restrictor and the main gate I! have been initially adjusted in the desired relationship to each other, the subsequent adjustment of the gate I! to increase or reduce the rate of production or, in other words, the volume of pulp discharged, necessitates also a corresponding ad- 7 ijustment of the restrictor.

Accordingly, the main gate H which is mounted in suitable guides to slide horizontally more or less across the opening in the discharge chute l8 has an internally screw threaded boss or lug secured to it, and

. a screw threaded shaft 28 runs through this boss and engages the threads thereof. A gear 21 is secured to this shaft in front of the bracket'23, this gear meshing with the gear 24. Secured to the forward end of the shaft 26 is a hand wheel or knob 28 by means of which the shaft can be revolved, such revolution serving to adjust both the gate l1 and the restrictor i4 simultaneously. The degree of this adjustment may be indicated by any suitable mechanism, that shown consisting of the so-called Tejax indicator. It comprises a graduated dial mounted inside the hand wheel 28, the dial being held stationary by a pendulum weight. Two hands operated by the shaft 26 or the hand wheel 28 revolve in front of the face of this dial, one of these hands being longer than the other and the two beingso geared together that the longer hand makes a complete revolution while the shorter one moves one graduated space on the dial.

With this arrangement the operator controls his production simply by revolving the hand wheel 28 in one direction or the other, as required, and the restrictor is automatically adjusted simultaneously with the adjustment of the gate and without any attention on the part of the machine tender. Any difference in the rate of adjusting movement of the two parts II and II which may be required can be produced by properly selecting the pitch of the threads on the shafts 22 and 26 or the ratio between the gears. In other words, a definite degree of restriction is required for a given production, and this relationship is predetermined by the initial setting of the parts and the ratio of the movement of the restrictor to that of the producion gate which, in turn, is determined by the pitch of the two adjusting screws or shafts. The indicator or gage 30 is useful in making production records.

Asabove indicated, the invention also makes provision for correcting automatically varia-,

tions in the consistency of the stock. Some compensation for these variations is produced simply by the mechanism above described due to the fact that the rate of discharge of the stock from the container I2 is dependent upon the hydrostatic head of stock in this container. As above stated, this head varies with changes in consistency, the head dropping with an increase in consistency (that is, with a higher proportion of solid constituents) and rising with a reduction in consistency. Obviously a lower head will re-- duce the rate of discharge of the stock, other conditions remaining constant, and vice versa.

A further control of the rate of discharge in response to variations in consistency is provided, however, by mounting a float 32 in the container l2 where it will rise and fall with these variations in hydrostatic head and connecting this float with the supplemental or correcting gate l8 so that it will operate the latter. The connections between these elements includes a stem 33 extending upwardly from the float and pivotally connected to one end of a lever 34, Figs. 2 and 3, fulcrumed at 35 in the stationary frame piece 38. A link 31 pivotally connected at its upper end to this lever issimilarly connected at itslower -end to one arm of a bell crank lever 38, the other'arm of which is connectedby another link 40 to and 4| secured fast to the gate l8, the connection of the link to the rod preferably being made adjustable, as shown in Fig. 2. This gate lies just below the production gate l1 and operates in horizontal guideways to slide more or less across the discharge opening at right angles to the movement of the latter gate. Consequently, the adjustment of this correcting gate always increases or decreases the area of the discharge opening by a certain deflnite percentage of that opening, regardless of the setting of the main production gate.

Assuming that the control has been set for an average consistency and the stock becomes heavier, the increased friction of the heavier stock flowing through the restricted inlet l5 lowers the level in the container 12', thus lowering the float 32. This movement operates through the connections just described to impart a closing movement to the correcting gate l8, thus reducing the volume of the stock being discharged. An opposite action takes place when the stock becomes lighter. In other words, the adjustment effects the rate of discharge or delivery of the stock in an inverse relationship to the change in consistency, an increase in consistency producing a decrease in the rate of delivery, 'and'vice versa. The amplitude of this adjusting movement of the gate in relation to that of the float may be changed through adjustment-of the screw 42. Fig. 3, which is mounted to revolve in the lever 44 but cannot move axially with reference to it. A nut 43 travels on this screw and the upper end of the rod or link 31 is pivoted to this nut. Consequently, by revolving the screw 42 in one direction or the other, the lever arm through which the movement of the float is transmitted to the correcting gate can be shortened or lengthened. A knurled wheel 44 secured fast to the screw facilitates the making of this'adjustment. Also, the adjacent portion of the lever 34 may be graduated, as shown inthe drawings, to coop-- erate with a pointer 45 carried by the nut 43 to assist in making production records. It may be noted, however, that" once this adjusting screw has been set, any further adjustment of it usually is not necessary.

The inner end of the lever 34 may conveniently be connected to the stem 33 by means of a collar 46 slidable on the stem but secured to it by a set screw. Also, a pointer 41 preferably is mounted in this collar to swing over a stationary arm 48 suitably graduated to indicate the position of the float.

When the consistency of the stock increases beyond a desired value, it is necessary to add diluting water to it. Since the volume of water so added should be proportioned to the increase in consistency, it may also be controlled automatically by the float 32. As shown in Figs. 1 and 2, this diluting water is. conducted through a. pipe 50 and discharged through a spray head 5| into the mixing chamber 1 where it is mingled with the stock and becomes well mixed with it just before the mixture flows into the container 12. The control of such flow is effected by means of a balanced valve 52 connected into the pipe line 50 and placed under the control of the float. As best shown in Fig. 2, the valve stem 53 is pivoted to a horizontal lever 54 on to which a weight 55 is adjustably mounted, the lever being fulcrumed at 56. A link 51 connects the outer end of this lever with a horizontal lever 58, one end of which is fulcrumed at 60 on the frame part 36, while its opposite end is pivotally connected at 6|, Fig. 3, to an arm 62 rigid with the collar 46. The leverage exerted by the float through these connections may be varied by connecting the lower end of the link 51 into any one of a series of holes drilled through the member 58. Normally, or at average consistency and below, the weight 55 holds the valve 52 closed, but when the float 32 drops, clue to an increase in consistency at some predetermined point above average, it operates through the connections just described to open said valve more or less, depending upon the degree of increase in weight of the stock. The resulting introduction of diluting water directly into the stream of stock about to enter the control chamber or float chamber immediately exerts a correcting action on the consistency of the stock. It becomes lighter, flows more rapidly into the latter chamber, and thus raises the float. During the interval between the time when the float calls for diluting water and the answer to that call, the automatic correcting gate l8 has, of course, been partially closed to reduce the quantity of stock discharged, but as soon as the effect of the. diluting water is felt, the automatic gate opens again to a position determined by the degree of correction in consistency. If for any reason the stock should become unduly diluted, the upward movement of the float produced by the higher level in the control chamber would first shut off all the diluted water and simultaneously therewith would operate the correcting gate. The latter operation would continue unimpaired by the connections between the float and the valve 52 after all diluting water had been shut oif, since the connection of the rod or link 51 to the lever 54 does not restrict the rise of the link after the valve 52 has once been closed. Thus the mechanism will operate to correct very dilute consistencies by making the discharge opening much larger than normal and thereby permitting the passage of the very dilute stock in the added volume necessary to produce a sheet of substantially correct weight.

From the foregoing it will be evident that the invention provides an apparatus which responds automatically to changes in the character of the stock to control the delivery of stock to the paper making wire in such a manner that variations in weight of the sheet being produced are reduced to negligible limits. In addition to controlling the rate of delivery, the apparatus also adds automatically the necessary degree of diluting water to correct excessive concentration of solids in the stock. After the initial settings have been made the only control which the machine tender is required to operate is the hand wheel 28 for adjusting the production gate. The other manual adjustments remain unchanged for all ordinary conditions. Thus the care and attention required on the part of the operator are reduced and since the apparatus 'feels automatically changes in the consistency of the stock which the attendant could not possibly detect until he sees their effects in the production of the web, a far more uniform sheet is produced. .A contributing factor to this advantageous result is the addition of the diluting water when required to the stream of stock just before it enters the control chamber so that the correcting agent is applied almost instantly when the need for it is felt.

While I have herein shown and described .a preferred embodiment of my invention, it will be understood that the invention may be embodied in other forms without departing from the spirit or scope thereof. Also, that it is useful in other relationships than that specifically described where essentially the same functions are to be performed.

Having thus described my invention, what I desire to claim as new is:

1. In an apparatus of the character described, the combination of a head box equipped with weirs dividing it into a stock supply compartment, an overflow compartment, and a stock mixing compartment, a container having an inlet leading from said mixing compartment and also having an outlet for the discharge of stock from said container, a gate controlling the discharge of stock through said outlet, said inlet being constructed to offer a substantial degree of resistance to the flow of stock into the container whereby the head of stock in said container will vary with changes in the consistency of the stock, means for delivering diluting water into said mixing compartment, a fioat in said container, and connections under the control of said float for causing changes in its level to adjust the volume of diluting water so delivered and for simultaneously adjusting said gate to change the rate of discharge of the stock from said container.

2. In an apparatus of the character described, the combination of a head box equipped with weirs dividing it into a stock supply compartment, an overflow compartment, and a stock mixing compartment, a container having an inlet leading from said mixing compartment and also having an outlet for the discharge of stock from said container, a gate controlling the discharge of stock through said outlet, said inlet being constructed to offer a substantial degree of resistance to the flow of stock into the container whereby the head of stock in said container will vary with changes in'the consistency of the stock, means for delivering diluting water into said mixing compartment, a float in said container, a valve controlling the flow of diluting water to said mixing chamber, and mechanism operated by said float for simultaneously adjusting said gate and said valve, said mechanism including a lever system and said system having means adjustable to vary the relationship between the adjusting movements of said valve and said gate.

container, a gate controlling the discharge 01 stock through said outlet, said inlet being constructed to utter a substantial degree of r istance to the flow of stock into the container whereby the head of stock in said container will vary with changes in the consistency of the stock, means for delivering diluting water into said mixin'g compartment, a float in said container, and connections under the control of said float for causing changes in its level to adjust the volume of diluting water so delivered.

4. An apparatus according to claim 1 in which said inlet includes a restrictor adjustable to vary the resistance offered by the inlet to the flow of stock through it into said container, in combination with a second gate cooperating with the first gate to control the discharge of .stock through said outlet and mechanism common to both said restrictor and said second gate for adjusting them simultaneously and in a predetermined ratio.

ERNEST POIRIER.

CERTIFICATE OF CORRECTION.-

Patent No. 2,205,925. June 11, 191 0.

' ERNEST POIRIER.

It is hereby certified that error appears in the printed specification of the above nunbered patent requiring correction as follows: Page 2, second column, lines 18 and 19, strike out the words "or the ratio between the gears" and insert the same after "shafts" and before the period in line 25; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

' Signed an sealed this 15th day of August, A. D. 19140.

Henry Van Arsdale, Acting Commissioner of Patents.

Images