US1726750A - Pulp-feed regulator - Google Patents

Description

Sept. 3, 1929.

G. E. MAYO PULP FEED REGULATOR Filed 0G13. l, 1928 Imvcntor EM Gtorncg S 6 -Fourdrinier screen or refininfg r Patented Sept. 3, 1929i.

GEORGE E. IAYQ OF POTSDAI, NEW YORK.

PULP-FEED REGULATOR.

Application illed October 1, 1938. Serial N0. 809,670. y l

The invention relates to the art of paper making, and more particularly to an improved device for controlling the rate of iiow of semi-liquid pulp from a stuff .box to a engine.

In the making of paper om ulp it is necessary that the-amount of soli material in the pulp from the stuff box or chest be delivered to the Fourdrinier screen at a deli; nitely fixed rate Iin order that the finished sheet of paper be pf uniform thickness. For the urpose of obtaining such a constant feed or ow` from a stuff box to a Fourdrinier screen or refining engine, it has been sug-l gested to provide means for automatically controllin the volume of the pul delivered per unit 0% time, but this method as the disadvantage of merely controlling the volume of the pul delivered per A unit of time without provi ing any means for cpmpensatin for the variations in the pulp mixture itsel It is obvious that, when the rate of feed of the entire ulp mixture is maintained constant and t e `ratio of solid to water in the mixture varies, the amount of solid delivered to the screen per unit of time will also vary and will result in variations in the thickness of the finished paper. f

In Letters Patent No. 1,248,972, of December 4, 1917, granted to I. J. Witham and myself, we described a device for controlling the A feed from a stuff box to a Fourdrinier screen container was built up in varying degree in level of the pulp in the stuff-box being in this in such a wayas to cause a substantiall constant amount of solid material to be delivered per unit of time, the device being so'arranged as to compensate for variations of the ratio of solid to water in the mixture. Brieiiy stated, the device described in the above mentioned patent consisted of 'a hollow conical air container suspended in a stu box 'and immersed in the mixture contained therein with its base alone open to the mixture.. The air container mentioned was connected with a source'of com ressed .air supply which delivered air to t e container at as nearly a constant rate as possible and at a pressure sufficient to prevent the mixture from ascending into'the container, the air from within the container instead continuously escaping therefrom. Due to the fact that a pulp mixture of var 'ng consistency or density offered greateror ess resistance to the escape of air from the container, the pressure within the accordance with the ratio of pulp to water in the mixture, which ratio determines the density of. the pulp mixture. B connecting the container to an air-operate controlling the pul feed ate controllin flow of pulp from t e stuff ox we utilize the varying pressure in the container to control the feed of pulp in such a way that, though a varying quantity of mixture was delivered per unit of time, the rate of iow f solid material to the Fourdriner screen was maintained substantially constant.

While the above described device has worked admirably, it has been found diicult to furnish compressed air to the container at va perfectl constant rate,"s0 that at times the rate of ow of pulp from the stuff box has been influenced not only by the ratio of mechanism pulp to water in the mixture but also by the by the ratio of solid to water in the pulp mixture," whereby variations the ,ratio cause a greater or less amount of pulp to flow from the stuff box so that the rate of flow of l solid material from the stuff., box is always constant. A

Another ob'ect of this invention is to rovide Imeans o the character described w ich requires a minimum of attention and whichvis sim le and economical to construct.

ith these and other objects in view, the I nature of which will more 4fully appear, the invention will be more clearl understood by a reading of the following etailed description, the appended claims, and the two views villustrated in the accompanying drawings, in which: f L if Figure 1 is a plan view of-a stuffbox embogymg my invention, pand igure 2 is a vertical sectional view taken on the line 2-2 of Figure 1.

Like numerals desi ate corresponding parts in the two views illustrated.

\ In the-drawings there is shown a stu box A filled with ulp B which is introduced into the stu box t rough a pipe C from a um or other source of supply (not shown he stuff box is provided with an overow partition 1 by means of which excess pulp is discharged into a pipe l2 through which the excess 1s led back to the source of supply, the

way maintained constant, regardless of the amount of pulp being used. The stuff box is further provided with a discharge opening 1 across which extends a strainer grid 1", the rate of discharge or feed of pulp through the opening being controlled by a pulp feed gate 1 journaled in bearings 1d in the strainer grid 1b.

Suspended within the stuftn box by any suitable means and extending into the pulp B is an air container 3. The said container ,is open to the pulp at a point below the level thereof, preferably at its lower end, but closed at its upper end by the plate 5. The plate 5 may be provided with a flange 6 for attaching it to the container 3.

In the drawings I have shown the air container'3 as of cylindrical shape, though of course a container of any other shape such as rectangular, or triangular shape in cross section, could also be used.

A casing 7 is rigidly mounted upon the stud box by means of brackets 8, and in this casin is located a diaphragm 9 comprising top an bottom plates 10 and 11 respectively and collapsible side walls 12, the bottom plate11 being fixed to the bottom ofthe casing7, while the top plate 10 and the side wall 12 are spaced from the adjacent walls of the casing andare free to move 'relative to the casing and at the urge of air pressure within the diaphragm chamber formed between the plates 10 and 11 v and walls 12. The diaphragm chamber is designated 9 and communicates with the interior of the air container 3 by means of a pipe line 13 which enters the container at 14 and the diaphragm chambervat 15, a valve 16 being interposed in the pipe line for shutting off communication of the diaphragm with the air container when desired. A gate operating arm 17 is fulcrumed toa bracket 18 on the casing 7, as at 19, and extends from the fulcrum 19 across and beyond the stuff box. A diaphragm arm 20 is' pivoted at one end to a pair of lugs 21 on the casing 7 and is provided at its other end with a boss 22 which extends through thetop of the casing 7 and rests upon the top plate 10 of the diaphragm to move up and down therewith. Slidably mounted on the gate operating arm is an abutment 23 which may be locked in any desired lposition of adjustment by means of a set screw 23a. The arm 17 overlies the arm 20 so that this abutment rests uponthe diaphragm arm 20 and causes the gate operating arm 17 to be rocked about the fulcrum 19 when the` diaphragm top plate.10 is moved up or down in a mannerto be hereinafter described. Obviously, by changing the position of the abutment 23 relative tothe p1vot 21 and the fulcrum 19, the amount of movement'imparted to the gate operating arm 17 by a given moveent of the d1aphragm arm 20 may be varied.

At the outer end of lthe gate operating arm 17 a number of weights 24 is adjustably slidably carried and serves to urge the buter end of the said arm 17 downwardly. A link 25 provided with a link adjusting turnbuckle 25a is pivoted at one of its ends to the gate operating arm 17 as at 26 and has its other end connected to a lifting ring 27 on the gate 1 for raising and lowering the said gate as the gate operating arm 17 is raised or lowered in a` manner to be presently described.

In the drawings there is also shown a pressure gauge 28 of conventional type mounted on the top plate 5 of the air container 3, the said auge communicating with the container and being actuated by the pressure therein.

The manner of operation of the device may be briefly described as follows: It is assumed that the valve 16 has been opened to allow the interior of the air container 3 to communicate with the diaphragm 7. .Pulp is then introduced into the stuff box through the pipe C, and', rising in the stuff box, will entrap a quantity of air in the container. When the pulp on the outside of the container has reached the level shown in Figure 2 it will overflow the partition 1 and be maintained at-this level as previously described. Due to the pressure exerted by the column of pulp in the stuff box, some of the pulp will rise within the air container 3 and compress thel air entrapped therein, the rising of the pulp inside of the said container stopping' at such a level that the pressure exerted by the entrapped and compressed air is just balanced by the otherwise unbalanced head of pulp indicated at h. Assuminor that the pulp so initially introduced is of the proper working consistency, the abutment 23 and the weights 24 are then adjusted along the gate operating arm so as to cause the gate 1 to be held in such an open position as will allow the rate of flow of pulp from the stuff box, which will result'in deliverying the solid material at the desired rate. As long as the ratio of solid material to water in the pulp mixture remains constant, the pressure of the air entrapped in the container 3 will remain the same and the gate 1 will remain stationary, thus permitting a constant feed of pulp, and, since the ratio of solid to water is constant, a constant feed of solid material will likewise be assured.

If, however, the ratio of solid material to water in the pulp decreases, it will be necessary to open the gate farther to allow a greater feed of pulp in order to still feed solid material at the same rate. Thegate will be automatically opened as follows: When the ratioy of solid matter to water decreases, the densit of the pulp mixture will increase due to t e fact that water has a higher specific gravity than the solid material used. The increase in density of the pulp will result in a greaterA upward pressure being exerted b' the pul due to the head of pu p indicate at h, an the level of the pulp within the container will thereby be raised until the entrapped air has been compressed to such a degree as will balance the diminished head of pulp L. The increased pressure of the air in thecontainer acts throughthe pipe 18 and on the under side of the diaphragm plate 10, raising the plate, which, by

means of the diaphragm arm 20 and the abut? ment 23, will in turn move the outer end of the gate operating arm upward to lift the gate and allow a greatery feed of -pulp from the stuf'll box to compensate by an increased volume flow of pulp of gre'aters density for a will be delivered from the stuff box.

y The gauge 28, being actuated by air under pressure in the air container 3, can be calibrated to accurately indicate the ratio of solid material to water in the pulp mixture, since the pressure in the container is entirely dependentl upon this ratio.

It will be gathered from the foregoing that the container 3 is in the nature of an air trap in which an unchanging body of air is trapped by the pulp in the stuff box and compressed in degree according to the consistency of the said pulp. v x

It is apparent. that I have provided a device Iwhich may be used to control the feed 'of pulp from a stuff box in such a way as will insure a constant feed of solid material regardless of variations in the consistency of the pulp. My device is extremely reliable and accurate, since for its operation it depends only upon -the consistency ofthe pulp and not upon any outside influences which Amight be subject to continued variations l tending to reduce the efiiciency of the device. f

It is obvious that my pulp feed regulator may be used in connection with the feeding of other mixtures of solid matter and liquid, and it. is of course to be understood that 'the details of structure and arrangements Y pulp solid flowing through the feed gate per' given time unit, said operating means including an air container confining an unchanging body of air therein and open to the pulp at a point below its level in the stuff box, and pressure responsive means communicating with the container and actuated by the pressure of the air confined therein for positioning the gate and regulating the flow of pulp from the discharge openmg.

2.' In a pulp feed regulator, the combination with a stuff box having a pulp discharge opening, of a pulp feed gate, and means for operating the gate to regulate the amount of pulp solid flowing through the feed gate per vgiven time unit, saidoperating means including a fluid container confining an unchanging body of fluid therein and open to the pulp at a point below its level in the stuff box, and pressure responsive means communicating with the container and actuated by the pressure of the fluid confined therein for positioning the gate and regulating the flow of pulp from the discharge opening.

3. In a pulp feed regulator, the combination with a stuff box having means for maintaining a constant level of pulp therein, and a pulp discharge opening, of a pulp feed gate, and means for operating the gate to regulate the amount of pulp solid flowing through the feed gate per given time unit, said operating means including an air container confining an unchanging body of air therein and open to the pulp at a point below 4 its level in the stuff box, and pressure responsive means communicating with the container and actuated by the pressure of the air confined therein for positioning the gate and regulating the flow of pulp from the discharge opening.

4. In a 1pulp feed regulator, the combination with a stuff box having a pulp discharge opening of a pulp feed gate and means for operating the gate including an air container within the stufll box and open to the'pulp at a point below the level thereof for confining an unchanging body of air within the container, pressure responsive means communi eating with the container and actuated by the pressure of the air therein, and adjustable means connected to said pressure responsive means and to the gate for operating the gate when the pressure responsive means is actuated..

5. In a pulp feed regulator, the combination with a stuff box having a pulp discharge opening of a pulp feed gate and means for operating the gate including an air container within the stud box and open to the pulp at a point. below the level thereof for confining an unchanging body of air within the container, pressure responsive means communicating with the container and actuated by the pressure of the air therein, a gate operating arm, and means adjustably positioned on the arm and actuated by the pres- 6. In a pulp feed regulator, the combina` i tion with'a stuff box having aypulp discharge opening of apulp feed gate and means for operating the gate including an'air container within the stu' box andopen to the pul atta point lbelow the level thereof lfor con ing an unchanging body of air within the container, pressure responsive means communieating with the container and actuated by the pressure of the air therein`,a gate operating arm, means adjustably positioned on the arm and actuated by the pressure' responsive means for'operating the arm and the gate, and weights adjustably positioned on the arm and serving to urge it downwardly.

7. Ina pulp feed regulator,`the"combina tionwith al stufl:` box having a'pulp discharge opening of a pulp feed gate and means for op-A erating the gate including an air container within the stuff box and open to the pulp at a point below the level thereof for confining an unchanging bodyf of air within the container, a pressure responsive diaphragm communicating with the container and actuated by the pressure -of the air therein, a. piv-otedy` diaphragm. arm adapted to be actuated by contact with the diaphragm, a pivoted gate operating arm overlying the diaphragm arm, an abutment adjustabf gate operating arm for contact with the diaphragm arm, and means connecting the gate operating arm to the gate at a point remote from the pivot on said arm. f

8. In a pulp feed regulator, the combination with a stuff box having a pulp discharge opening of a pulp feed gate and means for operating the gate including an air container Within the stuff box and open to the pulp at a point below the level thereof for confining an unchanging body of air within the container, a pressure responsive diaphragm communi eating with the container and actuated by the pressure of the air therein, a pivoted diaphragm arm adapted to be actuated by contact with the diaphragm, a pivoted gate operatingarm overlying the diaphragm arm, an abutment adjustably positioned 'on the gate oplerating arm for contact with the diap ragm arm, mea/ns connecting the gate operating arm to the gate at a oint remote from the pivot on said arm, an adjustable means for urging the gate operating arm downwardly.

9. In a pulp feed regulator, the combination with a stuff box having means for maintaining a constant level of pu'lptherein of y 1 positioned. onl the u an air container within the stuff box and open to the pulp at a point below the level thereof for confining an unchanging body of air within the container, and a pressure indicating gauge communicating with the interior ofsaid container and responsive tothe pressure therein.

' 10. In a pulp feed regulator wherein is provided a stuff box havin a discharge opening and a gate to control .t e opening;'means to trap an unchanging body of fluid in amanner for having its pressure varied in accordance with variations in density of pulp in the stuff box, and means actuated by the pressure of the said body of fiuid to control the position of Ithe said gate. u v y 11. In a pulp feed regulator, a stuff box having means to maintain a constant level of pulp therein and a pulp discharge opening, a

gate to cont-rol the discharge opening, a pressure actuated diaphragm, a fluid trap open at one point to communication with the pul in the stuff box beneath the level thereof an at another point with the diaphragmV and closed throughout otherwise to trap therein an unchanging body of fluid in a manner for causing the pressure of the trapped fluid to vary in accordance with variations in the den- 4 lsity of the pulp in the stuff box, and means connected to the control gate and actuated by the diaphragm to position the gate according to the degree of density of the pulp in the stuff box.

12. In a pulp feed regulator wherein provided a. stuff box having a discharge opening and a gate to control the opening; means to trap an unchanging body of fluid in a manner for havin its pressure varied i'n accordance with varlations in density of pulp in the stuff box, and means actuated by thepressure of the said body of fluid to control the position yof the said gate, said last named means comprising a pressure responsive diaphragm communicating with the trapped body of fluid and actuated by the pressure of the said bod Vof fluid, a pivoted diaphragm arm adapte to be actuated by contact with the diaphragm,

a pivoted gate operating arm overlying the diaphragm arm,'means to connect the gate and gate operating arm for movement together, and an adjustable abutment member for causing the diaphragm arm and gate operating arm to interengage for the purpose described. V

In testimony whereof, I have hereunto subscribed my name.

GEORGE E. MAYO.

Images