US1884075A - Consistency responsive device - Google Patents

Description

Oct., 25, 1932. s. E. MEYERS CONSISTENCY RESPONSIVE DEVICE Filed June l5, 1931 5 Sheets-Sheet l "UMHN v..

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Patented Oct. 25, 1932 UNITED .STATES PATENT OFFICE SIDNEY E. MEYEBS, OF LOCKPORT, NEW YORK, lATSSIGrNOR OF ONE-HALF TO ERICSSON H. l

MERBITT, OF LOCKPORT, NEW YORK CONSISTENCY RESPONSIVE DEVICE Application led June 15, 1931. Serial N'o. 544,359.

This invention relates to consistency responsive devices and more particularly to consistency control devices arranged to modity the viscosity of iluid suspensions, such as paper stock in paper mill beaters.

The invention has for its object generally an improved construction and arrangement of parts, which is eiiicient, economical and readily manufactured.

More specifically, an object of the invention is to provide a device which is highly sensitive to changes in consistency of fluid suspensions, such as paper stock and is adapted to respond quickly to anysuch variations 35 to rectify the same.

A further object of the invention is to provide a device, in which the addition of modifying fluid to the suspension is controlled by degrees and with great precision.

Another objectV of the invention is to provide a p ositive system for regulating the addition of modifymg lluid by means of a relay or other agency arranged to utilize an eX- ternal source of energy for doing the regnlating work.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

This application is a continuation in part of my co-pending application, which has become Patent No. 1,810,111, issued June 16, 1931.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a horizontal plan view of a paper mill beater provided with an improved consistency responsive device constructed in accordance with the invention;

Fig. 2 is a vertical cross section taken on line 2,-2 in Fig. 1 looking in the direction of the arrows; 5'() Fig. 3 is a view partly in section and partly in side elevation, the section being that of the heater and taken on the line 3--3in Fig. 1, looking in the direction of the arrows; and

Fig. 4 is an enlarged view partlyin sec- 55 tion and partly in elevation, showing on an enlarged scale the details in the construction of the relay or pilot motor mechanism here employed in connection with the invention.

Referring now to the drawings and particularly to Figs. 1 t0 3, there is illustrated a conventional beating engine adapted vfor accomplishing the process known as beating in the manufacture of paper and the like. Such beating engines are commonly 65 referred to as beaters.

The beater shown comprises a tub 1() which has a mid-feather or central partition 11 eX- tending from a point near one end of the tub to a point near the other, thereby dividing the tub to provide a single circuitous passage about the same through which the paper stock moves in a directiony indicated by the arrow a. This movement of the stock is produced by means of a driven roll 12 75 which extends substantially completely across one side of the beater and has a driving pulley 13 on its shaft, to which power is transmitted in order to drive the roll. In order to accomplish the beating action, the roll 12 80 is provided with a plurality of transversely disposed blades 14 arranged parallel to the axis of the roll. These blades engage with the oncoming stock as it moves in the beater passage and causes the stock to move along Se the bottom of the tub and then up over the back-fall shown at 15. This action of the roll 12 produces a normal difference between the hydraulic level of the stock which has just passed over the back-fall and that of the stock which Hows under the blades 15. This difference in levels causes a flow of the stock in the passage about the mid-feather; conseuently there is an inclination or slope of t e stock in its flow between two successive ints in the passage about the mid-feather. lllhis slope has been ascertained to be a true function of the consistency or percentage of the solid material supended in the stock as ointed out in my co-pending application, gerial No. 318,676 referred to above. The difference in level between two successive points in th'e beater which are suliciently disp tant to give a readily ascertained dilerential is taken as the measure ofthe slope and hence of the consistency, the two points being conveniently located for example on opposite sides of the mid-feather.

In the practice of the present invention, responsive elements are disposed at points 16 and 17 and arranged to respond quickly to changes in the hydraulic level, these points being taken on opposite sides of the midfeather adjacent the section line 3-3 as shown in Fig. 1. These elements are in turn connected to actuate a suitable differential mechanism shown generally at A18 which controls the valve 19 for regulating the admission of iuid for modifying the consistency of the suspension in the bea-ter. This fluid, which may be water, is admitted through the nozzle 20, here shown as a pipe disposed substantially completely across one slde of the beater a short distance in advance of the roll 12. The actuation of valve 19 by differential mechanism 18 is here controlled by an intermediate means or relay comprisin a pilot motor indicated generally at'21, whichA 1s connected to valve 19 by a cable 22.

The responsive elements here shown comprise stand- pipes 25 and 25 which depend into the beater to points near the -bottom of the passage as shown. Each of these pipes preferably has its lower end terminating in a bell as shown at 26 and 26 respectively. Suitable means for the securing of the standpipe; to the sides of the beaterare shown at 2 In order that changes in the hydraulic level wit-hin the pipes 25 and 25 may be quickly responded to, the hydrostatic pressure associated with such pipe is taken as the index to the height of the suspension in the circuitous passage on the exterior of the pipe. This pressure is then balanced against a suitable elastic pressure, so that any changes therein may be transmitted thereby to the differential mechanism. The source of elastic pressure here `shown is a pneumatic one, where 30 denotes an air reservoir arranged to be kept properl filled with air under pressure by means o a power pump 31. Pipe connections are shown at 32 leading from the reservoir 30 to a closed chamber 33 on the top of stand-pipe 25. A pressure-reducing valve 34 is shown in this pipe connection beyond which is a pet cock 35 kept constantly closed, there being a branch connection 36 leading to a chamber in the differentiai mechanism as hereinafter more fully explained. Similar connections 32 lead to the chamber 33 of the other stand- pipe 2,5. This connection likewise has a pressure-reducin valve 34', a bleeder-valve 35 and a branc connection 36 which leads to another chamber in the differential mechanism. By this arrangement, it is seen that the valves 34 and 34 may be adjusted to admit a supply of compressed air so that the rate of escape from the ends of pipes 25 or 25 maintains a pressure in the chambers 33 and 33' which just balances the hydrostatic pressure registered in the stand- pipes 25 and 25 when the normal consistency of the suspension in the beater obtains. Any change in the hydrostatic pressure in the pipes 25 and 25 reacts to change the pressures in the chambers 33 and 33 which results in a change in the pressures normally maintained in the differ- .,ential mechanism.

preferred are shown in F ig. 4, where 40 denotes a casing which houses a pair of chambers having movable walls disposed so that their expansion normally opposes one another. This is conveniently achieved by providing corrugated expansible bellows 41 and 42 each sealed on one side by the end walls of the chamber 4() and on the other by walls 43 over which are disposed opposed spiders 44. The spiders 44 are shown as having radial members extending outwardly across the Walls 43 from their central columns 45 and extend toward each other and bear upon the lower end of an actuating lever 46, here shown as L-shaped and pivoted at 47 in an upper part or turret 48 on the casing 40. In the arrangement shown, it is seen that one arm of the L-shaped lever depends between the expansible diaphragms While the other extends through an' opening in the side of the turret and has a counterweight 49 depending from its outer end. A link 50 is connected to an intermediate portion of this latter extending arm and connects the lever 46 to a second lever 51 pivoted at 52 to the casing of the pilot motor 21. This pilot motor may be of any convenient variety adapted to be operated by means of an external supply of energy. lVater power however is generally available in plants of the paper industry and this pilot motor is shown as of the hydraulic variety, for example, a reciprocating piston motor, the admission of water under pressure to actuate this motor being controlled by means of a pilot valve 53 that is arranged to be actuated by the lever 51.

The pilot valve 53 has a member 54 connected to be moved by a rod 55 passing through the stuiling box 56 and reci rocated `by motion transmitted from the ever 51.

dinal passages formed cin the walls o thev casing about the ciltral passage in which member 54 moves. n consequence both ends of member 54 receive equal supplies of motor fluid. When the member`54 is displaced from its neutral position, water is admitted to one or the other of the ends of the cylinder of motor 21.

A clearance space is also provided about the valve memberwith which the other end f of the cylinder communicates when the valve member 54 moves. This is conveniently provided by forming member 54 with a reduced or waste portion so placed that when member 54 is in normal position it just closes passages 57 and 58. From this, it will be seen thatwhenever the valve member 54 is moved so as to place one end of thec linder of the motor in communication with't e supply of motive ud, the other end is at the same time placed in communication with the exhaust, whereby the piston 59 is free to move until the valve member 54 resumes its neutral position when further movement of the piston 59 is stopped.

g Motion of fthe piston 59 thus caused by a movement of the pilot valve member is einployed to actuate the valve 19 regulating the admission of modifying fluid to the beater. To this end, the piston 59 has a rod 62 to which the upper end of the cable 22 1s connected, and which in turn is connected to the lever arm of valve 19.

In order to check the motion of the valve 19 when a. suliicient motion has taken place,l

to accomplish the desired modification of the consistency, the piston 59 is permitted only limited motion, i.4 e. it is short stroked or caused to move in steps. Acordinglyia compensating means is associated with the motor 21 which here comprises an auxiliary rod 63, secured to the rod 62 so as to move on the outside of the motorcylinder, arranged to lift one end of a compensating lever 64, which is associated with the pilot valve 53. This lever is of the loating variety and has its other end 65 pivoted to the valve rod 55. An intermediate point of this lever is pivoted at 66 to the link 67 which is connected at 68 to the lever 51.

In Fig. 3, there is shown connected with the fluid supply a suitable water filter 7 0, a means such as a pressure-actuated electric signal 71 for indicating pressure changes which occur in the differential mechanism, and a peep-hole 72 in the casing 40 for viewing7 the differential mechanism.

he operation of the lpresent consistency res onsive device is as fo ows:

uming that paper stock is moving in the c ircuitious passage about the beater, and that sufficient air is supplied to pipes 32 and 32 to displace al1 il from the stand-pipes 25 and 25 (preferably the air is supplied at such a rate as just to escape from the bottom of the ipes and bubble up through the stock) the va ves 34, 34,'35 and 35 being so adjusted that when normal consistency obtains the leverv 46 in the diierential mechanism is at its mid-point, then, if any change occurs in the consistency, for example-if it becomes more viscous, the `slope will become more steep and the hydrostatic pressure at the stand-pipe 25 becomes relatively less so that v adrop in pressure travels along the pipe 32 to the chamber of the diii'erential mechanism communicating with pipe 86.

' In consequence, the lever 46 is caused to move to the left by reason of the superior pressure in .the chamber on the right. This movement of the lower end of lever 46 to the left, as will be seen by reference to Fig. 4, causes the lever 51 to move upwardly and consequently the'valve rod 55 to move upwardly whereby motive iiuid is admitted to the lower end of the cylinder of the motor 2l. A n upward movement of the piston 59 is accordingly initiated which allows the cable 22 to move under the influence of the weight 22 so as to open the valve 19 and admit modifying liquid at a predetermined rate through the nozzle 20. 1

The compensating mechanism associated with the pilot motor "21, is brought into operation by this movement of the valve 19 causing it to stop in a certain position when it has beenpartially o ned. This is seen to be accomplished by e piston rod 62 lifting the auxiliary rod 63, so as to lift the outer end of lever 64. By so doing,'fthe pivot 65 at the other end of the lever is caused to descend, drawing downwardly the valve rofl 55 so that memberr54 assumes normal position and shuts oii further admission of motive fluid to the cylinder of the motor 2l.

The valve 19 is thus caused to remain in al partially opened condition noted, admitting v a small amount of modifying liquid which is and 25' is seen to cause a pressure drop in the chamber communication with pipe 36 and a pressure rise in the chamber communicating with pipe 36', so that the lower end of lever 46 is accordingly moved back substantially to its .initial neutral position. This motion causes lever 51 to be moved downwardly which consequently draws down the valve rod 55 so as to open the passage 57 to the top of the cylinder of the motor 21. This will cause the piston 59 to move downwardly thereby causing the cable 22 to effect a closing/ of the valve 19. When this is done, it will be seen that this movement of the piston causes` the auxiliary rod 63 also to move and drop the outer end of the lever 64, thereby bringing the valve member 54 back to its original position. This again stops the motion ot' piston 59 so that valve 19 when closed remains closed. It is thus seen that further modication of the consistency of the suspension in the beater ceases when normal consistency has been regained.

In the event that the rate at which fluid was supplied through nozzle 20 in the first instance is not sufficient to rectify the consistency, the slope accordingly becomes more steep and causes a further movement of the lever 46 to the left, so that valve member 54 is again moved -up and a further upward movement of the piston 59 ensues so as to effect a further opening movement of the valve 19. This causes an admission of the modifying fluid at a greater rate than initiall This increased rate should bring back the consistency to normal, but in the event that it does not and a steeper slope ensues, it is seen that the valve 19 is given a further partial opening movement.- Thus it is seen that by the present invention, the regulation takes place in small steps, each having an opportunity to bring about the desired condition of consistency. In this wa conditions of consistency are closely hel in practice within very narrow limits. It is also seen that the changes in hydrostatic pressures at the stand- pipes 25 and 25 are substantially immediately transmitted to the differential mechanism which at once sels up a motion of the relay device which releases the energy supplied to the pilot motor for effecting the step-by-step regulation desired.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a consistency responsive device, the

combination with a passage through which a fluid suspension continually moves, of hydrostatic means located at two successive points in said passage for ascertaining the relative levels vthereat, a differential mechanism associated with said h drostatic means and adapted to be actuated differences in the relative levels at said hydi'ostatic means, means for admitting a consistency modifying fluid to the suspension in said assage and a relay actuated by said di erential mechanism for moving said fluid-admitting means.

2. In a consistency responsive device, the combination with a passage through which a fluid suspension continually moves, of hydrostatic means located at two successive points in said passage for ascertaining the relative levels thereat, a differential mechanism associated with said h drostatic means and adapted to be actuated differences in the relative levels at said hydiostatic means, means for admitting a consistency modifying fluid to the suspension in said assage, and a pilot motor actuated by said) differential mechanism arranged to move said fluid-admitting means step-by-ste 3. In a consistency responsive evice, the combination with a passage through which a fluid suspension continually moves, of hydrostatic means located at two successive points in said passage for ascertaining the relative levels thereat, a differential mechanism associated with said hvdrostatic means and adapted to be actuated by differences in the relat1ve levels at said hydrostatic means, a valve for controlling the admission of fluid to the suspension in said passa and a hydraulic motor ractuated by sai differential mechanism arranged to mve said valve in a step-by-step manner.

4. In a consistency responsive device, the combination with a passage through which a fluid suspension continually moves, of hydrostatic means located at two successive points in said passage for ascertaining the relative levels thereat, a differentialmechanism associated with said hydrostatic meansl and adapted to be actuated y differences in the relative levels at said hydrostatic means, a valve for controlling the rate of admission of consistency modifying fluid to the suspension in said passage, a ilot motor actuated by said differential mec anism connected to move said valve, and compensating means associated with said motor for limiting its movement when a predetermined movement has taken place.

5. In a consistency responsive device, the

combination with a passage through which a fluid suspension continually moves, of hydrostatic means located at two successive points in said passage for'ascertaining the relative levels thereat, a differential mechanism associated with said hydrostatic means and adapted to be actuated by dierences in the relative levels at said hydrostatic means, a main valve for controllin the rate of admission of consistenc mo ifying fluid to the suspension in sai passage, a hydraulic motor having a art connected to move said main valve, a pilot valve actuated by said diiferential mechanism for controlling the supply of motive fluid to .said motor, and compensating means associated with said pilot valve arranged to be actuated by said motor for a predeterminedmovement of said main valve to i-estore said pilot valve to normal whereby a step-by-step operation of said motor ensues.

6. In a consistency responsive device, the combination with a passage through which a iuid suspension continually moves, of stand-pipes located at two relatively distant points in the path of movement, elastic pressure supply means for balancing each of the hydrostatic pressures obtaining at said stand-pipes, opposed pressure responsive devices actuated by the differential in said balancing pressures, means for admitting a consistency modifying iiuid to the suspension in said passage, and a relay actuated by said pressure diierential for moving said Huidadmitting means.

7. In a consistency responsive device, the combination with a passage through which a iiuid suspension continually moves, of standpipes located at two relatively distant points in the path of movement, elastic pressure supply means for balancing each oi the hydrostatic pressures obtaining at said stand pipes,opposed pressure responsive devices actuated by the diii'erential in said balancing pressures, a valve for controlling the admission of iuid to the suspension in said passage, and a hydraulic motor actuated by said diiierential mechanism arranged to move said valve in a step-by-step manner.

8. In a consistency responsive device, the combination with a passage through which a fluid suspension continually moves, oi standpipes located at two relatively distant points in theV path of movement, elastic pressure supply means or balancing each of the hydrostatic pressures obtaining at said standpipes,opposed pressure responsive devices actuated by the diiierential in said balancing pressures, a valve for controlling the rate of admission of consistency modifying fluid to the suspension in said passage, a pilot motor actuated by said diiierential mechanism connected to move said valve, and compensating means associated with said motor for limiting its movement when a predetermined movement has taken place.

9. In a consistency responsive device, the combination with a passage through which a Afluid suspension continually moves, of Standpipes located at two relatively distant points in .the path ot movement, elastic pressure supply means for balancing each of the hydrostatic pressures obtaining at said standpipes, opposed pressure responsive devices ac- 'tuated by the differential in said balancing pressures, a main valve for controlling the rate of admission of consistency modifying iuid to the suspension in` said passage, a hydraulic motor having a. part connected to move said main valve, a pilot valve actuated by said diierential mechanism for controlling the supply of motive iuid to said motor, and compensating means associated with said /pilot valve arranged to be actuated by said motor for a predetermined movement of said main valve to restore said pilot valve to normal whereby a step-by-step operation of said motor ensues.

10. In a consistency responsive device, the combination with a passage through which a fluid suspension continually moves, of standpipes located at different successive points in said passage provided withclosed tops, pipe connections for admitting air under pressure to said standpipes in amounts sufficient to balance the hydrostatic pressures at said standpipes where normal consistency obtains, pressure chambers disposed to have opposed movable walls, connections for moving said walls in response to changes in the differential between said hydrostatic pressures, a valve for admitting fluid to modify the consistency of the suspension in said passage, and a pilot motor connected to movesaid valve in response to a movement in said walls.

11. In a consistency responsive device, the combination with a passage through which a iiuid suspension continually moves, of standpipes located at diierent successive points in said passage provided with closed tops, pipe connections for admitting air under pressure tc said stand-pipes in amounts sufficient to balance the hydrostatic pressures at said stand-pipes where normal consistency obtains, pressure chambers disposed to have opposed movable walls, connections for moving said walls in response to changes in the diHerentia-l between said hydrostatic pressures, a valve `for controlling the admission of iiuid to the suspension iii said passage, a hydraulic motor having a piston connected to move said valve, and means actuated by the motion of said walls for controlling the supply oi" motive Huid to said motor.

12. In a consistency responsive device, the combination with a passage through which a iuid suspension continually moves, of standpipes iocated at diiierent successive points in said passage provided with closed tops, pipe connections for admitting air under pressure to said stand-pipes in amounts suiiicient to balance the hydrostatic pressures at said stand-pipes where normal consistency obtains, pressure chambers disposed.` to have opposed movable walls, connections for moving said walls in response to changes in the ies iis

dierential between said hydrostaticl pressures, a valve for controlling the admission of uid to the suspension in said passage, a hydraulic motor having a piston connected to move said valve, means actuated b the motion of said walls for controllin t e supply of motive fluid to said motor, andgcoxnpensating means associated with said motor for restoring said last named means to normal l0 position when a predetermined motion of said valve has taken place. In testimony whereof I aix my si ature.

SIDNEY E. ME RS.

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