US3573160A - Tapered manifold stock distribution system for a papermaking machine with movable wall therein - Google Patents

Abstract

THE DISCLOSED STOCK DISTRIBUTION SYSTEM PROVIDES AUTOMATIC AND CONTINUOUS ADJUSTMENT TO VARIATIONS IN STOCK FLOW VELOCITY IN A PAPERMAKING APPARATUS. A TAPERED MANIFOLD COMMUNICATES ACROSS A FLOW CHANNEL TO DISTRIBUTE PAPER STOCK UNIFORMLY ONTO THE FOURDINIER WIRE. THE TAPERED MANIFOLD CONTAINS A SEMIRIGID DIAPHRAGM WHICH FORMS A WALL OF THE INTERIOR MANIFOLD CHAMBER. SENSORS ARE PROVIDED ACROSS THE WIDTH OF THE FLOW CHANNEL TO MONITOR STOCK FLOW AND DETECT FLOW VELOCITY IRREGULARITIES. EACH SENSOR CONTROLS THE SHAPE OF THE TAPERED MANIFOLD DIAPHRAGM AT A POSITION CORRESPONDING TO THAT OF THE SENSOR. THE EFFECTIVE TAPE OF THE MANIFOLD IS THUS CHANGED AT THE CORRESPONDING POSITION PERMITTING THE VELOCITY OF STOCK ISSUING FROM THAT POSITION IN THE MANIFOLD TO BE ADJUSTED TO A REFERENCE LEVEL. THE INVENTION FURTHER PROVIDES MEANS FOR DISCHARGING FLUID FROM THE LEADING EDGES OF DEFLECTORS AND SPACERS IN THE FLOW CHANNEL TO PREVENT FIBER HANG-UP. ALSO, MEANS ARE PROVIDED FOR APPLYING EXTERIOR PRESSURE TO THE FLOW CHANNEL TO PREVENT DISTORTION OR RUPTURE DUE TO HIGH INTERNAL PRESSURES.

Description

March 30, 1971 OMS 3,573,160

K. L TAPERED MANIFOLD STOCK DISTRIBUTION SYSTEM FOR A PAPERMAKING MACHINE WITH MOVABLE WALL THEREIN Filed Jan. 29, 1969 4 Sheets-Sheet 1 INVENTOR. KAS/M/R LOPAS BY BLA/R, CESAR/ AND 57. ONGE A TTORNEYS March 30, 1971 K. LOPAS PAPERMAKING MACHINE W Filed Jan. 29, 1969 1TH MOVABLE WALL THEREIN 4 Sheets-Sheet 2 BLA/R, CESAR/ AND 87. ONGE ATTORNEYS March 30, 1971 OPAS 3,573,160

K. L TAPERED MANIFOLD STOCK DISTRIBUTION SYSTEM FOR A PAPERMAKING MACHINE WITH MOVABLE WALL THEREIN Filed Jan. 29, 1969 -4 Sheets-Sheet 5 ATTORNEYS Marsh 30, 1971 K, LQPAS 3573,16 TAPERED MANIFOLD STOCK DISTRIBUTION SYSTEM FOR A v PAPERMAKING MACHINE WITH MOVABLE WALL THEREIN Filed Jan. 29,' 1969 4 Sheets-Sheet 4 INVENTOR. KA SIM/R LOPA 5 BY BLAIR, CESAR! AND SZONGE ATTORNEYS United States Patent 3,573,160 TAPERED MANIFOLD STOCK DISTRIBUTION SYSTEM FOR A PAPERMAKING MACHINE WITH MOVABLE WALL THEREIN Kasimir Lopas, 118 Skyview Drive, Stamford, Conn. 06902 Filed Jan. 29, 1969, Ser. No. 794,863 Int. Cl. D21f 1/06 US. Cl. 162259 9 Claims ABSTRACT OF THE DISCLOSURE The disclosed stock distribution system provides automatic and continuous adjustment to variations in stock flow velocity in a papermaking apparatus. A tapered manifold communicates across a flow channel to distribute paper stock uniformly onto the Fourdrinier wire. The tapered manifold contains a semirigid diaphragm which forms a wall of the interior manifold chamber. Sensors are provided across the width of the flow channel to monitor stock flow and detect flow velocity irregularities. Each sensor controls the shape of the tapered manifold diaphragm at a position corresponding to that of the sensor. The elfective tape of the manifold is thus changed at the corresponding position permitting the velocity of stock issuing from that position in the manifold to be adjusted to a reference level. The invention further provides means for discharging fluid from the leading edges of deflectors and spacers in the flow channel to prevent fiber hang-up. Also, means are provided for applying exterior pressure to the flow channel to prevent distortion or rupture due to high internal pressures.

BACKGROUND OF THE INVENTION In the manufacture of paper sheet, dilute, fibrous paper stock is discharged in a sheet-like stream from an elongated nozzle or slice onto a moving screen (Fourdrinier wire) for drying. It is important that the flow of stock onto the wire be kept uniform in a spatial and temporal sense so that a smooth, even layer of stock is continuously laid on the wire. This permits the production of high quality paper, free from imperfections and of uniform consistency throughout.

In the past, however, it has been extremely diflicult to achieve a uniform flow of paper stock from the slice. The fluid stock is generally delivered to a headbox containing the slice through a delivery system comprising round pipe. The fluid must then make the transition from flow in round pipe to flow through the generally rectangular crosssection of the headbox. This transition has resulted in flow irregularities which produce velocity differentials across the stream discharged from the slice, resulting in lack of uniformity in the layer on the wire and eventually in the final paper sheet.

Accordingly, a tapered manifold stock distributor has been devised for the stock flow transition. In general this is a tubular chamber into which the stock is introduced with the direction of flow thereof generally perpendicular to the direction of flow in the headbox. Means are provided along the length of the tapered manifold to gradually divert portions of the stock flow into the headbox. A small portion of the stock is also permitted to flow straight through the manifold to an outlet to be recirculated.

It will be understood that since stock is being gradually diverted out of the tapered manifold along the length thereof, there is a gradual but continuous drop in the volume of stock in the manifold in the direction of flow and accordingly a drop in flow pressure. The manifold is thus constructed with a tapering cross-sectional area in the direction of stock flow to compensate for the volume change. This change in cross-sectional area requires careful design so that the flow of the stock diverted to the headbox along the length of the .manifold remains uniform. If the flow is not maintained uniform, i.e., if the flow of the diverted stock at one end of the manifold differs substantially from that at the other end, the flow differentials may persist through the headbox and out the slice to produce a non-uniform layer of stock on the Fourdrinier wire resulting in poor quality paper.

The problem with prior art tapered manifolds is that the degree of taper, which is fixed, is dependent upon a number of factors including stock consistency and velocity. These factors however are variable, and subject to constant change as the papermaking process continues. The prior art solution has been to design the manifold tape for an anticipated average stock flow. Significant variations in stock flow in the manifold, however, still produce flow differentials at the slice which affects paper quality.

Accordingly, representative objects of the present invention are to produce a variable, tapered manifold stock distribution system capable of automatically adjusting to variations in stock flow velocity and of producing a smooth and uniform flow onto the Fourdrinier wire of a papermaking apparatus.

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

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

SUMMARY OF THE INVENTION The present invention relates to a variable, tapered manifold stock distribution system for papermaking apparatus and more particularly to a tapered manifold stock distribution system in which the interior cross-section of the manifold is automatically varied, to compensate for variations in the flow of stock in the system and to provide uniform flow at the slice.

The variation in the cross-section of the tapered manifold of the invention is accomplished by means of a semirigid elastomer diaphragm secured within the manifold and comprising a wall of the interior manifold chamber. Adjustment means are provided to flex the diaphragm at predetermined positions to effectively change the crosssectional area of the manifold at that position. This in effect changes the manifold taper at that position to compensate for varying conditions of stock flow or consistency.

The means causing flexure of the diaphragm are controlled by sensors in the distribution system between the tapered manifold and the slice. In a preferred embodiment the sensors are placed in a flow channel which is connected to the tapered manifold at one end and which has the slice at the opposite end thereof. The sensors are preferably spaced over the width of the flow channel; however, in situations where a headbox or the like rather than a flow channel is used, the sensors may be placed in the pipes or spreaders connecting it to the manifold, or in the headbox itself.

The sensors are preferably of the fluid velocity sensitive type and monitor the stock velocity at predetermined spaced intervals in the flow channel. If stock velocity exceeds or falls below a predetermined level, the sensors detect the change and actuate means causing flexure at corresponding positions in the manifold diaphragm. The flexure resulting alters the manifold taper to compensate for either the excess or deficient stock velocity at the sensor location. Thus a substantially uniform stock velocity profile is maintained in the distribution system between the tapered manifold and the slice so as to obtain a uniform flow of stock onto the Fourdrinier wire.

The invention also provides for novel deflectors and spacers in the flow channel. The deflectors act to divert the stock flow from the manifold to the flow channel while the spacers reinforce the flow chamber and facilitate the even flow of stock therethrough. Means are provided for purging the deflectors and spacers with fluid to prevent the hang-up of stock fibers on the leading edges thereof. The purging may be done with white water recirculated from within the distribution system or with purge water supplied from a separate source.

The invention further provides means for supporting the distribution system which includes means for applying fluid pressure to the exterior of the flow channel. This prevents the deflection or rupture of the flow channel as a result of the high internal pressure generated during the papermaking operation.

BRIEF DESCRIPTION OF THE DRAWINGS 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 side elevation view in section taken along line 11 of FIG. 2 showing the distribution system of the invention in position in a papermaking apparatus.

FIG. 2 is a top plan view of the distribution system of FIG. 1 with a portion broken away to show the deflectors and spacers in the interior of the flow channel.

FIG. 3 is an enlarged sectional view of a portion of the stock distribution system taken along line 3-3 of FIG. 2, and illustrating diagrammatically the hydraulic system which controls actuation of the variable, tapered manifold.

FIG. 4 is a greatly enlarged top plan view of a deflector of the invention.

FIG. 5 is a greatly enlarged top plan view of a spacer of the invention.

FIG. 6 is a sectional view of a spacer in position in the distribution system taken along line 66 of FIG. 5.

FIG. 7 is a greatly enlarged partial sectional view of a portion of the variable, tapered manifold of the invention.

FIG. 8 is a partial sectional view taken along line 88 of FIG. 2 and looking down the stock distribution system.

Similar reference characters refer to similar parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 there is shown the stock distribution system of the invention in position in a papermaking apparatus. In general the system comprises a variable, tapered manifold 10 supported on a pedestal 12. Dilute, fibrous paper stock is fed through manifold 10 and into a flow channel 14 which comprises an elongated chamber of generally rectangular cross-sections supported from below by posts 16 and from above by beams 18. Flow channel 14 terminates at the end opposite manifold 10 in an elongated nozzle or slice 20 from which stock is discharged onto a moving Fourdrinier wire 22 shown supported on a breast roll 24 adjacent slice 20.

More particularly, as shown in FIG. 2, tapered manifold 10 comprises a generally tubular member 26 of tapering cross-section. The taper proceeds from a relatively large inlet opening 28 through which stock enters the distribution system, to a relatively small outlet opening 30 through which a portion of the stock flow is recirculated in the papermaking apparatus.

As shown in FIG. 3, manifold 10 contains an interior manifold chamber 32 defined by the sidewalls 34 of tubular member 28 and by a semirigid diaphragm 36 preferably formed of an elastomeric material. Diaphragm 36 is secured in fluid tight relation to the manifold sidewall 34 by rivets or bolts 38, and is positioned on sidewall 34 to leave a separate small chamber 40 below. Reinforcement against excessive axial flexure is preferably provided in diaphragm 36 by a series of reinforcing rods 42 (FIG. 7) molded into and running the length of diaphragm 36 in the direction of stock flow.

To change the effective taper of manifold 10 and thus compensate for stock flow irregularities, means for altering the shape of diaphragm 36 comprise a plurality of pistons 44 secured to diaphragm 36 at intervals alon the length thereof as shown in FIG. 8. The spacing of pistons 44 will depend upon a number of factors and may vary from machine to machine dependent upon design and intended application. For most applications however, a spacing of about one foot will be satisfactory. Leaf spring supporters 46 are preferably mounted on each piston 44 below and in contact with the bottom of diaphragm 36 as shown in FIG. 7 to provide lateral support. 'Each piston 44 passes through manifold wall 34 below chamber 40 (FIG. 7) and is actuated normal to the surface of diaphragm 36 in the direction of the arrows shown in FIG. 8. The force of piston 44 is distributed evenly across diaphragm 36 by the action of leaf spring support 46. The actuation of each piston 44 may be done electrically or mechanically, but preferably it is done hydraulically by means of a hydraulic cylinder 48 connected to each piston 44 below manifold 10. The hydraulic system for actuating cylinders 48 is discussed in more detail below.

Referring now to FIG. 3, the upper portion of manifold 10 is open and is provided with edge flanges 50 and 52 which are connected by bolts 54 and 56 respectively to the flanged ends 58 and 60 of flow channel 14. Flow channel 14 thus closes the opening in manifold 10 and communicates with interior manifold chamber 32 to convey paper stock from manifold 10 to slice 20 as shown in FIG. 1.

Flow channel 14 comprises a closed rectangular chamber 62 formed by flat top and bottom plates 64 and 66 spaced apart in parallel planes and welded or similarly joined by side plates 68 and 70 (FIG. 2). Top plate 64 is angled downward (FIG. 1) at the end of flow channel 14 adjacent the Fourdrinier wire 22 to form with bottom plate 66 an elongated slice 20. Preferably, the downwardly angled portion of slice 20 is hinged or otherwise made adjustable so that the spice opening 21 can be varied as desired.

Referring to FIG. 2, it can be seen that the direction of stock flow in manifold 10 is at right angles to the axial direction in which the stock flows in channel 14. Accordingly, means are provided to divert the stock flow from manifold 10 to flow channel 14. These means comprise a plurality of deflectors 72 of generally hydrofoil shape (FIG. 4) mounted in flow channel 14 adjacent the area of communications with manifold 10. Each deflector is provided with a plurality of bolt holes 74 and is mounted by bolts 76 (FIG. 3) in flow channel 14 between top plate 64 and bottom plate 66. Deflectors 72, in addition to diverting stock flow, serve both to support top plate 64 and to maintain the proper spacing between top plate 64 and bottom plate 66.

As shown in FIG. 4, the leading edge 78 of each deflector 72 is curved in a manner to intersect the stock flow in manifold 10, and to smoothly deflect it at an angle through the inter-deflector spaces 79 (FIG. 8) and ito axial flow in flow channel 14. A problem arises, however, with the use of deflectors since fibers from the paper stock solution have a tendency to become caught on or to hangup on the deflector leading edge 78. To prevent this, means are provided to discharge fluid from leading edge 78 against the direction of stock flow. Referring to FIG. 4, a recess 80 is provided adjacent leading edge 78. A channel 82 communicates with recess 80 and opens onto the front of leading edge 78. As shown in FIG. 3, when each deflector 72 is mounted in the stock distribution system an inlet 84 is connected through top plate 64 into recess 80. Inlet 84 carries fluid (preferably white water recirculated from the papermaking process or purge 'water from a separate source) into recess 00 where it flows out channel 82 against the flow of paper stock to dislodge any accumulated fibers on leading edge 78.

In addition to dflectors 72, spacers 84 (FIGS. 1 and 2) are positioned in groups at ntervals along flow channel 14 between top plate 64 and bottom plate 66. The groups of spacers 84 are positioned between the posts 16 and beams 18 which support flow channel 14. The function of spacers 84 is to support top plate 64 of flow channel 14 and to maintain the separation of top and bottom plates 64 and 66. Spacers 84 are preferably hydrodynamically shaped as shown in FIG. to permit the stock to flow smoothly thereover. Spacers 84 thus minimize flow irregularities n flow channel 14.

1 As with deflectors 72, spacers 84 are provided with bolt holes 86 and are mounted by bolts 88 in flow channel 14 as shown in FIG. 6. Each spacer 84 is also provided Wlth a recess 90 connected by a channel 92 to the leadmg edge 94 thereof (FIG. 5); they are mounted in flow channel 14 1n communication with an inlet tube 96 (FIG. 6) so that white water or purge water can be discharged through channel 92 to prevent hang-up of paper stock fibers on din ed e94.

as d iscu ssed above, the shape of diaphragm 36 is altered to change the effective taper of manifold in order t: compensate for any flow irregularities in flow channel 1 Accordingly, means are provided to sense flow irregularities in flow channel 14, and to effect a change of shape in diaphragm 36. These means compns'e1 a plurality of velocity sensitive sensors 98 spice at predetermined intervals over the width of OVfV channel 14 (FIG. 2) and extending into the interior of flow channel 14 as shown in FIG. 3. One suitable type 0 sensor is a purged Pitot tube. Sensors 98 may be placed in any position in flow channel 14 but are preferably spaced from deflectors 72 so as not to be effected by any turbulence caused by the diverslon of stock flow from manifold 10. Sensors 98 signal and control the actuation of pistons 44 (FIG. 8) which are connected to and regulate the shape of diaphragm 36. Sensors 98 may exert their control through electrical, mechanical, pneumatic or like means; preferably, however, they control pistons 44 through pressurization of a hydraulic system as shown in FIG. 3.

Specifically, each sensor 98, except the reference sensor 98R, is hydraulically connected to the cylinder 48 of the piston 44 at a corresponding position in manifold 10. A hydraulic line 100 connects each sensor 98 to one side of its pressure differential valve 102. Each pressure valve 102 comprises a valve cylinder 104 contalning a valve piston 106 freely mounted for axial movement therein. Valve plston 106 carries enlarged end plugs 108 and 110 WhlCh respectively serve to open and close valve inlet 112 and outlet 114 as piston 106 moves axially within valve cylinder 104. Valve inlet 112 is connected to an external source of hydraulic pressure while outlet 114 serves as a pressure relief valve. Valve piston 106 is biased towards the center of valve cylinder 104 by a pair of coil springs 116 and 118 at either end of piston 106. The tension on springs 116 and 118 is adjusted through screws 120 and 122 which have washers 124 and 126 aflixed to the end pressing against springs 116 and 118. As will be seen from the following discussion, the pressure level at which valve 102 will be actuated may be regulated by adjustment of screws 120 and 122.

The reference sensor 92R is preferably located at the center of flow channel 14, although it may be located at any of the sensor positions shown in FIG. 2. By placing the reference sensor at the center, however, the amount of deflection required in diaphragm 36 is optimally minimized. Accordingly, the system is adjusted so that the velocity at sensor 98R is at a desired level for the anticipated volumetric rate; thereafter the velocity in any other portion of flow channel 14 may be referenced thereto. Of course if the flow rate changes the reference velocity level changes. The reference velocity is established by fixing the height of piston 44R, the piston corresponding in position to reference sensor 98R as shown in FIG. 8.

Although reference sensor 98R is not connected to piston 44R in manifold 10, it is hydraulically connected to each pressure valve 102 of the other sensor 98. Referring back to FIG. 3, a hydraulic line 128 from reference sensor 98R is connected into each pressure valve 102 at the end opposite the connection from the corresponding velocity sensor 98. Thus, the pressure in the valve chamber surrounding spring 116 depends upon the velocity at reference sensor 98R and this will be the case in each pressure valve 102 in the system.

As is further shown in FIG. 3, a hydraulic line 130 connects the bottom of each hydraulic cylinder 48 to the center of the corresponding pressure valve 102 while the other side of cylinder 48 is hydraulically connected with the small chamber 40 below diaphragm 36. It is preferable that the pressure in chamber 40 be kept equal to or slightly below, e.g., about 0.5 p.s.i.. below the pressure in manifold chamber 32. For this purpose a differential pressure regulator 132 having hydraulic lines 134 and 136 respectively connected into manifold chamber 32 and chamber 40 is provided in the system.

Stock fibers tend to accumulate or hang-up on the leading edge 138 of each sensor 98, and also about the opening 140 from manifold chamber 32 to pressure regulator 132, in a manner similar to that discussed with reference to deflectors 72 and spacers 84. To prevent such accumulations, a rotometer 142 (-FIG. 3) is connected into each sensor 98 and 98R and discharges a fluid against the flow of stock; the fluid may be white water recirculated from Within the system or purge water from an outside source. A similar rotometer 144 is connected into hydraulic line 134 of pressure 132 to maintain ,opening 140 clear.

The operation of the distribution system of the invention can best be understood with reference to FIG. 3. Assume that the stock flow at the position in flow channel 14 monitored by the sensor 98 has a higher velocity than the reference stock flow at sensor 98R. Under these conditions line becomes pressurized by sensor 98 and thus pressurizes the chamber surrounding spring 118 in pressure valve 102. Since the pressure at the opposite end of pressure valve 102, that is in the chamber surrounding spring 116, is maintained at the reference pressure, valve piston 106 is forced to the left, opening inlet 112. High pressure fluid from the source to which inlet 112 is connected is thus permitted to enter the valve chamber between plugs 108 and and pressurizes hydraulic line this in turn causes piston 44 to rise, deflecting or flexing diaphragm 36 upwardly at that position. Manifold 10 is thus decreased in cross sectional area in the vicinity of the upwardly actuated piston 44.

The decrease in manifold cross section in an area results in a decreased flow of stock through the deflectors 72 in that same area. Thus, a decreased flow of stock occurs all the way down fiow channel 14 in line with the upwardly deflected portion of diaphragm 36, which means a decreased flow against the sensor 98 under discussion. The decreased stock flow at sensor 98 causes the pressure to drop in line 100 with a concomitant drop in pressure in the valve chamber surrounding spring 118. The pressure drop permits valve piston 106 to be pushed to the right by the combined action of spring 116 and the reference pressure in the chamber surrounding spring 116. When the pressure in the chamber surrounding spring 118 drops to the reference pressure in the chamber surrounding spring 116, piston 106 stops and comes to rest at a neutral position shown in FIG. 3 wherein it closes off both inlet 112 and outlet '114.

It can be seen that a reverse cycle of movement of piston 44 and a similar but reversed correction will occur if the flow velocity at sensor 98 should be diminished below the reference flow at sensor 98R.

In the manner described above, the distribution system of the invention continuously and automatically adjusts itself to any variation in stock flow velocity across flow channel 14. Thus, flow velocity variations across the flow channel are substantially eliminated by constantly adjusting diaphragm 36 to provide flow velocities corresponding to the velocity sensed at reference sensor 98R.

Another problem arises in stock distribution systems due to the great pressures which are built up inside the flow channel during operation. These pressures may amount to to p.s.i. when stock is flowing and this results in extremely high pressure forces on the upper and lower plates 64 and 66, which may be 100 to 250 inches in width. Such high pressure may cause the plates 64 and 66 to buckle or may rupture the bolts 76 and 88 (FIGS. 3 and 6) which secure plates 64 and 66 about the deflectors 72 and spacers 84. Deflection of plates 64 and 66 will change the volume of flow channel 14 and thus introduce irregularities in the stock flow. To counteract internal pressure and prevent deflection or rupture of flow channel 14, a rolling diaphragm 146 is mounted (as shown in FIG. 3) in the space between each beam 18 and the support bar 148 upon which beam 18 rests on top plate 64. The walls of rolling diaphragm 146 define an internal pressure chamber 150 which may be pressurized with fluid through an inlet 152 to counteract the internal pressure within flow channel 14. An equal and opposite reaction force to the pressure within rolling diaphragm 146 occurs against bottom plate 66 through interaction with the support plate 154 atop post 16. While four assemblies of beam 18, rolling diaphragm 146 and post 16 are shown in FIGS. 1 and 2, the number of assemblies necessary to support a given flow channel 14 will vary and will depend upon the design pressure of the system and the inherent structural strength of the flow channel assembly.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efliciently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, 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.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

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

1. A stock distribution system for a papermaking machine comprising in combination:

(A) a tapered manifold (1) containing an interior manifold chamber,

(B) means within said tapered manifold forming a movable wall of said interior manifold chamber,

(C) distribution means in communication with said manifold chamber for conveying stock therefrom to a slice,

(D) sensing means for sensing variations in stock flow velocity across said distribution means, and

(E) adjustment means connected to said sensing means and connected to said movable wall means for adjust ing the positioning of said wall means in response to signals from said sensing means to compensate for the stock flow variation and adjust the stock flow to a reference velocity level.

2. A stock distribution system as defined in claim 1 wherein said distribution means comprises a flow channel communicating at one end with said tapered manifold and incorporating a slice at the opposite end thereof for the discharge of fibrous paper stock onto the F ourdriuier wire of a papermaking apparatus.

3. A stock distribution system as defined in claim 1 wherein said means forming said movable wall of said interior manifold chamber comprises a semi-rigid diaphragm.

4. A stock distribution system as defined in claim 3 wherein said sensing means comprises a plurality of fluid velocity sensors spaced at predetermined intervals over the width of said distribution means.

5. A stock distribution system as defined in claim 4 wherein said adjustment means for moving said semi-rigid diaphragm comprises a plurality of pistons spaced along the length of said diaphragm and connected thereto at predetermined intervals, each said pistons being connected to and responsive to actuation by one said sensor at a corresponding position in said distribution means to exert pressure on and alter the shape of said diaphragm in a manner to adjust the velocity of stock flow at said position to a reference velocity level.

6. A paper stock distribution system for use in papermaking apparatus comprising in combination:

(A) a tapered manifold (1) containing an interior manifold chamber,

(B) a flow channel (1) communicating at one end with said tapered manifold and (2) incorporating a slice at the opposite end thereof for the discharge of fibrous paper stock onto the Fourdrinier wire of the papermaking apparatus,

(C) a plurality of fluid velocity sensors 1) spaced at predetermined intervals over the width of said flow channel,

(D) a diaphragm (1) comprising a wall of said interior manifold chamber, and

(E) a plurality of pistons (l) spaced along the length of said diaphragm and connected thereto at predetermined intervals,

(2) each said piston being actuated by a said sensor at a corresponding position in said flow channel to exert pressure on and to alter the shape of said diaphragm and thereby change the interior cross section of said tapered manifold whereby the velocity of stock flow within said flow channel is maintained substantially constant.

7. A stock distribution system as defined in claim 6 including a plurality of deflectors in said flow channel in the area of communication with said tapered manifold, said deflectors being shaped to divert the flow of stock from one direction in said tapered manifold to another direction in said flow channel and including means thereon for discharging fluid from the leading edges thereof against the direction of stock flow to prevent the accumulation of paper stock fibers on said leading edge.

8. A stock distribution system as defined in claim 6 and further including a plurality of spacers in said flow channel aligned with the direction of stock flow in said flow chamber and each having means thereon for dis charging fluid from the leading edge thereof against the direction of stock flow to prevent the accumulation of paper stock fibers on said leading edge.

9. A stock distribution system as defined in claim 6 including support means for said flow channel having means for applying fluid pressure to at least one wall of said flow channel to counteract the forces of internal pressure and prevent substantial deflection of said wall.

References Cited UNITED STATES PATENTS 3,351,522 11/1967 Lopas l62343X S. LEON BASHORE, Primary Examiner R. H. TUSHIN, Assistant Examiner US. Cl. X.R.

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