US2589638A

US2589638A - Paper machinery

Info

Publication number: US2589638A
Application number: US684980A
Authority: US
Inventors: Stephen A Staege
Original assignee: Black Clawson Co
Current assignee: Black Clawson Co
Priority date: 1946-07-19
Filing date: 1946-07-19
Publication date: 1952-03-18
Anticipated expiration: 1969-03-18

Description

March 18, I952 s. A. STAEGE 2,589,638

PAPER MACHINERY Filed July 19, 1946 2 SHEETS-SHEET l 8 INVENTOR. 3: 1. a sn BY W9w 86 WK ATTORNEYS March 18, 1952 s. A. STAEGE 2,589,638

PAPER MACHINERY Filed July 19, 1946 2 SHEETS-SHEET 2 IN V EN TOR.

ATTORNEYS Patented Mar. 18, 1952 PAPER MACHINERY Stephen A. Staege, Hamilton, Ohio, assignor to The Black-Clawson Company, Hamilton, Ohio, a corporation of Ohio Application July 19, 1946, Serial No. 684,980

11 Claims.

This invention relates to paper making, and more particularly to stock supply systems for paper making machines. This application is a continuation-in-part of application Serial No. 607,820, filed July 30, 1945, for Paper Machinery, now Patent No. 2,540,301 issued February 6, 1951 and assigned to the same assignee as this application.

One of the principal objects of this invention is to provide for continuous control of the flow conditions of stock approaching the forming member of a paper mechine to avoid abrupt changes in velocity or pressure and to maintain the desired smooth and uniform flow conditions across the width of the stock supply substantially continuously to the forming member.

Another object is to provide for dissipating without turbulence the velocity energy of stock entering the stock inlet passage of a paper machine at high velocity while at the same time avoiding abrupt or substantial changes in flow conditions such as might tend to cause flocculation or lump formation.

An additional object is to provide a stock inlet passage for a paper machine adapted to receive stock at high velocity and including a Venturi portion capable of dissipating the velocity energy of the stock with minimum turbulence and adapted. to supply the stock to the forming member in substantially uninterrupted flow without the formation of pools or slow moving reservoirs of stock tending to cause abrupt or substantial changes in the flow conditions.

It is also an object of this invention to provide a stock supply system for a paper machine wherein optimum flow conditions may be maintained in the stock inlet passage over a wide range of speeds of the forming member.

A further object is to provide a stock supply system for a paper machine wherein the volume of flow of the stock at the slice may be readily varied over a wide range while maintaining substantially uniform flow conditions through the stock inlet.

Another object is to provide a stock supply system wherein the flow of stock into the inlet passage may be at a substantially higher velocity than at its point of delivery to the forming member in order to maintain the stock in properly mixed condition and to prevent the heavier constitutents from settling out even when the machine is operated at comparatively low speed.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the .appended claims.

In the drawings- Fig. 1 is a schematic view of a circulating and stock supply system in accordance with the invention for a cylinder type paper machine, showing the path of flow of incoming stock and collected white water as supplied to and discharged from the paper forming parts;

Fig. 2 is a fragmentary view similar to Fig. 1 showing a stock supply system in accordance with the invention for a Fourdrinier type machine; and

Fig. 3 is a view similar to Fig. 1 showing a stock supply system in accordance with the invention for a Fourdrinier type machine and including a by-pass connecting the inlet passage or head box with the suction side of the circulating pump to control the volume at the slice.

Referring to the drawings, which show preferred embodiments of the invention, in Fig. ,1 the vat is indicated generally by the reference character l0 and includes the vat circle II with the rotary forming member or cylinder mold 12 mounted therein. A tapered vat inlet 15 supplies the incoming stock to the vat, as described in more detail hereinafter, and the usual mold slice l6 and adjustable rotary slice [1 may be provided as desired. The vat has an overflow compartment 20, with the overflow dam being lowered or removed when using the means for maintaining the vat level described in the above noted application Serial No. 607,820.

The white water is withdrawn from vat I0 through pickup 22 located in the vat, and it is fed through conduit 23 into white water pump 24, new stock from the regulating box being introduced into conduit 23 from pipe 25 directly ahead of pump 24 as shown. The level in the vat is maintained by the white water spill dam 26 shown in dotted lines in Fig. 1, the overflow from which may be discharged to the sewer as indicated at 27.

The discharge of the white water pump is supplied through conduit 30 to a suitable screen 32, the reject from which is removed as shown at 33 and discharged. The screened stock is withdrawn through conduit 36 and delivered into the conduit 31 which also receives the overflow from the overflow compartment 20, a branch conduit 38 also being provided for return of a portion of the white water directly into the stock overflow. Control of flow from overflow compartment 20 is provided by a butterfly valve t0, and provision is made for power operation of this valve, such mechanism being shown as comprising a reversible electrical motor 4| operatively connected to cause rotation of the valve by belt or sprocket 42. Automatic control of the operation of this motor may in turn be provided by means such as the liquid level control shown in detail in said application Serial No. 607,820, such control being effective to move the valve to a more open position when the liquid within the vat rises above the desired 3 level and to move the valve to a more closed position when the liquid within the vat falls below the desired level.

A circulating pump 45 delivers the stock from conduits 36 and 31 through a conduit 46 which is preferably branched at 41 to supply the stock to a counterfiow inlet 50, shown as of the construction disclosed in Patent No. 2,347,717 assigned to the same assignee as this application.

' Within this inlet 50 is a pair of oppositely tapered,

transversely extending conduits and 52 separated by a vertical baffle 54 positioned immediately below and parallel to a common discharge orifice 55 which is substantially narrower than the corresponding dimensions of the tapered conduits 5 i52 and extends transversely across substantially the entire width of the inlet passage 15. The branched'conduits 4! supply stock to the larger end of each of these tapered conduits, and there is thus provided a cross flow of stock through orifice 55 which gives substantially uniform pressure and flow of stock at relatively high velocity into the inlet passage 15 and across its entire width.

As a result of the restricted dimensions of the discharge orifice 55 with respect to the tapered conduits 5l-52, there is during operation a substantial presure differential across this orifice which develops a definite velocity condition in the fiow of stock therethrough, this velocity flow providing for thorough mixing and distribution of the stock and high uniformity across the entire width of the inlet passage. It is desirable to maintain the pressure differential and velocity of flow substantially uniform across the passage for maximum uniformity of sheet formation, and also to dissipate the initial velocity energy of this stock before it reaches the forming member in order to avoid objectionable turbulence tending to non-uniform sheet formation. Accordingly, the present invention provides for obtaining these results by means of the tapered construction of the inlet passage 15, which is shown as formed to coact with orifice 55 in the manner of a Venturi.

In Fig. l the counterfiow inlet passage 55 is shown as positioned with its discharge orifice 55 spaced at'a substantial distance from the point of delivery of stock to the forming member l2, thus providing for substantial travel of stock between the orifice 55 and the forming member.

The portion of the inlet l5 adjacent the discharge orifice 55, i. e. the lower portion 60 as shown in Fig. 1, has its walls GI and 62 relatively diverging away from the discharge orifice and at a relatively small angle, this angle being not more than about and a satisfactory example being a total included angle of the order of 7 /2" or an increase of approximately A per inch of travel. This tapered construction provides for gradually and progressively increasing the cross-sectional area to at least approximately four times the total area of the discharge orifice 55. The remaining portion 65 of the inlet passage [5 is shown as generally of at least as great cross-sectional area as the larger or upper end of the tapered passage portion 66, this portion 65 being smoothly curved to direct the stock from the tapered passage portion to the slice and the forming zone of the forming member with minimum turbulence or pockets where stock could collect and fiocculate to form a lumpy condition.

With the above construction, the stock entering the inlet passage l5 through the discharge orifice 55 with a relatively high velocity of flow has its velocity energy gradually absorbed and dissipated within the tapered Venturi passage portion 66 with minimum turbulence. At the same time, the construction of the adjacent passage portion 55, which is shown as of substantially the same capacity as the larger end of the Venturi portion 60, provides for directing the stock is a smooth and substantially uninterrupted flow directly to the forming zone without the formation of pools or slow moving reservoirs of stock such as may cause abrupt or substantial changes in flow conditions with resulting tendency toward flocculation and lump formation. With this stock supply system as shown and described, control over the flow of stock is maintained continuously from the entry of the stock by way of the discharge orifice 55 throughout the length of the inlet passage 15 and up to as close to the actual forming zone as is practicable. All the stock between orifice 55 and the forming member is kept in constant motion towards the forming member at a velocity which is constant across the width of the'inlet passage, changes in velocity being substantially uniform laterally and taking place smoothly and with minimum turbulence.

Fig. 2 illustrates an inlet passage similar to that shown in Fig. 1 as applied to a Fourdrinier type paper machine. In this construction, the forming wire 10 travels over a breast roll H, and stock is supplied through the slice or orifice 15, the width of which may be adjusted vertically by the adjusting mechanism indicated generally at E6. Forward and backward adjustment of the slice may similarly be made by the adjusting mechanism indicated generally at 11.

In Fig. 2, the stock is supplied to the slice and forming member through a counterfiow inlet 85 and tapered inlet passage in substantially the same manner as shown and described in connection with Fig. 1. The inlet includes tapered conduits 8| and 82,, a bafile 84 and arestricted discharge orifice 85 common to both of the tapered conduits. Stock is supplied to the larger end of each of these tapered conduits, as described in connection with Fig. 1, through branched conduits indicated fragmentarily at 86. The inlet passage includes a portion 96 constructed similarly to the portion 60 as described in connection with Fig. 1 and providing a Venturi passage adapted to receive the stock entering through the orifice 85 and to dissipate the velocity energy thereof as the stock is transmitted to the slice. The remaining portion 9! of the inlet passage is curved, as shown, to convey the stock from the tapered portion directly to the slice and forming Wire in a substantially uninterrupted flow and with minimum turbulence. A rotating perforated cylinder may be positioned as indicated adjacent the slice, and the stock flows through this cylinder to assure that the fibers will be properly dispersed throughout the water as the stock passes through the slice onto the forming wire.

The operation of the construction shown in Fig. 2 is substantially the same as described in connection with Fig. 1 with respect tocontrol of the flow of stock between the counterfiow inlet 80 and the forming member. The stock is initially supplied through conduit 86 under sufficient pressure to provide a flow through orifice 85 at a definite and substantially uniform velocity across the width of the inlet passage. As this stock enters the Venturi portion 90'of the inlet passage, the progressively increasing capacity of the passage provides for dissipating the velocity energy of the stock smoothly and with minimum turbulence. The curved passage portion 9| provides for directing the stock in smooth and continuous flow to and through the rotating perforated cylinder 05 and into the forming zone itself. This construction of controlled flow passage avoids formation of pools or slow moving reservoirs of stock capable of causing abrupt changes in flow velocity and thus facilitates maintaining the proper smoothness of the stock and freedom from lumps. As in the case of the construction shown in Fig. 1, the changes in velocity conditions are uniform laterally and take place smoothly throughout the entire extent of the inlet passage, thus greatly contributing to maximum uniformity of sheet formation.

Fig. 3 illustrates a stock supply system similar to that of Fig. 1 but applied to a Fourdrinier type paper machine and embodying means for varying the volume of flow of the stock to the forming member while maintaining optimum flow conditions through the orifice of the counterflow inlet. In Fig. 3, the forming wire I travels over breast roll HM, and the white water draining from the forming wire is collected in the wire pit or other collecting trough I02 and flows through a pipe I03, joining with new stock supplied through pipe IM from a suitable regulator box, to a circulating pump I05 such as a centrifugal pump. The resulting stock mixture is supplied through a, pipe I06 to a suitable screening machine 101, the flow through pipe I06 being shown as controlled by a suitable valve I08. From the screening machine the stock flows through conduit I09 to a counterfiow inlet III) similar in construction and operation to the counterfiow inlet 50 shown and described in connection with Fig. 1. The stock discharged through the discharge orifice III of inlet IIO passes through a stock inlet passage similar to that shown in Fig. 2 and including a tapered Venturi portion II2, contiguous with orifice III, and a curved portion I I3 which cooperate to convey the stock as described in connection with Fig. 2 directly to the slice M5, the latter being provided with adjusting means I I0 and II! similar to those shown in Fig. 2.

As was explained in connection with Fig. l, the counterfiow inlet H0 is preferably operated under pressure conditions such that the flow of stock through the restricted discharge orifice I I i is at a definite velocity, these conditions having been found to give satisfactory results from a standpoint of thorough mixing of the stock and uniform distribution and velocity across the entire width of the inlet passage. The optimum flow conditions for a particular inlet of this type will depend upon the particular design and construction of the inlet, but in general it has been found that if such velocity is varied over any considerable range, the preferred uniform conditions may not be maintained. On the other hand, it is desirable from the standpoint of proper control of sheet formation that the volume of flow of the stock through the slice be properly correlated with the speed of the forming member. Furthermore, it is sometimes found desirable or necessary to vary quite widely both the speed of a given machine and the volume of flow of the stock at the slice, but with the inlet designed to give optimum results over particular range of flow rates, if the velocity falls substantially below the preferred range, some settling out of the heavier constituents may occur, particularly in the case of stock containing substantial quantities of clay or other types of loading material, with resulting departure of the sheet characteristics from those desired. The present invention accordingly provides control means such that the velocity at the inlet I I0 may be maintained within the range giving optimum uniformity of flow even though the volume of flow of the stock through the slice I i 5 may be very much lower.

In accordance with the invention, these results are obtained with the construction shown in Fig. 3 by drawing off from the inlet passage suiiicient stock to reduce the volume at the slice to a value such that the desired volume of flow is obtained. As shown in Fig. 3, there is provided a slot I20 positioned between the Venturi portion I I2 of the inlet passage and the slice, and this slot extends completely across the width of the lowest side of the inlet passage parallel to the slice. A header I2 I is positioned below slot !20 and in direct communication therewith, this header being of large enough cross-section, as shown, to provide that the pressure differential across slot I20 will be substantially the same throughout the width of the inlet passage in order that the amount of stock withdrawn from the passage will be the same across its width, thus assuring uniform lateral pressure at the slice. Header I2I is in turn provided with one or more pipes I22 bypassing the slice and connecting with pipe I03 on the suction side of pump I05 as shown. The connection from pipes I22 to header I2I may be made at one or both ends of the header, or in some cases at several points in addition to the two ends, as maybe found desirable to maintain the proper uniform pressure differential across slot I20 as stated. Regulating means such as a valve I25 may also be provided for controlling the flow through pipe I22 in accordance with the pressure conditions to be maintained at the slice.

With this construction as shown, when the valve I25 is closed, all the stock transmitted by the inlet IIO will be conveyed through the inlet passage iI2I I3 to the slice and forming member, substantially as described in connection with Fig. 2. Similar continuously uniform control over flow conditions will be afforded as with the construction shown in Fig. 2, and regulation of flow conditions within the range giving preferred results may be readily attained by varying the speed of pump I05 or by throttling its discharge through pipe I06 betweenthe pump and screening machine. In this manner, the volume of flow of the stock through the slice may be readily controlled over a substantial range.

The by-pass construction illustrated in Fig. 3 affords alternative or supplemental control over fiow conditions, both independently of the rate of flow through the inlet passage, with the latter being maintained at its optimum value, and also in conjunction with the above described control to adapt the system to even wider ranges of speeds and rates of flow. Thus for a given speed or rate of delivery of pump I05, resulting in a uniform flow rate through the inlet, as valve I25 is opened. stock will be drawn off uniformly across the width of inlet passage, and the rate of flow of the remainder of the stock will be correspondingly reduced through the slice. This control may be readily obtained automatically, by operation of valve I25 through automatic level or pressure control means such as the type shown in the above noted application Serial No. 607,820.

As an example of the degree of control and range of conditions afforded by the above con.- struction, the volume range through a typical counterfiow inlet of the illustrated construction could be varied in the ratio of two to one with little difiiculty, and if desired probably over a range of three to one or even somewhat greater. By the use of the recirculation principle of this invention, however, the range of volume of flow at the slice could be extended to six to one or even considerably higher while still maintaining only a relatively small change in the inlet flow volume such as two to one, thus assuring best operating results.

It will accordingly be seen that the present invention provides a stock supply system for a paper machine of either the cylinder or Fourdrinier type, wherein the control over the flow conditions is continuous throughout the system and also highly uniform laterally throughout the inlet passage and substantially continuously up to the forming zone. In this supply system, the flow of stock into the inlet passage may be at controlled velocity to assure uniform mixing and distribution, and the velocity energy of this velocity stock is smoothly absorbed and dissipated before it reaches the forming zone, thus avoiding turbulence and abrupt velocity changes tending to produce flocculation or lump formation. It also provides for readily varying the flow conditions throughout the supply system, and particularly for uniform control over the volume of flow through the slice over a wide range while maintaining optimum flow conditions elsewhere in the system.

Reference is made to my copending application Serial No. 780,456, filed October 1'7, 1947, and assigned to the same assignee as this application.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparaus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In a stock supply system for a paper making machine including a forming member, the combination of means forming a slot orifice extending across the full width of said machine, means for discharging stock through said orifice at a definite and substantially uniform velocity and with substantially uniform distribution of fiber across the entire extent of said orifice, a chamber corresponding in width to that of said orifice and of substantially greater cross-sectional area than said orifice from which the stock is delivered directly onto said forming member, and walls forming an inlet passage connecting said orifice with said chamber to conduct said stock from said orifice to said chamber, said passage being of substantially the same width as said orifice and said forming member, said passage walls diverging at a predetermined small angle in the direction of flow from said orifice to provide with said orifice a Venturi passage for dissipating with minimum turbulence the velocity energy of said stock entering said passage through said orifice, said diverging passage continuing with substantially undiminished effective flow area up to said chamber for delivery of said stock to said chamber with minimum turbulence and flocculation, and said angle of divergence between said passage walls being not more than 10 to maintain said stock between said orifice and said chamber in continuous advancing motion to said forming member ata decelerating velocitywhich is sub stantially constant across each cross-sectional area of said passage.

2. In a stock supply system for a paper making machine including a forming member, the combination of means forming a slot orifice extending across the full width of said machine, means for discharging stock through said orifice at a definite and substantially uniform velocity and with substantially uniform distribution of fiber across the entire extent of said orifice, a

chamber corresponding in width to that of said orifice and of substantially greater cross-sectional area than said orifice from which the stock is delivered directly onto said forming member, and walls forming an inlet passage connecting said orifice with said chamber to conduct said stock from said orifice to said chamber, said passage being of substantially the same width as said orifice and said forming member, said passage Walls diverging at a predetermined angle of not more than 10 to maintain said stock between said orifice and said chamber in continuous advancing motion to said forming member at a decelerating velocity which is substantially constant across each cross-sectional area of said passage, said passage continuing with substantially undiminished effective flow area up to said chamber for delivery of said stock to said chamber with minimum turbulence and flocculation.

3. In a stock supply system for a paper making machine including a forming member, the combination of means forming a slot orifice extending across the full width of said machine, means for discharging stock through said orifice at a definite and substantially uniform velocity and with substantially uniform distribution of fiber across the entire extent of said orifice, a chamber corresponding in width to that of said orifice and of substantially greater cross-sectional area than said orifice from which the stock is delivered directly onto said forming member, and walls forming an inlet passage connecting said orifice with said chamber to conduct said stock from said orifice to said chamber, said passage being of substantially the same width as said orifice and said forming member, said passage walls diverging at a total included angle of approximately 7%? in the direction of flow from said orifice to provide with said orifice a Venturi passage for maintaining said stock between said orifice and said chamber in continuous advancing motion to said forming member at a decelerating velocity which is substantially constant across each cross-sectional area of said passage, said diverging passage continuing with substantially undiminished effective flow area up to said chamber for delivery of stock to said chamber with minimum turbulence and flocculation.

4. In a paper machine having a forming member and provided with a stock inlet including a pair of oppositely tapered cross flow conduits arranged in side by side relation and having a common restricted discharge orifice extending across the full width of said machine through which the stock is discharged at a definite and substantially uniform velocity and with substantially uniform distribution of fiber across the entire extent of said orifice, the combination of a chamber corresponding in width to that of said orifice and.

of substantially greater cross-sectional area than said orifice from which the stock is delivered directly onto said forming member, and walls forming an inlet passage connecting said orifice with said chamber to conduct said stock from said orifice to said chamber, said passage being of substantially the same width as said orifice and said forming member, said passage walls diverging at a predetermined small angle in the direction of flow from said orifice to provide with said orifice aVenturi passage for dissipating with minimum turbulence the velocity energy of said stock entering said passage through said orifice, said diverging passage continuing with substantially undiminished effective flow area up to said chamber for delivery of said stock to said chamber with minimum turbulence and flocculation, and said angle of divergence between said passage walls being not more than 10 to maintain said stock between said orifice and said chamber in continuous advancing motion to said forming member at a declerating velocity which is substantially constant across each cross-sectional area of said passage.

5. In a stock supply system for a paper making machine including a forming member, the combination of a stock inlet passage leading to said forming member and of substantially the same width as said forming member throughout the entire length thereof, means including a conduit having a discharge orifice extending across the entire width of said machine for supplying stock to said inlet passage at a pressure and under fiow distribution conditions providing a flow of stock through said orifice into said passage at a definite and substantially uniform velocity across the width of said passage and with substantially uniform distribution in said stock flow as delivered through said passage to said forming member, the walls of said passage diverging at an angle of not more than 10 in the direction of flow therethrough to maintain said stock between said orifice and said forming member in continuous advancing motion to said forming member at a decelerating velocity which is substantially constant across each cross-sectional area of said passage and to deliver said stock to said forming member in a smooth flow and with minimum turbulence, and means for drawing off stock from said inlet passage at a position downstream in the direction of flow from said energy dissipating means to said forming member and spaced upstream from the point of delivery of said stock to said forming member to reduce the volume of flow of said stock delivered to said forming member while maintaining a higher velocity flow of stock through said orifice to maintain said uniform fiow and distribution conditions therein.

6. In a stock supply system for a paper making machine including a forming member, the combination of a pair of oppositely tapered conduits arranged transversely across said machine and each adapted to be supplied at the larger end thereof with stock under pressure, means forming a slot orifice common to said pair of conduits and extending across the full width of said machine through which said stock is discharged from said conduits at a predetermined velocity of flow and width substantially uniform distribution of fiber across the width of said machine, said orifice being of restricted cross-sectional area relative to said conduits to maintain said predetermined velocity substantially higher than the velocity of flow of said stock in said conduits and substantially uniform across the width of said machine, means adjacent said forming member forming a chamber corresponding in width to said orifice and of substantially greater crosssectional. area than said slot orifice, and walls forming an inlet passage of substantially the same width of said orifice and said forming member for conducting stock from said orifice to said chamber, said walls being arranged to diverge at a predetermined total included angle of not more than 10 in the direction of flow of said stock from said orifice to said chamber to maintain said stock between said orifice and said chamber in continuous motion towards said forming member at a decelerating velocity which is substantially constant across each cross-sectional area of said passage and to dissipate with minimum turbulence the velocity energy of said stock as said stock fiows from said orifice to said chamber while maintaining substantial uniformity of fiow conditions in said stock across the width of said machine.

7. In a stock supply system for a paper making machine including a forming member, the combination of a pair of oppositely tapered conduits arranged transversely across said machineand each adapted to be supplied at the larger end thereof with stock under pressure, means forming a slot orifice common to said pair of conduits and extending across the full width of said machine through which said stock is discharged from said conduits at a predetermined velocity of flow and with substantially uniform distribution of fiber across the width of said machine, said orifice being of restricted cross-sectional area relative to said conduits to maintain said predetermined velocity substantially higher than the velocity of fiow of said stock in said conduits and substantially uniform across the width of said machine, means adjacent said forming member forming a chamber corresponding in width to said orifice and of substantially greater cross-sectional area than said slot orifice, and walls forming an inlet passage of substantially the same width of said orifice and said forming member for conducting stock from said orifice to said chamber, said walls being arranged to diverge at a total included angle approximately 7 in the direction of flow of said stock from said orifice to said chamber to dissipate with minimum turbulence the velocity energy of said stock as said stock flows from said orifice to said chamber while maintaining substantial uniformity of flow conditions in said stock across the width of said machine.

'8. In a stock supply system for a paper machine of the cylinder type including a forming member and a vat in which the forming member operates, the combination of a pair of oppositely tapered conduits arranged transversely across said machine and each adapted to be supplied at the larger end thereof with stock under pressure, means formin a slot orifice common to said pair of conduits and extending across the full width of said machine through which said stock is discharged from said conduits at a predetermined velocity of flow and width substantially uniform distribution of fiberacross the width of said machine, said orifice being of restricted cross-sectional area relative to said conduits to maintain said predetermined velocity substantially higher than the velocity of flow of said stock in said conduits and substantially uniform across the width of said machine, and walls forming an inlet passage of substantially the same width as said orifice and said vat for conducting stock from said orifice to said vat, said walls being arranged to diverge at a predetermined total included angle of not more than 10 in the direction of fiow of said stock from said orifice to said chamber to maintain said stock between said orifice and said vat in continuous motior towards said vat at a decelerating velocity which is substantially constant across each cross-sectional area of said passage and to dissipate with minimum turbulence the velocity energy of said stock as said stock fiows from said orifice to said vat while maintaining substantial uniformity of flow conditions in said stock crosswise of said passage and throughout substantially the entire length thereof.

9. In a stock supply system for a Fourdrinier paper machine including a forming member, the combination of a pair of oppositely tapered conduits arranged transversely across said machine and each adapted to be supplied at the larger end thereof with stock under pressure, means forming a slot orifice common to said pair of conduits and extending across the full width of said machine through which said stock is discharged from said conduits at a predetermined velocity of fiow and with substantially uniform distribution of fiber across the width of said machine, said orifice being of restricted cross-sectional area relative tosaid conduits to maintain said predetermined velocity substantially higher than the velocity of flow of said stock in said conduits and substantially uniform across the width of said machine, means adjacent said forming'member'forming a closed chamber corresponding in width' to said orifice and of substantially greater cross-sectional area than said slot orifice,and walls forming a totally enclosed inlet passage of substantially the same width of said' orifice and'said forming member for conducting stock from said orifice to said chamber, said' passage being of substantially the same cross-sectional area as said chamber at the point of connection thereof to said chamber, said walls being arranged to diverge at a predetermined total included angle of not more than in the direction of flow of said stock from said orifice to said chamber to maintain said stock between said orifice'and said chamber in continuous motion towards said forming member at a decelerating velocity which is substantially constant across each cross-sectional'area of said passage and to dissipate with minimum turbulence the velocity energy of said stock as said stock flows from said orifice to said chamber while maintaining substantial uniformity of flow conditions in said stock across the width of said passage over substantially the entire length thereof.

10; A stock supply system for a paper making machine including a forming member, comprising a stock inlet passage leading to said forming member and of-substantiallv the same width as said forming member throughout the entire lengththere'ofimeans forming a restricted intake orifice extending across the entire width of said inlet passa e, supplv means includin a pump for dischar ing stock throu h said orifice at a definite velocity providing substantially uniform distribution in said stock across the width of said passa e, said passa e being of substantial length between said orifice and said forming member. the-wallsof said assa e diver ing away from said orifice in the direction of flow therethrough at an an leof not more than 10 to eifect progressive increase of the cross-sectional area of said passa e-with respect to said orifice and to eifect absorption of t e velocitv ener y of said stock discharged through said orifice with deliverv of said stock to said forming mem'oer in a smooth flow and with minimum turbulence, said inlet passage having a slot extending across substantially the entire width of the lower side thereof at a position spaced downstream from said orifice in the direction of flow to said forming member and spaced upstream from the point of delivery of said stock to said forming member, a header positioned below said slot to receive stock flowing from said passage through said slot, a pipe for conducting stock from said header to the suction side of said pump to reduce the volume of stock at said forming member while maintaining said definite velocity of flow and uniform distribution of said stock through said orifice, and means for regulating the flow of stock through said pipe to maintain a predetermined volume of stock at said forming member.

11. A stock supply system for a paper making machine including a forming member, comprising a stock'inlet passage of substantial length leading to said forming member and of substantially the same width as said forming member, a plurality of oppositely tapered cross flow conduits arranged transversely of said inlet passage and having a common restricted discharge orifice arranged longitudinally thereof to provide communication from ,both' thereof across substantially the entire width of said passage, a pump for supplying stock'to each of said conduits at a pressure sufiicient to effect a flow of stock through said orifice at a definite velocity providing substantially uniform distribution in said stock across the width of said' passage, the walls of said passage diverging away from said orifice at an angle of not more than 10 and cooperating therewith to provide a 'Venturi passage adapted to receive said stock from'said orifice and to dissipate the velocity energy thereof with minimum turbulence, said passage continuing with substantially undiminished effective flow area from said orifice to said forming member to convey said stock in substantially uninterrupted flow from said orifice to said forming member, said inlet passage having a slot extending across substantially the entire width of the lower side thereof at a position spaced downstream in the direction of flow from said Venturi passage and spaced upstream from the point of delivery of said stock to said forming member, means for conducting stock from said slot to the suction side of said pump to reduce the volume of fiow of said stock to said forming member while maintaining said definite velocity flow and uniform distribution of stock through said orifice, and means for regulating said flow of stock through said slot to maintain a predetermined volume of stock adiacent said forming member in accordance with the speed thereof.

STEPHEN A. STAEGE.

REFERENCES CITED The following references are of record in the file of this patent:

. UNITED STATES PATENTS Number