US3165439A

US3165439A - Stock feeding apparatus for web making machines

Info

Publication number: US3165439A
Application number: US222836A
Authority: US
Inventors: Lejeune Pierre; Maillard Louis De
Original assignee: Ateliers Neyret Beylier et Piccard Pictet
Current assignee: Ateliers Neyret Beylier et Piccard Pictet; Societe Grenobloise dEtudes et dApplications Hydrauliques SA SOGREAH
Priority date: 1961-09-15
Filing date: 1962-09-11
Publication date: 1965-01-12
Anticipated expiration: 1982-01-12

Description

Jan. 12, 1965 Filed sept P. LEJEUNE ETAL STOCK FEEDING APPARATUS FOR WEB MAKING MACHINES 5 Sheets-Sheet l Jan. 12, 1965 P. LEJEUNE ETAI. 3,155,439

sTocK FEEDING APPARATUS FOR WEB MAKING MACHINES Filed Sept. 11, 1962 3 Sheets-Sheet 2 Jan. 12, 1965 P. LEJl-:UNE ETAL 3,165,439

STOCK FEEDING APPARATUS FOR WEB MAKING MACHINES Filed Sept. 11, 1962 5 Sheets-Sheet 5 INVENTORS P/EARE fi/UNE Y LOU/5 MMA/14,90

@Mg/P3 54%@ ATTO/QA/E United States Patent 3,165,439 STOCK FEEDING APPARATUS FR WEB MAKING MACHINES y Pierre Lejeune and Louisde Maiilard, Grenoble, France, assignors to Ateliers Neyret-Beylier &`Piccard-Pictet (NEYRPIC), -Grenoble, France, a f corporation of France, and Societe Grenobloise dEtudes et dApplications Hydrauliques (SGREAH), Grenoble, France, a corporation of lili-ancev Filed Sept. 11, 1962, Ser. No. 222,836 f Ciaims priority, application France Sept. 15, 1961 2 Claims. (Cl. 162-337) This invention relates to apparatus for the feeding of stock onto a web forming surface such as is employed in pulp mills for the manufacture of paper, cardboard, and other types of sheet material.

In the use of apparatus ofthe indicated type, a frequent occurrence is llocculation and decantation of the charges which are high-ly detrimental to the quality of the product being manufactured. As a rule, liber llocculation takes place in the header usually employed in such apparatus for accumulating a quantity of the stock to be fed to the web forming means and especially in those parts of the speed at which the machine is operating, and have suchvalues that all possibility of liber llocculation and decantation is avoided.

The aforesaid objects are achieved in accordance with the invention by providing such apparatus with a closed circuit of pulp carrying liquid embodying the following features:

(a) Means are provided to assure a constant llow rate of the liber stock that is at least equal to the maximum rate of injection of such stock into the machine for any rate of speed at which the machine is to be operated.

(b) To accommodate the flow rate of the fiber stock to the different speeds at which the machine may operate, the excess of the liber stock which is fed toward the machine and which is recirculated in the closed circuit, is utilized to control the means for feeding new liber stock into the circuit, so that such feeding means will deliver to the circuit an amount of pulp carrying liquid which carries sullicient liber stock to precisely compensate for the liber stock which is being discharged to the machine.

(c) Means are also provided to deliver to the machine a sufficiently high rate of flow of the liber stock to make sure that any variations in the speeds at which the machine may operate will not cause excessive decelerations in the rate of llow of the fiber stock at any part of the closed circuit.

The invention contemplates that the means for'feeding new fiber stock into the closed circuit may be controlled either by the variation of the liquid surface of the header, or by the variation of the pressure of gas in a closed chamber on such liquid surface of the header, or by the variations in .the height of a weir over which the excess fiber stock llows into the header.

In accordance with one form of the invention, the header may constitute a tank, the upper end of which is associated with an overflow chamber having one side thereof functioning as an overflow gate or weir over which the excess liber stock llows into the header tank.

ice

In accordance with another form of the invention, the liquid surfaces of the header tank and the overflow chamber are maintained at a constant differential level, which may be zero in some instances.

In accordance with a further form of the invention, the i utilization of a gas pressure control of the feeding means may be accomplished by the application of either a positive, negative, or zero pressure, as compared with atmospheric pressure, to the liquid surfaces in both the header tank and the overflow chamber.

A closed circuit embodying the aforesaid control feaby the circulating pump and consequently, a constant rate of llow of the liquid to the web forming means.

It hasv been found that in order to make certain that the machine will operate satisfactorily at highly variable speeds, it is necessary to provide in addition to the means for supplying the liquid stock at a sulliciently high constant rate of llow, 4an overflow gate or weir at the overflow chamber which is of great length, approximately threeor four times the width of the liber web which is being formed -by the machine. Preferably the length of the gate in each machine is a function of the output-rate characteristics of the machine and such that the gate is capable of discharging into the header tank large quantities of the liquid stock under a slight head and without the consumption of a considerable quantity of air. It has been found that an overflow gate of such great length also improves the transverse stability of the liquid level in the header tank and therefore tends to equalize the pressures above the place of Yentry of the new liber stock into the closed circuit. Also owing to the slight height of the gate there is obtained a satisfactory damping of the heavy turbulences and pressure waves which might occur in the output of the circulatory pump as a result of the instability of the pump.

It is preferred in accordance with the invention to construct the gate or Weir so that it is in fact constituted of a plurality of llow-olf gates capable of assuring a stable surface flow throughout the length of the overflow chamber toward the header tank. The individual gates in the system forming the overall gate or Weir may be predetermined in number and disposed in parallel relation and lengthwise in the direction of the circuit flow. It is con- Vtemplated that the overflow elements forming the individual gates may be coupled in pairs so as to provide between them spouts which channel the surface llow in the overflow chamber to the header tank. A weir construction of this type, it has been found, is of special advantage in maintaining the p-iezometric head in the liber or pulp distributing means constant at a controlled value notwithstanding slight fluctuations in the total flow which may be due, for example, to an accidental fluctuation in the speed of the circulating pump.

It is to be noted that as the llow of stock, in'accordance with the invention, is maintained constant in the area approaching the web forming means for a given machine, regardless of the speed of feed of the machine or the rate of injection of the new stock into the closed circuit, it is possible to predetermine the total llow and K EdSAQ Patented Jan. 12, 1.965l

It is n of the invention will become more apparent from a perusal of Vthe following description of several embodiments' of the invention which aregivenf by way of example, when read with reference to` the accompanying drawings, in which FIG. 1 is a schematic view showing in vertical sect-ion a closed circuit embodying the invention and providedl with a closed header which ymay be under positive or negative pressure; Y

FIG. 2 is a schematic elevational view, partly in section, of the apparatus shown in FIG. l, the view being taken along the `line 2-2 of FIG. 1;

FIG. 3 is a perspective view of an end portion of the overilow gate associated with the header;

FIG. 4 is a schematic` vertical sectional view `of the stock distributor included yin the closed circuit; the viewy being taken along the line 4-4 of FIG. 5;

FIG. 5 is a horizontal sectional View of the stock distributor taken along the line 5 5 of FIG. 4; f

FIG. 6 is a schematic vertical sectional view showing another form of header that may be employed in the closed circuit; and Y FIG..7 is a view similar to FIG. 6 showing still another header construction embodying the invention.

As above indicated, FIG. l of the drawings shows a stock lfeeding system in which the parts are arranged in a closed circuit in accordance with the invention soas to effect a constant ilow rate of the'stock material in fully distributed condition in the liquid regardless of the speed of the machine or the rate of 4injection of the new stock,

and without danger of ilocculation and decantation of the stock at any portion of such system. In such system, the material to ybe circulated is drawn from a header tank generally designated by the reference character A. The header tank is supplied by the new stock feeding means generally designated B and by the liquid stock which is in excess of that required .by the machine C and which flows into the upper end of the header tank A from an overflow chamber generally designated D. The liquid stock resulting lfrom the combination of both of these sources of supply is withdrawn 4from the header tank A by a pump P and forced by the latter into a distributor generally designated E for asusring that'the stock ilbers supplied from both sources are distributed evenly throughout the liquid before the constant recirculating flow is passed through the pipe 3 to the slice F.

The header tank A is in the nature of a hopper the body 1 of lwhich has a substantially rectangular crosssectional area and is inclined at an angle of approximately 45 with the horizonal. The lower end of the hopper body is connected with a pipe l1 which leads tothe pump P. The entry end of the pipe 11 is located approximately centrally of the width of the tank body 1 and between two vertically disposed baflle walls 9 which rise from the bottom'of the tank body near such pipe entry end. Also centrally located between the lower ends of the baille walls 9 is the discharge end of a diffuser i8 which forms part of the stock feeding means B and which is of a construction known to the art. The intake of the diffuser is regulated by a gate valve 31 that is operated by a servo-motor 30 which is controlled by the excess ilow returning to the header tank as will hereinafter become more clear. f

The ynew stock supplied to the header tank by the diffuser 18 is a very even mixture of water and fibers and is directed toward a baille which Vis formed between the Llower ends of the baille walls 9 against the opposite wall 36 of the tank body 1 so as to dispense the charge being delivered by the diffuser into the excess stock material substantially iilling the header tank. The two baf- V ile walls 9 are built high enough in thejtankbody l to effect as muchas possible a uniform distribution of the new stock from the diffuser 18 in the excess stock in the tank before the combined tlowsV pass out of vsuch tank body into the pipe ll.

The pump P delivers the'circulation ilow through a pipe l2 into vthe distributor E which is shown more clearly in FIGS. 4 andS of the drawings.V It will be noted from a comparison of these iigures with FIG. 1, that the dis-' tributor E- comprises a casing thatis generally cylindrically-shaped with itsv central axis' disposed transversely to the direction of the circulation ilow .in the machine. The length vof the `casingis'at least equal to the width of the fiber sheetwhich is beingformed by the machine C. The casing of distributor Eis `formed so thatadjacent tothe discharge slot 13 .thereofit is provided .withV a baille 2 which directs thecircuit flow into a double curve` as it passesthrough the distributor. The baille 2 has a length equal to the length of the distributor casing, or the distributing chamber thereof. It will also be noted from these iigures thattheV discharge end of the duct l2 is substantially tangent to the periphery of the distributing chamber so that the stock is introduced tangential-ly into such chamber and flows ina curve towards Y the baille 2 which turns it back through. an angle of approximately 180 to direct the dow across the distributor to the opposite wall portion thereof above the discharge end ofthe duct l2. The ilowY is then turned through another 'approximatelyl80 curveV toward the discharge slot 13, as is indicated by the ilow Varrows in FIG. 4 of the drawings. In vorderpto dampen this double helicoidal movement of the stock through the distributor E, the duct l2 is constructed so that cross-sectional area decreases towards its discharge end. As will be observed from a comparison `of FIGS. 2, 4 and 5 'ofthe drawings, the duct 12 has a circular conilguration at the terminus of its entry end and from adjacent such terminus Vhas a generally flattenedform which increases/in width 'from the entry end W-W thereof to the discharge end V-V thereof so that the opening lformed by the .latter` and constituting the entry opening for the distributor casing is'slotdikel in configuration. Accordingly, the decreasev in crosssectional area of the duct l2 is accomplished by progressively decreasing its height toward the discharge -end V-V. This decrease is'quite substantial, approximately 30%, i.e., the cross-sectional area of the duct l2 at its discharge end V-V is about 30% less than the cross-sectional area of the duct atits entry end W-W'. Y

It will be observed more clearly in FIG. 5, that the discharge end ofthe duct or pipe 12 has a width approximately one-third the length of the distributor casing and is connected with theV central portion lof such chamber. It has been found necessary that in order to make the flow of stock discharged .by the duct 12 into the distributor, feed outwardly to the ends of the Vdistributor charnber instead'of flowing only through the central portion of such chamber; a second baille 2 capable of accomplishing this purpose shouldgbe provided in the path of the liquid llow shortly after it is discharged intor the distributor E and before it cornes into contact with theY upper baille 2. Thissecond baille 2 is positioned centrally of the distributor E adjacent to the discharge end of duct 12 and Vhas a length which approximates the width Vof the duct l2.v Thus the stream of stock discharged by the vduct l2 will shortly after its entry into'the distributor E strike baille 2 which will further cut down its. speed of flow and direct substantial portions thereof to the two ends of the distributor chamber, as is indicatedby the arrows in FIG. 5, the stock then rising throughout they length of the chamber'into contact with the upper baille 2. As alresult of the action of the duct l2,`and bailles 2, 2', they rate of llow of the stock will be regularly Ydivided so that the ilow rate of thestock reaching the discharge slot 13 will have a perfectly even distribution throughout the entire width of such slot without breaking the homogeneity of the stock fed into the duct 12.

The discharge slot 13 extends substantially the entire length lof the casing of distributor E and has a length equal to the width of the liber web being formed by the machine. The stockdelivered to conduit 3 is conducted by the latter to the slice F and to the overflow chamberv D both of which are connected to the upper discharge end 14 of such conduit. lThe conduit 3 throughout its length is of uniform width, namely, a width equal to the width of the liber web being produced, The height of the conduit 3 progressively increases towards the discharge end 14 of the conduit, so that at the latter its crosssectional area is substantially double the cross-sectional area of the slot 13. The relation of such cross-sectional areas is such that the rate of circulatory flow through such elongated conduit and delivered thereby is at all points suiciently high enough to prevent flocculation and decantation of the charges, and such that the stock is not decelerated to disadvantage in the region lof the slice F.

The slice is composed of two lips 15, 16 and a pivoted plate 4 which form a flattened discharge nozzle having a discharge aperture of a width equal to the width of the web which is ybeing formed on the traveling belt of the machine C in the usual manner. The lips 15A and 16 are rigid and integral with the conduit 3 and are slightly convergent toward the discharge end of the nozzle. The upper lip 16 terminates short of the terminal end of the nozzle and the top outer end of the nozzle beyond such lip is formed by the outer free end of the pivoted plate 4. It will be noted in FIG. l that the plate 4 is hinged for adjustable movement about a shaft 17 to provide a control vfor the flow of the stock to the .forming belt of the machine. The shaft 17 which forms part of the slice, is mounted on the exterior of the upper lip 16 so as not to interfere with the flow of the stock to the forming belt and is in position to enable ready adjustment of the plate 4 to comply with the requirements of the machine.

The portion only of the stock flowing up through the conduit 3 that is required to form the particular sizeof web it is desired to manufacture, passes through the slice to the forming belt of the machine. The remaining portion of the stock flows up through an elongated discharge opening or slot provided in the upper end of the conduit 3 above the slice F. Connected at its lower end to discharge slot 35 is the overflow chamber D through which the excess stock passes on its way to the header tank A. As will be seen from a comparison of FIGS. l-3 of the drawings, the overflow chamber D is a unit assembly which is pivotally connected by means of a shaft 8 to the wall 36 of the header tank A irl order that it may be swung away from the conduit 3 to a position in which the parts thereof may be made more accessible for cleaning and repair. As is shown more clearly in FIG. 3 of the drawings, the unit above the l-ine of pivot S' is provided with a wall 37 which forms a continuation of the header Wall 36 and has a width equal to the width of the latter. It will be understood therefore that the width of the unit is equal to the width of the header tank so that the latter receives a flow of the excess material extending throughout its entire width. This width of both the overflow unit and the header tank is equal to the length of the discharge slot 35 and consequently equal to the Width of the conduit 3 andthe web being formed on the machine. However, the overflow unit is constructed so that the actual overflow surface thereof is substantially greater than the width of the liber web being formed. It

Cil

has been found, that best results are obtained if the overall width of the overllow surface provided for the excess stock is approximately three or four times the width of the liber web formed in the machine. As has been previously indicated, it has been found that such a long overflow surface is necessary for the satisfactory operation of a machine which Works at variable flow rates while operating over a wide ran-ge of speeds.

The aforesaid result is obtained in the construction disclosed in FIG. 3 by extending through the inclined wall 37 of the overow unit a plurality of vertically disposed hoppers 6 which are in communication at their lower ends with the discharge slot 35 or" the conduit 3. The hoppers 6 have a common end wall '7 which extends down to the slot 35 and has a width equal to the width of the inclined wall 37. The hoppersare formed in spaced relation along the end wall 7 and each haveV additionally two side walls 5 provided at their upper ends with rolled

edges

38, 38. which constitute the overflow edges of the hoppers. The'other ends of the hoppers are provided with raised end portions 39 which prevent the discharge of the stock over such ends and cause the stock to flow over the edges 38 thereof. It will thus be understood that the excess stock flowing up through the slot 35 will enter the lower ends of all of the 4hoppers 6 extending across the entire width of the upper end of the header tank A, and will rise in such hoppers to overflow the

edges

38, 38 thereof, and llow down between the side walls 5 of the hoppers to the inclined wall 37 and from thence into the header tank A, as is indicated by the arrows f in FIGS. 2 and 3 of the drawings. Because the stock is forced to flow over the edges 3S, 38 of the hoppers 6 rather than the ends of such hopper-s blocked by the raised end portions 39, the combined overflow surface attained is approximately three or four times the width of the overow unit D and the header tank A. As the provision of these hoppers necessarily restricts the overall cross-sectional area of the overllow chamber, the wall 7 of the unit is inclined outwardly from the discharge slot 35 and each of the side walls 5 of the hoppers 6 is convexly-shaped to maintain the combined crosssectional area of the spouts substantially constant from the discharge slot 35 to the edges 38 of such hoppers and substantially equal to the cross-sectional area of such discharge slot 35.

The overflow unit D assures a nearly constant liquid surface level N1, in FIG. 1, above the distributor E. Means are also provided so that the liquid surface N2 in the header tank A is utilized to control the input by the feeding means B of the'new stock into the header tank so that the surface level N2 will maintain itself at a slightly lower level than that of N1. In this manner the useful output admitted into the header tank A by the feeding means B will compensate accurately for the stock that is utilized by the slice F to form the ber web in the machine. The means for accomplishing thisV purpose may be any suitable rneans'known to the art for controlling the servo-motor 30 associated with the gate valve 31, such as the electrical device designated 19 for indicating variances of the level N2 from a given height.

As is shown in FIG. l the upper end of the header tank A may be closed to form a closed chamber 39 above the surface levels N1, N2 and in which a pressure or vacuum maybe built. With such a construction, it is possible to regulate the rate of discharge of the stock by the slice F into the machine C without affecting the operation of the pump P, since the intake and discharge of the pump will be subject to the same pressure or vacuum through the header tank A, and the overflow chamber D, conduit 3 and distributor E, respectively, irrespective of the change in the rate of flow of the stock through the slice F. The pressure in the chamber 39 may be controlled for example, with the aid of a vacuum pump 24B connected by a pipe 21 to chamber 39 and controlled to modify the pressure in the latter as needed. The chamber may have a manometer 22 to give a constant reading of the pressure in chamber 39 and a hand valve 23 may be provided to enable manual control of such pressure. There may be associated with the hand valve 23 an automatic valve 24 capable of providing a line control of such pressure.

In FIG. 6 of the drawings there is shown an open header tank A and the overflow chamber D is formed by an end wall 7 rising vertically from` the discharge slot 35 of the conduit 3', side wallsr(notlshown) and a How-off gate constituted ofa plate ZSeXtending Vacross vheader tank A may be regulated by an adjustable automatic device 19 and servo-mechanism 29 in the same manner as previously described with respect to the embodiment of FIG. 1. In this construction, however, the liquid level' of theV header tank A is maintained at a slightly lower height than the liquid level in the header Y tank A.

The embodiment of FIG. 7 shows a submerged type of dow-off gate 27 which may be incorporated in either an openheader A as shown in FIG. 6, or in a closed header A as shown in FIGS. 1 and 7. It will be noted that the overow surface of the gate 2'7V is far enough below the liquid surface that the discharge thereover Vis submerged and that the liquid levels in the header A" and in the overow chamber D are joined so as to in effect constitute one continuous surface, as indicated by the reference N3 in FIG. 7'of the drawings. In the case of a closed header, such as the header A thislevel yN3 will remain constant and the extensible vertical baffle or gate member 27 should be set at such a height that the ow from the overow chamber D" toward the header tank A is accomplished without any appreciable-loss of charge. The rate of llow of the stock through the slice F in this construction, may be controlled in the manner described with respect to the embodiment of FCL 1, namely, by controlling the pressure in the chamber 39' above the level N3.

In the case of an open header, such as shown in FIG. 6, Vthe level N3 will be variable andcan be utilized in the mannerof the embodiment of FIG. 6, to control the rate of injection of the new stock into the header tank A. In this embodiment, the level mark may be regulated by :granges` Y bottom end of said overflow chamber, and `means for controllingtheY rate of ilow of the stock through ,saidv slice to the machine. Vj Y 2. A device such as deiinedfin claim l, including means controlled byv the excess of stock returned to said header tank for controlling the rate` of feed of said feeding means to compensate the circuit exactlyforY the stock removed therefrom by said slice and thereby maintain substantially constant the iiow rate of the stock to said liber distributor means. L f.

3. A device. such as defined in claimr2, inwhich said feeding means includes an adjustable feed valve, and in which Said controlledmeans includes means for actuating said feed'valve, and means associated with the liquid y level in said header tank and operative upon a change in such Alevel from'a given height to operate said actuating means to cause said valve to adjust theniiow'of said feeding means solas to restore such given height.

. 4. A device such as deiinedrinrclaim l in which said liow controlling Ymeans comprises an yadjustable Vbaille having one edge disposed in the llow'of said circuit and Y movable relative to such ilow to vary the rate thereof past adjustmentof the height of the extendable vertical baffle may be made without departing from the spirit of the ini vention, or the scope of the following claims.

We claim: v

' 1. A device for feeding stock to a web making machine, comprising arranged in a closed circuit, a header tank and an overflow chamber positioned in adjacent relation so that stock rising in such chamber will overflow into the upper end of said header tank, means for feeding new stock into said header tank below the surface level thereof and into intermixture with the stock therein from said overflow chamber, means spaced from said header tank in.

the circuit for distributing the stock, means for pumping the combinedmixture of stockl from said header tank intosaid distributor means at a given substantially constantV flow rate greater than the rate of ilow of the stockV required by the machine and such that the flow in all portions in such circuit is sutlciently high to prevent occulation, a slice associatedl with the machine and j constructed and arranged toptake a portion of the volume of stock fed to said distributor means, means for conveying from said distributor means suchportion of the stock to said slice and the stock in excess thereof to the such edge. f

`5. A device such as vdefined in claim l, in which said distributor means comprises a housing having a discharge slot substantially equal in width to the'width of the liber web being formed yand an entry opening having a width considerably less than the width of said discharge opening,v the chamber in said housing having a width approximatelyw the` width of the liber web and having located therein tlow directing baille means of a width equal to the width of said chamber for changing the path of flow of the stock admitted through said entry opening.

6. A device such as defined in claim 5, in which said 4.distributor means has located within the distributing charnber thereof a second ilow directing baffle means of a width considerably less than the width ofsa'id'chamber for causing a portion at least of the. stock admitted through vsaid entry opening to llow toward the endsof said chamber before coming into contact with said irstbaiile means.

7. A device such as definedy in claim l, in which. the stock in said overflow chamber passes over an overflow edge having an overall width considerably greater than the width of the web being formed in the machine.

8. A device ysuch as-defined in claim l, in which said overflow chamber includes overflow-means having a width substantially equal to the width of said header tank and having an overow edge providing an overall width considerably greater ythan the width of said header."-

9. A device such as dened in claim 8, in which said overflow means is composedof a plurality of overflow ducts each of which has a pair of spaced overflow edges arranged transversely to theA widthV of said header tank.

10. A device for feeding stock comprising an overliow chamber for directing excess of the stock into the upper end of a header tank, said overflow chamber cornprising a plurality of individual ducts arranged as a series in spaced side-by-side relation and having opposing side walls formed at their upper edges to yprovide liquid overflow edges over which the stock ilows into the spaces between said ducts, therend walls of saidV ducts being configured to direct the stock rising in said ducts over said sideoverow edges.v

11.V A device for feeding stock comprising ,a distributor for distributing the stock comprising a generally cylindrically-shaped casing having a length approximating the width of a ber web to bev formed from such stock and having an elongated, slot-like entry opening extending longitudinally of said casing and arranged in tangential relation to the periphery ofthe chamber therein, and said casing having a longitudinally extendingk discharge slot of a length'substantially equal to the klength of said casing, the length of said entry opening being considerably less than the length of said dischargeV slot, said casing containing within the chamber thereof ini, spaced opposed relation to Ysaid entry vopening .a baffle element said chamber twice before passing out through said discharge slot.

12. A device' for feeding stock to a web making machine, comprising a closed circuit, means connected to one point of said circuit for variably feeding a flow of stock int'o saidV circuit, and means connected to a second spaced point of said circuit for discharging stock into said machine including a discharge port having a.

predetermined width comparable to the width of the web being formed, said closed circuit including a iirst portion extending between said points of connection of said feeding means and said discharge means and wherein the stock flow is substantially constant and in excess of the maximum output yflow possible in said discharge means, and said closed circuit including a second portion separate from said rst portion and extending between said points of connection of saiddischarge means and said feeding means and'being provided with flow oi means for controlling said feeding'means, so as to mainsecond circuit portion, and said second point being located the start of said first circuit portion and the end of said 1,821,198 Zimmerman Sept. 1, 1931 1,890,251 Fowler Dec. "6, 1932 2,329,799 Thorsen Sept. 2l, 1943 ,n 2,351,905 kBasler June 20, 1944 2,465,445 Goldsmith Mar. 29,1949 2,788,719 Bennett Apr. 16,1957 2,934,142 Ikavalko Apr.-` 26, 1960 3,010,510 Cirrito Novj28,` 1961 FOREIGN PATENTS between'the end of said first circuit portion and the start of said second circuit portion, said first circuit portion comprising a pump, a first conduit connected at its entry end Yto said pump and having a width substantially less than said discharge port, a'second conduit connected at its discharge end to said discharge means and having the same width as said discharge port, and a distributor locatedbetween said two conduits and connected to the discharge end of said iirst conduit and to the entry end of said second conduit, saidv distributor having deection means for diverting laterally the stock fed therein from said rst conduit, and said distributor having lthe same width as said discharge port and discharging into the entry end of said second conduit.

References Cited in the iile of-this patent UNITED STATES P.AflqEl`'1l`Sl y446,331 Canada Jan. 20,k

Claims

1. A DEVICE FOR FEEDING STOCK TO A WEB MAKING MACHINE, COMPRISING ARRANGED IN A CLOSED CIRCUIT, A HEADER TANK AND AN OVERFLOW CHAMBER POSITIONED IN ADJACENT RELATION SO THAT STOCK RISING IN SUCH CHAMBER WILL OVERFLOW INTO THE UPPER END OF SAID HEADER TANK, MEANS FOR FEEDING NEW STOCK INTO SAID HEADER TANK BELOW THE SURFACE LEVEL THEREOF AND INTO INTERMIXTURE WITH THE STOCK THEREIN FROM SAID OVERFLOW CHAMBER, MEANS SPACED FROM SAID HEADER TANK IN THE CIRCUIT FOR DISTRIBUTING THE STOCK, MEANS FOR PUMPING THE COMBINED MIXTURE OF STOCK FROM SAID HEADER TANK INTO SAID DISTRIBUTOR MEANS AT A GIVEN SUBSTANTIALLY CONSTANT FLOW RATE GREATER THAN THE RATE OF FLOW OF THE STOCK REQUIRED BY THE MACHINE AND SUCH THAT THE FLOW IN ALL PORTIONS IN SUCH CIRCUIT IS SUFFICIENTLY HIGH TO PREVENT FLOCCULATION, A SLICE ASSOCIATED WITH THE MACHINE AND CONSTRUCTED AND ARRANGED TO TAKE A PORTION OF THE VOLUME OF STOCK FED TO SAID DISTRIBUTOR MEANS, MEANS FOR CON-