US3076502A - Flow distributor - Google Patents

Description

Feb. 5, 1963 D. E. ROBINSON 3,076,502

FLOW DISTRIBUTOR Filed Jan 8. 1960 5 Sheets-Sheet 1 INVENTOR. DAVID E. ROBINSON 4 j ju j %m# M his ATTORNEYS.

Feb. 5; 1963 D. E. ROBINSON 3,076,502

FLOW DISTRIBUTOR Filed Jan. 8. 1960 5 Sheets-Sheet 2 INVENTOR. DAVID E. ROBINSON hlS ATTORNEYS Feb. 5, 1963 D. E. ROBINSON FLOW DISTRIBUTOR 5 Sheets-Sheet 3 Filed Jan. 8. 1960 INVENTOR. DAVID E. ROBINSON his 'ATTORNEYS.

, Feb. 5, 1963 D. E. ROBINSON FLOW DISTRIBUTOR Filed Jan. 8. 1960 i l "It". Ill/Hil 'lmhw IIII ""11"" MUM mm 5 Sheets-Sheet 4 INVENTOR. DAVID E. ROBINSON his ATTORNEYS Feb. 5, 1963 D. E. ROBINSON 3, 7

FLOW DISTRIBUTOR Filed Jan. 8. 1960 s Sheets-Sheet s FIG INVENTOR. DAVID E. ROBINSON his ATTORNEYS United States 3,076,502 FLOW .DISTRJBUTQR .David RobinsonyNorwalk, Conn, .assignorto Time, Incorporated, New York, N.Y., acorporation of New .York

Filed JaniS, 1960, Set. No.'1,262 12' Claims. (Cl. 162-4939) This invention relates to a flow system for'delivering *pulp furnish to a forming machine such as a Fourdrinier or wet-end machine, and moresparticularly to a novel divider and 'fiow spreader. designed toprovide to an elongated slice, pulp furnish of annifornr consistency and amount across the face of the. slice.

"Prior to the :present invention, means for .dividing the flow of :the pulp furnishtor extrusion. from a slice in one improved system has-been comprised of a. single duct leadingfrom a storage vat with two or more take-off ducts leading therefrom, each take-oft duct being divided into additional .ducts .eventually leading to the slice. Generally, the divisioniotthe flowv is from one duct into two, with :the axes of the two positioned at substantial angles .with respect to the intake duct, the whole system involving numerous sections wherein the direction of flow is substantially. altered. .Primary disadvantages of such a system include: (1) The sudden changes in the direction of flow create vortices or eddies causing flocculation ofthe pulp; and (2) the division of pulp furnish, not being simultaneously to all of the final 'ducts, is such as to provide vfurnish of unequal amounts, consistency, and pressure across the faceof the slice.

In the formation of lightweight grades .ofpaper, the creation of fiocs is detrimental in creating light anddark areas in the sheet, while unequal distribution'and pressure of the -rnulti-sided configuration, having its apex pointed in a direction opposite to the direction of flow. of the pulp, and acomplementary shaped outer duct having walls cooperating with thesides of the. cone. The cone sides and duct walls are adapated to converge in a direction towards the base of the. cone, and in the direction of flow, to become concentric at'the base, and joined, to forms multiple .number of individual ducts having equal cross-sectional areas of an isosceles, trapezoidal or other configuration. This simultaneous division of flow into the desired number of multiple ducts of equal cross-sectional area provides a greater guarantee that furnish of equal consistency and amounts will be supplied to all points cross the face of the slice.

Also to'provide an even and continuous flow free of vortices, eddies, and other flock forming conditions, and further to avoid any abrupt change in the direc- .tion of flow, the apex of the cone is designed to have an angle less than or equal to approximately 14. Also, to prevent any clogging of pulp in the flow divider, there may be provided at any e'dge projecting into the flow a flat or rounded surface incapable of collecting pulp Ifibers or the like.

The flow spreader leading to the slice may comprise essentially a multiple numberof rectangular and adjacent ducts and outlets therefor positioned across the intake of the slice, having a cross-sectional area, height, and width, which, when added together, substantially equal the ate" 3,075,592 Patented Feb. 5, 1963 dimensions of the slice. "The primary purposes of the how spreader are to avoid any abrupt change in the cross-sectionalarea of the flow which would cause undesirable vortices and flocculation of the pulp, and to evenly distribute the furnish from the ducts across the slice nozzle. Actually, any. arrangement designed to distribute pulp furnish or the like across an elongated surface is operable with the'fiow divider.

It is contemplated that the fiowdivider may have many uses, in additionto that with respect to a pulp flow systern as described, wherein theprimary purpose is to divide the flow of a single duct simultaneously, and substantially instantaneously into a multiple number of ducts without substantially changing the direction of-tlow. For instance, it-may be desired to modify the divider to obtain other than equal flow outputs in the multiple ducts, in'which case it is apparent that the present invention provides an extremely accurate means for so doing.

A flow corrector may be provided betweenthe spreader -and-slice nozzle to eliminate variations in the velocity of flow coming from the spreader duct outlets. it is apparent that, in the spreader ducts, the velocity of the pulp furnish will be the least adjacent the walls of the duct and greatest in =thecenter, creatingvelocity tongues or an uneven velocity pattern at the duct outlets.

One such flow corrector for eliminating these velocity tongues is disclosed in applicants copending application Serial No. v1,263, filedJanuary 8, 1960, entitled Flow System for Paper Formers.

The ducts between the .fiow'divider and flow spreader may be rectangular. or circular and, if the latter, the transition from rectangular to circular in the fiow divider and back to rectangular in the flow spreader should be gradual to avoid undesirable vortices and flocculation.

Other objects and advantages of the invention will become apparent upon further consideration of the specification and accompanying drawings, in which:

FIG. 1 'is abottom perspective view of a portion ofa flow Idivider of the present invention;

. FIG. 2 'isra top perspective view of the flow divider of FIG. 1;

FIG. 3 isa side cross-sectional view of the flow divider;

FIG. 4 is a section view taken along line 4-4 of FIG. 3;

FIG. 5 is a section view taken along line 5-5 of F163;

FIG. 6 is a section view taken along line 66 of FIG. 5;

FIG. 7 is a schematic view'of. a flow system using the fiow divider and spreader;

FIG. 8 is a plan view ofa flow. spreader;

FIG.- 9 is a cross-sectiona1 viewtaken along line 9-? i or FIG. 8;

FIG. 10 is across-sectional view 'of a modified form of the invention;

FIG. 11 is aview taken along line11111 of FIG. 10;

FIG. 12 is a view taken along line i2-12 of FIG. 10.

Referring to FIG. -7,there is illustrated schematically -a flow system utilizing the present invention comprising a storage vat'2, a duct 4 leading from the storage vat and "including a standard Allis-Chalmers ACAP pump 6, a

flow divider 8, multiple ducts '19, leading from the fiow divider section to aflow spreader 12, -a iiow correction chamber 14, and a slice 16.

As shown in FIG. 7, the flowdivi-derd is positioned between a single duct inlet 4 and multiple ducts 10 leading therefrom, and comprises means intermediate the .two whereby the flow is equally, simultaneously, and almost instantaneously divided into the multiple ducts without any substantial change:in the direction of flow, .or significant change'in the velocity of flow. The divider .itseliis comprised essentially of a multi-sided cone 18 located in the center of an encompassing duct 4 and having an apex 2h pointed in a direction opposite to the direction of flow of the pulp. The angle at the apex of the cone is preferably from 12 to 14", providing a gr dual transition or change in the direction of flow without separation of the flow from the sides of the cone or duct walls, and the axes of all the component parts are substantially parallel. An angle greater than 14 may cause such separation, at least at high velocities of flow, and may e influential in the formation of vortices and flocculation of the pulp. The length of the cone up to its base 22, in the illustrated embodiment, is approximately eighteen inches in an eight inch duct, but this dimension may be varied depending on the diameter of the duct, velocity of flow, and the like.

About two-thirds of the Way up the cone, the duct wall in section 24, FIGS. 2 and 3, assumes a multi-sided configuration complementary to that of the cone. For the remaining third of the distance, the sides of the cone diverge to the dimensions of the base 22, shown in FIG. 4, while the walls of the duct constrict (FIG. 3) until at the base 2?. they adopt the hexagonal configuration 26, FIG. 4, concentric to that of the cone. Also at this point, the duct walls and cone sides are joined by walls or partitions 28, FIG. 5, to form the multiple four-sided isosceles trapezoidal ducts 39, illustrated in FIG. 5. These walls also serve to support and hold the cone in position. In the disclosed embodiment of the present invention, the cone and duct are shown as hexagonal in cross-section, merging to form the six separate ducts '30, but obviously this could be modified as desired to form more or less ducts leading from the divider.

On the leading edges of the walls 28 of the multiple ducts 39, a rod 32, FIGS. 1, 5 and 6, is positioned, acting to deflect pulp fibers away from the leading edge, and to prevent build-up of fibers thereon.

Each of the ducts it as shown in FIGS. 2 and 5, progressively transforms from the isosceles trapezoidal configuration 33 to a circular configuration 34, and the circular ducts then lead to the flow spreader 12, FIG. 7. The forming of the ducts is accomplished by extrusion.

The flow spreader 12 is illustrated as comprised of circular ducts 36 which progressively assume a rectangular configuration at outlets 38. The formation of the pipes in this area is again accomplished by an extrusion process. The circular ducts, in the described embodiment, are two inches in diameter, but it is contemplated that between the flow divider and flow spreader other shapes and dimensions may be used, depending on the application.

The flow spreader outlets 38, FIG. 9, are rectangular outlets positioned adjacent each other of height and combined width approximately equal to the dimensions of the slice is. The walls at this point are as thin as possible and the ducts as close as possible to prevent any flow separation or creation of vortices as the pulp is extruded from the ducts. These outlets may open directly into the slice it or there may be interposed between the slice and spreader outlets a flow correction chamber 14 designed to reduce variations in the velocity of the flow emerging from the outlets.

One such correction chamber is disclosed in copending application Serial No. 1,263, relating to Flow System for Paper Formers. It is apparent that the multiple duct outlets 1% of the fiow distributor cause a flow pattern at the outlets comprised of a number of elongated velocity tongues positioned at each outlet, each tongue being caused by the relatively faster flow in the center portions of the duct, and slower flow at the sides thereof due to resistance of the sides of the duct. These tongues will be more pronounced at higher velocities of flow, and will produce light and dark areas in the formed paper known as slice streaks. To avoid slice streaks it is important that the flow be corrected and that an essentially uniform pressure face be presented at the slice. The box-like chamber 1 2', using a rod 49 positioned therein, from four to twelve inches in front of the spreader outlets, and parallel to the face of the flow, is able to red .ce variations in the velocity of flow from 20% to about 17 Although the flow correction chamber 14 as disclosed in the above-mentioned copending application Serial No. 1,263 is of considerable usefulness with respect to the present invention, the combination presenting a highly uniform flow at the slice, any such flow correction means may be used. Actually, a chamber comprised of a box having a rectangular cross-section, if of sufiicient length, will cause a certain reduction in variations in the velocity pattern.

One modified form of the flow divider is illustrated in HG. 10, showing a cone 5% having a circular cross-sectional area throughout. Tie apex 52 is provided with a parabolic curver. surface 54- which merges with wall 56 at about point 58, the Wall 55 forming an angle of 14 with the vertical axis of the cone. To form a continuous unbroken surface on the cone, the slope of the parabola at the point of intersection with wall 56 must also be 14". In this way the angle of 14 defines the overall shape or configuration that the divider will take.

The duct wall in this embodiment is designed to fiare outwardly, but at an angle slightly less than 14, preferably at about 12". Thus, in the direction towards the base of the cone, there is a gradual convergence of the cone and duct walls, the degree of convergence being dependent on the diameter of the duct and the diameter of the cone and slope of the cone wall. The apparent objective is to maintain as close as possible, an equal cross-sectional area of flow throughout division of the flow.

As illustrated in FIGURES 11 and 12 there is a transition area where the flow is simultaneously divided from a unitary flow confined by the two concentric walls, 5% and 69, FIG. 12, into a multiple flow confined by a multiple number of flow ducts, 62 formed by transverse positions As illustrated in FIG. 11, the uniquely sloped ducts are gradually transformed into circular ducts which are led to a flow spreader in the manner described above. Again the leading edges of the portions 64 are curved to prevent build up thereon and the number of ducts formed may be varied depending on the application contemplated. In the illustrated embodiment, the number of ducts is twenty (20).

From the above, it is apparent that a novel flow system is provided capable of dividing the flow and distributing it across a slice in a manner avoiding abrupt changes in the direction of flow or significant changes in the crosssectional area of flow which might cause flocculation or unequal distribution of the pulp. '1' here is also provided,

by the invention, a divider capable of more evenly and uniformly dividing the pulp furnish.

While the invention has been described and illustrated in several forms, it is apparent that the components may be further modified without departing from the spirit and scope of the invention, and that the scope of the invention shall be considered limited only as specifically set forth in the appended claims.

1 claim:

1. In a flow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising a first duct at the intake end thereof and an annular array of elongated multiple ducts at the opposite end thereof, an elongated probe positioned within said first duct and having a base and an apex directed opposite to the direction of flow in said duct, and means extending between said not and probe base supporting and holding said probe '11 position, said first duct, probe sides and last named neans defining free, unobstructed and open ends of the ntalte portions for said multiple ducts.

2. A flow di ider as claimed in chair. 1 wherein said probe has an axis parallel to the line of flow and an angle between the axis of the probe and sides of the probe of from 12 to 14 at the apex.

3. In a fiow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising a first duct at the intake end thereof and an annular array of elongated multiple ducts at the opposite end thereof, an elongated probe positioned within said first duct having a base and an apex directed opposite to the direction of flow in said duct, and means extending between said duct and probe base supporting and holding said probe in position, said first duct, probe sides and last named means defining free, unobstructed and open ends of the intake portions for said multiple ducts, and said first duct, probe and multiple ducts having axes substantially parallel to each other.

4. In a flow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising a first duct at the intake end thereof and an annular array of elongated multiple ducts at the opposite end thereof, an elongated probe positioned within said first duct and having a base and an apex directed opposite to the direction of flow in said duct, means extending between said first duct and probe base supporting and holding said probe in position so that axis thereof is aligned with the axis of said first duct, said first duct, probe sides and last named means defining free, unobstructed and open ends of equal cross-sectional area of intake portions for said multiple ducts, the axes of said multiple ducts being parallel to those of said probe and said first duct.

5. In a flow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising a first duct at the intake end thereof and an annular array of elongated multiple ducts at the opposite end thereof, an elongated probe positioned within said first duct having a base and an apex directed opposite to the direction of flow in said duct, means extending between said duct and probe base supporting and holding said probe in position so that the axis thereof is aligned with the axis of said first duct, said first duct and probe being concentric in the area of the base of said probe and having a multiple number of sides and with said last named means defining free unobstructed and open ends of equal cross-sectional area of the intake portions for said multiple ducts, said open ends having an isosceles trapezoidal cross-sectional configuration.

6. A flow divider according to claim 5 wherein said probe has a hexagonal pyramid shape, and wherein the multiple number of ducts number six.

7. In a flow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising a single duct at the intake end thereof and an annular array of elongated multiple ducts at the opposite end thereof, the axes of said multiple ducts being substantially parallel to the axis of said single duct, means for simultaneously dividing the flow from said single duct into said multiple ducts without substantially changing the direction of flow or the cross-sectional area of flow comprising a probe positioned in said single duct, the apex of which is directed in a direction opposite to the direction of flow and the axis of which is aligned with the axis of said single duct, the sides of said probe and said duct being concentric in the area of the base of said probe and defining free unobstructed and open ends of equal cross-sectional area of intake portions for said array of multiple ducts to thereby divert the flow to said array of multiple ducts.

8. A flow system for providing pulp furnish of uniform consistency to a slice comprising a first duct leading from a storage vat, a fiow spreader means having a series of outlets positioned transversely across and leading into the slice to deliver furnish equally across the slice, multiple ducts leading to said outlets, and a fiow divider means positioned intermediate said spreader and said first duct adapted to divide the flow equally from said first duct to said multiple ducts, said divider comprising a cone having an axis aligned with the axis of said first duct and projecting into the flow and a base whose sides cooperate with the multiple ducts to form a part of their wall at the duct intakes, said first duct and cone sides cooperating to define free and unobstructed open ends of intake portions for said multiple ducts whereby a single flow is divided into multiple flows without substantial change in the direction of flow.

9. In a flow system for a paper forming machine arranged to transport pulp furnish from a pulp vat to a slice of said machine, a flow divider comprising, in combination, a single intake duct and multiple outlet ducts, a cone positioned within said single intake duct having a base and an apex directed in a direction opposite to the direction of flow, said cone base and intake duct comprising and defining free unobstructed and open ends of intake portions for said multiple ducts.

10. A flow divider, according to claim 9, wherein said duct wall and cone base form circular, concentric configurations.

11. A flow divider, according to claim 9, wherein the apex of the cone is of a parabolic configuration.

12. A flow divider according to claim 11, wherein the cone sides form an angle of approximately 14 with the axis of the cone, the duct being substantially concentric with the cone sides but forming an angle of approximately 12' relative to the cone axis and converging on the cone sides, said duct, cone sides, and multiple ducts being thereby adapted to maintain a substantially constant crosssectional area of flow.

References Cited in the file of this pat t UNITED STATES PATENTS w 1,017,638 McCoole Feb. 13, 1'912 2,110,4301 Swanson Mar. 8, 1938 2,347,130 Seaborne Apr. 18, 1944 FOREIGN PATENTS 146,077 Sweden July 6, 1954

Claims (1)

1. IN A FLOW SYSTEM FOR A PAPER FORMING MACHINE ARRANGED TO TRANSPORT PULP FURNISH FROM A PULP VAT TO A SLICE OF SAID MACHINE, A FLOW DIVIDER COMPRISING A FIRST DUCT AT THE INTAKE END THEREOF AND AN ANNULAR ARRAY OF ELONGATED MULTIPLE DUCTS AT THE OPPOSITE END THEREOF, AN ELONGATED PROBE POSITIONED WITHIN SAID FIRST DUCT AND HAVING A BASE AND AN APEX DIRECTED OPPOSITE TO THE DIRECTION OF FLOW IN SAID DUCT, AND MEANS EXTENDING BETWEEN SAID DUCT AND PROBE BASE SUPPORTING AND HOLDING SAID PROBE IN POSITION, SAID FIRST DUCT, PROBE SIDES AND LAST NAMED MEANS DEFINING FREE, UNOBSTRUCTED AND OPEN ENDS OF THE INTAKE PORTIONS FOR SAID MULTIPLE DUCTS.

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