US3363580A - Multiple valve pump - Google Patents

Description

Jan. 16, 1968 L, LOGUE 3,363,580

' MULTIPLE VALVE PUMP Filed Jan. 19, 1966 2 Sheets-Sheet l H nllllmll m IN VENT OR. LELAND H. 'LOGUE A TTQRNEZS Jan. 16, 1968 Filed Jan. 19, 1966 L. H. LOGUE MULTIPLE VALVE PUMP 2 Sheets-Sheet 2 LELAND LOGUE AITORNEYS United States Patent 3,363,580 MULTIPLE VALVE PUMP Leland H. Logue, Denver, Colo., assignor to Denver Equipment Company, Denver, Colo., a corporation of Colorado Filed Jan. 19, 1966, Ser. No. 521,718 11 laims. (Cl. 103151) ABSCT OF THE DISCLUSURE This invention relates to a flow through piston adapted for vertical reciprocating movement in a vertically extending pump body to pump slurries. Such a piston comprises a generally horizontally extending piston head of circular planfrom and a substantially greater diameter than thickness. The piston head is provided with marginal sealing means for sealing contact with the wall of the pump body. A plurality of vertical flow passages extend through the head. These flow passages are preferably equally spaced radially about the vertical axis of the head. An elastomeric sealing ring is mounted on the head about the upper margin of each of the passages. The diameter of the seal ing ring is substantially the same diameter as that of the passages. A clamping plate overlies the head and has a plurality of vertical apertures formed therein and of such size as to overlie the outer margins of each sealing ring to clamp them in place of the head. A central guide pin and a plurality of peripheral guide pins extend vertically above the clamping plate and have reduced shank portions passing through the clamping plate and secured to the head and forming shoulders to engage said clamping plate and to secure the position. Said piston also includes a plurality of balls.

This invention lies in the field of pumps for regulating and controlling the flow of thickened .pulps or slurries and is directed particularly to an improved valving construction and arrangement which increases efficiency and results in trouble-free performance and longer pump life.

Modern industrial and civic operations call for the handling and transporting of many types of semi-fluid mixtures such as coal and ore slurries and pulps of many materials including sewage. Many varieties of pumps are presently available which are suited to this type of work. One of the most satisfactory is a generally vertically arranged pump body having a bottom inlet with a check valve and a vertically reciprocatable piston also provided with a check valve which draws the mixture in through the bottom inlet and raises it to the upper part of the pump body where it is discharged through a simple outlet opening at a level which will produce the desired flow.

The rate of reciprocation of the piston is usually maintained constant and the length of stroke is varied to produce or modify the desired quantity rate of flow. Such a pump normally has a single check valve at the inlet and a single check valve centrally located in the piston head. These valves are poppet valves having large valve stems which extend in the flow passages and greatly decrease their areas and flow capacities. The smaller pumps produce flows as low as five gallons per minute while the larger pumps produce flows as high as 500 gallons per minute. It will be readily seen that substantial flow restrictions seriously reduce their efficiency.

In an effort to overcome this disadvantage the valves must have a long vertical stroke which in turn produces a long closing time during which reverse flow can occur. This also tends to reduce the eficiency. In the larger size pumps, for lines of six to ten inches, these poppet valves, which are usually iron or steel, are very large and heavy, many being in excess of 100 pounds in weight. Consequent- Patented Jan. 16, 1968 See ly the closing action produces a severe pounding. When it is considered that such pumps operate at 25 to 40 strokes per minute it can be seen that such continuous pounding drastically reduces pump life.

The present invention overcomes the difficulties mentioned above by providing a construction which utilizes multiple valves for both the inlet and the piston, and in which the valves do not reduce the area of the flow passages and are so much lighter that the pounding effect is eliminated. Generally stated, the pump indicates a vertically extending hollow pump body having an inlet in its lower portion and an outlet in its upper portion. A generally planar partition extends across the lower portion above the inlet and is provided with a plurality of vertical circular flow passages therethrough for upward flow or" the liquid-solid mixture in response to the pump suction. A valve ball is provided for each of the valve seats formed at the upper terminus of the respective flow passages. It moves freely upward in response to the upward flow and seats by gravity promptly at the inception of reverse flow to retain the mixture in the pump body.

The pumping action is produced by a vertically reciprocating piston located in the pump body above the partition. The piston head is generally planar and horizontal like the partition and is similarly provided with a plurality of vertical flow passages and valve balls. The piston may extend entirely across the pump body and be provided with any suitable sealing means for sliding sealing engagement with the wall of the pump body. However, it is preferred to make the piston head somewhat smaller in diameter and use an annular diaphragm which is secured at its inner margin to the piston head and at its outer margin to the pump body Wall to avoid the sliding wear resulting from the handling of abrasive material. The balls seat by gravity and seal the piston during its upward movement to raise the mixture through the pump body. When the piston is lowered into the mixture retained in the lower part of the pump body, the balls are unseated by the relative upward flow of the mixture through the piston head.

It has been determined that the maximum flow passage area for a given diameter of piston or partition is obtained when three flow passages are provided at equal distances from the central vertical axis and equally angularly spaced about the axis. The diameter of each ball is between approximately 145 percent of the diameter of the flow passage and preferably about thereof to provide satisfactory seating while requiring a relatively small vertical movement to achieve maximum flow. When the balls are unseated, no part of them protrudes into the flow passages to reduce the effective flow area, with the result that maximum flow is obtained with any given size of passages.

In order to obtain quick and easy seating and unseating of the valve balls as well as minimum shock on closing, a proper relation should be maintained between the specific gravity of the ball material and that of the mixture being handled. The commonly used cast iron or steel poppet valves are very heavy and require excessive force to raise them from their seats. The impact force on closing is correspondingly high and the continuous pounding is detrimental to the valves and seats and also the rest of the structure, so that maintenance costs are high and total machine life is much shorter than it should be. It has been determined that when the valve balls of the present invention have a specific gravity in the approximate range of to 380 percent of that of the slurry they are readily unseated by the upward flow force and they seat again with very little shock. At the same time they are heavy enough to close quickly under gravity force. The usual slurries or mixtures normally encountered in the field generally have an approximate specific gravity between about 1.05 to 2.5. One of the ball materials which has been found to be highly satisfactory is a high aluminum oxide ceramic having a specific gravity of about 3.7 to 4.0. In addition to having the right specific gravity, this material is very hard and highly resistant to abrasion and its service life is at least as great as that of any other part of the system.

Various other advantages and features of novelty will become apparent as the description proceeds in conjunction with the accompanying drawings, in which:

FIGURE 1 is a front elevational view of a pump incorporating the invention;

FIGURE 2 is a sectional elevational view of the pump body and the working elements housed therein; and

FIG. 3 is a plan view of the piston head and certain cooperating elements.

The type of pump in which the invention is incorporated is generally illustrated in FIG. 1 in which a structural steel base has mounted thereon a pump body 12, drive mechanism 14, and motion translation mechanism 16. The pump body is hollow and comprises a bowl shaped lower portion 18 having a mixture inlet 26, and an upper cylindrical housing portion 22 having a trough shaped discharge outlet 24. It may also be provided with a cover or splash plate 26.

The drive mechanism 14 includes a gear box 28 on which is mounted a motor 30 having a driving pulley 32 connected by belts 34 to driven pulley 36 mounted on the shaft 38 of the gear reduction assembly, not shown, located within gear box 28. Shaft 40 extending from the gear box carries a disk 42 provided with an eccentric pin 44 serving as a crank. The lower end of connecting rod 46 is pivotally connected to pin 44 and the rod extends upwardly to the motion translation mechanism 16.

Mechanism 16 includes a pair of upright columns 48, one at each side of the pump body 12, mounted fixedly at their lower ends on frame 10 carrying at their upper ends a rocker shaft 50. A rocker block 52 is pivotally mounted on shaft 50 and carries a driving yoke or clevis 54 extending to the left as seen in FIG. 1. A shaft 55 extends to the right and is rigidly connected to the rocker block to transmit driving forces thereto. Drive block 58 is slidably mounted on shaft 56 from end to end and is provided with a lateral extension 60 having a centrally located pivot 62 connected to the upper end of connecting rod 46. The free end 64 of the extension is threadedly connected to adjusting shaft 66 which is rotatably mounted at one end in rocker block 52 and provided with a hand wheel 68. The opposite end of shaft 66 is rotatably mounted in bracket 70 and is provided with a second hand wheel 72.

Shaft 66 may be rotated by either of the hand wheels to move drive block 58 to any point along shaft 56, thus setting pivot 62. at any desired distance from rocker shaft 50. Since the stroke of the connecting rod 46 is constant because of its connection to crank pin 44, the adjustment of block 58 serves to vary the effective pumping stroke of the assembly. Pump shaft 74 is pivotally connected at 76 to clevis 54 to be vertically reciprocated thereby when motor 30 is activated, and the length of its stroke varies inversely with the distance between pivot 6-2 and rocker shaft 50.

The principal details of construction of the mixture handling assembly are illustrated in FIG. 2. While the entire basic pump body may be a single casting it is preferred to make it in three parts as shown, including a cylindrical housing 22, a frusto-conical bowl portion 78 and a tapered lowermost bowl portion 80, to which is attached an inlet flange 82 carrying inlet pipe 20. The various parts are secured together with conventional bolts and nuts, using appropriate gaskets or sealing material where necessary. Mounting ears 84 are provided for attachment to a support such as base 10.

A check valve assembly in the lower portion of the bowl includes a partition 86 which may be a separate plate extending across the bowl but preferably is cast integral with member 80. Three circular apertures 88 extend vertically through the partition to serve as flow passages for the slurry or other mixture to be pumped. They are preferably of the same diameter and are equally spaced radially from the central vertical axis 99 and are also equally spaced angularly about the axis. An elastomeric sealing ring 92 is mounted at the upper terminus of each passage and is preferably of substantially the same diameter as the passage. The rings are angle shaped in cross section with outwardly extending flanges or lips. The rings are held in place by a clamping plate 94 having openings of such size and location that the plate will overlie the flanges of rings 92. The clamping plate may be unitary or divided into sectors individually clamping the rings.

Dual purpose guide pins 96 are provided and serve both to guide the movable portions of the valve assembly and to hold the clamping plate in place. The pins have an upper portion which is polygonal in section to receive a wrench, and a lower reduced portion 98 which is threaded to be secured in tapped holes 100 in the partition. The shoulder 10?. formed by the reduced portion engages the upper surface of clamping plate 94- to secure it as shown. One pin is mounted on the central axis and six other pins are equally spaced about the margin of the plate to produce a series of triangular guide sets.

A valve ball 104- is associated with each passage and has a diameter about 30 percent greater than the diameter of the passage. With these proportions the ball fits down into the seal ring sufficiently to provide an adequate seal and yet needs to be raised only about one quarter of its diameter to provide an annular flow path at least as large as that through the passage. The guide pins are slightly spaced radially from each valve ball to allow ansolute freedom of vertical movement while restricting its lateral displacement to a very small amount.

It will be seen now that when a suction is produced above the check valve assembly just described, an up ward flow of a liquid-solid mixture will occur through passages 88 and raise the valve balls off their seats to the dotted line position. The mixture will flow around all sides of the ball without restriction, and maximum flow and maximum efficiency will result. As mentioned above, the specific gravity of the ball is about one and one-half to two times the specific gravity of the mixture, which minimizes the force necessary to raise it. At the same time the ratio is great enough to permit the ball to return by gravity rapidly to its seat when the fiow ceases or starts to reverse. In addition, the shape and relation of the ball and seat are such that an annular venturi is formed Whenever the ball is raised to any extent. The upward flow through the venturi produces a pressure reduction which restrains the ball against excessive upward movement on opening, and any reverse flow produces a similar force which accelerates the closing. The rapid closing is highly desirable because it minimizes the loss of mixture which has been raised.

The actual pumping effect is, of course, produced by the vertically reciprocating piston 106 which is preferably located as shown directly above the partition and check valve for compactness. However, it is to be under stood that the pump body may be made as laterally expansive as desired and the piston can be completely laterally displaced from the partition and check valve assembly. As shown, it is centered on the vertical axis 90, and housing 22 is cylindrical and coaxial with axis 90. Piston 106 includes a horizontally extending generally planar head 198 of circular planform made up of two substantially identical disks 110, 112;.

The head may extend entirely across the housing and be equipped with a conventional sealing ring for sliding engagement with the wall of housing 22 but this is not desirable because of the abrasive character of most of the material handled by pumps of this type. Instead, matching grooves 114, 116 and 118, 120 are formed in the parts 110, 112 and 22, 78 respectively, and an annular diaphragm 128 of tough, flexible material is provided. An inner marginal bead 122 is fitted into grooves 114, 116 and an outer marginal bead 124 is fitted into grooves 118, 120 and the parts are clamped together as shown to provide a completely sealed but relatively movable connection. If desired, Single grooves may be provided at each margin and the diaphragm may have corresponding beads.

The construction of the piston head and its associated parts is substantially identical to that of the partition 86 and its associated parts. Circular vertical passages 126 are formed through disks 112 and 110 and are shaped and spaced the same as passages 88. The same sealing rings 92, clamping plate 94 and guide pins 95 are used, and the guide pins are threaded into the lower plate 112 to secure the entire assembly. Valve balls 104 are also identical and function generally in the same Way. The plan view of FIG. 3 shows the relation of various parts, including the triangular arrangement of the sets of guide pins 96 around each of the passages 126 to allow free vertical movement of valve balls 104 but to restrict their lateral movement to a very limited amount. Clamping plate 94 is cut away at three places as shown for clearance purposes and is further shown as actually divided into three sectors 130, which serve the same purpose as a unitary plate.

Piston head 108 is carried for its vertical reciprocating movement by a spider frame 132 comprising three arch shaped legs 134 rigidly secured to plate 110 as best seen in FIG. 3, and forming a junction 135 on axis 90 above the piston head. A tapped hole 138 is formed in the junction to receive the threaded end 140 of pump shaft 74. When the drive mechanism, previously described is activated, shaft 74 reciprocates vertically and raises and lowers piston 106.

Considering piston 106 to be at rest initially, valve balls 104 are seated on rings 92 and the piston is sealed. When the piston is raised it will raise any mixture already above it for ejection thereof and draw more mixture into the pump body below it. When the mixture rises to the level of outlet through 24 it will flow out. When the movement of the piston is reversed, it will press down on the mixture below it. Such action will unseat the valve balls from the piston and result in a flow of the mixture upward past said unseated valve balls. Such action also insures that the valve balls in the check valve assembly are seated upon check valve assemblys sealing ring 92. Actually, of course, no mixture is raised during the down stroke of the piston. When the piston reaches the bottom of its stroke, the valve balls will promptly seat by gravity and seal the piston for the next up stroke. Movement of the balls w ll be controlled and facilitated by the venturi action previously described.

It will be seen that during the period of flow through passages 88 and 126 there is no structure in the passages to cut down their area and interfere with flow, as in the case of poppet valves having stems which are guided in the passages at all times. The multiple openings, particularly in sets of three as described, give maximum passage area for a given size of piston or partition. The use of valve balls having the proper specific gravity makes for rapid and easy opening and closing, and the comparatively low weight reduces pounding to a minimum. The material used for the valve balls is a high aluminum oxide ceramic produced by the Coors Company under the trade name Coors A99. It has a specific gravity of the order of 3.7 to 4.0, and a hardness of 9.8 on the Mohs mineralogy scale of 10. The halls are used as fired and have a smooth textured surface finer than fine sanding. One of the advantages of these balls over others, such as lead balls covered with rubber or rubber balls impregnated with powdered lead is that they are perfectly uniform and balanced so that they have no tendency to strike the seats eccentrically, which delays sealing and damages the seats. Because of their hardness, they are practically immune to wear.

It will be apparent to those skilled in the art that various changes may be made in the construction and arrangement of parts as disclosed without departing from the spirit of the invention, and it is intended that all such changes shall be embraced within the scope of the following claims.

I claim:

1. A pump adapted for handling liquid pulp mixtures 0r slurries, comprising: a hollow pump body having a mixture inlet in its lower portion and a mixture outlet in its upper portion; a horizontally extending partition in the lower portion; a plurality of vertically directed circular apertures forming flow passages through said partition and spaced uniformly about the periphery of a circle in the plane of said partition; each aperture having an annular valve seat; a valve ball associated with each seat and freely vertically movable upwardly out of contact therewith to provide an annular flow path for upward movement of a mixture through said partition and movable downwardly into contact with each seat to form a seal therewith and prevent reverse flow; a piston in said pump body and vertically reciprocatable to pump a mixture upward through said pump body to said outlet; said piston having a horizontally extending head provided with means to sealingly engage the wall of the pump body; a plurality of vertically directed apertures forming flow passages through said head and spaced uniformly about the periphery of a circle concentric with the vertical axis of said head; each aperture having an annular valve seat; a valve ball associated with each seat and freely relatively movable vertically upward out of contact therewith to provide a flow path for relative upward movement of a mixture through said head and relatively movable downward into contact with each seat to form a seal therewith and prevent reverse flow; said partition and said piston head each being provided on its upper surface with an elastomeric ring surrounding each flow passage for sealingly receiving a valve ball; an apertured clamping plate having aperture margins overlying marginal portions of said elastomeric rings; vertically extending guide pins for limiting lateral movement of said valve balls; said guide pins passing through said clamping plates and being threadedly secured to the partition and piston head respectively to lock said clamping plates in clamping relation; and means to raise said head with its valves closed to pump mixture upward in the pump body to the outlet and draw additional mixture through the partition, and to lower said head with its valves open into the additional mixture in the lower portion of the pump body.

2. A pump as claimed in claim 1; said piston head and the wall of said pump body being circular in planform; and said means to sealingly engage the wall of the pump body comprising an annular flexible diaphragm having an inner margin secured to the piston head and an outer margin secured to the wall of the pump body.

3. A pump as claimed in claim 2; said pump body comprising a lower bowl portion and an upper housing portion releasably secured together and an annular seating groove in at least one of the portions; and said diaphragm having an outer marginal bead clamped in said groove between said body portions.

4. A pump as claimed in claim 1; each valve ball having a diameter varying in the range of approximately to percent of the diameter of the flow passage.

5. A pump as claimed in claim 1; each valve ball having a diameter equal to approximately 130 percent of the diameter of the flow passage.

6. A pump as claimed in claim 1; said valve balls having a specific gravity in the range of to 380 percent of the specific gravity .of the mixture.

7. A pump as claimed in claim 1; said valve balls having a specific gravity of about 3.7 to 4.0.

8. A pump as claimed in claim 1; said valve balls being formed of a hard ceramic material.

9. A pump as claimed in claim 1; each valve ball, when unseated, cooperating with its respective valve seat to define an annular venturi passage which serves to restrain excessive departure of the valve ball from the seat upon upward flow of mixture through the passage and to accelerate closing action upon reverse flow.

10. A flow-through piston particularly adapted for vertical reciprocating movement in a vertically extending pump body to pump slurries, comprising: a generally horizontally extending piston head of circular planform and of substantially greater diameter than thickness; said head being provided with marginal sealing means for sealing contact with the wall of the pump body; a set of three vertical flow passages of equal diameter extending through said head, equally spaced radially from the vertical axis of said head and equally spaced angularly about said axis; an elastorneric sealing ring mounted on said head about the upper margin of each of said passages and being of substantially the same diameter as said passages; a clamping plate overlying said head and having three vertical apertures therein so located and of such size as to overlie the outer margins of each sealing ring to clamp them in place on said head; a central guide pin and a plurality of peripheral guide pins extending vertically above said clamping plate and having reduced shank portions passing through said clamping plate and secured to said head and forming shoulders to engage said clamping plate and secure it in position; a set of three balls, one associated with each of said passages and adapted to seat by gravity on said sea-ling rings and to be freely raised vertically by relative upward movement of slurry material through said passages and restricted in lateral displacement by said guide pins; and a supporting spider frame having elements connected to marginal portions of said head and extending upwardly and inwardly to a central junction spaced above said valve balls and guide pins; said frame having means at said junction for attachment to an actuator member.

11. A pump adapted for handling liquid pulp mixtures or slurries comprising: a hollow pump body having a mixture inlet in its lower portion and a mixture outlet in its upper portion; a generally horizontally extending partition in the lower portion; a plurality of generally vertically directed circular apertures forming flow passages through said partition; a valve ball associated with each seat and freely vertically movable upwardly out of contact therewith to provide an annular flow path for upward movement of a mixture through said partition and movable downwardly into contact with each seat to form a seal therewith and prevent reverse flow; a piston in said pump body and vertically reciprocatable to pump a mixture upward through said pump body to said outlet; said piston having a generally horizontally extending head provided with means to engage sealingly the wall of the pump body; a plurality of generally vertically directed apertures forming flow passages through said head; each aperture having an annular valve seat; a valve ball associated with each seat and freely relatively movable vertically upwardly out of contact therewith to provide a flow path for relative upward movement of a mixture through said head and relatively movable downwardly into contact with each seat to form a seal therewith and prevent reverse flow; said partition and piston head each being provided on its upper surface with an elastomeric ring surrounding each flow passage for sealingly receiving a valve ball; an apertured clamping plate having aperture margins overlying marginal portions of said elastomeric rings; vertically extending guide pins for limiting lateral movement of said valve balls; said guide pins passing through said clamping plates and being secured to the partition and piston head respectively to lock said clamping plates in clamping relation; and means to raise said head with its valves closed to pump mixture upward in the pump body to the outlet and draw additional mixture through the partition, and to lower said head with its valves open into the additional mixture in the lower portion of the pump body.

References Cited UNITED STATES PATENTS 992,837 5/1911 Winterhotf 103-151 1,036,398 8/1912 Winterhoff 103-178 1,791,615 2/1931 Dorr 103-451 2,308,876 1/ 1943 Hammett 137512.l 2,405,322 8/1946 Nisbet lO3-225 FOREIGN PATENTS 175,375 2/ 1922. Great Britain.

DONLEY J. STOCKING, Primary Examiner.

WILLIAM L. FREEH, Examiner.

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