US 2958293 A
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Description (OCR text may contain errors)
Nov. 1, 1960 R. F. PRAY, JR 2,958,293
SOLIDS PUMP Filed Feb. 25, 1955 50 Z/ 2 5/ FIG-2 55 5g :0 2'0 2 /l j 14 j /1 F76? 1V /4- J7 l z' FIG. I
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SOLIDS PUMP Reuel Ford Pray, Jr., San Francisco, Calif., assignor to Western Machinery Company, San Francisco, Calif., a corporation of Utah Filed Feb. 25, 1955, Ser. No. 490,491
3 Claims. (Cl. 103-103) This invention relates to improvements in liquid flow centrifugal pumps, and particularly to a new form of solids pump where the pump housing is entirely open on the interior and where, during the operation, the vortex within the pump housing forms the carrying medium and develops the suction and pressure heads necessary for pumping.
It is a well-known fact that conventional centrifugal pumps have a pump housing which is almost completely filled with a rotating impeller or the like. Such a condition requires the material being pumped to follow relatively narrow passages from the center feed to the periphery of the rotating impeller, thus limiting not only the size of a solid which may pass through the pump in susnited States Patent The invention further resides in the combination, con- 7 pension, but is frequently the cause of jamming, clogging,
breaking and binding, requiring costly shutdowns for maintenance and repair. Accordingly, it is an object of the present invention to provide a centrifugal pump in which anything which will pass through the discharge, will pass through the pump without jamming, clogging, breaking and binding, thus eliminating the inconveniences and expense of shutdowns.
It is another object of the invention to produce a pump which has increased capabilities for handling all types of materials in suspension, including all sizes which are capable of being passed through the inlet. 9
It is another object of the invention to provide a centrifugal pump where the impeller is entirely out of the pulp flow, leaving an open passage with nothing to impede the substantially free flow through the pump.v
Another object of the present invention is to provide a centrifugal pump having an impeller recessed in a well of the pump housing opposite the inlet and having a profile generated on a radius parallel with the case housing and substantially equal to the discharge.
It is another object of the present invention to provide such a pump with recessed pocket impeller, spaced from the inlet in such a way as to give the least amount of directional change to the inflow and to keep the maximum amount of pulp from directly contacting the impeller upon entering the pump housing.
It is a further object of the present invention to provide an inlet flow which will contribute motion to, and enhance the activity of the vortex in the pump housing, but which will also be compatible with the vortex established in the pump housing.
It is a further object of the present invention to provide a centrifugal pump which is capable of handling all types of materials in suspension, such as soft and friable materials, abrasive materials, waste materials and fibrous materials, whether in heavy or light concentrations, and handle them with a minimum period of residence in the pump housing.
Further objects are to provide a construction of maximum simplicity, economy and ease of assembly and disassembly, also such further objects, advantages and capabilities as will fully appear, and as are inherently possessed by the device and the invention described therein.
companying drawings, and while there is shown therein a preferred embodiment and one variant thereof, it is to be understood that the same is merely illustrative of the U invention and that the invention is capable of modification and change and comprehends other details of construetion without departing from the spirit thereof, or the I scope of the appended claims.
Referring to the drawings:
Figure 1 is a front elevational view of the solids pump of the present invention;
Figure 2 is a horizontal section taken on the line 2-2 and looking in the direction of the arrows;
Figure 3 is a fragmentary horizontal sectional view of member 10 which is an extension of the inlet pipe (not;
shown) and has the usual flange pipe connection 11 for attachment to an inlet flow pipe. member 10 is flared and flanged as at 12 for liquid-tight connection with the cover plate 14, which is both flanged at 1511 and at 15 for liquid-tight connection with the inflow member 10 and the pump housing or casing 16, respectively. The pipe housing has marginal flanges 17 and 18 which respectively cooperate with the flange 15 of the cover plate 14 and the flanges 20 of the bearing bracket and housing generally designated 21.
It will be observed that the flow passage through coupling member 10 is both curved downwardly in a vertical 0 plane and inwardly in a horizontal plane, as is clearlyshown on Figures 1 and 2. This special compound curvature takes advantage of the flow characteristics of fluids around pipe bends and gives the inflowing fluid a prerotational spin which is of marked advantage in the operation and efliciency of the pump. The flange 15a of the cover plate 14 cooperates with the flange 12 of the inflow member 10 to form a liquid-tight joint and may be held in such position by bolts 22, or by any other suitable means. It is equally apparent that merely by loosening the bolts 22 and removing them, the inflow member 10 can be completely removed and access afforded to the chamber 24 as well as the recessed impeller 36, are
available for ready examination and maintenance. The inner face 25 of the cover plate 14, which forms one end wall of the pumping chamber 24 in the form of a surface of revolution of convex curvature, is a continuation of the reverse curve coinciding with the line of the compound curve 25a of the inlet member 10.
The pump casing 16 has a tangential outlet 26 formed integral therewith, having a terminal connecting flange 27 for liquid-tight engagement with the outlet flow pipe. The transverse face 30 of the pump support housing 21, from which projects the annular flange 20, forms a support not only for the stuffing box 31 through which passes the shaft 32, but also supports the wear plate 33. The wear plate 33 has its peripheral edge portion 34-turned upwardly or outwardly to make it dish- The other end of the I like, as shown in Figure 2. The perimeter 35 lies adjacent the inner surface of the pump housing-16. 1
Attached to the shaft 32 is a torque developing impeller 36 which is commonly referred to as a recessed impeller, because the peripheral edge thereof is solid aroundthe entire perimeter 35a and joins the series of tangential vanes 38 to form pockets. The surface 35 of the impeller 36 defined bythe edges of the vanes 38 is in the form of a surface of revolution of concave curvature arranged in axially spaced substantially coaxial and substantially parallel relation to the surface 25' and defines with surface 25 a unidirectional at least substantially unobstructed vortical flow path' through the pumping chamber 24.
Also, the location of the impeller 36 is important. It will be seen, by reference to Figure 2, that the profile or surface 37 of theimpeller 36 is developed on a radius which is substantially parallel with the-opposite surface 25 of the cover plate member 14, and so completes the reverse curve passage substantially equal to that of the inlet member and defined by the axis 25a. The impeller, therefore, with respect to the flow, is recessed in the wall opposite the inlet, and out of the pulp flow through the vortical flow paths through the pump chamber 24 and with suflicient clearance provided between the impeller 36 and the wear plate 34.
The recessed impeller 36 is secured to the shaft 32 forrotation therewith by any suitable means, such as by the nut 40 or any other suitable means;
The inlet member 10 may be supplied with a quickacting dump valve 41 for emergency use. An outlet opening 42 is provided in the bottom portion thereof against the mouth of which the valve 43 is seated and held in sealed position normally by the action of 'the linkage involved in lever arms 44, 45 and 46, and by the angle fulcrum hanger 47.
The operation of the pump for the pumping of solids in suspension involves the new concept of providing the pumping action while maintaining the pumping chamber 24 within the housing 16 entirely open for the substantially free flow of pulp therethrough. When the pump is operated, the torque-developing impeller 36 is rotated by the shaft 32, which is coupled 'to'any suitable prime mover, such as a motor (not shown). The feed coming into the pump through the inlet member 10 is given a preliminary counterclockwise spiral motion before it is delivered to the pumping chamber 24. This is because of the compound curved shape of the inlet member 10. The rotation of the impeller 36 develops a swirling vortex in the incoming fluid suspension. The rotation of the vortex is in a counterclock wise direction and forms a swirling mass where the solid materials tend to be thrown toward the perimeter within the casing 16 by centrifugal force. So effective is the forced vortex established by the rotating impeller 36 that the solid materials in the incoming pulp rarely ever contact the impeller 36 or its blades 3=8,and since only a minimum amount of solids is ever in contact, wear on the impeller 36 and blades 38 is reduced to a minimum. So effective is the vortex thus established and the prerotational swirl established by the delivery inlet member 10, that the prerotated pulp flow is delivered directly into the swirl of the fast moving vortex Within the pump housing 16. Most of the particles or solids are discharged, that is to say, pass the peripheral limits .of .thepurnp chamber, in less than one revolution due to the centrifugal force induced by the vortex action and pass out through the outlet 26 located at the tion and the pressure heads necessary for the pumping pump chamber discharge point so that the period of residence is reduced to a minimum.
Because it is the vortex established by the impeller 36 which does the pumping, performance characteristics are produced which are not equalled by any other pump. The. .vortex created causes the pulpin the. mainpump chamber 24 .to rotate, thus developing both. the..suc-
action. Asindicated before, the curvature'of the passage through the inlet member it), the cover plate housing surface 25 and the pro-file 37 of the impeller 36, show that the impeller 36 is completely out of the vortical flow path from inlet to discharge, leaving the pumping chamber 24 substantially free for pulp flow. Thus, flow of the pulp through impeller vanes and small passages, necessary in the conventional pump for solids and thelike, hasbeen substantially reduced.
The recessed impeller 36 located out of the direct pump inlet flow permits the handling of coarse, abrasive, soft, or fibrous materials with equal facility. There is no damage from the breakage of friable particles or to soft articles such as fruit and pickles carried in suspension. The strong positive suction provides security against clogging of the suction line and complete nonclogging operation results, regardless of the solid concentration involved.
In the operation .it should also be observed that the vortex established within the chamber 24 by the rotating impeller 36 extends backwardly into the feed line of the member 10 and draws particles into the moving stream to assist the free rotation, not unlike the water spout of a hurricane. In this manner the inlet flow path'of the pulp. not only receives a prerotation, but is under the influence of the vortex at the time it enters into the motion. of the vortex. Thus, the infeed is. made without any loss from abrupt directional changes in flow direction.
It is, therefore,'apparent that the operation of the pump of the present invention is entirely different from centrifugal pumps which require material to follow relatively narrow passages from the center feed to the periphery of the rotating impeller, resulting in jamming, clogging, breaking and binding.
Referring now to Figure 3, the wear plate 33a is merely a flat plate attached to the face 30 of the bearing housing 21. It will also be observed that the perimeter 35b of the impeller 36a is adjacent the inner volute wall 16a of the pump housing 16, replacing the position of the wear plate. Identical advantages are obtained with this variant form and obviously greater peripheral speed to the vortex may be attained at any given r.p.m. due to the increased diameter of the recessed impeller 36a.
In Figure 4 the inlet member 10 has been replaced by a center or straight line inlet feed member 50, having the usual coupling flanges 51 for attachingto the feed line and 52 for liquid-tight coupling with the flange 15a of the cover plate 14. In this instance the prerotational feed due to the compound curves of the member 10 are not obtained, but, as has been previously described, the action of the vortex within the pump chamber 24 extends into and influences the pulp in the feed line so that to this extent a prerotational feed is obtained and the same delivery into the vortex is likewise obtained to prevent losses from abrupt directional changes in the inflow.
One of the very obvious advantages obtained by the construction shown herein is the availability of all parts of the pump without complete dismantling. Although the nature of the structure minimizes the wear factors, nevertheless the availability of all parts for observation and repair is a major feature and results in a solids pump which permits the utmost in economical operation.
As shown in Figure 1, the inlet feed member 10 may be provided with a quick dump valve for instantaneous drainage of the pump and line. In the event, through some sheer inadvertence, the inlet line becomes clogged or some obstruction is encountered in the pumping chamber, operation may be instantly diverted by merely pulling up on the hand lever 46 of the quick acting dump valve 41. Through the linkages this will immediately remove the valve 43 from its seat 42, and divert any flow from the-pump.
Another. distinct. advantage secured bythe structure of the solids pump described herein is that angular adjustment of the discharge direction can be attained by simple rotation of the pump housing 16.
1. In a swirl chamber pump, means defining an unobstructed pumping chamber having one end wall in the form of a surface of revolution of convex curvature, a second end wall in the form of a surface of revolution of concave curvature arranged in axially spaced substantially coaxial and substantially parallel relation to said first end wall and forming therewith a unidirectional unobstructed vortical flow path, a substantially concentric inlet through said one end wall, and a peripheral volute wall spanning the space between the peripherally opposed edges of said first and second end walls and forming a volute outlet passage directly communicating with the periphery of said vortical flow path as defined by the outer periphery of said spaced walls; and means outside said flow path forming a part of said second end wall for inducing vortical fluid flow through the unobstructed vortical flow path of said pumping chamber and said volute outlet passage whereby fluid flow through said chamber from said inlet to said outlet passage is effected while maintaining the path of fluid flow free of clogging producing obstructions.
2. In the pump defined in claim 1, said vortical flow inducing means comprising and said chamber defining means including a rotatable impeller having an end face the profile of which defines said chamber second end wall.
3. In a swirl chamber pump, means defining a substantially unobstructed pumping chamber having one end wall in the form of a surface of revolution of convex curvature, a second end wall in the form of a surface of revolution of concave curvature arranged in axially spaced substantially coaxial and substantially parallel relation to said first end wall and forming therewith a unidirectional substantially unobstructed vortical flow path, a substantially concentric inlet through said one end wall, and a peripheral volute wall spanning the space between the peripherally opposed edges of said first and second end walls and forming a volute outlet passage directly communicating with the periphery of said vortical flow path as defined by the outer periphery of said spaced walls; and means outside said flow path and forming a part of at least one of said end walls for inducing vortical fluid flow through the substantially unobstructed vortical flow path of said pumping chamber and said volute outlet passage whereby fluid flow through said chamber from said inlet to said outlet passage is effected while maintaining the path of fluid flow free of clogging producing obstructions.
References Cited in the file of this patent UNITED STATES PATENTS 1,074,606 Christoph Oct. 7, 1913 1,238,260 Casey Aug. 28, 1917 2,635,548 Brawley Apr. 21, 1953 2,655,868 Lindau Oct. 20, 1953 2,680,409 Sebens l June 8, 1954 FOREIGN PATENTS 68,594 Germany May 10, 1893 421,528 Great Britain June 7, 1934 445,115 Italy Feb. 8, 1949 446,498 Italy Mar. 18, 1949 473,253 Great Britain Oct. 8, 1937 488,639 Germany Jan. 9, 1930 523,096 Belgium Oct. 15, 1953 885,200 Germany Aug. 3, 1953