US2273420A - Centrifugal pump - Google Patents

Description

R. D. SCHOTT GENTRIFUGAL PUMP Feb. 17, 194,2'.

Filed Feb. 17, `1941 2 Sheets-Sheet 1 Patented Feb. 1 7, 1942 Rudolph D. Schott, Pomonalcalif., assigner to Pomona Pump Co., Pomona, Calif., a. corporation of Delaware Application February 17, 1941,v Serial No. 379,182

(Cl. S-103) for translating substantially lateral or horizontal movement of the fluid or waterinto ve'lrticalylift` thereof, and wherein the .lateral motion is imparted to the waterby rotating impeller members positioned within the body of Water.

It is common in such pump constructions tov accompanying drawings.

useone or morestages, including a bowl and im- I peller member for each such stagefin order to effect the desired lift and toobtainthe desired efficiency of lift.

I have dsccvered thatvthe efficiency of operation of'a Dump of the above set forth type may be increased materially by so forming the ends of the vanes provided for directing the up-ilow of the fluid lor water as to reduce the power consumption heretofore required in order to direct the fluid upward. I

I have discovered that by forming the ends of the yanes in a manner which I prefer to deneas of bulbous shape, that the pow'er consumption required for the raising of the water or fluid is ma- In the drawings:

Figure 1 is a sectional elevation of a centrifugal pump embodying my invention. -Figure 2 is a' sectional view taken substantially on the line 2-2 of Figure 1 illustrating the vane end of the said pump on an enlarged scale, illus'tratingl diagrammatically the direction of impact of the fluid or water againstthe bulbous end of the vane.

Figure 3 is a view similar to Figure 2 illustrating theoretically the direction of fluid travel over the vane end.'

Figure 4i'is a comparative plotting of the percent efiiciency against volume of vlift illustrating in 'dotted lines the curve of the pump embodying my invention as compared with the curve shown in full lines of the same pump minus, or not embodying, my invention.

Figure 5 is a side elevation mainly in vertical p section of a niodiii'edform of impeller centrifugal .terially decreased over substantially they entire operating range of such a pump structure. I

' It is therefore the primary object ofv this invention and toward which this invention is directed, to provide a centrifugal pump having greater operating efficiency than pumps of similar construction heretofore widely manufactured and used.

`Another object of this invention-is to provider a pump of the centrifu fluid lifting type particularly adapted for raising water in wells which includes a bowl member having directional vanes operable in conjunction with rotary impellers for changing thedirection of flow of wateras set in motion by said impellers and which varies have a bulbous endfin the path of the water as set Vin motion Vby tlie'fsaid impellers.

Other objects and advantages of this invention it is believed will be 'apparent from the hereinafter set-forth description of a preferred pump embodyingmy invention.

In the embodiment of my invention as illus-` trated in Figure l, there is shown an impeller bowl type of centrifugal pump including a pump rod I which carries one or more impellers! operating within bowlI members 3. The bowl and impellers may-be of any desirabletyp'e 'of structure which is well known in the' art, and any desired number of such bowl and impeller assemblies may be connected together, depending upon the conditions of the installation. {,lhe bowls are generally connected togetheras indicated at 4 and are connected to the discharge pipe 5. The shaft lis-supported at the lower end of the assembly in "a bearing member 6 formed in a supporting member 1 secured to the lower bowl 3.

The well pipe 8 which maybe a screen member, extends below the supporting member' 'I. .As is well understood in this art, each of the bowl members 3 is formed to provide a plurality of directional passages S-dened by-vane members I0 which change thedirection of 4ilow of the uid or-water setn motion b'y means of the impellers 2. The imp 1ers 2 are of the multiple type, including a pluralityv of blades II. l The impellers are secured to the shaft I by any suitable or clesirable means such. as through the medium of the tapered bushing I2. VThe bowls 3 each preferably provide a bearing support I3 for th' shaft I formed in the central hub portion Ilfjoined to In accordance withmy invention, the vane end I which lies in the path of the fluid or water set in motion by the impeller 2 and is the advanced end of the vanes, is formed bulbous, as

ditions of fiow pattern developing increased turbulence, eddying, and changes of pressure differences flowing over the advanced ends I5 of the vanes III.

By forming theadvanced bulbous sections I5 of the vane end I5, I am enabled to meet changesv of flow as indicated in Figure 2 so that should the direction of impact of the uid or water against the bulbous end I6 change, as indicated by the different arrows I'I, the direction of impact against the bulbous ends willbe at al1 times substantially tangent to the surface. This insures greater uniformity of flow pattern over the said bulbous ends and will produce a greater constance of efliciency of lift of water as compared with power input overthe varying conditions of operation.

A much more important 4characteristic of the bulbous end I6, however, is found in the fact that it enables me to attain a greater efficiency of operation under the same conditions of operation and over substantially the entire range of operating conditions of such a pump. The reason l for this totally unexpected increase in efficiency due to the use of this type of structure is difiicult of explanation, 'I'he loss of emciency in a pump of this character is due to hydraulic losses. These hydraulic losses are variable, depending upon conditions of flow.

There of course is a constant loss of efficiency attributable to friction losses in the -mechanically operating elements as, for example, the losses occasioned by the rotation Aof the shaft through its bearing elements; these `latter losses, however, being constant, are not the losses here considered or included Within the term hydraulic losses.

As will be observed particularly from Figures 2 and 3, the bulbous end I6 has its advanced surface, or the one first in the line of ow, curved so as to maintain substantially tangential impact with the flow and at the rear is recessive, as in- I dicated at I8, as compared with the body of the The particular proportions indicated vane I0. are not essential to the attaining of the high degree of eihciency, but the'particular shape contributes thereto because the'bulb end I6 is by this means formed in such \manner that its periphery substantially follows the unobstructed line` of flow ofl the fluid as the same is indicated in Figure 3 by the lines IS. 'I'he bulbous end as thus formed vacts to ll the void 2i! which forms onthe impact of the water or fluid againsty the advanced edge I6' and by being recessive .at I8, prevents pressure application by the fluid against the vane I0 at the rear of the advanced edge I6'. The bulbous end is thus made in form to compensate for the' tendency of a void 2U to form as a result of flow of fluid over the obstruction provided by a vane end, so that increase of turbulent flow and eddy currents are not developed at the start of the changing direction of iiow'of the fluid as-it is directed through the passages 9 which divert the iiow upwardly and in directions to properly enter the areas 2| of the next impeller 2. l

In Figure 4 I have illustrated the efliciency curves of my pump as hereinabove described and p the curve of the same pump operating under the same conditions but not including the bulbous ends I6. The efIiciency curve 4of the pump e'mbodying my invention is illustrated by the dotted line 22. The efliciency curve of the pump of the same construction operating under the same conditions but not having the bulbous end I6 is illustrated by the curve 23. The pump 'operating to produce the eiiiciency curve 23 is the same as has been manufactured and sold and used for many years, and in this structure the advanced ends of the vanes were, as has been common in this art for many years, formed to a substantial knife edge. From'Figure 4 it will be noted that the increase in efficiency of operation of the pump embodying my invention is in the neighborhood of 6%'to 10% throughout the Anormal entire range of operation, and the curves are of eihciency over differing and increasing volume discharges from the pumps.

In the modified form of my invention as illustrated in Figure 5, I have shown what is commonly known inv this art as the enclosed impeller type of centrifugal lift pump as compared with that known in the art as the open end impeller type of construction shown in Figure 1.

' In the modified form of Figure 5, Jthe same numerals have been utilized to indicate the same parts, with the addition of an exponent a thereto, and the same conditions of operation and construction prevail throughout this modified form of construction inso far as this inventionis concerned, the principal difference of construction being that inthis form the impeller 2a has at its lower end an enclosing flange 30a defining enclosed impeller passages 3|a entirely withinV the structure of the impellers 2a. In the modification of Figure 1 the impeller passages are defined between the impeller and the bowl and not Within the structure of the impeller.

In applicants copending application, Serial No. 394,517, filed. May 2x1, 1941, for Bulbous steam turbine blade, l"applicant is claiming his invention as particularly adapted to use in structures other than centrifugal pumps and particularly as related to turbine construction.

Having fully described my invention, it is to be understood that I'do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. In a pump of the class described, including an impeller, and a bowl member having a plurality of vanes defining flow passages operative to change thedirection of fiow of the fluid induced in the fluid by the impeller wherein the advanced ends of the vanes have a bulbous form 2. In a pump of the class described, including an impeller, and a bowl member having a plurality of vanes defining flow passages operative to change the direction of flow of the fiuid induced in the fluid by the impeller wherein the advanced ends of the vanes are bulbous in form, including a curved advanced end which is recessive at its rear to substantially fill the void otherwise produced by the flow of fluid over the advanced edge.

3. In a pump of the class described, including an impeller and a bowl member having a plurality of vanes defining flow passages operative to change the direction of flow of fluid induced in the fluid by the impeller wherein the advanced edges of the vanes are .of curved form providing a protuberance in the line of flow of the fluid, the curve being of greater diameter than the normal thickness of the vane and wherein the thickness`of the vane edge decreases from its greatest diameter to the normal vane thickness.

4. In a pump o f the class described, including an impeller, a bowl member having a plurality of vanes defining flow passages operative to change the direction of flow of the fluid induced in the uid by the impeller wherein the advanced end of the vanes are rounded ina direction transverse of the ow and substantially tangential to the impact of the fluid therewith, the rounded edge having a radius of curvature greater than one-half the vane thickness, and where the curve of the'V rounded edge merges into the vane behind the rounded end.

5. In a pump of the class described, including an impeller, a bowl member having a plurality of vanes defining flow passages operative tov change the direction of flow of the fluid induced in the fluid by the impeller wherein the advanced edge of each vane is of curved form providing a protuberance in the line of flow of the fluid, the said protuberance being of greater thickness than the normal thickness of its vane.`

6. In a pump of the class described, including an impeller; a bowl member having a plurality of vanes defining flow passages operative to change the direction of the flow of the fluid induced in the fluid by the impeller wherein the advanced edge of each vane provides a rounded protuberance in the line of fluid flow of greater thickness than the normal vane thickness, each side of the vane adjoining the protuberance at the rear thereof providing a curved surface

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