US2623466A - Dual discharge pump - Google Patents

Description

4 INVENTOR .WALTER H. TINKER M p4 f4 1w ATTORNEY 2 SHEETS-SHEET l w. H. TINKER DUAL DISCHARGE PUMP Dec. 30, 1952 Flled Nov 1, 1948 FIG.

Dec. 30, 1952 w. H. TINKER DUAL DISCHARGE} PUMP 2 SHEETSSHEET 2 Filed Nov. 1, 1948 INVENTOR WALTER H. TINKE AT TOR N EIY Patented Dec. 30, 1952 DUAL DISCHARGE PUMP Walter H. Tinker, St. Louis, Mo., assignor to Fairbanks, Morse & Co., Chicago, 111., a. corporation of Illinois Application November 1, 1948, Serial No. 57,691

2 Claims. (01. 103-2) This invention relates to improvements in centrifugal pumps, and concerns more particularly an improved pump assembly of dual discharge character, embodying a single impeller of novel construction.

The principal object of the present invention resides'win the provision of an improved centrifugal pump assembly including separate volutes and embodying a single impeller common to the volutes, the impeller being of a unitary or one-piece construction, characterized by distinctly separate sets of fluid passages one set for each of the volutes, wherein the passages of one set have their discharge ends radially beyond the discharge ends of the other set of passages, the pump assembly thus afiording dual, differential pressure fluid delivery.

Another object is to aiford a centrifugal pump assembly providing a casing structure having separate volute chambers, and a single impeller of the character indicated in the foregoing object, affording separate sets of fluid passages each discharging into one of the volute chambers, wherein the assembly includes an effective provision embodied in part in the impeller structure,

for effecting a fluid seal of the impeller between the volute chambers such as to preclude all but a negligible minimum of fluid leakage from one volute chamber to the other.

Another object resides in the provision of an improved impeller for a pump of the character indicated, wherein the impeller provides separate sets of fluid passages, a fluid intake axially of the impeller and communicating with the inner ends of the passages of both sets, and means in the impeller intake effective to cause a division of the intake fluid into radially separate streams, one stream supplying the passages of one set and the other stream supplying the passages of the remaining set.

A further object is to provide a pump assembly of the character above indicated, which is suitable for use in connection with a jet booster pump, wherein one fluid discharge of the pump is utilized to energize the booster pump.

Yet another object is to provide a pump assembly as indicated, in which the separate fluid discharges of the pump may be led to independent points of use.

Other objects and advantages of the present invention will appear readily from the following description thereof as illustrated in the accompanying drawing, wherein:

Fig. 1 is a view in vertical elevation, of a centrifugal pump assembly including a jet booster pump, with portions of the pump assembly and piping shown in section, showing the presently improved impeller structure;

Fig. 2 is a fragmentary sectional view of the assembly, illustrating a jet pump and a modified manner of delivering energizing fluid to the jet pump;

Fig. 3 is a fragmentary sectional view of the intake portion of the pump housing assembly, illustrating a modification in respect to the use of the present pump;

Fig. 4 is an enlarged, fragmentary sectional view through the centrifugal pump, illustrating the novel features of impeller construction according to the present invention;

Fig. 5 is a view in plan as taken from line 5-5 in Fig. 1, showing one of the pump volutes;

Fig. 6 is a similar view but taken along line 6-6 in Fig. 1, showing the other pump volute;

Fig. 7 is a transverse section through the impeller, as viewed from line 1-1 in Fig. 4, showing one set of passages thereof, and

Fig. 8 is a transverse section through the impeller as viewed from line 8--8 in Fig. 4, showing the other set of passages thereof. Referring first to Fig. l, illustrated there is a et boosted centrifugal pump assembly in which is embodied the present invention. The pump assembly shown includes a pump casing providmg a lower casing section l0 adapted as a base section for mounting over the upper end of a well pipe (not shown), and an upper casing section ll supporting on the top thereof, a pump drive motor l2. Casing section II is formed to provide an internal transverse wall I4 having a central opening l5, and an impeller housing [6 of volute character (Fig. 5) on the upper side of the wall l4 and over said opening [5. The housing affords a volute chamber I8 having a fluid outlet or discharge neck 19 extending to and opening through the side wall of the casing section, for fluid delivery to a discharge conduit 20 which for example, may lead to an irrigation system.

Base section It of the casing assembly provides a fluid chamber 22 separated from the upper casing section by the wall I4 of the latter, and includes an impeller housing 23 therein, preferably of double or twin volute character (Fig. 6) affording substantially diametrically opposite fluid outlets 24. Housing 23 forming the volute chamber 26, is disposed in cooperative adjacence to the lower side of wall I4 over opening l5 thereof, with the discharge outlets 24 opening directly to the casing chamber 22. Extending below the central eye 2! of volute housing 23 is a conduit extension 23 terminating at the bottom wall 30 of casing section it in axial fluid-receiving registry with an inlet opening 3| in wall 35, the latter opening being threaded to receive the threaded end of a suction pipe 32. Base section Hi further has a lateral opening 34 shown closed by a plug 35, Fig. l, and an opening 35 in bottom wall 35, threaded to receive a conduit 38. As appears from Figs. 1, and 6, the volute 23 is considerably larger in the radial direction, than the volute it, this for a purpose to appear.

Included in the present pumping assembly is a jet booster pump unit enerally designated at, 39,

arranged in the suction line between a suction intake and foot valve device 40 and the suction conduit or pipe 32. The jet pump maybe of well known construction, providing a jet nozzle 42 having its inlet 53 in communication with the conduit 38 and its discharge end 44 relatively spacedfrom but in alignmentwith the intake end 45 of a Venturi tube 41, thelatter connecting with the lower end of suction pipe 32. Well fluid passing upwardly through the foot valve intake, is received in the jet chamber 48 surrounding the jet nozzle 42, for passageto and through the Ven turi tube. V

The depending drive shaft 55 of motor 12 extends through an upward extension 5| of volute casing l5, and has mounted on its lower end a centrifugal impeller 52 of a novel character in accordance with the present invention, the impeller extending through wall opening and being operative in both volute chambers l5 and 26. With particular reference now to Figs. 4, '7 and 8, the impeller 52 is comprised of a unitary member preferably provided as a single casting of bronze or other suitable metallic material, formed to have a shaft mounting hub 54 at one end, a portion 55 of a given diameter for operation in the volute housing IS, a central portion 55 disposed in the opening 15 of wall 14, and an end portion 53 of a diameter exceeding that of the portion 55, operable in the larger volute housing 23. The impeller thus is of peripherally stepped form to adapt itto the volutes of differing size. Further, the impeller includes an axial, hub-like extension 55 externally reduced for a, close running fit in the eye 27 of volute housing 23 (Fig. 4), the running fitbeing such as to preclude material leakage or fluidby-pass from the suctionconduit 28 around theimpeller sections 59 and 53 to the volute chamber 25. j

Asappears in Fig. 4, the impeller inits central portion 55, is provided with an outstanding annular rib or flange 50 which is received in an annular shouldered recess 62 formed in the margin of the wall opening [5. Flange 65 has a close running fit in said recess 52, such as to afford a running seal against more than a negli gible amount of fluid leakage between the volute chambers 25 and l8. Such seal materially improves the efficiency of the present pump.

Continuing as to the features of the impeller, the impeller is formed to have a suction intake provided by an axial bore of stepped character, afiording a large diameter bore 53 and a small diameter bore 64 coaxial with bore 53 and extending therefrom toward the shaft hub end of the impeller, the small diameter bore being closed at its inner'end, as shown. Bore 64 extends through the section '56 and'into the section 55 of the impeller, while the bore 53 extends through the hub-like extension 59 and into the section 58, the bore 53 being open at the outer end of extension 55, in fluid-receiving communication with the suction conduit portion 28 of the volute housing 23. At the junction of the bores 63 and 64 is a shoulder provided as an annular, wedgeshaped projection having its annular apex or tip 5? directed toward the open, fluid inlet end of the large bore 53. The purpose served by the wedge projection will appear presently.

Formed in the impeller end section 55 and partly through the central section 56, is a set of discharge passages 53 (Figs. 4 and 7) defined by vanes '50 and lateral wall surfaces ll of the impeller member. Each passage has its inner end '12 open directly tothe small bore 55, and its outer end open on the periphery of impeller section 55. Moreover, in the presently preferred example each passage 58 has a spiral trend diverging outwardly toward its outer open end 14, as viewed in Fig. 7, and further has an arcuate trend convergently from its inner end 72, as shown in the sectional view of Fig. 4, the latter being in a plane normal to the plane of Fig. 7. In the larger diameter impeller section 58 is-another set of discharge passages i5 defined by vanes 75 and lateral wall surfaces 78 of the impeller. Each passage '15 has its inner end 19 open to the large bore 63 in the region of the annular wedge-like projection 55 such that the latter radially underlies the passage opening, while the outer end 55 of each passage 15 opens on the periphery of the impeller section 58. Furthermore, although the passages F5 are generally similar to passages 58in respect to a divergent spiral trend as viewed in Fig. 8, and a convergent arcuate trend as appears in'Fig. 4,they difier not only in length as is obvious, but in the degree of arcuate trend as appears in Fig. 4. As there shown, the trend in the immediate region of the outlet opening 55 of each passage 15, is more nearly transverse to the impeller axis than is the case in respect to the outlet l iof each passage 68, while the trend in the region of the intake opening 19 is less inclined to the radial than is the case in respect to the inlet opening 72 of each passage 68. Such differences in the character of the impeller passages 15 are here presented to facilitate flow efficiency and high pressure fluid discharge, particularly since in the preferred pump assembly according to Fig, l, --fluid discharged by the impeller passages i5 is utilized to energize the jet booster pump, as this will appear presently.

In addition to the foregoing, impellereifectiveness and efficiency are'enhancednot only by curving the impeller vanes '65 and i5 oppositely to the direction of impeller rotation indicated by-the arrow in each of Figs. '7 and 8, but also'and importantly here, by giving the intake end portions of these vanes a predetermined angular direction or inclination to the bore circle of the associated suction intake bore of the impeller. In each case, the inclination of the inner end or inner tip portion of each vane in the set, is determined in accordance with the diameter-of the associated suction bore, such as to'promote substantially shockless entry of fluid to the impeller-discharge passages formed by the vanes. Thus in the present embodiment and as will be appreciated by reference to- Figs. 7 and 8, the entrance or pick-up surface Ella of each vane i5 is given a predetermined inclination to the circular margin-of suction bore 54, while the pick-up surface l fiaof each vane 75 has a different predetermined inclination to the circular margin of suction bore 63. Such inclinations are indicated by the angle A in the first case (Fig. 7), between the entering tip of the vane and a tangent to the bore circle passing through the vane tip at the circle, and the similar angle B in the second case (Fig, 8), the angle B being greater than the angle A by reason of the greater diameter of suction bore 63 relative to that of bore 64.

Turning now to the operation of the pumping system shown by Fig. 1, well fluid passing upwardly in the suction line enters the impeller intake bores 63 and 64. The wedge-shaped projection 66 at the juncture of the impeller bores 63 and extending at about the angle shown, is eflective upon the suction flow to divide the same radially into an outer annular stream directed by the projection into the inlet ends of the impeller passages 75, and an inner stream directed into the smaller bore 64 for flow to and through the impeller passages 68. The impeller passages 15 deliver fluid at high pressure, to the volute chamber 26 from whence the high pressure fluid passes out the volute discharge outlets 24 into the casing chamber 22. From chamber 22 the fluid flows through conduit 38 to the nozzle 42 of the jet booster pump 39 for energizing the latter in a well known manner, the jet energizing fluid of course, combining with the well fluid delivered to the impeller intake.

The inner fluid stream entering the impeller bore 64, is discharged through the impeller passages 68 at a pressure materially less than the pressure discharge from the passages I5. Such fluid then passes from the volute chamber [8 through the discharge neck I 9 to the delivery line 23, the latter as shown, having a flow control valve 82 therein.

From the foregoing it will appear now that the present invention affords a dual discharge pump of centrifugal type, embodying a single, unitary impeller providing separate or independent high and low pressure fluid delivery through separate volutes. While the invention is suitable in particular, for deep well pumping with suction lift augmented by a jet booster pump, wherein the operation is as above described in connection with the disclosure according to Fig. 1, it will be appreciated that the single impeller, dual discharge pump may be employed very effectively, in shallow well pumping in which a jet pump is unnecessary. Conversion to shallow well use may be effected readily, merely by removing the jet pump unit, extending the suction conduit 32 directly to the foot valve and suction intake device 40, and closing the casing opening 36 by a suitable plug 83 as illustrated in Fig. 3. Eflective pumping then will obtain only through the impeller passages 68 to discharge delivery through line 20, the impeller portion containing passages 15 then running idle. However, in shallow well pumping full use of the dual discharge function of the pump may be had by removing the plug 35 closing opening 34 (Fig. l), and leading a conduit (not shown) from said opening to a point of fluid use, as for example, to a pressure tank supplying water for domestic or other use. The high pressure discharge effected by the impeller passages 15 is especially suitable for the latter purpose, as will be appreciated, while the low pressure delivery through line 23 may be used for irrigation or other use requiring low pressure, large volume flow of fluid. It is to be noted here that fluid delivery may be eflected both through line 20 and a line from the casing opening 34, in the dee well, jet pump arrangement of Fig. 1, but in such case, it will be '6 appreciated that there will be a decrease in the effectiveness of the jet pump because of the divi sion of high pressure fluid discharge between the jet pump and the line from casing opening 34.

In the instance of a deep well system wherein the diameter of the well casing is not suflicient to accommodate a suction line and jet booster arranged as shown in Fig. 1, the compact arrangement as illustrated by Fig. 2, may be employed. As there shown, the well casing 9|] is employed as a delivery conduit for the jet operating, high pressure fluid from the pump casing chamber 22. A fitting 9| is secured to the upper end of well casing 90, the fitting providing an elbow conduit 92 which is connected to chamber opening 36 by a short length of pipe 94. High pressure fluid thus is delivered downwardly in well casing 39 about the suction pipe 95 and Venturi tube 96, to the inlet of the jet nozzle 98 of jet pump unit 39. To prevent by-pass of the jet energizing fluid to the well suction intake I00, the well casing below the jet unit, is closed by suitable seal rings I32.

Having now fully described and illustrated the present invention, what is desired to be claimed and secured by Letters Patent is:

1. An impeller for a centrifugal pump, com prising a unitary member with a stepped periphery and having separate sets of discharge passages therein, with one set of passages opening on one peripheral step and another set of passages opening on another peripheral step of the member, the member further having a fluid inlet bore in direct communication with one set of the passages, and a portion of the member between said sets of passages providing a wedgeshaped projection terminating in an annular tip within the fluid inlet bore and in the proximity of the set of passages directly communicating with said inlet bore, the said portion of the member thereby defining a coaxial reduced diameter extension of said inlet bore leading to the other set of passages, the wedge-shaped projection being effective for dividing the fluid entering said inlet bore into radially separate streams individual to the sets of discharge pasages in the impeller.

2. A centrifugal pump assembly including a casing having an internal transverse wall with a central opening and means forming volute chambers on opposite sides of the wall over said opening, the marginal wall defining said opening in the wall member providing a shouldered recess, and an impeller comprising a unitary member with a continuous stepped periphery operable in said volute chambers and extending through said opening in the wall so that the stepped impeller periphery and the shouldered recess engage to effect a running seal of the impeller in the opening, the impeller being provided with separate sets of discharge passages therein, with one set of passages opening on one peripheral step of the member to one of the volute chambers on one side of the running seal and another set of passages opening on another peripheral step of the member to the other of the volute chambers on the other side of the running seal, the impeller being further provided with a fluid inlet bore in direct communication with one set of the passages and with a portion of the member between said sets of passages providing a wedge-shaped projection terminating in an annular tip within the fluid inlet bore and in the proximity of the set of passages directly communicating with said inlet bore, the said portion 7 of the member thereby defining a, coaxial I6?- duced diameter extension of the inlet bore. leading to. the other set of passages, the Wedgeshaped projection being effective for dividing the fluid entering said inlet bore into radially separate. streams, individual to the sets of discharge passages.

WALTER H. 'I'INKER.

REFERENCES CITED The foil'owing references are of record in the file of this patent:

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