US2956505A

US2956505A - Self-priming centrifugal pumps

Info

Publication number: US2956505A
Application number: US701198A
Authority: US
Inventors: Walter K Jekat; John H Doolin; Theodore R Esatow
Original assignee: Worthington Corp
Current assignee: Worthington Corp
Priority date: 1957-12-06
Filing date: 1957-12-06
Publication date: 1960-10-18
Anticipated expiration: 1977-10-18

Description

Oct. 18, 1960 w. K. .JEKAT Erm.

SELF-PRIMING CENTRIFUGAL PUMPS Filed Deo. 6. 1957 WALER KJEKAT JOHN HDOQLIN THEODQRE Rr-:Sllg/ FIG. 2

United States Patent G SELF-PRIMING CENTRIFUGAL PUMPS Walter K. Jekat, West Orange, John H. Doolin, New Providence, and Theodore R. Esatow, Westfield, NJ., assignors to Worthington Corporation, Harrison, NJ., a corporation of Delaware Filed Dec. 6, 1957, Ser. No. 701,198

11 Claims. (Cl. 10B- 113) This invention relates generally to a self-priming centrifugal pump adapted to be operated at diiferent capacities or heads by pre-selecting an impeller of a particular diameter according to the capacity or head required. More particularly, this invention contemplates providing this pump with novel means for retaining the self-priming feature regardless of the diameter size of the impeller selected.

In order to adapt this self-priming centrifugal pump for assembly line manufacturing techniques and to fuliill the requirements of the user; as for example a pump capable of delivering a variety of capacities and heads and still retaining the self-priming features, it has been found necessary to adapt the standard casing of the self-priming centrifugal pump to accommodate impellers of varying diameters. However, with this provision of varying impellers the self-priming feature of the pump has been seriously arrested.

The present invention overcomes the foregoing objection by providing the pump with a novel recirculation tube, having the novel prime retention characteristic of the apparatus disclosed in application, Ser. No. 576,442, iled in 1956, now United States Letters Patent No. 2,831,434, which is readily mounted in a pump that includes therein the pre-selected impeller providing the head and capacity required by the user.

Specifically, the invention contemplates a novel tube, readily mounted in the pump casing, that is pre-selected to coact with a particular impeller so that the operative relation between the tube and the impeller will provide the rapid self-priming characteristics for these centrifugal pumps.

It is therefore an object of this invention to provide a novel tube vin a self-priming centrifugal pump which will permit the retention of the self-priming feature in pumps adapted to operate with impellers of varying diameters.

It is another object of this invention to provide means .for the novel tube which maintain same in operative rela-L tion with the impeller to provide for the retention of the rapid self-priming characteristic demanded by the user.

It is a further object of this invention to adapt these self-priming centrifugal pumps for assembly line manufacturing techniques.

Further objects and advantages of the invention will become evident from the following description with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of the self-priming centrifugal pump including the novel recirculation tube in section.

Figure 2 is a vertical section taken on line 2-2 of Figure l, and

Figure 3 is a vertical section showing a modified form of the invention.

Figure 4 is a part section showing a modified form of the adjusting means.

Referring particularly to the drawings, Figure 1 shows a self-priming centrifugal pump, generally designated 10,

I which includes a casing 11 having a suction ,chamber 12,

ICC

a discharge chamber 13 and an impeller chamber or volute 14 preferably formed as integral portions of said casing. Impeller chamber 14 is adapted to receive one end of a shaft 15 which extends through a packing gland 16. An impeller 17 disposed in the impeller chamber 14 is mounted on the end of the shaft 15 by any suitable means such as threaded member 18 so that the impeller is iixed to and rotatable with the shaft 15. Rotation is imparted to the shaft 15 and impeller 17 by any suitable type of prime mover, generally designated 19, such as a gas engine which is preferably coupled to the shaft 15 at its other respective end in any well known manner and hence not more fully described herein. The usual front plate 40 is mounted in the front portion of the casing and in association with the impeller to provide a suction inlet thereto. v

Upon rotation of the shaft 15, the impeller 17 flows iiuid from the suction chamber 12 to the impeller chamber '14 through iiow passage means 20, providing communication between impeller chamber 14 and discharge chamber 13, and then to the discharge chamber 13 for use in the system in which the self-priming centrifugal pump .is operatively associated.

As is the usual practice in the art, prime on start-up is provided for by liquid that remains in the suction chamber 12 and discharge chamber 13 after pump Shutdown. A reservoir characteristic is provided for in these chambers v12 and 13 by valve means 21 which function, as is well known in the art and hence not more fully described, to provide for the retention of the initial prime for the pump. To provide for theretention of the prime during pump operation and after the initial prime liquid has been llown to the discharge chamber, the pump casing 11 is provided with novel means, generally designated 22, which are associated in operative relation with the impeller 17 whereby the self-priming characteristic is retained without regard to the diameter size of the impeller selected for operation in the pump.

Speciiically, this novel means 22 comprises a recirculation chamber or guide means 23 formed in the casing 11 in spaced relation with the impeller chamber 14 and includes tiow passage means 24 which provides forfluid communication between the discharge chamber 13and the impeller chamber 14. f

,Slidably disposed in the recirculation chamber 23 isa recirculation tube 25 which includes liow passage means 26 which preferably coincide with the ow passage means 24 on the recirculation chamber 23 to provide for return flowof fluidffrom the discharge chamber 13 to the impeller chamber 14. Provision is made in the casing 11, to be hereinafter described, for the retention of the leading and

trailing edges

27 and 28, respectively, in close clearance with the impeller 17 so that the effect of the' eddies in the impeller chamber acting on the fluid returning from kthe discharge chamber thereto is substantially arrested.

In order to limit the entry of the recirculation tube 25 into the impeller chamber and to maintain the leading and

trailing edges

27 and 28, respectively, in close clearance with the impeller selected for operation in the pump 10, tube 25 is provided with stop means 29 which preferably take the form of a shoulder which sits on a coacting stop means 30, preferably taking the form of a shoulder, on

`the recirculation chamber 23. It is not intended to limit these foregoing stop means 29 and 30 to the form shown in Figure l hereinabove described; it is to be understood that they may take any form which effectively limits and maintains the tube 25 in close clearance with the impeller 17, as for example the form shown in Figure3 to be hereinafter described.

It is evident with the provision of the compact recirculation means 22 as hereinabove described, that these selfpriming centrifugal pumps are readily adapted for as- 3 sembly line manufacturing techniques and in addition the prime characteristic is retained with the ready insertion of a novel tube in operative position after the impeller providing the required head or capacity has been selected.

To this 'end theyleading 'edge 27 can be 'cut back to provide smoother how, should a small diameter impeller be 'selected for operation.

During operation of 'the pump it -is imperative .that the tube 25 be maintained in operative relation with the impeller 17 described hereinabove. To this end a spring member 31 or the llike is `disposed in the recirculation chamber.23 and held in operative relation with the port 25 by a plug element 32 'associated therewith and mounted in the casing 11 las lis shown in the drawings.

Accordingly, it is vevident that from the foregoing description that the disclosed pump not only retains the rapid :flow rate necessary for rapid self-prirning but also discloses` a pump that is readily adapted for assembly line manufacturing technique,

In operation and after the initial prime fluid in the reservoir 12 is flown to the discharge chamber y13,

through flow'passage means 20, itis returned tree of air,

vwhich is separated Atherefrom in the `dischar-ge chamber, 4to the impeller chamber 14 through

flow passages

24 and 26 inthe Irecirculation means 22. r[his process keeps repeating itself until all the air is exhausted from the suction -chamber 12.

After the air is exhausted the pump continues to pump .the :duid present through lthe how passage means 20 into the discharge chamber 13 where it is in `turn passed through pump outlet 33 to use or other desired disposal.

kExcept for` the modified form of stop means generally designated 35' the construction and operation of the pump shown in Figure 3 is otherwise identical to that shown in lFigure 1 of the 4drawings and described hereinabove. Thus Figure 3 `shows the stop 'means 35 as a stem 30 connected Vat one end to the base portion 29' 'of the recirculation tube 25 in any menner known in the art and at its other end is threadably received by a plug member 36' mounted in the casing 1l. To prevent the seepage of pressurized fluid along the portion 37' of the stem threadedin the plug 36 and to prevent damage to :the Vend extending outwardly of thecasing 11 the stem is provided W-ithfa cap 3S" 'threadably mounted thereon and in fluid 'sealing relation with the stem 29' at the top`39 of plug 36'.

It will be noted that with this provision of :stop means 35 .the tube 25 can be adjusted in close clearance with the impellershould there'be a displacement of same for any reason, `such .as a wearing ofthe leading and trailing edges of thesport '25.

'To `adjust the tube 25 the cap 38' is removed, if in the form shown in Figure `3, `and the stem 30 is manipulated to adjust the tube' in close clearance with the impeller 17 -It is evident that the flow passage means 26 in the tube 25 must be yadapted to coa-ct with tlow passage means 24 in the event :that'the tube -is adjusted after its selection for operation. To this end flow passage means 26 may be oversized as isV shown in Figure 3 of the drawings.

If the cap 38 is in theform shown in Figure 4 manipulation of said cap is all that is necessary to adjust the port 25 in close clearance with the impeller, as is evident to those skilled Vin the art.

It will be understood that the invention'is not to be limited to the specific construction or arrangement of par-ts shown b ut that 'they lmay be widely modied within the inventiondefined by the claims.

`What is 'claimed is:

1. In .a self-priming centrifugal pump comprising a casing, including integral therewith a suction chamber, a discharge chamber, and an impeller chamber, said impeller chamber having flow passage means interconnecting'said 'discharge chamber and said suction chamber,

d said impeller chamber being 4adapted to accommodate impellers of `different diameters one at a time and for iiowing fluid -from said suction chamber through said flow passage means to said discharge chamber, guide means in said casing providing a recirculation portion therein in communication with said impeller chamber and said discharge chamber, -a detachable recirculation tube slidably disposed in said guide means and having one of the ends thereof extending into said impeller chamber, huid passage means in said tube communicating withsaid discharge chamber .and said impeller chamber through the recirculation portion of said guide means whereby fluid `ilown to said discharge chamber may be returned from said discharge chamber through 'said recirculation tube to said impeller chamber, the end of said detachable recirculation tube extending into said impeller chamber having leading .and trailing edges in close clearance with the outer periphery of the impeller mounted in said impeller chamber, stop means on said tube and coacting stop means in said guide means engaging the stop means Von said tube for maintaining the leading and trailing edges on .the end of said tube extending into said impeller chamber in close clearance with the outer periphery of .the impeller, andmeans in said casing and operatively associated with said recirculation port and adapted to hold same in operating position.

2. In the self-priming centrifugal pump claimed in claim 1 wherein'the stop means on said tube comprises `a shoulder and lthe stop means in said casing comprises a cooperating shoulder -for engagingthe shoulder on said Itube and means in said casing -for urging said shoulder on .said tube in abutment with the shoulder in said casing.

3. In the sel-fepriming centrifugal pump claimed in claim 2 wherein themeans for urging said shoulder on said 4tube in abutment with the shoulder in said casing comprises a spring mounted in said casing and in pressing relation with the end of said recirculation tube remote from 'the end extending into .the impeller chamber.

4. In a self-'priming centrifugal pump comprising a casing, including integral therewith a suction chamber, a discharge chamber,l and an impeller chamber, said impeller chamber having ow'passage means interconnecting said discharge chamber and said suction chamber, said "impeller chamber beingadapted lto accommodate impellers of diierent diameters one at a time wherein the particular impeller Ymay vary from a predetermined minimum diameter to ha 'predetermined maximum diameter whereby the selected impeller hows fluid Ifrom said suction chamber to said discharge chamber, guide means in said casing providing a recirculation portion 'therein in communication with said impeller chamber and said discharge chamber, a detachable recirculation tube slidably disposed in said guide means and having one of 'the ends thereof extending .into said impeller chamber, -uid 'passage means in said tube communicat- 4ing with said discharge chamber and said impeller chamber through the recirculation portion of said :guide means whereby huid .downto said discharge chamber may be returned :from said discharge chamber through said recirculation tube to said impeller chamber, the end of said detachable recirculation tube extending into said "impeller chamber having leading and trailing edges in prises a cooperating'shoulder Vfor engaging the shoulder on 'tube Yand means in said casing for urgingsaid shoulder on said port in abutment with the shoulder in said casing.

6. In the self-priming centrifugal pump claimed in claim 5 wherein the means for urging said shoulder on said tube in abutment with the shoulder in said casing comprises a spring mounted in said casing and in pressing relation with the end of said recirculation tube remote from the end extending into the impeller chamber.

7. In a self-priming centrifugal pump comprising a casing including a suction chamber, a discharge chamber and an impeller chamber as integral portions thereof, a flow passage means in the impeller chamber for communicating the suction chamber with the discharge chamber being adapted, said impeller chamber to accom-modate impellers of `different diameters one at a time wherein the selected impeller may vary from a predetermined minimum diameter to a predetemined maximum diameter whereby the selected impeller flows uid from said suction chamber to said discharge chamber, guide means in said `casing including a recirculation portion `for communicating the impeller chamber with the discharge chamber, a detachable recirculation tube slidably disposed in said `guide means and having one of the ends there extending into said impeller chamber, fluid passage means in said recirculation tube communicating the :discharge chamber with the impeller chamber and through the recirculation portion of the guide means whereby fluid owed to said discharge chamber may be returned from said discharge chamber through said recirculation tube to said impeller chamber, the end of said detachable recirculation tube extending into said impeller chamber having leading and trailing edges in close clearance with the outer periphery of the impeller mounted in said impeller chamber, means in the casing and operatively connected to Said recirculation tube for maintaining same in operable position relative said impeller, said last mentoned means comprising a stem member disposed in the casing and connected to the base of said recirculation tube at one end and adjustable means operatively connected to the other end of said stem member for moving the leading and trailing edges of said recirculation tube relative said impeller.

8. In the self-priming centrifugal pump claimed in claim 7 wherein the means for maintaining the recirculation tube in operable position relative said impeller comprises a stem member connected to the base portion of the recirculation tube at one end and extending outwardly out of said casing at the other end, and the adjustable means being threadably connected to the portion of said stem extending out of said casing for maintaining the leading and trailing edges on the end of said tube in close clearance with the outer periphery of lthe impeller.

9. In a self-priming centrifugal pump comprising a casing including a suction chamber, .a discharge chamber and an impeller chamber `as integral portions thereof, a ilow passage means in the impeller chamber for communicating the suction chamber with the discharge chamber being adapted, said impeller chamber to accommodate impellers of different diameters one at a time wherein the selected impeller may vary from a predetermined minimum diameter to a predetermined maximum diameter whereby the selected impeller ows uid from said suction chamber to said discharge chamber, guide means in said casing including a recirculation portion :for communicating the impeller chamber with the discharge chamber, a detachable recirculation tube slidably disposed in said -guide means and having one of the ends thereof extending into said impeller chamber, iluid passage means in said recirculation tube communieating the discharge chamber with the impeller chamber and through the recirculation portion of the Aguide means whereby fluid owed to said discharge chamber may be returned [from said discharge chamber through said recirculation tube to said impeller chamber, the end of said detachable recirculation tube extending into said impeller chamber having leading `and trailing edges in close clearance with the outer periphery of the impeller mounted in said impeller chamber, and adjustable means in the casing and operatively connected to said recirculation tube for maintaining same in operable posi-tion relative said impeller.

10. In a self-,priming centrifugal pump comprising a casing including a suction chamber, `a `discharge chamber Iand an impeller chamber as integral portions thereof, a ow passage means in the impeller chamber for communicating the suction chamber with the discharge chamber being adapted, said impeller chamber to accommodate impellers of dilferent ldiameters one at a time wherein the selected impeller may Vary from -a predetermined minimum diameter to a predetermined maximum diameter whereby the selected impeller flows uid from said suction chamber to said discharge chamber, `guide means in said casing including a recirculation portion for communicating the impeller chamber with the discharge chamber, a detachable recirculation tube slidably disposed in said guide means and having one of the ends thereof extending into said impeller chamber, fluid passage means in said recirculation tube communicating the discharge chamber with the impeller chamber and through the recirculation portion of the yguide means whereby uid flowed to said discharge chamber may be returned from said discharge chamber through said recirculation tube to said impeller chamber, the fluid passage means in said recirculation tube being of larger dimension than the recirculation portion of said `guide means, the end of said detachable recirculation tube extending into said impeller chamber having `leading and trailing edges in close clearance with the outer periphery of the impeller mounted in said impeller chamber, means in the casing and operatively connected to said recirculation tube for maintaining same in operable position relative said impeller, said last mentioned means comprising a stem member disposed in the casing and connected to the base of said recirculation tube at one end and adjustable means operatively connected to the other end of said stem member for moving the leading and trailing edges of said recirculation tube relative said impeller.

1l. In the self-priming centrifugal pump claimed in claim 10 wherein the means for maintaining the recirculation tube in operable position relative said impeller comprises a stem member connected to the base portion of the recirculation tube at one end and extending outwardly out of said casing at the other end, and the adjustable means being threadably connected to the por- .tion of said stem extending out of said casing tor maintaining the leading and trailing edges on the end of said tube in close clearance with the outer periphery of the impeller.

References Cited in the le of this patent UNITED STATES PATENTS 2,100,365 Stratton Nov. 30, 1937 2,109,804 Saxe Mar. 1, 1938 2,222,725 Saxe i Nov. 26, 1940 2,291,760 Rupp Aug. 4, 1942 2,405,836 LaBour Aug. 13, 1946 2,477,079 Mueller July 26, 1949 2,594,501 Ruthman Apr. 29, 1952 2,798,439 Longnecker July 9, 1957 2,831,434 Paashaus Apr. 22, 1958 FOREIGN PATENTS 679,246 Great Britain 1-- Sept. 17, 1952 903,781 Germany Feb. 11, 1954