US2332875A - Self-priming pump - Google Patents

Description

Och 26, 1943. A c. sTRATToN 2,332,875

SELF-PHIMNG UMP Filed July 30, 1941 Patented Oct. 26, 1943 SELF-'PRIMING PUMP Albert C. Stratton, Ridgewood, N. J., assigner to Alfred S. Marlow, Ridgewood, N. J.

Application July 30, 1941, Serial No. 404,599 4 Claims. (Cl. 10S-1,13)

My invention relates to improvements in selfpriming pumps. It relates more particularly to the means for the construction of self-priming centrifugal pumps wherein the operation` of the pump impeller with residual liquid is adapted to cause the pump to prime itself and subsequently discharge its full capacity without the employment of mechanical devices.

Centrifugal pumps may be broadly divided into two types, volute and turbine. In my Patent 2,281,175 bearing Serial Number 359,662, I dis-` close a self-priming pump construction of the turbine type. This present invention provides a new and novel construction of a self-priming pump employing the turbine type but also applicable to a volute of two or more ports with-a consequent simplication of parts, i. e. without ports, and a resulting improvement in pump performance.

'I'he following objects'are accomplished by my invention. The ii'rst is that the device herein disclose, by avoiding the use of the single volute, makes possible lower cost of construction of a centrifugal self-priming pump. It is recognized in the art that one of the principal elements of cost in a centrifugal pump is the volute casing enclosing the impeller. A second is that the construction herein disclosed permits the use of smaller pump cases than is possible with the conventional volute type of self-primingcentrifugal pumps. A third is that the pump parts and cases -are symmetrical. A fourth is that greater ability to exhaust air is obtained byl having a short fluid travel from impeller to reserve tank. A fifth is that the pump impeller is ymore effectively sealed, thus making it possible to develop a more perfect vacuum within the pump suction. A sixth is that the simplicity and symmetry of design makes possible the construction of multi-v stageslf-p'riming pumps which have heretofore been impractical.

Turbine type pumps, having two or preferably more diffusion vanes and. passages for directing the liquid away from the impeller, are well known to the art; thattype vbeing preferred for pumps `having more than one stage. My invention em- Reading on Figures land 2 of my drawingf they consist of main housing 23, and cover plate 2|, having a suction connection 20 and a suction chamber I9. w Impeller III having vanes II, is supported and driven by shaft I2, having bearing member I3, contained in rear extension 29,'having stuilng box I4, bearing extension I5 and ball bearings.V I6, and is enclosed by fixed diffusion disc I1 which is provided with suction passage I8 connecting with said suction chamber I9 and said suction connection 20 in cover plate 2|. Combination check valve and gasket 22 is used to seal the suction passage where cover .plate 2| and diffusion disc I1 meet and covers valve opening 22a.

Diusion disc I1 and impeller I Il are completelyY enclosed by main housing 23 and cover plate 2|, so Ithat. liquid placed within main housing 23 will submerge diffusion disc I1 and impeller Ill. A flange 30 forms part of rear housing extension 29 and serves to position theA stationary vanes 26 of diffusion discv I1. A suitable discharge con-k nection 24, is provided having a removable plug 25, which may be removed to permit filling the mainl housing 23 with liquid. Diffusion disc I1 is further provided with vanes 26, and passages 21, evenly spaced about the rotating impeller. The vanes 26 and passages 21 between the vanes can be made to conform to the design'known in the art as diffusion vanes; their purpose being to direct'the liquid away from the impeller III, and cause a transition from velocity head to pressure head within passages 21.` It will be noted that passages 21 communicate directly with the impeller periphery at their inner and smaller end and open into the interior of main housing 23 at their outer and larger ends. Thus when'main housing 23 is filled with liquid, this liquid also enters and iills passages 21 of diffusion disc I1. When impeller I .f is not rotating the liquid within main housing 23 will ilow through the diil'usion vanepassages 21 and fill all uuid openings in impeller I0. and the suction passage I8. Check valve 22 prevents the liquid from being siphoned into the suction pipe when the pump is shut down. thus retaining priming liquid within the pump during shut down periods.

In operation, reading on Figures 1 and 2 the main housing 23, and all the interior passages within said housing are lled with the liquid through .opening at removable plug 25. When impeller l is made to revolve in the designated assente signs, methods, and materials may be employed for obtaining the same results within the scope' of any claim without departing from the scope or vspirit of my invention.

I claim:

1,y A priming means as herein described, comprising in combination an enclosing case for direction as shown by arrow i0a,` centrifugal force exhausts the liquid from impeller passages lla forming simultaneously a diiierence'in pressure between the empty impellerV passages Ila and the liquid'lled diiusion passages 21. Be- -cause of this difference in pressure the liquid in passages 21 flows against the periphery of inipeller I0 and due to impact with the rotating impeller, is broken into a mechanical mixture of air and liquid having greater volume than the liquid alone. This mechanical mixture, partly because oiits increased volume and partly due to the centriiugal force from impeller I0, is caused to flow out of passages 2l into the interior of main hous ing 23, where the air and liquid separate due to a reduced velocity of ilow. Thus by this process air is removed from vane passages ila, suction inlet i8 and suction chamber le and any suction hose or piping that may be connected to the pump suction 2li, and is subsequently discharged` from the residualA liquid in main housing 23 through the top discharge connection it. This process continues until suiiicient vacuum is developed to lift the liquid to the pump thus conipleting the priming operation. When all air is f exhausted and the pump primed, the entire pump interior, including passages 2l, impeller passages lia and suction passage I8, will be entirely iilled with liquid, forming a continuous unimleded now of liquid through the pump interior. It will be noted that under this invention all of the ad vantages and high pump efdciency of the turbine pump are retained. The water passages are all direct, as short as possible, and unobstructed by automatic devices. I have built a pump of this construction having a transparent cover so that the functions herein described can be watched when the pump is in operation. In

practive I ind that a vilent turbulence isv created at the inner tip-of each and all diusion vanes, this mixture of water and air owing outward along the outer side of each and all diiusion vanes and forming eddies immediately outside these passages, the air being liberated in these eddies and rising to the top of the tank. I also found that there was a ow of substantially airfree water owing backward toward the impeller periphery along the inside of each vane thereby bringing air-free water to the impeller periphery for turbulence. When priming is completed the entire pump interior. becomes solid with water which iiows alilrefrom all diiusion passages.

The construction here shown leads itself to the I addition of as many stages as required within the limits of good design: thus while I have shown a single stage pump the same construe tion applies to a multiple stage pump of a eqn-A struction disclosed in my Patent #2,281,175, Se rial Number 359,662.

While I have illustrated my invention in dit ferent ways and using dierent materials and means, still I do not intend' to limit myself to those particular means, designs, methods or ma= terials, as it is apparent that other means, de=

holding a substantial quantity of reserve liquid, a rotatable centrifugal impeller surrounded by a Vseries of guide vanesv defining diusion passages beginning at the periphery of said impeller and ending outwardly therefrom, a wall adjacent said impeller extending substantially beyond the im= peller periphery to denne a portion of said dit fusion'passages said guide vanes then submerged in said reserve liquid held by said case, a suction inlet connection joined to said wall communicating to the region of the center of said impeller and a discharge outlet from said case, communication between said reserve liquid and said iinpeller being only through said diusion passages.

2. A priming means as herein described, com prising in combination an enclosing case for holding a substantial quantity of reserve liquid, a rotatable centrifugal impeller surrounded by a series of guide vanes defining diffusion passages beginning at the periphery of said impeller and ending outwardly therefrom, a disc facing said impeller on one side, extending substantially beyond the impeller periphery andexposed to said reserve liquid on the .other side, said guide vanes being submerged in said reserve liquid held by said case, a suction inlet connection Ajoined to said disc communicating to the region of the center of said impeller and a discharge outlet from said case, communication between said reserve liquid and said impeller being only through said diffusion passages.

3. A priming means as herein described, comprising in combination an enclosing .case for holding a substantial quantity of reserve liquid, a rotatable centrifugal impeller surrounded by several divergent liquid passages beginning at the periphery of said impeller and terminating outwardly therefrom and forwardly in the direction of said impellerrotation, a disc facing said imller on one side iinperforate to the passage oi liquid therethrough extending substantially to the termination of the said divergent liquid pas sages, said impeller and said disc submerged in said reserve liquid held by said case, a suction inlet connection in communication with the central region of said disc and a discharge outlet from said case.

d. A self-priming pump embodying diffusion passages, as herein described, comprising a case holding reserve liquid and having a suction inlet and a discharge outlet, within said case and an

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