US2451030A - Centrifugal pump - Google Patents

Description

Oct. l2. 1948. I F. c. JONES 2,451,030

CENTRIFUGAL PUMP Filed Nov, 29. 194e 2 sheets-sheet 1 FIG. I. y

INVENTOR.

FRED. C.JONES.

F. C. JONES CENTRIFUGAL PUMF 2 Sheets-Sheet 2 Filed Nov. 29. 1946 FIGS.

INVENTOR. FRED.C..JONES.

BY /Gf i? Patented Oct. 1,2, 1948 CENTRIFUGAL PUMP n l Fred C. Jones, Teaneck, N. J., assigner to Ralph B. Carter Company, Hackensack, N. J., a corporation of New York Application November 29, 1946, Serial No. 712,894 1 claim. (ci. 10a-11s) This invention relates to pumps and more particularlyto self-priming pumps and to a new method of priming.

It has for lts principal objects the accomplishing of afasterprime; a more positive control of the bypassed priming liquid; completely auto. matic control of bypassed liquid to provide and maintain maximum overall pump capacity and veiiiciency; a. self-cleaning, non-clogging type of liquid bypass control valve of great advantage jwhen vpumping liquids containing foreign matter; and a. more compact arrangement of the casing.

The invention consists of a casing having a centrally disposed tubular wall forming a suction passage communicating with the eye of an impeller. and supplied by the source of liquid supply, surrounded by a discharge chamber formed by the casing walls to receive the liquid from the impeller, communicating with the discharge pipe, the tubular wallhaving a passage with an orifice at one end communicating with the suction passage, and an orifice at the other end communicating directly with the discharge chamber, with a spherical member disposed at a distance from the llast named orifice, said distance and the weight of the spherical member being such that the spherical member is moved towards and against said last named orice upon a. predetermined quantity and velocity of flow of the liquid from the last namedoriflce to the other orifice, and isheld in sealing position against said orifice during the pumping action of the pump when the liquid is free from air or gas, the said sealing position being'interrupted during the priming action of the pump, when the discharge ch'amber liquid entrains gas or air, the respective pressures in the suction passage and in the dicharge chamber cooperating to hold the spherical member in sealing position or not.

The invention includes also a cylindrical velocity conduit extending below the suction passage wall and into the discharge chamber-,tc induce a conoidal liquid flow within the sphere of action of which the spherical member is drawn, when the discharge chamberv liquid is substantially free of entrained gas `or air, that is when the pressure of the discharge chamber liquid is such as to bring the'conoidal flow within th'e contour of the sphere, the sphere is drawn along by lthe flow.

The invention will be more fully described hereinai'ter, embodiments thereof shown inthe drawings, and the invention' will be finally pointed out in the claim.

Inthe accompanying drawings,

Fig. 1 is a side elevation view of a pump, constructed in accordance with' my invention, to the lshaft of which a prime mover such as an electric motor (not shown) may be connected; y

Fig. 2 is an end sectional view of the same, taken online 2-2 of Fig, 1;

Fig. 3 is a vertical section taken on line 3-3 of Fig. 1; Figs. 2 and 3 vare of reduced size.

Fig. 4 is a sectional view of the bypass valve portion of said pump with the valve in a closed position;

Fig. 5 is a sectional view looking down on the bypass ball valve andvalve guides only, taken on line 5-5 of Fig. 1; and

Fig. 6 is a diagrammatic view showing the operation of the valve.

Similar characters of reference indicate corresponding parts throughout the various views.

Referring to said drawings, th'e casing I0 has a priming chamber II of which volute I4, suction inlet I3, and discharge chamber I2, may or may not be integral parts. As shown in the drawings, the above parts are vcast integral.

An impeller I5 is rotated'by a shaft I8 within the volute case section I4. A section of suction pipe or hose I9 leading from the source of supply for conducting liquid to the pump, is connected with a suction connection 20 suitably bolted to the casing I0. This connection 20 h'as :a seat for a check valve assembly 2|, 22, and 23, as known, which assembly extends into the suction inlet I3.

A section of discharge pipe or hose 24 for conductingliquid and gas or air away from pump is at the upper part of the casing I0, A seal arrangement Il prevents the entrance or escape of air or gas or liquid to the interior of the casing I0, from the shaft side.

Suction inlet I3 is arranged within the casing I0 for conducting gas and liquid from th'e pipe I9 to the eye of the impeller I5.

Discharge chamber I 2/is arranged for storage of kpriming liquid and forconducting gas and liquid from discharge opening of volute I4 to and out of discharge pipe 24.. The discharge chamber I2 extends around the walls l3a and I3b forming the horizontal portion of the suction passage I3, and extends to the lower part of the casing Ill. Y

Suction passage I3 and discharge passage I2 are interconnected by bypass port passage 29. This passage 29 may be of th'e straight tubular type opening as shown or of any other design, such as nozzle jet, venturi, etc. which might aid in 3 entrapping more gas with liquid at point of en trance te impeller.

Resting at some point below the bypass passage Il is a ball valve 32 within the influence of liquid passing from the lower part of the chamber I2 thru the bypass passage 23 into the suction passage I3.' The ball 32 is guided by a guide or series of guides 33 to assure its remaining in the sphere of influence of the bypassing liquid.

It has been found that on certain types and sixes of pumps, a bypass passage arranged as a. nozzle with whole bypass and ball valve assembly arranged at an angle, gives greater gas handlingability. In the embodiment shown the bypass passage is formed by a tubular projection 29a depending from the wall I3b, the upper oriiice 30 being in the wall |3b and the lower orice 3i being at the lower end of the projection. Both oriiices are circular. The axes of the bypass passage 2l passes through the center oi' the ball or approximately thereto.

. .The important improvement is the arrangement lof the orice 30 of the bypass passage 29 in line with the wall l3b of the suction passage I3 and the arrangement of the other oriilce below the wall l3b, with the center of the ball substantially co-axially disposed wi-th the axis of the passage between these two orifices, and with the .weight of the ball subject to stream flows of liquid entering orice 3l and discharging at oriilce 30,

. the velocity forces of such stream flows causing the gravity and weight of the ball to be overcome, so that the ball is raised against orifice 3i in order to close the same. The ball is/con- `structed of sufiicient weight and allowed to rest at a distance away from bypass passage orice ,3i so that these two factors (weight and distance) combine to hold it in position shown in Fig. 1 on all priming conditions, up to and including the .maximum .priming pressure diil'erential, but the [weight and distance is not great enough to hold ball 32 in this position when pumping (even under minimum pumping pressure dineren-tial which is always greater than maximum priming pressure differential). When priming ends and pumping begins, the ball 23 follows the line of ilow and is carried upward closing bypass passage 29 and taking the position shown in Figure 4. It will remain in this position under all pumping conditions.vcompletely closing the bypass, orifice 3|. thus preventing all recirculation, and maintaining maximum pump eiliciency and capacity. As soon, however, as the pump "loses its prime" and Apriming conditions again prevail, ball 32 imme- 'diately drops away from bypass passage 3|, thus opening it to liquid flow and allowing recirculation to accomplish a repriming of the pump. As an example of the weight and distance, for a pump ot 77 G. P. M. capacity, the weight is 21/2 ounces and the distance from the center of the ball to the center of the oriilce 3| is one inch.

Plugs or covers 2i, 2l, and 3l are screwed in or attached to the casing Il to facilitate inspection,

-assembly anddrainage.

The operation is as follows:

, Let us nrst take pump as shown in Fig. l. The entire casing i is illled wi-th liquid which automatically nlls all parts thereof, including volute Il and passages I2. I3 and 22. The suction pipe I2 is extended downward to and submerged in liquid to be pumped. The discharge pipe 24 is lead away to a. point of liquid discharge. Shaft Il is then rotated by motive power attached thereto,

the gas in the suction line is entrained. This mix-ture of gas and air is thrown by the impeller out into the discharge line where the gas or air separates and passes oil' thru the discharge line, and the gas or air free liquid again is bypassed to the suction passage. This recirculation process is continued until all gas is-exhausted from the pipe I 9 and suction passage I3 and therefore liquid from -the supply source drawn to and into the .pump impeller. Pump is then said to be primed and continues to pull liquid from source of supply pipe I9 and throws it out into discharge pipe 24 without recirculation (until suction line becomes "uncovered," or until gas or air is allowed to enter suction line), when recirculation again takes place until the gas or air is removed, and the pump is again primed.

The above described is the known action of a centrifugal pump, and the reference to bypassed, is made generally as bypass recirculation is also known. i

However, without control of the bypvss passage a. continuous recirculation of a portion of the liquid takes place materially lowering the pump ca-4 pacity and eiliciency. Various pumps at present on the market control and attempt to close this,-

bypass passage when pump is pumping and open, it when pump is priming by various types of au.

tomatic and manual control.

The present invention provides a positive trouble-free control oi' this passage. to wit: as

long as the pump is priming, the ball valve 22 rests of its own weight at the bottom o! the.per

mitted valve travel and liquid freely passes thru Under all conditions of pumpl bypass passage 29. and priming, a pressure diil'erential exists between the discharge chamber I2 and the suction passage I3 when the pump is running, and pressure is always greater in the discharge chamber i2 than in the suction passage I3. This causes varying' quantities and at varying velocities of liquid to pass upward thru the bypass passage 23. The greater the pressure dierential, the greater the quantity of liquid bypassed. For practi-V cal purposes, the maximum pressure dinerential, vwhen priming, can be said to be when the partial vacuum in the suction line approaches the maximum of which the pump design is ca-v pable of pulling. We shall call this for purposes of description maximum priming pressure diiferential. Also the maximum pressure dinerential when priming is approached, is when the sucdiierential is always greater than the maximum priming pressure diierential. This fact permits the new and positive method ot bypass control.

' It means in fact that the quantity and velocity of liquid bypassed upward thru the bypass passage 29 is under all conditions greater when pumping liquid than when priming, and in con- `rotating impeller Il. The action at this point is 'the same as any centrifugal pump, and some oi' sequence the ball is raised to close the oriilce 3|. when the pumping action begins after the priming action ends.

With an understanding oi' a sphere characteristic action in a'ow of liquid, of interest here only to the extent that the sphere attempts to get into 5 I and stay in the line of iiow, the action of the ball valve control becomes quite evident.

I have described several forms of my invention, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claim.

I claim: l

In a centrifugal pump having a casing with a central cylindrical chamber formed of walls in the casing, forming a` suction passage, a supply pipe at one end thereof, an impeller at the other end thereof having itseye aligned with said suction passage, and a discharge chamber in said casing communicating` with said impelier, and surrounding said central cylindrical chamber, and having a discharge opening, one of said walls of the central chamber having an opening Atherethrough, providing an orifice spaced between the ends of the central chamber and spaced from the impelier, subject to the suction action of the ow l in the central chamber, a cylindrical extension having one end in registration with said orice, and having its other end in communication with the uid in the discharge chamber, forming a ve-l "loclty conduit bypass passage, a spherical member of larger diameter than the open end of the extension, a cage for the spherical member for holding it spaced-from said open end, within the velocity ilow of the bypass passage during priming and moved to close the open end, when the 5 pressure in the central chamber is suiciently less than the pressure in the discharge chamber to draw the spherical member to said open end, until priming again becomes necessary, the closed position of the spherical member on the extension 10 preventing recirculation and the open position permitting recirculation of the ldischarging fluid.

. FRED C. JONES.

REFERENCES CITED l5 The following references are o'f record in the file of this patent: UNITED STATES PATENTS

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