US2938471A - Shallow well jet pump - Google Patents

Description

y 1950 c. JACUZZI ETAL I 2,938,471

SHALLOW wsu. JET PUMP Filed Aug. 26, 1957 2 Sheets-Sheet 1 Q 9 K a Q N Q o N m l a N N N e, s X s I S 3 IH .111 W J53 g (I) m nvve/vro s 8 CAND/DO JACUZZ/ FLOYD M NASH 2 JOSEPH G. P/PE T77 A T TO/PNEVS May 31, 1960 c. JACUZZI ETAL 2,938,471

SHALLOW WELL JETPUMP Filed Aug. 26, 195'? 2 Sheets-Sheet 2 //vv/v TO/PS CAND/DO JACUZZ/ F L OVD M. NASH JOSEPH G. PRETT/ Way/Z! A T TO/PNE V5 United States Patent SHALLOW WELL JET PUMP Candido Jacuzzi, Lafayette, and Floyd M. Nash and Joseph G. Pretti, Berkeley, Calif., assignors to Jacuzzi gros Inc., Richmond, Calif., a corporation of Cali- Filed Aug. 26, 1957, Ser. No. 680,217

3 Claims. (Cl. 103-262) This invention relates to pumps, and more particularly to shallow well pumps provided with a Venturi tube nozzle suction arrangement serving as an injector, to boost output and pressure of said pump.

It is well known in the art that for proper functioning, the Venturi tube inlet nozzle must be carefully positioned in relation to the Venturi tube to provide a critically dimensioned annular space between the end of said nozzle and said tube and to cause satisfactory flow of liquid through said tube for maximum efficiency. It is also known that said annular space tends to become clogged with dirt and that cleaning entails dismantling of the pump and a subsequent repositioning of said nozzle with respect to said tube.

An object of this invention is to provide means by which the correct nozzle tube positional relationship can immediately be realized without time-consuming and meticulous adjustment.

Another object of the invention is to provide a shape for the nozzle-to-tube suction surface which will preclude the clogging of said surface.

A further object of this invention is to permit limited axial movement of said nozzle with respect to'said tube without modifying said suction surface and appreciably reducing the efiiciency of the system.

Further objects and advantages will be brought out in the following part of the specification.

Reference should be had to the accompanying drawings for a better understanding of the invention.

Figure 1 is a vertical sectional view of a centrifugaljet pump, showing the same in full scale.

Figure 2 is a perspective view of the impeller of said pump with part of one circular plate broken away.

Figure 3 is a perspective view of the diffuser in permanent connection with the Venturi tube.

Figure 4 is a plan view of the diffuser and the Venturi tube, when seen from the inlet side of the pump.

Referring to the drawings in detail, pump housing is provided with inlet port 12 and outlet port 14, said ports being internally threaded to accommodate inlet and outlet conduits, not shown. Nozzle 16 is fitted within inlet port 12 and is provided with an O-ring 18 to insure a seal and a tight fit. Tube 22 is provided with a cylindrical counterbore, and constricted cylindrical extremity of said nozzle normally abuts the shoulder seat 23 forming the end of said counterbore. When in place, the inner diameter of said extremity is equal to the inner diameter of the adjoining Venturi tube action.

Four channels 24, 26, 28 and 30, spaced 90 apart and rectangular in cross-section, are formed in the wall of said Venturi tube inwardly directed from the inlet end of said tube. These channels are disposed at an angle with respect to the longitudinal axis of the Venturi tube, with said angle being such that imaginary line projections of the channels would mutually intersect the tube axis at approximately two-thirds of the length of the tube from the inlet end thereof. Said angle is approximately 7. We have found that such channels t n 2,938,471 Patented May 31, 1960 formed at approximately such an angle materially increases the efliciency of operation of the pump, as compared to previously known pumps of this type in which there is provided an annular suction space between the nozzle and tube. r

Said Venturi tube is secured in fixed relation to the diffuser 32. Impeller 34 is in threaded engagement with extension 36 of shaft 38. The liquid is prevented from reaching the body of shaft 38 by a shaft seal assembly which is disposed in fixed relation to housing cap 40 and which comprises seat 42, spring 44, flexible seal ring 46 and annular retainer cup 48. O-ring 50 maintains housing cap 40 in sealed relation with housing 10, said housing and said cap being in threaded engagement with each other. Cap 40 is integral with housing 52 enclosing bearings 54 and 56. Sheave 58 is held in tight relationship with shaft 38 by means of set screw 60.

The subject pump is well suited for use by devotees of the do-it-yourself cult. The housing 10 is provided with wing brackets 62 so that it may be clamped to any appropriate supporting surface. A drive belt is reeved around sheave 58 and a sheave carried by the shaft of any suitable electric motor, e.g. /e- /2 horsepower. After the housing 10 is first filled with water so that the pump may prime itself, the motor is started, whereupon impeller 34 directs water into and through the diifuser which serves to convert the velocity to pressure.. A part of the pressurized water leaves the housing through outlet 14, while the balance is re-cycled through the channels 24, 26, 28, 30 to induce the in-flow of water from nozzle 16.

Due to the novel channel-defined suction space between the nozzle and Venturi tube, this pump offers improved performance characteristics over comparable pumps. With a hp. motor driving the impeller shaft at 4000 r.p.m., the pump will deliver 475 gallons/hr. at 10 feet of head, 350 gallons/hr. at a 20 foot head, and 120 gallous/hr. at a 30 foot head. With a /2 hp. motor driving the pump at 7000 r.p.m., 500 gallons/hr. are pumped at an foot head, 400 gallons/hr. at a foot head, 250 gallons/hr. at a foot head, and 100 gallons/hr. at a foot head.

Cylindrical nozzle extension 20 can be readily inserted in seat 23 of tube 22 without the necessity of any careful adjustment, and that the end of said extension could be moved along its axis relative to Venturi tube 22 as much as of an inch without the suction area or pump efliciency being materially changed. With conventional pumps having an annular space between the nozzle tip and Venturi tube, a variation of a few thousandths of an inch of the nozzle tip position causes a drastic reduction in the efiiciency of operation of the pump. Furthermore, suction inlet ports 24, 26, 28 and 30, by virtue of their relatively considerable width, do not get clogged and are self cleaning.

What is claimed is:

1. Apparatus of the type described comprising an openended flow tube having inlet and outlet ends, a cylindrical counterbore relatively short in length formed axially in the inlet end of said tube, a nozzle having an open cylindrically shaped tip, said tip extending into said counterbore and having a sliding fit therein, and a plurality of slots formed in the side wall of said tube disposed radially outwardly from said counterbore for a distance less than the thickness of the wall of said tube, said slots extending inwardly of said tube from the end surface of the inlet end thereof past the inner end of said counterbore.

2. The apparatus of claim 1, said slots having outer walls which are mutually disposed at a small angle with respect to the longitudinal axis of said tube and which are convergent in the direetion of the outlet end of said tube.

3. The apparatus of claim 2, said tube being a Venturi tube, said small angle being approximately 7, and the length and depth of said slots being related to the length 5 9 Said b s a m n y pmie iq 9 th uter walls of said slots mutually intersect the longitudinal axis of said tube approximately two-thirds of the way along said axis from the inlet end toward the outlet end of said tube.

UNITED STATES PATENTS Atkins Feb. 16, 1875 Huston Sept. 11, 1883 Marsh Jan. 19, 1886 Wrentmore May 19, 1936 Sargent Nov. 14, 1939 Blair Oct. 26, 1943 Conery Aug. 26, 1952

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