US2690129A - Self-priming pump - Google Patents

Description

Se t. 28, 1954 B. c. BOECKELER SELF-PRIMING PUMP Filed Nov. 19, 1949 3 Sheets-Sheet l FIGI FIG. 9

M R, '1 m m2 j M ATTORNEYS Sept. 28, 1954 B. c. BOECKELER SELF-PRIMING PUMP File'd Nov. 19, 1949 3 Sheets-Sheet 3 INVENTOR ATTORNEYS 755mg, 871M144, 7 /034 13mm Patented Sept. 28, 1954 2,690,129 SIELF-PRIMING PUMP Benjamin Clark Boecke signor to The Hydroj ct Corporation,

ler, Trenton, Mich., as-

Trenton,

Mich., a corporation of Delaware Application November 19, 1949, Serial No. 128,264

1 Claim. 1

This invention relates to rotary pumps and vacuum pumps and has for its principal object a combination of rotary pump and vacuum pump providing a self-priming and/or gas eliminating rotary pump unit of exceptional simplicity. More particularly, my invention provides a selfpriming rotary pump unit with but a single moving part in a very compact structure. .The term rotary pump is used herein to define the class of pumps having a rotary member, namely, centrifugal, turbine, propeller and rotary pumps. The combination of my invention fills the need for a simple, efficient and trouble-free pump unit to pump various liquids, for example, water and chemicals, notably volatile liquid fuels such as gasoline or petrol and solvents. In addition to priming the rotary pump, the vacuum pump functions to remove gas from the liquid such as the vapors which are released in various organic liquids.

My invention comprises a rotary pump having an impeller, and a vacuum pump having a shell for confining a liquid annulus which is rotatable on the impeller shaft and a jet pump, and a duct connecting the suction side of the vacuum pump with the jet pump to remove air, gas'or vapor (hereinafter called gas) from the suction side of the pump and prime the pump. Advantageously, I mount the rotary member of the pump with its suction and discharge chambers and the shell for confining the liquid annulus in a compact integral housing. The combination also includes means to maintain a uniform quantity of liquid in the annulus, preferably by duct means connected to the rotary pump, and means for removing excess liquid from the annulus to maintain it at uniform depth.

One of the important features of my invention is the provision of a jet pump arranged to receive moving liquid from the liquid annulus to create the vacuum and suck gas from the intake side of the rotary pump in priming the pump and in eliminating at least a part of the gas from the liquid, and gas not so eliminated will be eliminated on the discharge side of the pump.

These and other objects of the invention will be better understood after considering the following discussion taken in conjunction with the accompanying drawings, in which: I

Fig. 1 is an end view of a self-priming rotary pump unit of the invention.

Fig. 2 is a plan view of the pump of Fig. 1 with parts broken away;

Fig. 3 is a side view of the unit of Fig. 1 with parts broken away;

Fig. 4 is a sectional view along line 4-4 of Fig. 1;

Fig. 5 is a sectional view along line 5-5 of Fig. 3;

Fig. 6 is an enlarged sectional view of a jet pump used in the pump unit;

Figs. 7 and 8 are diagrammatic illustrations of a pump unit embodying the invention, as more particularly illustrated mechanically in Figs. 1 to 6, and

Fig. 9 is a sectional view of another embodiment of pump unit of the invention.

The pump unit illustrated in Figs. 1 to 5 comprises a housing I consisting of an end member 2 for enclosing the liquid discharge chamber 3 of the centrifugal pump, an interior wall member 4 for enclosing the suction chamber 5 of the centrifugal pump, and another wall member 6 with an attached end plate 7 for enclosing the vacuum pump chamber 8. The drive shaft I0 is directly connected to the electric motor H and passes centrally through the cover 1 and partition I 2. The shaft carries on the inner end any suitable impeller 53 for the liquid being pumped. The impeller ring it is in engagement with the partition I5 and provides a central opening for directing the flow of liquid from the suction chamber 5 to the impeller. The volute I6 for the impeller is attached to the partition l5 and is within the discharge chamber 3. Where the shaft passes through partition I2, it is sealed against the passage of fluid by any suitable seal H such, for example, as one having a spring, bellows, seal ring and collar. The seal is mounted over the shaft between the impeller and partition l2 and is held in sealing position by the spacing ring I8. A similar seal '20 is mounted on the shaft where it passes through the cover I. Seal I! prevents the flow of fluid between suction chamber 5 and the vacuum pump chamber 8, while seal 20 prevents the flow of fluid between vacuum chamber 8 and the outside.

An annular shell 22 is mounted on and keyed to the shaft l0 and, of course, rotates with the impeller. The shell comprises a flat disc 23 with radially disposed vanes 24 and a short cylindrical portion 25 from which extends inwardly a radially disposed wall 26 which has a sufliciently large central opening to provide for the entrance of the hub 27 of the cover I. The shell is accordingly enclosed within the chamber 8.

The suction chamber 5 has an inlet port to which the pipe 28 for the supply of the liquid to be pumped is connected. The discharge chamber 3 has a discharge port to which the pipe 29 for the discharge of liquid is connected.

The jet pump 30 for priming the centrifugal pump is permanently connected in a fixed position to the hub 21 by a tubular extension 3| in which isformed the duct a which leads to the low pressure. zone of the jet pump. Duct a enters the hub and then passes upwardly through the cover I (Fig. 1) to a space or enlargement 32 (Figs. v3 and 5) in member from which the capillary 33 connects through partition l2 to the suction chamber and the jet pump is accordingly connected to evacuate chamber 5 in priming the centrifugal pump.

With reference to Figs. 2and 3, it will be seen that the capillary 33 passes from the space 32 through the partition and into a space informed in the casting, portion 4 of the housing, which has a'bore hole therethrough for :the continuance of duct (1 into chamber 5. Theoutside of the bore hole is closed with plug .34. Space 34 may be filled with wire mesh, and capillary 33 is of such a size, say, from 0.030 to 0.065 inch in diameter, as to restrict the flow of liquid while passing suiiicient gas to effect rapid priming.

I prefer to employ a-jet pump as particularly described andclaimed in my copending application serial Number 128,265, filed November 19, 1949, now Patent No. 2,632,597 issued March 24, 1953. Such a jet pump has the characteristic feature of removing up to 2.2 volumes of gas for each volume of liquid passingthrough the device and to pull exceptionally low vacuums.

When the pump is at'rest, a body of liquid is trapped in the shell 22 and when-the pump is in operation the liquid assumes the form of a rotating annulus 35 (Fig. 5). The entrance 36 of the jet pump is located in the liquid annulus and the high velocity liquid flows through the device to the discharge outlet 3'! creating the vacuum in duct a. In order to prevent an excessive amount of liquid accumulating'in the annulus, the skimmer 3B is mounted in a fixed position on the hub 21 and is set to skim ofi the excess to maintain the required depth of annulus. Skimmer 38 is capable of developing such a pressure as to conveythe liquid into the discharge gas separating chamber (Figs. 7 and 8) which-is under pressure. The central opening of the skimmer connects to duct 1) which passes upwardly through the cover 1 (Figs. 1, 4 and 5) and outside as a pipe which enters the discharge chamber 3. .It may also connectto a waste line :or to the separating chamber as in Figs. '7 and 8. Apart of duct b may be restricted to form a capillary of from 0.030 to 0.065 inch in diameter to control the flow of liquid. These capillary sizes are suitable for pumps having capacities in the order of 20 gallons per minute. Larger size pumps require larger capillaries. Duct c extendsfromthe discharge chamher 3 of the centrifugal pump through the upper portion of the housing into the cover I, thence downwardly to the capillary 39 in the hub 21 and into the space within the shell. The primary purpose of duct cis to take off any gas collecting in chamber 3 and also'to vent any air carried back through duct 1). As an incidental feature, it carries liquid from the discharge chamberto the liquid annulus. Inorder to dischargegases from the chamber 8, the vent d (Fig. 1) is formed inthe upper portion of the cover I. Some liquid unavoidably accumulates in thechamber 8 and this liquid is removed through duct e and re- -53.feet per second is obtained which turned to the liquid annulus where it is desired to save the liquid.

The self-priming centrifugal pump of the invention is illustrated diagrammatically in Figs. '7 and 8 and the operation of the pump will be more readily understood with reference to those diagrams. With the electric motor operated at such a speed as to drive the shell 22 at a peripheral velocity of around 54 feet per second, the effective head of the liquid would be around 44 feet. Some slippage of the liquid must be taken into consideration. With the motor turning at 1750 R. P. M. and with the shell having an inside diameter of 7 inches, an annulus velocity of about is capable of giving a'shut off vacuum of about 26 inches of mercury, or an absolute pressure of some 4 inches.

After the liquid annulus has been established and a stream of the liquid is forced through the jet pump, gas is sucked through duct a from the suction side of the centrifugal pump, chamber 5, and is dicharged :through the jet pump along with the liquid into shell 22. The gas may be allowed to escape to the atmosphere through the vent duct d, as shown in Fig. l, or through the space around the shaft, as shown in Fig. 7, or in the case of gases which must be confined, sent to an adsorbing device not shown. After evacuation of the suction side of the centrifugal pump has been achieved, the pump operates in the normal manner by sucking the liquid through pipe 25 and discharging it to the discharge gas and separating chamber from which it is directed to the place of use. Some liquid as well as vapor accompanies the gas discharged through the duct (1 and it is accordingly necessary to provide makeup liquid to maintain the operating liquid annulus. Duct 0 extends from the discharge gas separating chamber, whichis equivalent to chamber 3 of the centrifugal pump, to the shell. The capillary 39 in duct 0 is of such a size, say, from 0.035 to 0.065 inehin diameter, that it will provide but aslight excess of liquid over that required. In order to maintain the proper'thickness of liquid annulus, the skimmer 38 removes the excess and directs itthrough duct b to the discharge gas separating chamber.

Some liquid unavoidably enters the chamber 8 and if allowed to accumulate would interfere with the operation of the shell. The vanes on the shell, Fig. 4, imparts such a velocity to the liquid which collects in the chamber that it is forced to flow through duct 6 and be returned to the liquid annulus in the shell.

Figs. '7 and 8 illustrate an arrangement of apparatus comprising the self-priming centrifugal pump unit of the invention for advantageous use in connection with the pumping of gasoline or petrol from an underground storage tank to a pipe or hose 45 which leads to a dispensing means. The vacuum pump removes gas or vapors from the suction side of the centrifugal pump for priming purposes and also removes vapors or other gases which may accompany the liquid and are therefore separated so that a gas-free liquid may be discharged from the dispensing means.

Fig. 9 illustrates a rotary pump and vacuum pump combination mounted in the casing 50. The vacuum pump comprises the chamber 5|, rotatable shell 52 which is mounted on the shaft 53, and jet pump 54. The jet pump connects through duct 55 to "the suction chamber 55 of the rotary gear pump. The skimmer 5'! regulates the thickness of liquid annulus and discharges the excess liquid out of the pump through duct 58. Gear 59 is keyed to shaft and drives gear 60. Both gears operate in pressure chamber 61 in the usual manner.

The vacuum pump operates ina manner similar to the vacuum pump of Fig. 1. The vacuum created by the jet pump 54 evacuates chamber 56 and liquid is sucked through the inlet 62 to prime the pump. The rotary pump then functions in the usual way and discharges the liquid under pressure through outlet 63. Duct 58 may be connected to outlet line 63.

I claim:

A self-priming pump unit comprising a rotatable liquid pump having a discharge chamber, a vacuum pump including a jet pump, a rotatable shell for receiving liquid, the vacuum pump having an inlet positioned to receive liquid from a rotating annulus of liquid caused by rotation of said shell, means for conducting liquid entering said inlet to the jet pump, a gas inlet for the jet pump communicating at one side with the suction side of the liquid pump and at its other side with the jet pump at a position to have gas from the suction side of the liquid pump drawn therethrough when liquid is passing through the jet pump, thereby to evacuate the suction side of the liquid pump to cause liquid to flow to the suction side of the liquid pump for priming the liquid pump, a duct connecting the discharge chamber of the liquid pump with the space within said shell, means in said duct to control the flow of liquid to provide make-up liquid for the annulus formed within the shell, and means for rotating said shell.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,591,388 Jennings July 6, 1926 2,134,686 De Lancey Nov. 1, 1938 2,153,360 Auger Apr. 4, 1939 2,166,530 Morgan July 18, 1939 2,260,600 Boeckeler Oct; 28, 1941 2,368,528 Edwards Jan. 30, 1945 2,461,865 Adams Feb. 15, 1949 FOREIGN PATENTS Number Country Date 597,751 Great Britain Feb. 3, 1948

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