US2457388A

US2457388A - Injector-impeller pump

Info

Publication number: US2457388A
Application number: US601872A
Authority: US
Inventors: Kenneth R Lung
Original assignee: Flint & Walling Manufacturing Co Inc
Current assignee: Flint & Walling Manufacturing Co Inc
Priority date: 1945-06-27
Filing date: 1945-06-27
Publication date: 1948-12-28
Anticipated expiration: 1965-12-28

Description

Dem 1948- K. R. LUNG INJECTOR'IMPELLER PUMP Filed June 27, 1945 Patented Dec. 28, 1948 UNITED STATES PATENT OFFICE INJECTOR-IMPELLEB PUMP Kenneth R. Lung, Kendallville, Ind., assignmto Flint & Walling Manufacturing Co. Inc., Kendallville, Ind., a corporation of Indiana Application June 27, 1945, Serial No.- 601,872

6 Claims.

This invention relates to features of widening the range of use of impeller type of rotary pumps, more particularly in association with a variable injector or jet type of pump.

This invention has utility when incorporated with a rotary pump, wherein there is an injector primary stage provided with a jet-control effected by the difierential between the delivery pressure of the second stage rotary pump and the supply pressure or suction to the primary pump stage.

Referring to the drawings:

Fig. l is a side elevation of an embodiment of the invention as an automatic pumping unit for maintaining in a particular range water pressure tank, the pump being electrically operated in drawing water from awell;

Fig. 2 is an enlarged section on the line 11-11, Fig. 1, showing the details of the diaphragmoperated needle valve for the venturi of the injector' stage pump; and

Fig. 3 is a fragmentary showing of an adaptation wherein the needle valve be not axially of the impeller stage pump, but may be remote therefrom, as in the shaft to a water well.

An electric motor I has axially aligned therewith an impeller type of rotary pump 2 in a housing 3, mounted on a common base 4 with the mounting for the motor I. A riser line 5 from a water well has a discharge or port 6 into the housing 3. From the top of the housing 3, the pumped water from the well is conducted by a pipe I to a storage tank 8. From a port 9 in the housing 3 pulsations may act thru a duct III to operate a diaphragm type of'air pump it to introduce air as a cushion in the upper portion of the tank 8, thereby the better to hold the pressure upon water withdrawals. The compressibility of the air makes possible intermittent operation of the pump unit in holding the tank pressure within a desired range.

A pressure delivery chamber l2 from the impeller pump 2, has, in addition to the take-off flow pipe I, a port l3 having a duct it, extending to a manually set or adjusted pressure responsive control or electric switch l5. This automatic control may be set for cutting off the motor 5 as the pressure in the tank 8 reaches 40 lbs. per sq. in., with a cutting back of the motor to start at once the pressure in the tank falls to 20 lbs. per sq. in.

Axially of the impeller pump 2 and directed theretoward is a continuously open Venturi nozzle is having a throat i with a convex zone entrance it to the throat it. As this pump unit is intermittently operated, at each starting, there is a pull or suction in a continuously open way or passage ts from the port 9 leading to the zone It and the throat II. This means a pump stroke at the pump ll acts to put air into the tank 8.

Additionally there is communication by

passage portions

20, 2|, from the port 6 to the zone 18 and the throat I'I. Besides outflow .by the pipe I, the pressure control by the pipe or duct l4, there is from the pressure chamber l2, in the housing 3 a jet or tapered nozzle 22 having a continuously open discharge port 23 axially of the Venturi nozzle l6 and its coaxial throat l1 and entrance zone Hi.

In developing the two-stage unit of injector or jet and rotary impeller pump, importance has resided in proportioning the continuously openpressure supply jet nozzle port 23 diameter to be of six tenths to seven tenths of the diameter of the throat I1, over a range of pressure drop from no water delivery to a maximum number of gallons of water per hour, short of cavitation. It is to be noted that the relation between the diameters of the port 23 and the throat I! establishes that the area of the port 23 is in the range of 36% to 49% of the area or cross section or the throat ll, upon the fact basis that with like lineal dimensions the effective area relation is to be taken as the square thereof.

Under the invention herein, as the suction be decreased, the number of gallons per hour may be increased, and with a marked decrease in the power demand to achieve such as beyond the initial cavitation. To bring this about, the efiective area of. the nozzle port 23 is modified. This control factor is introduced automatically. A needle valve or stem 24 coaxial with the tapered nozzle 22 is shifted by a diaphragm 25 to vary the maintained clearance relation of the convex contour of the member 24 as to the opening 22.

Bolts 26 clamp housing axial terminal section 2? to the housing main portion 3 to hold the flexible diaphragm 25 therebetween. Between the diaphragm 25 and the section 21 there is thus formed a chamber 28 in communication by a passage 29 and thru an opening 30 in the clamped portion of the diaphragm 25 with a passage 3 in communication with the suction passage portion 26. A compression helical spring 32 in the chamber 28 tends yieldably to thrust the needle member 2a to protrude in an effective area reduction position as to the port 23. In the housing $3 on the other side of the diaphragm 25 from the chamber 28, is a chamber 33 in the housing 3!. A partition guide 3% provides a slideway for a stem 35 from the head or member 2%,

A head or enlargement 36 on the guide nut 34 provides a stop in the chamber 33 for the diaphragm 25, thereby precluding any shifting of the element or member 24 to fully close the port 23.. The rod or stem 35 for the member 24. as protruding thru the diaphragm 25 and passing axially of the spring 32, may .be centered and is freeto slide in and out of a tubular boss 31 axially from the housing section 21. A port 38 provides'communication from the pressure chamber l2 to the chamber 33. As the pump unit opcrates, there is a decrease in the pressure in the chamber 28, and an increase in the pressure in the chamber 33. The setting of the yieldable means 32 is a control factor to determine the range of pressure differential required to develop automatically the advantages of modification for the port 23 as to the throat ll.

Instead of locating the pump 2 in the housing 3, a housing 35 thru a duct39 may extend to a remote place, as into the shaft of a water well and there be connected thru the nozzle l6 and a housing 40 with the riser line or intake 5. A pressure chamber 4| .in the housing 39 (Fig. 3)

has duct 42 to the housing 40 with a chamber .3

to the jet nozzle 22. Additionally in the housing 40 is a suction chamber 44 to the zone l8.

From the lower portion of the chamber 44 there is a port 45 to a chamber 46 in which is a bellows type diaphragm or partition 41. compression spring 48 thrusts a shoulder 49 against a stop 50 in thereby limiting the shift of a rod or stem 5! mounting the element or needle valve 24 short of fully closing position as to the port 23. From the chamber 43 there is a passage 52 along the stem 5| thru the guide-nut-providing stop 50 to a chamber 53 within the sylphon" or bellows 41. As the differential pressure between the chambers 43, 53, and the chambers 44, 46, becomes greater, the spring 48 is compressed. This causes the member 24 to be retracted in thereby automatically increasing the net effective area of the port 23. Resultantly, this means an increase in the number of gallons to be pumped per hour.

More specifically, an example may be taken of a centrifugal stage pump with an injector booster stage therefor. Such a pump at lift for starting may require 625 watts at initial or top pressure of 62# per sq. in. Therefrom it may have a pressure drop to 28# per sq. in. at 580 gallons of water delivery per hour for this latter performance, a power of 655 watts is to the limit where. cavitation begins. This unit at lift, at starting takes 635 watts to develop 58s pressure maximum with no delivery. At 420 gallons per hour it shows a pressure drop to 33# per sq. in. and a power requirement of 645 watts cavitation follows at further delivery volume attempt. In this comparison, a third performance figure is for lift, at which 640 watts will develop 57 4 pressure at no delivery. A maximum delivery is of 305 gallons per hour at 32 1? and 650 watts load. Under the automatic control from the total effective head, there is retraction of the needle 24. This leaves a greater effective nozzle area at the port 23, for greater quantity of discharge liquid from the impeller pump to be recirculated thereto thru the Venturi section. This greater flow increases the suction action in the throat I8. The result is a higher pressure discharge and an increase in performance efficiency of the booster. From this basis, it is to be noted that with the nozzle modification for reduced efiective area there A helical 4 is less volume of liquid to pass and improved pump efllciency at low pressure. Conversely a nozzle effective area increase gives greater liquid volume recirculated. This makes possible the improved, pump efliciency at higher pressure.

The pattern for the advantages arising in this automatic pressure responsive control in extending the useful range for pump operation is shown by figures on performance. With the spring 32 or 48 to provide an initial location for the control of the reciprocable member 35 or SI for the needle valve 24, the cavitation at 15' is moved over from 580 gallons per hour delivery, to 830 gallons per hour, however, with the delivery pressure now dropped to 17# per sq. in. In this connection the automatic control is not a holdoff until cavitation at 580 gallons per hour, but has gradually slightly raised the pressure to show per sq. in. at 580 gallons per hour. or more importance still is the fact that instead of requiring 655 watts, the load is 5'70 watts; and at 830 gallons per hour, 17# per sq. in., the load is down to 535 watts.

The figures for 20' suction, and the automatic control to decrease the effective area of the nozzie 23 at the needle 24, does not have cavitation at 420 gallons per hour with 610 watts (instead of 645 watts), at 33# per sq. in., and carries on thru to 20# per sq. in., 670 gallons per hour at 510 watts power consumption.

Still more pronounced efficiency advantage follows in the instance of 25 lift, which at 305 gallons per hour, at 36# pressure per sq. in., requires 620 watts; while 470 gallons per hour, at 16# per sq. in. delivery pressure, to cavitation, take 460 watts.

From the foregoing performance data, it is to be noted that as the injector pump approaches what had been cavitation, the pressure responsive interduct control between supply and discharge functions automatically, slightly to build up the discharge pressure and with a quite material decrease in power consumption. The eiliciency on the 15 lift is improved 31%; the 20 lift and the 25 lift 48%, on the bases above set forth.

Details of the impeller as to the venturi are shown in Patent 2,274,987 Lung, Mar. 3, 1942, Self-injector rotary pump.

What is claimed and it is desired to secure by Letters Patent is:

1. A rotary pump having an intake port, a tube discharging into said intake port, said tube having an expanded end remote from said pump converging to a restricted throat, a supply passage for the pump connected to the expanded end of the tube, a nozzle having a port coaxial with the tube and directed across said supply passage into said expanded'end of the tube, a needle valve centrally positioned in and' never completely closing said port, a suction chamber, a duct between the chamber and the supply passage, an additional chamber, said pump having a discharge passage provided with a duct to the additional chamber and to the needle valve side of the nozzle for flow discharge about the needle valve toward the throat, and pressure responsive control, means coacting between the chambers, said means having connection therefrom to the needle valve to vary the effective cross-sectional area for flow between the needle and port.

2. A rotary pump having an intake port and a discharge passage, a Venturi tube discharging into said intake port, said tube having an entrance, 9. supply passage for the pump directed to said entrance, a nozzle directed across the supply passage and having a port coaxial with the tube, a needle valve centrally of the port and at all times maintaining the port open, a pressure responsive control chamber having direct duct communication with the supply passage, an additional chamber having independent duct communication from the dischargepassage, said duct having communication with the nozzle for flow therefrom about the valve toward the throat, said duct communications being at all times open, pressure actuated means coacting with the chambers, and a transmission connection from the means to the needle valve to modify the flow area of the port.

3. A rotary pump having an intake port and a discharge passage, a Venturi tube discharging into said intake port, said tube having from an entrance thereto a restriction forming a throat, a supply passage for the pump to said entrance, a pressure delivery chamber having a central port nozzle therefrom directed coaxially of the tube across the supply passage, a needle valve having flow spacing at all times thereabout as to the port, an additional chamber having direct duct communication with the supply passage, independent duct communication from the discharge passage to the delivery chamber, and transmission means coacting from between the chambers to shift the valve relatively to the port to vary the cross section of a flow stream into the tube throat in passing the nozzle in its flow course from the pump discharge passage.

4. A rotary pump having an intake port and a discharge passage, a Venturi tube in communication with said intake port, there being an entrance to the tube extending to a throat restriction, a supply passage for the pump to said entrance, a member providing a pressure delivery chamber including a nozzle having a port directed across the supply passage and coaxially of the tube, a needle valve mounted in the chamber and in thenozzle spaced from the port, an additional chamber having direct duct communication with the supply passage and also having a movable partition common with and spacing the additional chamber from the delivery chamber, and needle valve actuating means having connection from the partition, whereby pressure change in the supply passage reacts, thru the partition as modified by the pump discharge pressure in the pressure delivery chamber, for shifting the needle valve to change the effective stream cross-section from the nozzle in thereby 6 coacting for stream cross section change from the supply passage into the throat.

5. A rotary pump having an intake port and a discharge passage, a Venturi tube in commu nication with said intake port, there being an entrance to the tube inwardly tapering to a throat, a supply passage for the pump to said entrance, a nozzle having a pressure delivery chamber supply thereto, said nozzle having a port in a range up to one half the cross-sectional area of the throat, said nozzle'directing said port across the supply passage and coaxially of the throat, means for varying the eifective area of the port including a needle valve coacting at all times against fully closing the port, an additional chamber having duct communication with the supply passage, said delivery chamber having duct communication with the pump discharge passage, said duct communications being maintained open at all times during pump operation,

.and inter-chamber responsive control means connected to shift the needle valve relatively to the port to vary the efiective cross-section of the port to leave the throat cross-sectional area relatively more great.

6. A rotary pump having an intake port and a discharge passage, a Venturi tube in communication with said intake port, there being an entrance to the tube extending to a restricted throat, a supply passage for the pump to said entrance, a nozzle, a pressure delivery chamber mounting the nozzle for discharge across the supply passage and coaxially toward the throat, an additional chamber having duct communication with the supply passage, duct communication from the discharge passage to the delivery chamber, a flexible diaphragm forming a par-' tition between the chambers, a valve needle in the nozzle, and a mounting for the needle connected to the diaphragm to vary the effective nozzle cross-section.

KENNETH R. LUNG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS