US2612844A - Priming means for centrifugal pumps - Google Patents

Description

Oct. 7, 1952 A. "L. GRISE PRIMING MEANS FOR CENTRIFUGAL PUMPS 2 SHEETSSHEET 1 Filed Aug. 24, 1950 (In M INVENTOR Anna 11. 60

BY (1 W TTORN Ys Oct. 7, 1952 A. L. GRISE PRIMING MEANS FOR CENTRIFUGAL PUMPS Filed Aug. 24, 1950 144mm L. G /o'i INVENTOR 9 M ATTORNEYS Patented Oct. 7, 1952 PRIMING MEANS FOR CENTRIFUGAL PUMPs Alfred L. Gris, Springfield, Mass., assignor to Gilbert & Barker Manufacturing Company, West Springfield; Mass, a corporation of Massachusetts Application August 24, 1950, Serial No. 181,301

'. 6 Claims. (Cl. 103-113) 1 This invention relates to improved priming means for centrifugal pumps.

The invention has for an object the provision of a positively-acting displacement pump of variable capacity, arranged to operate at a high rate to rapidly exhaust air from the casing of the centrifugal pump'and its suction pipe and to operate at a substantially} less rate, after the centrifugal pump has been primed, and'to operate at zero rate when theoutlet of the centrifugal pump is closed.

The invention has for a further object the mounting of such a pump on a centrifugal pump, the impeller of which rotates on a horizontal axis, the priming pump having a suction connection to the top of the volute to avoid trapping of any substantial amount of air there by the rise of liquid in the casing of the centrifugal pump, as wellas a suction connection to the eye of the impeller.

The invention also has for an object theprovision of a standard for supporting the centrifugal pump with its axis horizontally disposed and in anyone of a plurality .of positions of angular adjustment so that the outlet of the centrifugal pump may be faced in differentdirections to suit different customers, the main casing of the centrifugal pump having a cover on which the priming pump is mounted and in which a suction connection for exhausing the volute is formed, such cover being capable of being fastened to the casing in a plurality of corresponding positions ofangular adjustment so that said suction connection may extend vertically to the top of the volute regardless of the angular position of the main casing.

These and other objects will best be understood from the following detailed GESCIiDtiOH-Of one illustrative example ofthe invention in'the accompanying drawings, in which:

Fig. l is a central sectional elevational view of a centrifugal pump embodying the priming means of this invention;

Fig. 2 is a cross sectional view taken on the line 2-2 of Fig. 1 and showing the variable-capacity priming pump in position for pumping at its maximum rate;

Fig. 3 is a fragmentary cross sectional view, taken similarly to Fig. 2 and showing the priming pump in non-pumping position; N

.Fig. 4 is a perspective view of the shiftable stator element of the priming pump; I

Fig. 5 is a view similar to Fig. 3 with the prim ing pump removed; j

Fig. 6 is an elevational view showing the inner face 'of the cover plate which partitions the pumping chamber of centrifugal pump from the pumping chamber of the priming pump;

Fig. 'l'is a sectional view taken on the line l-l of Fig. 6; and

Fig. '8 is a fragmentary sectional plan view showing the priming passages between" the, pumping chambersoi centrifugal and priming pumps.

Referring to these drawings, and first toFig. 1 thereof, the centrifugal pump includes a main casing l and a cover 2, secured to the main casing by cap screws 3. These casing members I and 2 afford between them a central chamber 4 receiving the impeller 5, which as shown is of the closed type and has a circular series of vanes 6 and a central eye 1, leading to the spaces between the vanes. The main casing I has in one side wall a v with the impeller and in this wall are a'series of tapped holes 9 which enable the flanged, end of a suction pipe (not shown) to be fastened to the casing. The main casing (Fig. 2) has formed therein the volute channel In, surrounding the chamber 4 and the impeller 5 and'terminating with an outlet II. The latter has fixed therein a bushing l2, providing a seat for e a checkyalve I 3, which has guide vanes l4 slid- 'ably'engagingthe inner peripheral wall of the bushing. A spring l5, acting between a cross bar l8, which is fixed at its ends to the casing l 'and diametrically spans the outlet passage H, and the valve until a sufficient pressure is built up in the centrifugal pump to open the valve.

The impeller 5 (Fig. 1 )-is keyed to one end of a drive shaft l1 and held against a shoulder on such shaft by a nut [8.

This shaft extends through the cover 2, through the pumping chamber of a priming pump mounted within a casing I 9, through a and into a bearing member 20'. The latter is secured by cap screws 21, which pass through a flange von member 20', through cover 20 and casing 19 and thread into cover 2. The shaft I! is entirely supported by the ball bearings 22 in member 20'. A suitable seal ring 23 is provided toprevent escape of liquid from the pumps along shaft H. The impeller has at its outer and'inner ends hollow hubs 24 and 2'5 (Fig. 8), respectively, which fit into openings in the casing l and cover 2, respectively, and prevent flow of liquid from the outlet to the inlet side of The pump, as thus far described, is of old central inlet 8' axially aligned holds the' latter to its seat cover 20 of the casing l9 and well known form and it will serve as an illustrative example of one form of centrifugal pump, in which the priming means of this invention may be embodied. The invention may be used with any centrifugal pump and does not depend on, nor is it limited to, the particular details of construction disclosed.

The centrifugal pump is supported with its drive shaft II horizontal bya standard 26 (Fig.

1). The inlet face of casing I is clamped against one side face of this standard by three cap screws 21 (Fig. 2) spaced 90 degrees apart. There are four tapped holes in casing I, spaced ninety degrees apart, and any three of them can be used to receive the three screws 21. The one tapped hole that is not used to receive a screw 2'! is marked 2'! in Figs. 1 andv 2. The casing I may be secured to standard 26 in four different positions such that its outlet I I may point vertically upward, vertically downward, or horizontally to the left or to the right. The standard 26 has a semi-circular recess (Fig. v2) in its upper end to clear the suction pipe and its flange.

The priming pump is ofthe positively-acting variable-capacity displacement type and is mounted within a housing comprising the -hollow casing I9 and the described covers 2 and 20, which as shown in Fig. 1, are applied to and close opposite sides of the hollow casing. The

interior of this hollow casing (Figs. 2 and 3) is cylindrical, except for two diametrically opposed recesses therein, each having parallel side walls and forming with their end closures 2 and cylinders 29 and 30. The stator of thepriming pump is shown separately in Fig. 4. It is in the form of an annular ring 3| with two diametrically-opposed projections 32 and 33 of rectangular cross section which form pistons .and are slidably engaged in the cylinders 29 and 30. respectively, as shown in Figs. 2 and 3. A spring 34, mounted in a radial hole in member I9 and acting between a plug 35, which closes the outer end of such hole, and the piston 32 tends to hold the stator in the position illustrated in Fig. 2. There are slots 33 and 3'! (Fig.2) in the sides of pistons 3I and 3 2 that enable the cylinders 29 and to communicate with, the inlet and outlet chambers 38 and 39, respectively, that are formed between the stator 3I and member I9 in which it is slidable. These chambers communicate at all times with the space within thestator by means of the notches 40 and 41, best shown in Fig. 4. Within the stator is mounted-a cylindrical rotor 42 fixed todrive:shaft ll-in coaxial relation. This rotor is radially grooved at angularlyspaced intervals to slidably receive vanes 43, which are held with their outer edges pressed againstthe internal periphery of ring 3| by means of two annular rings 43' which are locatedone in each of two recesses formed in opposite ends of rotor 42. v I

It is desirable to prevent the stator from being reversed in its casing and to this end a pin 44 (Fig. 3) is fixed to the cover 2 and projects into a. groove 44 located in the piston 33 offset from the center line of the latter.

The inlet chamber 38 is connected to the eye of the impeller. In the cover member .2 (Fig. 5,) is formed an arcuate groove 45 and an arcuate port 46 of less width than the groove connects the bottom of the groove :to a chamber 41 (Fig. 8), formed within the inner hollow hub 25 of the impeller and connected to the eye. of the latter by a series of holes 48 in the impeller. The inlet chamber 38 is also connected to the upper part 4 of the volute by a groove 49 (Fig. 5), formed in cover 2 and leading from groove 45 to a hole 50 (Figs. 3 and 5), which is drilled in cover 2 and communicates with the inner end of a hole 5I. The latter is also formed in cover 2 and extends outwardly to a notch 5|, the outer end of which opens to the outer periphery of a cylindrical part 52 of cover 2 and one side of which opens to the chamber 4. The cover has a cylindrical part 53 which as shown in Fig. 1 closely fits the opening in casing I. The part 52 lies between the part '53 and the volute I0 and is of slightly less diameter, than the opening in cover 2, thereby forming an annular groove 54 (Fig. 5) which communicates throughout its entire circumference with the volute I0. This groove may desirably be I used to supplement the passage 50, 5|, 5| above described.

"The outlet chamber 39 of the priming pump is connected to the outlet II at a location beyond the check valve I 3. This is effected by a passage 55 (Fig. 3) inicasing I9 and a tube 55 (Figs 1), which connects the outer end of passage 55 with outlet II...

-In operation, the inlet 8 of the centrifugal pump is comiectedto a suction pipe leading from a suitable source of liquid supply; the outlet II of the pump is connected to a delivery conduit,

leading to the'desired point of delivery and usually having a control valve, which can be opened to various degrees or closed; and the driving shaft I7 is connected to a, suitable power source, such as an electric motonfor example. In the initial priming of the piunp :all the air within the chamber 4 and passage. I Ilof the casing I2 will have to beexhausted, as well as the air in the suction pipe. The control-valve on the delivery conduit will be opened and the-motor set in operation to drive both theimpeller 5 and the rotor 42 of the priming pump. Initially, the stator 3I of the priming pump will: be held by spring 34 in position for them'aximum pumping rate. The positively-acting' priming pump will draw air from the suction pipe through the holes -48, chamber 41, port 46 and groove 45 and force it out through passage 55 and tube-.56-into the passage I I above pump will alsodrawair from the volute passage IIl-and the-chamber 4 by means of the conduit,

comprising the holes 50 and 5I and the notch 5|. -=Also, the. annular groove 54 aids in connecting thesvolutez passage III at all points around the impeller 5 to the inlet of the priming pump. This is 'a,,desirable feature although it is not necessarily essential-for all purposes. It should be noted that the slze'of outlet pipe 56 is such as to freely pass .allthe air that the priming pump can pump, when working at its maximum rate. Air continues to be eliminated from the suction pipe until-it becomes filled with liquid and then air is eliminated from the centrifugal pump casing and replaced with liquid until the latteriis full. The connection of the inlet of the priming pump to the upper portion of the volute avoids the trapping there of any substantial amount of air. As liquid enters the priming pump and is forced outwardly, the tube 58 presents a restriction to its flow, resulting in a rise in pressure which causes the piston 33 to move the stator 3I against the force, of spring 34 to decrease the pumping rate. This pressure is not, however, sufficient to shift the pump stator fully into neutral position. When the centrifugal pump is primed, it forces liquid outwardly: opening the check valve l3 and delivery of liquid throughithe delivery conduit occurs, the rate being controlled by the degree of opening of the'control valve. If such valve is partly closed, this will cause a rise in pressure and shift the stator of the primin pump to still further decrease its'pumping rate. When the flow is stopped by'closur'e of the control valve, the ensuing risein pressure will cause the stator of the priming pump to be shifted into neutral position. 1 As an illustration and without imposing limitations, the one particular example of pump disclosed is constructed to pump'liquid at therate of 200 gallons perminute when driven "at'th'e rate of 1750 R. P. M. It is shown=one-third"size in Figs. 1 and 2. The outlet tube 53 of -the priming pump is one half inch" copper tubing, which restricts the outflow of liquid sufiiciently for the purpose. If a three-quarter inl'chtube- I in four corresponding positions of angular adjustment so that the conduit 5! may always extend vertically upward to reach the upper part of the volute regardless of which way :thecutlet H faces. I ,V

The invention thus provides an unproved priming means for centrifugal-pumps including a positively-acting displacemehtpump capable of pumping at a high rate to quickly exhaust; air

' and prime the centrifugal pump and a means for reducing its capacity after the centrifugal pump has been fully primed. g i

What is claimed is:

l. The combination with a centrifugal 'pump having an impeller, a driving shaft therefor, a casing in which the impeller is mounted and which is provided with an inlet axially of the impeller and a volute passage surrounding the impeller and terminating with an outlet, and a check valve located in said passage near said outlet and opening outwardly in the direction of liquid flow, of a variable-capacity priming pump, comprising a rotor connected to be driven by said shaft, a stator encompassing the rotor and shiftable to vary the pumping rate, a casin in which the stator is mounted and which has inlet and outlet chambers respectively connected to said inlet and outlet and a cylinder connected to said outlet chamber, a piston connected to said stator and slidable in said cylinder and adapted to be moved by liquid pressure, and a spring for moving the stator in opposition to the piston and tending to hold the stator in its maximum pump-,

ing rate position.

2. The combination with a centrifugal pump having an impeller, a horizontal driving shaft therefor, a casing in which the impeller is mounted and which is provided with an inlet axially of the impeller and a volute passage surrounding the impeller and terminating with an outlet, and a check valve located in said passage near said outlet and opening outwardly in the direction of liquid flow, of a variable-capacity priming pump, comprising a rotor connected to be driven by'said shaft, a stator encompassing the rotor and shiftable to vary the pumping rate,

a casingin which the stator is mounted and which by liquid pressure, and a spring for movin said stator in a direction-opposed to that'in which it is moved byliquid' pressure 'andtending to hold the stator in its position formaximum pumping rate.

'3. In a centrifugal pump-"a two-part casing, an impeller rotatabl'etherein, said casing including main and cover element's, said main casing element'hav'ingin one wall an inlet axiallyof the impeller and inan 1'opposite wall'an opening axially of and larger infdiameter'than the impellerjsaid casing 11' vin'gja passage surrounding the impellen'nnd terminating in an-outlet, an outwardly opening; check valve" in said passage,

said cover element having a" cylindrical part closelyfitting 'sald opening and closing thesame and-"adapted to be secured to=the main casing ina plurality'of positions of angular adjustment,

a variable-"capacity priming pump mounted on 7 said coverelement and comprisihg a'rotor connected to be driveniby semi-share; a stator mwhich the rotor is mounted, a'basing in which I the stator is shiftably mounted, springineans tending-Etoholdthe stator in its maximum pumping rate position,'hydraulic means for moving the stator in opposition to the spring, saidpriming pump casing having inlet and outlet chambers, a conduit connecting said hydraulic v means and outlet chamber to said passage at a point between the-check-valve= and outlet, and a conduit extending fronifsaid inlet chamber outwardly in said cover and opening through the inner face thereof near its outerperiphery into said passage, and a conduit connecting said inlet chamber to said inlet.

4. In a centrifugal pump, a two-part casin an impeller rotatable therein, said casing including main and cover elements, said main casing element having in one wall an inlet axially or the impeller and in an opposite wall an opening axially of and larger in diameter than the impeller, said casing having a passage surrounding the impeller and terminating in an outlet, an outwardly opening check valve in said passage, a supporting standard for the pump and to which the main casing maybe fastened in a plurality of positions of angular adjustment with the axis of its inlet horizontal, said cover element having a cylindrical part closely fitting said, opening and closing the same and adapted to be secured to the main casing in a plurality of positions of angular adjustment corresponding to the firstnamed positions of angular adjustment, a variable-capacity priming pump mounted on said cover element and comprising a rotor connected to be driven by said shaft, a stator in which the rotor is'mounted, a casing in which the stator is shiftably mounted, spring means tending to hold the stator in its maximum pumping rate position, hydraulic means for moving the stator in opposition to the spring, said priming pump casing having inlet and outlet chambers, a conduit connecting said hydraulic means and outlet chambe: to: said passage at a point between the check valve and outlet, and a conduit extending-from said inlet chamber outwardly in-saidscover and opening through the inner face thereof near its outer periphery into saidpassage. and-a; conduit connecting'said inlet chamber tosaid inlet,-v

5. In a centrifugal pump, a casingrincluding main and cover elementman-impeller rotatably mounted in the casing, a drivewshaft fortheimpeller, the main casing element having in. one wall an inlet axially of; the impeller and. in the opposite wall an axial opening larger in diameter than the impeller and closed, by said, cover element, the latter having an outer portion closely fitting the opening andan innerportion of less diameter forming with the adjacent wall of the opening an annular groove communicating with the interior of said casing beyond. the impeller, said main casing element-having a. passage. surroundingthe impeller and terminating in an outlet, an outwardly opening check. valve in said passage, a variable-capacity priming pump mounted on said cover elementand. comprising a rotor connected to be driven by said shaft, a stator in which the rotoris. mounted, a casing in which the stator is shiftably' mounted, spring means tending to hold thestator in its maximum pumping rate position], hydraulic means for moving the stator in opposition to the spring, said priming pump casing having inlet and outlet chambers, a conduit connectingsaid hydraulic means and outlet chamber to said passage at a point between the check valve and outlet, and a conduit in said cover connecting said inlet chamber to said-groove. 1

6. In a centrifugal-pump; a two-part casing, an impeller rotatable therein, said casingincluding a main casing element and a cover element, said main casing element having in one wall an inlet axially of the impeller and in an opposite wall an opening axially of and larger-in diameter than the impeller, said casing havingapassage surrounding the impeller and terminating in an outlet, an outwardly opening check valve in said passage, a supporting standard for the pumpand 8 to which the main casing may be fastened in a plurality of positions of angular adjustment and with the axis of its inlet horizontal, said cover element having one cylindrical part closely fitting and closing said opening and another cylindrical part of less diameter forming with the wall of :said opening a groove opening into the casing and facing the impeller, a variable-capacity priming pump mounted on said cover element and comprising a rotor connected to be driven by said shaft, a stator in which the rotor is mounted, a casing in which the stator is shiftably mounted, spring means tending to hold the stator in its maximum pumping rate position, hydraulic means for moving the stator in opposition to the spring, said priming pump casing having inlet and'outlet chambers, a conduit connecting said hydraulic means and outlet chamber to said passage at a point between the check valve and outlet, and a conduit in said cover connecting said inlet chamber to said groove.

ALFRED L. GRIsE.

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

UNITED STATES PATENTS Number Name Date 1,447,854 Jennings Mar. 6, 1923 1,474,708 Drysdale Nov. 20, 1923 1,890,317 Durdin Dec. 6, 1932 2,064,421 Erskine Dec. 15, 1936 2,134,686 DeLancey Nov. 1, 1938 2,142,275 Lane Jan. 3, 1939 2,153,360 Auger Apr. 4, 1939 2,330,558 Curtis Sept. 28, 1943 2,430,337 Heckert Nov. 4, 1947 2,464,144 McConaghy Mar. 8, 1949 2,500,228 Adams Mar. 14, 1950 FOREIGN PATENTS Number Country Date 371,138 Germany Mar.'14, 1923

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