US2222725A - Centrifugal pump - Google Patents

Description

Nov. 26, 1940. A. C. SAXE CENTRIFUGAL PUMP Filed Oct. 18, 1938 2 Sheets-Sheet l V/ll/ll/IfI/ffl INVENTOR Arfhur C 50x2.

Nov. 26, 1940. A. c. SAXE CENTRIFUGAL PUMP Filed Oct. 18, 1938 2 Sheets-Sheet 2 \llllLl-llll' INVENTOR m 5 a w M A as i r AT TORNEYS Patented Nov. 26, 1940 CENTBIFUGAL PUMP "Arthur C. Saxe, Columbus, Ohio, assignor to The Jaegcr Machine Company, Columbus, Ohio, a

corporation of Ohio Application ocub r 1a, 1938, Serial No. 235,616

4 Claims. (01. 103-113) My invention relates to a centrifugal pump. It has to do, more particularly, with a centrifugal pump having means associated therewith for automatically priming the pump whenever prim- 5 ing is needed. I

One of the objects of my invention is to provide. a centrifugal pump which will beself-priming under practically all conditions of operation.

Another object of my invention is to providea l0. centrifugal pump having priming means of such a nature that the priming operation will be continuous until completed and will be carried out quickly and efliciently.

Another object of my invention is to provide a ll centrifugal pump embodying a priming chamber,

an impeller chamber, and a by-pass for conducting priming liquid from the priming chamber into the impeller chamber, said by-pass being under the control of an automatically operated valve which will be closed and will stay closed under normal conditions of operation but which will automatically open to supply priming liquid to the impeller whenever the pump needs priming. Another object of my invention is to provide a centrifugal pump of .the type indicated wherein the priming valve is provided with means for preventing closing thereof until the pump is completely primed and which is provided with means for holding the valve closed, after it is once moved into closed position, as long as the pump operates under normal conditions but which is so arranged that it will quickly open whenever the pump needs priming; I g

Another object of my invention is to provide a pump of the type indicated wherein the priming valve is operated by-means which is of such a nature that after the pump is primed, such means will not interfere to any appreciableextent with passage of liquid into and through the pump and,

consequently, will not detract from the capacity of the pump. l i

Another object of my invention is to provide controlling means for the priming valve which is of" such alnature and is so arranged that it will be substantially out of the'path of the liquid and air mixture, discharged by the impeller during priming, thereby making it possible to have the valve controlling means very sensitive so that the .valve will not start to close until water is actually discharged through the discharge line of the pump regardless of changing conditions within the pump.

In its preferred form, my invention contemplates the provision of a self priming centrifugal 55 pump which in its general structure is substantially the same as that disclosed in my Patent No. 2,061,521.

The priming valve and the controlling means therefor disclosed in my said patent works very efficiently and a largenumber of pumps embodying 5 this mechanism have been sold and operated very successfully. However, I have devised different means for controlling the priming valve which has certain advantages over that disclosed in my said patent. This means can be made very sensil0 tive so that movement of the valve towards closed position will not be initiated until water actually is forced from the pump through the main discharge outlet.

The preferred embodiment of my invention is 15 illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a perspective view partly broken away showing a centrifugal pump constructed 20 according to my invention.

Figure 2 is a vertical section taken through the pump illustrated in Figure 1. 2

Figure 3 is a vertical section taken at right angles to that of Figure 2. 25

Figure 4 is a horizontal section taken through the pump. V

Figure 5 is a more or less diagrammatic view showing the control plate of the valve operating means disposed in the discharge outlet of the With reference to the drawings, the main strum ture of the pump is substantially identical with that disclosed inmy Patent No. 2,061,521. Briefly, it comprises an exterior casing l of substantially drum-like form within which a 'priming compartment ,is formed which isadapted to be initially filled with water. The exterior casing is provided at one side adjacent the top thereof with an intake port 2.- ,This' port may beunder the control of a check valve or the check valve may be provided in the suction line which is adapted to be connected to the port 2'.The casing I is further provided with a main discharge 45 port 3 disposed at the topthereof.

Within the main casing l and adjacent the side thereof opposite to where the port 2 is formed, an impeller chamber 4 is disposed. This impeller chamber is of volute form and is disposed eccentrically withinthe casing I. The outer wall of this chamber is'formed by the side wall of the casing l. The impeller chamber is of considerably less width than the casing and is located adjacent the base of the casing so that there is impeller chamber.

indicated at 5.

The impeller chamber 4 has an impeller 6 01 the type disclosed in said patent rotatably disposed therewithin and an upwardly directed discharge opening 1 is provided for the impeller chamber. The location of this opening is illustrated best in Figure 2. It is disposed some distance below the main discharge port 3 and at one side thereof. The peripheral wall of the impeller chamber is continued, in a direction opposite to the direction of rotation of the impeller, past the discharge outlet 1 to form a blade 8 which serves to strip the air and water from the impeller as described in my said patent. from the impeller chamber through the discharge outlet 1 will pass into the priming compartment formed within the casing 3.

The priming liquid compartment may be designated generally by' the numeral 9. A portion or it is disposed above the impeller chamber formed by the space 5 and a portion of it is disposed along one side thereof as indicated by the numeral l0.

It is at all times in communication with the dis and the water discharged therefrom will not undercut sand and silt in the base of the pump casing as it did in my said patent structure. A cleanout opening l2 may be provided in the base of the casing adjacent the opening II.

A suction chamber I3 is formed within the casing l and is disposed within the space II) at the side of the impeller chamber. This suction chamber leads from the suction inlet 2 downwardly to a circular opening ll provided in the inner wall of the impeller chamber 4. This opening I4 leads substantially axially into the The suction chamber I3 is of substantially rectangular vertical cross section. Its lower wall I5 is spaced upwardly from the base of the casing. It is provided with a priming port l6 formed in its lower wall through which priming liquid may pass upwardly from the priming liquid compartment into the suction chamber and thence through the opening H into the impeller chamber. The priming opening IE extends upwardly and is directed laterally towards the opening It. This elbow member has an annular valve seat I8 formed on its lower end. The elbow member I! will direct the priming liquid towards the opening M and into the impeller chamber thereby guiding it away from the in-take port 2. v v

The means for controlling the priming port it takes the form of a valve plate l9. This plate is provided with a spring portion 20 which is secured to the lower part of the suction chamber l3 as at 2|.' The spring portion 20 normally serves to maintain the body portion of the plate l9 unseated from the seat l8 associated with the priming port. The spring portion 20 is of preselected resisting power. When the plate I!) is in its lower position, as indicated in Figure 2, the priming port is open to permit free flow of Fluid discharged the priming liquid from the priming liquid compartment into and through the elbow member I! which will direct it in a Ian-like stream through the suction chamber l3 and the opening l4 into the impeller chamber. When this plate is in raised position, as shown in dotted lines in Figure 2, it covers the priming port and stops the flow of priming liquid therethrough.

The means for moving the plate I! into its closed position comprises a control plate 22 which is pivoted as at 23 to the casing of the pump. It will be apparent from Figure 2 that this plate 22 is located between the discharge outlet I of the impeller chamber and the main discharge port 3 of the pump and to the right of outlet 3 (Figure 2). It is disposed in the path of liquid which passes to and is discharged through the main discharge port 3. During priming of the pump the plate 22 will occupy the position indicated by the full line in Figure 2. When the pump is primed it will occupy the dotted line position and'will be substantially out of the path of flow of the liquid so that it will not interfere therewith. The plate 22 is connected by a link 24 to the plate I. The upper end of this link is pivotally'connected as at 25 adjacent the pivot point 23 with the plate 22. The lower end of the link is connected as at 26 with the outer end of the plate' l9. Thus, a compound leverage connection is provided between the plate 22 and the plate I! to reduce the force necesary to raise the plate 22 and thereby raise the plate l9.

In the operation 01' this pump, as previously stated, the priming compartment is initially filledwith water. The priming valve will be open and the operating means therefor will be in the position indicated by the full lines in Figure 2. The impeller is then rotated. The impeller will draw priming liquid from the priming compartment, through the elbow member I1 and the priming port and this priming water will be directed through the opening ll into the impeller. As the priming water passes from the elbow member I! to the eye of the impeller, it will carry air therewith from the suction chamber l3 into the impeller chamber. The impeller will pump this air and'water mixture through the impeller chamber and discharge it through the outlet 1. The air and water mixture will be directed upwardly from the outlet 1 and around the top of theimpeller chamber. The air and water mixture will have substantially no effect on the control plate 22 and the water will merely recirculate in the priming compartment. Primcompartment to the impeller chamber. During this recirculation of priming water, air will be continuously removed from the suction chamber l3 and the suction line connected thereto. The priming port is restricted so that a quantity of priming water less than the pumping capacity of the impeller will be supplied thereto, so that theimpeller will draw air fromthe suction line with the priming water.

The priming valve will remain open until the pump is completely primed. This is due to the fact that the resistance of the spring 20 and the weight of members IS, and Here so selected that the valve will hang open until the fluid discharged by the impeller will have substantially no air mixed therewith and will flow towards the outlet 3 simultaneously striking the control plate 22. This liquid striking the control plate 22 will have the necessary velocity head to move the plate 22 to its dotted line position and, consequently, to seat the plate IS on the valve seat l8. At this time substantially all the air has been eliminated from the suction line and closing of the valve will interrupt flow oi priming liquid from the priming compartment to the impeller chamber. It' will be noted that when the valve tions and, consequently, will not detract to any appreciable extent from the capacity of the pump. It will be noted that the plate 22 is so disposed that it. is substantially out ofv the path of the water and air mixture discharged by the impeller and which recirculates during the priming operation. Thus. during priming the fluid discharged by the impeller has substantially no efiect on plate 22. Consequently, the controlling means can be made very sensitive and can be so set that the valve will not startto close until substantially solid water is discharged by the impeller and is forced towards outlet 3 striking plate 22 on its way. Due to the compound leverage the spring portion 22 may have relatively greater resistance which will aid in preventing closing of the valve until priming is completed.

It will be apparent that the velocity head of the liquid striking the plate 22 after priming is completed isthe main force tending to move the valveinto closed position. However, as soon as the valve plate l9- nears or reaches closed position, another force tends to close it or keep it closed as described in my said patent. This force which tends to keep the valve closed is an unbalanced hydrostatic force produced by the liquid in the priming compartment and in the dischargeline adapted to be connected to the port 3 and exerted at the valve plate.

This additional force is important. As previously indicated, when the valve plate l9 moves towards closed position, the control plate 22 moves away from the center of flow of liquid discharged by the impeller and when the valve is finally closed,'the plate is substantially out of the path of flow. Thus, the effectiveness of the velocity head force will decrease to a certain extent as the valve plate moves-into closed position. Furthermore, the resistance offered by the spring portion will increase. However, due to the fact that the valve is hydrostatically unbalanced and this unbalanced force becomes effective as the valve nears or reaches closed position to aid in keeping the valve closed, this additional the valve closed is practically eliminated and the velocity head of liqlid acting on control plate 22 is eliminated. The spring 20 and the weight of the associated parts of the valve-operating mechanism will serve at this time to overcome the hydrostatic unbalanced force and any suction force,

tending to keep the valve closed, and will cause the valve plate to swing open.

It will be noted fromFig ure 3 that I provide an opening 21 adjacent the valve plate-so that access may be had thereto.

Although I have stated that I use a spring normally tending to hold the valve plate open, I may use a preselected weight which is applied to the plate l9, although I prefer a spring. Also, the

weight or the spring could be applied to baiiie plate 22 rather than to .valve plate 19. i

In Figure 5, I show the control plate for the valve disposed in a different location. In this instance thecontrol plate 22a is disposed in a neck formed on the pump casing at the discharge outlet 3. The plate 22a is pivotedin this neck and is connected to the valve plate substantially as before. This plate is of less area than the cross-sectional area of the discharge neck so that there will be an annular space therearound.

When the valve is opened plate 22a is in the full line position indicated in Figure 5. When the valve is closed, plate 22a is in the dotted line position. The control plate will function exactlyas before and will not be moved until water actually flows through the discharge outlet 3.

It will be apparent from the above description that I have provided a self-priming. centrifugal pump having many desirable characteristics. The pump will be self-priming under practically all conditions of operation. The priming act n will be continuous until completed and l be carried out quickly and eiiiciently.

Many other advantages will be apparent from the preceding description, the drawings and the following claims.

Having thus described my invention, what I claim is:

1. A self-priming centrifugal pump comprising an outer casing adapted to form a compartment for priming liquid, said compartment having a main discharge port at its upper end, an impeller chamber disposed within said compartment and having a discharge outlet directed upwardly towards the main discharge outlet but being spaced therefrom, a suction chamber disposed within said casing and having its base spaced from the base of said casing, said suction chamber being in communication with said impeller chamber, a port formed in the base of said suction chamber for permitting flow of liquid from said priming compartment into said suction chamber,

a valve for controlling said port, said valve comprising a plate mounted for swinging movement below said suction chamber and adapted to be seated and unseated relative to said port, means for controlling movement of said plate, said means comprising a pivoted control plate located adjacent the upper end of said casing at a point between the discharge outlet of the impeller chamber and said main discharge port and means for connecting said control plate to said valve plate.

2. A self-priming centrifugal pump comprising an outer casing adapted to form a compartment for priming liquid, said compartment having a main discharge port at its upper end, an im-v peller chamber disposed within said compartment and having a discharge outlet directed upwardly towards the main discharge outlet but being spaced therefrom, a suction chamber distion chamber, a valve for controlling said port,

a said control plate being of less area than the main discharge port, and means for connecting said control plate to said valve plate.

3. A self-priming centrifugal pump comprising an outer casing adapted to form a compartment tor priming liquid, said compartment having a main discharge port at its upper end, an impeller chamber disposed within said compartment and having an upwardly directed discharge outlet leading into said priming compartment but being spaced from said main discharge port, a suction chamber disposed within said casing and having its base spaced from the base of said casing, said suction chamber being in communication with said impeller chamber, a, port formed in the base of said suction chamber for permitting flow of liquid from said priming compartment into said suction chamber, a valve for controlling said port, said valve comprising a plate mounted for swinging movement below said suction chamber, means of preselected resisting power for normally holding said platein open position, means for moving said plate into closed position, said means comprising a pivoted control plate located in said compartment adjacent the upper end thereof at apoint between the discharge outlet-oi the impeller chamber and said main discharge port so that it is substantially out of the path of ilow oi the air and water mixture discharged by the impeller during priming but is in the path 01 now of liquid forced to and through said main discharge port after priming is completed, said pivoted control plate being connected to said valve plate by compound leverage.

4. A self-priming centrifugal pump comprising an impeller chamber, a suction line leading into said impeller chamber, an impeller in said chamber, a container for priming liquid associated with said chamber, a priming port for controlling passage of priming liquid from said priming container to said impeller chamber, a discharge outlet leading from said impeller chamber and into said priming liquid container, a main discharge outlet leading from said priming container, a valve for controlling said port to permit passage of priming liquid to said impeller chamber when open but to substantially exclude passage of priming liquid thereto when closed, means for operating said valve to cause it 'to close when the pump is primed and to open when the pump needs priming, said means comprising a control member connected to said valve and located at a point remote from said valve, said member being disposed beyond the discharge outlet of the impeller chamber and being spaced therefrom a sufllcient distance so that itis substantially out oi. the path offlow oi! the air and water mixture

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