US3257955A - Flow control for turbine pump - Google Patents

Description

June 28, 1966 J. c. WORST 3,257,955

FLOW CONTROL FOR TURBINE PUMP Filed Feb. 4, 1964 2 Sheets-Sheet 1 INVENTOR. J'osEPH c. WORST H \5 AT ToRnEY June 28, 1966 J. c. WORST 3,257,955

FLOW CONTROL FOR TURBINE PUMP Filed Feb. 4, 1964 2 Sheets-Sheet 2 9 F'IG.7

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INVENTOR.

JOSEPH C. WORST ag/ W r-us ATTORNEY the annular pumping chamber.

United States Patent 3,257,955 FLOW CONTROL FOR TURBINE PUMP Joseph C. Worst, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Feb. 4, 1964, Ser. No. 342,510 6 Claims. (Cl. 103-97) My invention relates to pumps, and more particularly to a flow control for turbine pumps.

A turbine pump is that type of rotary pump having blades at the outer periphery of the impeller. Such rotary pumps move a pumped fluid along an annular path within a casing, from an inlet to an outlet. A dam is provided in the casing, adjacent the outlet, to direct the pumped fluid from the annular path to the outlet. Such pumps are often driven by a motor which performs more than one function, that is, it may drive some other mechanism as well as the pump. In such cases, it is often necessary to have the motor drive the mechanism but at the same time to avoid pumping action or to have less than full pumping action.

My invention provides a control over delivery of the pumped fluid which does not require stopping rotation of the impeller and the driving motor. It thus provides for greater fiexibility in operation than prior art structures.

It is an object of the present invention to provide an improved flow control for a turbine pump.

It is a further object of the present invention to provide a flow control for such pumps which does not require stopping and starting of the impeller.

My invention is best understood when described in conjunction with the accompanying drawing, illustrative of one embodiment of the invention, in which:

FIGURE 1 is a plan view, partly broken away, of the turbine pump of the present invention;

FIGURE 2 is a sectional elevation view, taken on the line 22 of FIGURE 1;

FIGURE 3 is a sectional plan view showing a detail, taken along the line 3-3 of FIGURE 2;

FIGURE 4 is a sectional elevation view of a portion of a turbine pump incorporating a modified form of flow control;

FIGURE 5 is a plan view, partly broken away, of a turbine pump showing another modified form of my invention;

FIGURE 6 is a sectional elevation view of a portion of a turbine pump illustrating another modification of my invention;

- FIGURE 7 is a view of a portion of the pump of FIG- URE 6 illustrating the flow control element in a dilferent position;

FIGURE 8 is a sectional plan viewtaken along the line 8-8 in FIGURE 6, showing a detail of the modification shown in FIGURE 6;

FIGURE 9 is a view of a portion of FIGURE 8 showing the parts in different positions.

Briefly, the pump of my invention, in one form thereof, comprises a casing, within which an annular pumping chamber is formed, and an impeller mounted for rotation within the casing. The impeller has peripheral radially extending flat blades. When the impeller is rotated, the radial blades entrain the pumped fluid and move it around The flow of pumped liquid is controlled by a dam, disposed adjacent the outlet from the casing on the downstream side of the outlet. The dam is movable between a first extreme position in which the dam blocks the anular pumping chamber to direct the fluid to an outlet and a second extreme position in which the fluid is carried in an anular path within the casing and no fluid is pumped through the outlet, and the dam may occupy intermediate positions for throttling.

. an alternate position.

"ice

Turning to FIGURES 1 and 2 of the drawing, it may be seen that a pump embodying the present invention has a casing 10 which'defines an annular pumping chamber 11. The casing 10 may be formed from a body element 12, and a cover plate 13 to facilitate assembly and any needed maintenance. These two elements are held in an assembled relation by any suitable means, such as by bolts 14. An inlet 15 is provided for admitting fluid from any desired source into the annular pumping chamber 11. Fluid is discharged from the annular pumping chamber 11 through an outlet 16.

Within the casing is an impeller 17, rotatable about the axis of a shaft 18. The impeller may bedriven by any suitable power source (not shown), such as an electric motor. The impeller 17 has a generally disc-like shape, with a planar circumferential web 19 extending into the annular pumping chamber 11. On the upper and lower sides of the web 19, spaced peripheral radial vanes 20 are formed. Each vane 20, considered individually, has a shape approximately that of a quarter circle. Thus, when the quarter circular vanes are formed on the opposite sides of the web 19, the profile of the peripheral surface of the impeller assumes a semicircular outline. The portion of the impeller 17 which extends into the annular pumping chamber 11 thus approximates a half torus.

The radially directed vanes 24 and circumferential web 19 formed on the rotor define fluid entraining pockets 21 spaced about the periphery of the impeller. These pockets 21 serve to entrain the pumped fluid and move it with impeller rotation within the annular pumping chamber 11.

In order to control the flow of pumped fluid entrained by the impeller 17, I provide a dam 22. This dam is placed adjacent the fluid outlet 16, on the downstream side of the outlet and between the outlet 16 and the inlet 15. As illustrated in FIGURE 1, the dam may be positioned on a radial line relative to the impeller 17. The dam is so shaped that, when in the position shown in FIG- URE l, the annular pumping chamber 11 is blocked.

As best shown in FIGURE 2, the dam 22 has a semicircular notch or recess 23 formed to correspond to the semicircular or half-toroidal shape of the impeller web 19 and vanes 20 which extend into the pumping chamber. The provision of such a notch in the dam 22 permits continuous rotation of the impeller 17, while deflecting the greatest amount possible of the entrained fluid carried by the impeller. The dam 22 in the radial positions serves a to deflect the pumped fluid from the annular chamber and discharge it through the outlet 16.

In order to provide for control over the flow from the pumping chamber 11, the darn 22 of my invention is movable between the radial position shown in the drawing and In the embodiment shown, movernent is provided by mounting the dam 22 on a shaft 24 which defines an axis tor rotation of the dam parallel to the axis of rotation of the impeller 17. When the dam 22 is rotated about the shaft 24 away from the flow-blocking position, the pumped fluid entrained by the impeller 17 is carried past the dam to circulate along an annular path within the pumping chamber 11. alternate position of the dam is approximately parallelto the flow stream lines, because it there presents the least resistance to annular flow. This position is perpendicular to a radial line on the impeller 17, or substantially parallel to a line tangential to the impeller. However, it may occupy any position which does not deflect the fluid to the outlet. If throttling operation is desired, the dam could be located at any intermediate position between the flowblocking position and the position permitting circulation within the annular chamber 11.

While the pivotal position of the dam 22 may be controlled by any suitable means, an electrical solenoid open The preferred ating a rack and pinion gear has been illustrated in FIG- URES 2 and 3 as one possible means. the dam shaft 24 carries a sector gear 25 at its end remote from the pump casing 10. The sector gear 25 is engaged by a rack 26 which is actuated by a solenoid 27. Control over actuation of the solenoid 27 may be exercised by any suitable switch, in response to any desired condition. Alternative actuation systems, such as hydraulic or pneumatic, might be employed In operating the pump of my invention, the impeller 17 may be driven continuously by any suitable power source. Since the fluid entrained by the impeller 17 moves with the impeller in its direction of rotation, the direction of flow through the pump casing may be reversed "by reversing the direction of rotation of the impeller 17. The discussion here assumes rotation in the direction indicated by the arrow in FIGURE 1. With the impeller 17 rotating in the indicated direction and a suitable source of fluid to be pumped connected to the inlet 15, fluid in the annular pumping chamber 11 is entrained by the vanes 20 and pockets 21 of the impeller 17 and carried around the pumping chamber. With the dam in the position shown. in FIGURE 1, the entrained fluid contacts the darn 22 adjacent the outlet 16.- The fluid is deflected by the darn from the annular path on which it is carried by the impeller 17, and is discharged from the pumping chamber 11 through the outlet 16.

To discontinue pumping of fluid through the outlet 16, solenoid 27 is energized to move the rack 26 to the left, thus rotating the dam member 22 to an alternate or flowpermitting position in which it does not block the flow of fluid in the annular chamber 11, that is, preferably to a position parallel to a line tangential to the impeller. The fluid entrained by the impeller 17 is then permitted to circulate along an annular path within the pumping chamber 11, and is not deflected to be discharged through the outlet 16. Upon de-energization of the solenoid 27 the rack 26 is returned to the position indicated in FIGURE 2 by a spring 27a, which is connected between the movable element 27b of the solenoid and a stationary flange member 270. This return movement of the rack rotates the dam 22 back to a flow-blocking position, again resulting in discharge of pumped fluid through the outlet 16.

If throttling operation is desired the control element may be arranged to position the dam at any of a plurality of positions between the flow-blocking position and the flow-permitting posit-ion, thereby achieving a variable flow through the outlet 16. For this purpose the rack 26 could be operated manually or indexed. to a plurality of positions by any conventional indexing mechanism to thereby position the darn 22 selectively in any of a plurality of throttling positions. If operated manually, for example, the end of the rack could be slidably mounted in a bracket and held in any selected position by a set screw.

In FIGURE 4 there is shown a modified form of my invention. The control arrangement of FIGURE 4 differs from that in the form illustrated in FIGURES l-3 in that the dam 28, corresponding to the dam 22 in FIGURES 1-3, in lieu of being pivotally mounted for control is mounted for reciprocal movement in a radial direction in the pumping chamber 11. In the position shown in solid lines in FIGURE 4, the darn 28 blocks flow of fluid in the pumping chamber and hence causes pumping of fluid through the outlet in the same manner as the dam 22 when the solenoid 27 in FIGURES 1-3, is connected with the dam 28 by a suitable linkage. Specifically, the dam 28 includes a rod 30 which extends radially outwardly through a seal 31 in the casing 10. The solenoid 29 is As there shown,

.the chamber.

connected with the rod 30 by a link 32. The link 32 is mounted at one end to an extension 33 of the movable element or actuator 34 of the solenoid, a spacer 34a being placed between the link 32 and the actuator 34. The other end of the link 32 is connected to the rod 30.

In the form shown in FIGURE 4 the solenoid may be moved between the extreme positions illustrated by the solid and dotted lines, that is, between a position in which the flow within the annular chamber is blocked by the dam and a position in which fluid is circulated within To state it another way, the dam is moved between the solid line position in which full flow is provided from the outlet of the pump and the dotted line position in which minimum or no flow is provided.

By the arrangement shown in FIGURE 4, intermediate, or throttling, positions may also be achieved Specifically, a collar 35 is adjust-ably mounted on the extension 33 of the actuator by means of a set screw 35a. When the collar is in the position shown in FIGURE 4 motion is provided before the collar engages the link 32 as the actuator 34 is moved to the left upon energization of the solenoid. Therefore, with the same length of stroke of the actuator a lesser movement of the dam is secured, and the dam is therefore moved only to a position intermediate the extreme positions illustrated by the solid and dotted lines. In this intermediate position circulation of fluid within the annular chamber is permitted, but on a reduced scale; part of the fluid is pumped through the external circuit and a throttling operation of the pump is achieved. The collar, of course, may be mounted in any desired position along the extension 33 to achieve diflerent degrees of throttling. When an on-ofl type of operation is desired, the collar 35 is moved directly into engagement with the link 32 so that full movement of the dam between its extreme positions, that is, movement between the solid line and dotted line positions, is achieved.

In FIGURE 5 there is shown another modified form of my invention wherein the need for external power actuation of the dam is eliminated and control of the position of the dam is effected by change in direction of rotation of the impeller. For convenience the elements which are similar to those used in FIGURES 1-3 have been given the same reference numerals. In this form of my invention the turbine casing, and specifically the portion 12 thereof, is formed to provide a recess 36 adjacent to the dam. The dam 37 is pivoted at 38 for movement between the solid line position and the dotted line position shown in FIGURE 5. The dam 37 is positioned ofl-center of the recess 36 so that, in the solid line position, the end 39 of the dam engages a shoulder 40 which forms a wall of the recess. This engagement of the dam and the shoulder holds the dam in the solid line position. The solid line position of the dam is achieved when the impeller 17 is driven in a counterclockwise direction indicated by the solid arrow in FIGURE 5. The force of the fluid pumped moves the dam in a clockwise direction about its pivot 38 until the end 39 engages the shoulder 40 to retain the dam in its flow-blocking position. In this condition of operation it will be apparent the direction of rotation of the impeller 17 is such that the passage 41 acts as the inlet and the passage 42 acts as the outlet of the pump.

When the pump is driven in the opposite direction, that is, in the clockwise direction indicated by the dotted arrow, the force of the fluid pumped causes the darn 37 to be pivoted about the pivot point 38 to the dotted line position shown in FIGURE 5. The dam is then essentially parallel to the flow of fluid and oflers a minimum of resistance to the flow thereof. Accordingly, the fluid is merely circulated within the chamber 11 by the pump. With the device of FIGURE 5 essentially full capacity of the pump is secured when the impeller is driven in the counterclockwise direction and essentially zero capacity when the impeller is driven in the clockwise direction.

If desired, a differential pump could be provided with the general arrangement shown in FIGURE 5, that is, a pump which provides pumping action in both directions of rotation but gives a greater pumping action in one direction than in the other. This result could be achieved by providing a stop to limit the movement of the dam in the counterclockwise direction short of the dotted position shown in FIGURE 5. Under these circumstances full capacity of the pump would still be achieved when the impeller was rotated in the counterclockwise direction, fluid being taken in at passage 41 and discharged at passage 42. On the other hand, when the impeller was rotated in the clockwise direction the dam would only partially block the flow of fluid in the chamber 11, resulting in a lesser pumping of fluid through the external connections. In this case the fluid would enter the pump through the passage 42 and would be discharged through the passage 41. In FIGURES 6-9 there is illustrated still another form of my invention in which the dam is moved by internal hydraulic pressure but the amount of movement thereof is determined by an external control. The dam 43, corresponding to the pivoted dam 22 in the form illustrated in FIGURES l-3, is pivotally mounted on a shaft 44 extending downwardly through the turbine casing. The dam is illustrated in FIGURE 6 in the flow-blocking position where full pumping capacity is secured in FIGURE 7 in the flow-permitting or circulating position where the the fluid is merely circulated in the chamber 11. Movement of the dam from the positon shown in FIG- URE 6 to that shown in FIGURE 7 is effected by the force of the fluid being moved by the impeller 17. This movement of the impeller in a direction corresponding to the counterclockwise direction in FIGURE 5 tends to move the dam from the flow-blocking position illustrated in FIGURE 6 to the circulating position shown in FIG- URE 7. Movement of the impeller in the clockwise direction tends also to move the dam to a circulating position, 180 from that shown in FIGURE 7.

The dam is maintained in the flow-blocking position shown in FIGURE 6 by a forked element 45 which is arranged to engage elongated member 46 mounted on the shaft 44. The forked element is connected to the movable element or actuator 47 of the solenoid 48. The forked element is biased to the right by a spring 49, corresponding to the spring 27a of FIGURE 2. In this position the elongated member 46 is received between the bifurcation of the forked element 45 and the dam is maintained in the flow-blocking position against the hydraulic force exerted thereon by the impeller. Full pumping action is thereby achieved.

To permit movement of the dam 43 to the circulating position under the influence of the hydraulic force exerted by the impeller, the forked element may be moved to the left by energization of the solenoid 48. Upon energization of the solenoid the forked element 45 is moved to the position shown in FIGURE 9, where it can be seen that the forked element is beyond the shaft 44 which forms the pivot axis of the elongated member 46. The elongated member is then free to move either to the position shown at 46a or.in the position shown at 46b in FIGURE 9. Specifically, if the impeller is rotated in the clockwise direction the elongated member assumes the position shown in solid lines at 46a; conversely, if

the impeller is rotated in the counterclockwise direction the elongated member assumes the position shown in dotted lines at 46b. -In either of these cases the darn 43 occupies a position which permits circulation of fluid within the chamber 11 and no pumping action occurs.

In the form of invention illustrated in FIGURES 6-9, therefore, the power for shifting from full pumping operation to non-pumping operation is furnished by hydraulic forces within the pump. The actual shifting is controlled by the external solenoid 48 in cooperation with the forked element 45 and spring 49.

While this invention has been described by reference to a particular embodiment, it is to be understood that numerous modifications may be made by those skilled in the art without departing from the spirit of my invention. It is therefore, the purpose of the appended claims to cover all such variations as come within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A turbine pump comprising:

(a) a casing defining an annular pumping chamber,

(b) an impeller mounted for rotation within said cas- (c) said casing having an inlet through which fluid enters said pumping chamber,

(d) said casing having an outlet through which fluid is discharged from said pumping chamber,

(e) a dam pivotally mounted in said pumping chamber adjacent said outlet,

(f) and selectively operable means connected ,to said dam for moving said dam between a first position, in which it blocks said pumping chamber to direct liquid into said outlet, and a second position, in which fluid is circulated along an annular path within said pumping chamber.

2. A turbine pump comprising:

(a) a casing defining an annular pumping chamber,

(b) an impeller mounted for rotation within said cas- (1) said impeller having a planar circumferential web and spaced peripheral radial vanes on said web for entraining fluid within said chamber,

(c) said casing having an inlet through which fluid enters said pumping chamber,

(d) said casing having an outlet through which fluid is discharged from said pumping chamber,

(e) a dam pivotally mounted in said pumping chamber adjacent said outlet,

(f) and selectively operable means connected to said dam for moving said dam between a first position disposed along a line radial to said impeller, in which it blocks said pumping chamber to direct fluid to said outlet, and a second position, in which fluid is circulated along an annular path within said pump ing chamber.

3. A turbine pump comprising:

(a) a casing defining an annular pumping chamber,

(b) an impeller mounted for rotation about an axis within said casing, said impeller having a planar circumferential Web and spaced peripheral radial vanes on said web for entraining fluid within said chamber,

(c) said casing having an inlet through which fluid enters said pumping chamber,

((1) said casing having an outlet through which fluid is discharged from said pumping chamber, and (e) a dam adjacent said outlet, said dam being pivot- .ably mounted for movement about an axis parallel to that of said impeller,

(f) and selectively operable means connected to said dam for moving said dam between a first position disposed along a line radial to said impeller, in which it blocks said pumping chamber to direct fluid to said outlet, and a sec-0nd position, in which fluid is circulated along an annular path within said pumping chamber,

(g) said darn having a recess therein conforming to the periphery of said web and said vanes When said (b) an impeller mounted for rotation within said.

ng (c) said casing having an inlet through which fluid enters said pumping chamber,

(d) said casing having an outlet through which fluid is discharged from said pumping chamber,

(e) a dam adjacent said outlet,

(f) a shaft for pivotally mounting said darn for move ment about an axis parallel to the axis of said impeller between a first position relative to said impel ler in which fluid is directed by said dam to said outlet and a second position in-which fluid is circulated along an annular path within said pumping chamber, said shaft having a portion extending externally of said casing,

(g) a sector gear mounted on said external portion of said shaft,

(h) a rack external of said casing engaging said gear,

and

(i) means for actuating said rack to effect rotation of said gear for moving said darn between said first and second positions.

5. A turbine pump comprising:

(a) a casing defining an annular pumping chamber,

(b) an impeller mounted for rotation within said casing,

(c) said casing having an inlet through which. fluid enters said pumping chamber,

(d) said casing having an outlet through which fluid is discharged from said pumping chamber,

(e) said casing having a shoulder therein,

(f) a dam pivotally mounted in said chamber adjacent said shoulder and between said inlet and said outlet,

(g) a portion of said darn engaging said shoulder in one direction of rotation of said impeller to retain said dam in a first position wherein said dam directs fluid from said chamber to said outlet, and

(h) said dam being moved to a second position by! the fluid in response to the other direction of rotation of said impeller so that the fluid is circulated within said chamber.

6. A turbine pump comprising:

(a) a casing defining an annular pumping chamber,

(b) an impeller mountedfor rotation within said cas- (c) said casing having an inlet through which fluid enters said pumping chamber,

(d) said casing having an outlet through which fluid is discharged from said pumping chamber,

(e) a dam pivotally mounted in said chamber for movement between a first position relative to said impeller in which fluid is directed by said dam to said outlet and a second position in which fluid is cir culated along an annular path within said chamber,

(f) said dam being urged toward said second position by hydraulic pressure developed by movement of said impeller, and

g) selectively operable stop means external of said casing for limiting the movement of said dam by said hydraulic-pressure to determine said second position.

References Cited by the Examiner UNITED STATES PATENTS 1,652,659 12/1927 Brady 103-96 2,277,210 3/1942 Cook 103-96 2,455,552 12/1948 Bower 10397 2,883,843 4/1959 Bochan 1033 2,969,739 1/1961 Clearman 1033 LAURENCE V. EFNER, Primary Examiner.

Claims (1)

1. A TURBINE PUMP COMPRISING: (A) A CASING DEFINING AN ANNULAR PPUMPING CHAMBER, (B) AN IMPELLER MOUNTED FOR ROTATION WITHIN SAID CASING, (C) SAID CASING HAVING AN INLET THROUGH WHICH FLUID ENTERS SAID PUMPING CHAMBER, (D) SAID CASING HAVING AN OUTLET THROUGH WHICH FLUID IS DISCHARGED FROM SAID PUMPING CHAMBER, (E) A DAM PIVOTALLY MOUNTED IN SAID PUMPING CHAMBER ADJACENT SAID OUTLET, (F) AND SELECTIVELY OPERABLE MEANS CONNECTED TO SAID DAM FOR MOVING SAID DAM BETWEEN A FIRST POSITION, IN WHICH IT BLOCKS SAID PUMPING CHAMBER TO DIRECT LIQUID INTO SAID OUTLET, AND A SECOND POSITION, IN WHICH FLUID IS CIRCULATED ALONG AN ANNULAR PATH WITHIN SAID PUMPING CHAMBER.

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