US1118383A - Centrifugal pump. - Google Patents

Description

E. THOMSON. CENTRIFUGAL PUMP. APPLICATION FILED NOV. 17,1913.

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m 4 w faw n A TE El STTES ATET ELIHU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CENTRIFUGAL PUMP.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed November 17, 1913. Serial No. 801,390.

To all whom it may concern:

Be it known that I, Emrm Tuomson, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new anduseful Improvements in Centrifugal Pumps, of which the following is a specification.

This invention relates to means for elevating fluids, as water, which is adapted for eneral use, but more particularly where it Is desired to raise the fluid to a considerable height and has for its object to provide a simple and eflicient structure for this purose. p In carrying out my invention 1 utilize the well known principle of the hydraulic ram in a new and efficient manner.

My invention comprises essentially an endless conduit which may take the form of a closed loop, a ump mechanism of any approved type or causing a circulation of fluid through the conduit, means for checle ing the flow through the conduit, and suitable inlet and outlet pipes.

The pump the piston type or the centrifugal type. When of the former type my invention avoids the use of tight packings and when of the latter, of hi h pressure series stages.

The principle 0 my invention, together with the novel features thereof, is fully explained in the following specification wherein l have described certain forms which my invention may take.

In the drawing Figure 1 shows a simple form of apparatus in connection with a pump mechanism of the piston type and illustrating the principle upon which my invention operates; Fig. 2 shows a preferred form of my invention wherein a centrifugal pump is used. Fig. 3 illustrates a modification, and Fig. 4 is a section through the rotary valve shown in Fig. 3.

Referring first to Fig. 1, the numeral 1 indicates a cylinder within which reciprocates the piston 2 which may be operated by the piston rod 3 in any desired manner as by hand or by a suitably connected motor. Communicating with opposite ends of the cylinder, preferably through the to and bottom thereof, is the endless con uit 4 shown in the form of a loop and forming with the cylinder 1 an endless passage for the flow of the fluid to be elevated. The

mechanism may be of eitheropenings into the cylinder 1 are provided with soft washers 6 and 6' forming valve seats against which the piston at the extreme ends of its stroke rests and with which it coiiperates to form a valve for stopping the flow through the conduit. 7 represents a suitable supply of fluid which might be a tank, pond, or well for instance, and from which leads an inlet conduit 8. In the present instance the pump is shown as being of the double acting type and the inlet pipe 8 is accordingly shown as communicating with the conduit at at points 9 and 10 located on opposite sides of the cylinder and in advance of which points and in the pipe 8 are seated inwardly opening check valves 11 and 12. Communicating with the cylinder 1 is the outlet ipe 13 within which is seated the outwar ly opening check valve 14 and communicating with which is an air chamber 15 as is usualin pumping systems generally.

The operation of the arrangement shown in Fig. 1 is as follows: Assuming the parts to be in the position shown with the piston 2 at the bottom of its stroke and resting on valve seat 6. It now the piston be moved upward the fluid column in conduit 4 will be set in circulation. This will continue until the piston reaches the top of its stroke when the seating of the same on valve seat (5' will check further flow through the con duit. This sudden checking of the flow will cause a building up of pressure in the cylinder beneath the piston due to the inertia of the fluid column in the pipe 4 and will as a result force the fluid out through the pipe 13. By this means the fluid can be elevated to a considerable height as is well understood in connection with the operation of the ordinary hydraulic ram. The valve 14 acts as a check valve to prevent flow from the conduit 13 back to the cylinder 1. Upon the upward stroke of the piston, as just described, the fluid forced out through pipe 13 will be replaced by fluid sucked in through conduit 8 and inlet 10, while on the reverse stroke the fluid will be replaced through conduit 8 and inlet 9. By this arrangement I avoid entirely the use of packings for the piston as obviously the same need not fit tightly in its cylinder.

In Fig. 2 I have shown a preferred embodiment of my invention. In this arrangement the flow of fluid through the conduit 4 means through shaft is produced by the centrifugal impeller 16 which may be operated by any suitable l7 andpulley wheel 18. Adjacent the impeller and inadvance of the same as regards the flow through the conduit 4, is the inlet pipe 19 in whichis a check valve 20. Beyond this inlet pipe is located the outlet pipe 21. havingthe check a which the valve 24: seats to check the flow.

valve Between the inlet and outlet pipe openings is located a valve seat 23 upon of fluid through the conduit 4:. The seating of valve 24: upon its seat 23 performs the same function as the seatingof piston 2 upon valve seat 6 or 6 explained in connection with Fig. 1. The valve 24 is nor- .mally'unseated and might be forced to its seat periodically in various ways in order to check the flow through the conduit in the operation of my mechanism. In the present instance it have shown the same as being held open by a coiled spring 25 surrounding the valve stem 26 and playing between shoulder 27 on the conduit 4; and an adjustable nut 28 carried by the stem 26. Con nected to the end of the valve stem 26 is one end of a lever 29 fulcrumed between its ends at 3.0 and having its opposite end connected to stem 31 of a piston 32. The piston 32 moves in a cylinder 33 and is responsive to the flow of fluid through the conduit 4:.

As a means for accomplishing this I connect the cylinder 33 to conduit 4: at a point adj acent a bend therein so that as the fluid flows around the bend a portion will be tangentially deflected against the piston 32 and build up a pressure thereagainst which will be proportional to the square of the rate of flow. As soon as the pressure on the piston becomes sufliciently great it will overcome the opposition of spring 25 and begin to seat the valve 24:. As the valve moves toward its seat it will begin to check the flow through conduit t. Due to the inertia of the-moving volume this checking of the flow will begin to build up the pressure behind. the valve and also on the piston and cause the valve to move quickly and firmly on to its seat. The seating of the valve 2% completely checks the flow through conduit 4 and the pressure resulting causes fluid to be forced out through pipe 21 as will be readily understood. As soon as the pressure drops again spring 25 will unseat piston 24: permitting once more the flow of fluid through the conduit 4:. In order to more quickly seat the valve 24, ll provide a lost motion connection between the stem 31 and the end of lever 29. Tbispermits the valve 24: to be forced to its seat independently of the piston 32 after such piston has moved the valve 2d a strig distance of its seat, the column of centrifugal pump with its simplicity a d ease of operation, and at the same time avoids the use of high pressure stages. This arrangement is. further very desirable in that it is entirely automatic in operation.

The form of the invention illustrated in Figs. 3 and at is thesame as that shown in Fig. 2 with theexcept'ion that in place of the automatically operated valve 24: T provide a positively actuated valve as shown at 33. This valve 33 is here illustrated as being of the rotary type and comprises a cylindrical shell opening at one end to the impeller and having a cut-away portion 34 inthe side. By the revolving of this cylinder the flow of fluid through conduit 4 is regularly permitted and checked. As a means of operating the valve 33 a suitable motor 35' suitably connected as through gearing 36 may be used. This motor may be the same as that used to operate the centrifugal pump or it n'iay be a separate motor as found most convenient or desirable.

fWhile l have shown specific forms of valves and operating means in Figs. 2 and 3 it is to be understood that this is only by way of illustration and that any suitable design of valve and operating means may be used and that the-valves of Figs. 2 and 3 may be either automatically or positively actuated. With the arrangement of the inlet and outlet openings as shown in Figs. 2 and 3, it will be noted that the pressure created -by the pump is added to that due to inertia of the fluid column during each cycle of operation.

with the apparatus which ll now consider to represent the best embodiment thereof; but

I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

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

1. -Means for elevating a fluid comprising an endless conduit for the circulation of fluid,an impeller for causing fluid to circulate in said conduit, means for chec v p is u the flow throughsaid conduit, an outlet pipe communicating with saidconduit, and an outwardly opening checkvalve in said outletpipe. v 2. Means for elevating a fluid comprising a conduit in the form of a closed loop, an impeller for causing fluid to circulate around said loop, means for ehecg the circulationan outlet pipe connected with a conduit in the form of a close the loop, and an outwardly opening check valve in said outlet pipe.

3. Means for elevating a fluid com rilsing, p, means for causing fluid to circulate around said loop, a valve in the loop for checking said circulation, an outlet pipe communicating with the loop, an outwardly opening check valve in said outlet pipe, an inlet pipe communicating with said loop, and an inwardly opening check valve in said inlet pipe.

4. Means for elevating a fluid comprising a conduit in the form of a closed loop, means for causing fluid to circulate around said loop, a valve in the loop for checking said circulation, an outlet pipe communicating with the loop, an outwardly opening check valve in said outlet pipe, an inlet pipe communicating with said loop, an inwardly opening check valve in said inlet pipe, and means for periodically operating said first named valve.

5. Means for elevating a fluid comprising a conduit in the form of a closed loop,

means for causing fluid to circulate around said loop, a valve in the loop for checking said circulation, an outlet pipe communicating with the loop, an outwardly opening check valve in said outlet pipe, an inlet pipe communicating with said loop, an inwardly opening check valve in said inlet pipe, and means controlled by the rate of flow of fluid in the loop for operating said first named valve.

6. Means for elevating a fluid comprising a conduit in the form of a closed loop, an impeller located in the conduit, means for operating the same, an inlet pipe adjacent the impeller, an inwardly opening check valve therein, an outlet pipe adjacent the inlet pipe, an outwardly opening check valve in said outlet pipe, a valve for closing the conduit, and means for operating said valve.

7. In an apparatus of the character described, the combination of a centrifugal pump, a conduit connecting the delivery side thereof to the suction side, a discharge pipe connected with the conduit, an outwardly opening check valve therein, a valve in the conduit between the discharge pipe,

and the suction side of the pump, and means for operating said last named valve.

In witness whereof, I have hereunto set myahand this twelfth day of November, 191 l ELIHU THOMSON.

Witnesses:

Joan A. MCMANUS, Jr., ALEX. F. MACDONALD.

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