US1467014A - Fluid-translating device - Google Patents

Description

Sept. 4, 1923. 1,467.014

H. F. SCHMIDT F FLUID TRANSLATING DEVICE Filed Sent. 30 1919 A TTORNEY Patented Sept. 4, 1%23.

UNHTEN STATES rarer orricn.

HENRY F. SCHMIDT, O1 PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING (10., A CORPORATION OF PENNSYLVANIA.

FLUID-TBANSLATING DEVICE.

Application filed September 30, 1919. Serial No. 327,566.

1 0 all whom it may concern:

Be it known that I, HENRY F. SCHMIDT, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Fluid- Trauslating Devices, of which the following is a specification.

This invention relates to fluid translating devires and particularly to ejectors for withdrawing condensate from condensers.

l ljectors have many advantages over ordinary condensate pumps when employed for the purpose of removing condensate, for the reason that they are simple, compact, have no moving parts, such as pistons and impellers and discharge the condensate in the hottest possible condition. However, a disadvantage of the ordinary condensate ejector is that it is not self-starting. A further disadvantage is that an open overflow connection is ordinarily provided between the ejector and the condenser, consequently the fluids passing the overflow port are subjected to the relatively low pressure existing in the condenser, and a certain amount at spilling and evaporation takes place duringthe normal operation of the ejector. A check valve is frequently provided in the overflow passage, but as it opens away from the ejector it does not wholly overcome the disadvantage mentioned.

An object of my invention is to produce a new and improved condensate ejector which is self-starting.

A further object is to produce a new and improved condensate ejector which is so arranged that the fluids passing the overflow port of the ejector during normal operation are not subjected to the pressure existing in the region of low pressure with which the overflow port connects.

A further objectis to produce a condensate ejector having avalve controlled overflow in connection with which means are employed for increasing the closing force exerted on said valve during normal overload conditions and for materially reducing the closing force when conditions are such as to necessitate the opening of the overflow valve.

These and other objects which will be made apparent throughout the further desectional, View of a fluid translating device embodying my invention. F 1g.'2 1s a diagrammatic sectional view of a fluid translating device and illustrates a modification of my invention. In Fig. 1, I have illustrated a condenser 5 having at its top an inlet port 6 for fluids to be condensed, hereinafter called steam, and at: its bottom a condensate collecting chamber or hot well 7. As shown, the hot well 7 is in open communication with the inlet of a condensate ejector 8. The ejector 8 is illustrated as consisting of a nozzle 9 and a converging diverging diffuser tube 10 arranged in the usual manner. The nozzle 9 pro ects into the hot well 7 at a point below the normal condensate level, and the diffuser is axially aligned therewith, hav ing its inlet located within the hot well and below the normal condensate level. The outlet of the diffuser tube 10 connects with a discharge conduit 11, in which I have shown ach eck valve 12 for preventing a reverse flow of fluids from the discharge pipe into the ejector when the ejector breaks, or is not in operat1on. Connected with the'pipe 11 between the checlrvalve,

12 and the outlet of the diffuser 10 is shown an overflow pipe 18 leading to the interior of the condenser 5. V

7 In the overflow pipe 13, I haveshown an overflow valve 14 adapted to be, controlled :,.1

by a piston 15. As illustrated, the piston 15 operates in a cylinder16 in one endof which is shown a spring 17 which tends to hold the valve 14 open. The other end ot' the cylinder 16, I have shown connected with the discharge pipe 11 by means of a pipe orpassagelS.

In operation the condensate in the-hot well 7 is entrained by the jet of motive fluid discharged tronrthe nozzle 9 and is carried into and through the diffuser 10 in the usual manner. H 10 a part ofthe velocity energy of the combined fluids is converted into pressureen- In passing through the difl user ergy in a manner well known to those slrilled T in the art. The pressure of the fluids as they are discharged from the diflt'user 10 is transmitted by means of the passage 18 to the cylinder 16 and under normal operating conditions is suilicient to overcome the force of the spring 17 and to hold the valve 11- closed. At the time of starting up, however,- the velocity head may not be sulli cient to expel the condensate against eX- ternal pressure, consequently the condensate is returned to the condenser through the overflow 13, the valve lat being open under such conditions. As soon as the ejector is capable of expelling the condensate against the external pressure, the valve lt is closed by the pressure of the condensate and consequently the discharge passage 11 is no longer subjected to pressure conditions eX- isting within the condenser.

If the amount oi condensate to be withdrawn from the condenser 5 is not equal to the minimum capacity or" the ejector 8,

the e'ector breaks that is it ceases to entrain and discharge condensate. As a result, the pressure in the discharge pipe 11 drops, the check valve 12 closes, the valve 14, is opened by the spring 17, and the pressure against which the ejector must discharge is reduced to the pressure existing in the overflow conduit 13. The valve 14: will remain open until normal operating conditions are reestablished, after which it is held closed. This is accomplished by so proportioning the strength of the spring 17 with relation to the opposing ditlerential pressure exerted by the fluid on the piston 15 and valve let, that the spring is just capable oi. opening the valve under conditions of overflow, whereas the preponderance of the closing fluid pressure over the spring is suflicient to positive y hold the valve closed -during normal operating conditions.

In Fig. 2, I have illustrated a condenser 19, which Is equ1ppedwv1tha condensate ejector 20, communication between the conauxiliary nozzle 26 axially aligi'led with the nozzle 22 and, in ell ect, extend ng through it into the combining chamber of the ejector. As shown, the nozzle receives motive fluid through an inlet port 27 and the nozzle 26 receives motive fluid, at a different pressure, if desired, through a separate pipe 28. As illustrated, the discharge of the diffuser 24L communicates with a discharge conduit 29 in which I nozzle 26 acting on the piston 3%.

have shown a check valve 30 for preventing the pressure in the discharge conduit irom backing up into the ejector when the latter is not in operation.

As shown, the overflow chamber 25 of the ejector communicates with the interior of the condenser 19 by means of a conduit 31. In this conduit I have illustrated an overflow valve 32, which is adapted to control communication between the chamber 25 and the condenser and which is controlled by two pistons and operating in axially aligned cylinders and 36. The piston 33 of greater diameter than the piston 3e and is subjected to the pressure of the fluids issuing from the ejector 20 by means of a passage 37 which connects the cylinder 35 with the discharge conduit The cylinder 86 communicates with the inlet pipefZS of the nozzle 26 through a passage 38 and consequently the piston 34 is subjected to the pressure of the motive fluid delivered to the nozzle 26. As shown, the connections are such that both fluid pressures tend to hold the overflow valve 32 in its closed position. A spring 43 is shown in the cylinder 35 below the piston 83, and is so adjusted that it is capable of opening the valve 32 in opposition to the combined fluid pressures on the pistons 33 and 34 when operating conditions are such that the velocity of the combined fluids dischargz'ed from the tube 23 is not capable of overcoming external pressure.

I have shown a valve 39 in the pipe 23, which, as illusl rated, is adapted to be controlled hythe longitudinal expansion and contraction of the condensate pipe 21, As illustrated, the valve 39 is connected to the pipe 21, by means of a motion multiplying device consisting otja lever 40 and a rod d1 so arranged that longitudinal movement of the pipe actuates the valve 39.

During the ;normal operation of the ejector 20, condensate from the condenser 19 flows through the pipe 21 to the ejector where it is entrained by the jets of motive fluid from the nozzles 22 and 26 and is discharged through the combining tube 23 and the difluser 24: into the discharge pipe Under such conditions the valve 32 in the overflow pipe 31' isheld closed by the pressure of the fluids discharged from the ejector 2O acting on the piston 33. and the pressure of the motive fluid delivered to the suit, the fluids passingthrough the overflow chamber are not subjected to the low pres As a reall) ing conditions, the small amount of con dens-ate coming from the condenser indicates a high vacuum, and as the condensate is relatively cool, the valve 39 will be closed or nearly closed, so that the auxiliary nozzle 26 will deliver little or no entraining steam. When large quantities of steam are delivered to the condenser 19, the vacuum drops to some extent and consequently the temperature of the condensate withdrawn from the condenser increases and causes the valve 39 to be opened and to thereby deliver more motive fluid to the auxiliary nozzle 26.

During normal operation, the pressure on the piston 33, and in some cases on both pistons, is relatively high and consequently the overflow valve is held shut. It is therefore evident that in the apparatus illustrated, the amount of motive fluid delivered to the ejector is increased when a large amount of condensate is to be withdrawn from the condenser and that the supply of motive fluid to the auxiliary nozzle 26 is partially or completely shut oil when only a small amount of condensate is to be with drawn. It is also evident that the force required to open the valve 32 varies with the pressure of fluid discharged by the ejector and to some extent with the amount of motive fluid delivered to the ejector.

In. the apparatus illustrated, the main nozzle 22 is designed to deliver expelling steam or motive fluid all the time the ejector is in operation and is preferably supplied with low pressure steam such as that discharged from other auxiliaries. The auxiliary nozzle 26 may be termed a booster nozzle. as its function is to deliver high pressure motive fluid or an additional supply of motive fluid and to assist in expelling the condensate when the supply of condensate is relatively large.

It will be understood that the illustrations are more or less diagrammatic, and par ticular attention is called to the fact that the control pistons of the valve 32, (Fig. 2) are diagrammatic to facilitate illustration and that the piston 34, exposed to steam pressure will, of necessity, be very small so that it will merely exert an augmenting force and will not withdraw the control from the piston This piston is, however, necessary, since it has been found that some means must be employed for increasing the resistance to overflow when a large quantity of steam is employed or when high pressure steam is employed in an ejector. Otherwise. the ejector will continually tend to break and it will be diflicult to establish su'lticient flow to overcome external resistance.

It will also be understood that the details of construction may be materially modified and that various changes, omissions, additions and substitutions may be madewithoutdeparting from the spirit and scope ot the invention as set forth by the appended claims.

What I claim is:

l. in combination with a condenser, an ejector for withdrawing water of condensation therefrom having an over-flow port provided therein, a passage communicating with said port and with the interior of the condenser, a valve in said passage for closing comniiunication between said port and vsaid condenser. and means for controlling said valve responsive to pressure at the'outlet of said ejector.

2. In combination with a condenser, an ejector for withdrawing water of con densati-on irom the condenser. a passage between an overflow port of said ejector and the interior of the condenser, a valve for controlling said passage, and means for increasing the closing force on said valve under conditions of normal operationand for decreasing the closing force under conditions necessitating the opening of said valve.

8. In combination with a condenser, an ejector for withdrawing water of condensation from the condenser, a passage between an overflow port of the ejector and the interior oi the condenser, a valve in said passage responsive to the pressure of fluid at the overflow and means responsive to an increase in pressure at the outlet of the eject-or for closing the overflow passage.

4-. In combination with an ejector, an overflow passage communicating" therewith, a valvein said passage opening in the direction of overflow ot fluid therethrough, and means responsive to an increase in pressure of the fluids passing through the ejector "for closing the valve.

5. In an ejector, an overflow valve openinp; outwardly in the direction of flow ot' fluid therethrough, means responsive to a decrease in pressure of the fluids passing through the ejector for opening said valve, and means responsive to an increase in pressure of the fluids for closing the valve.

6. In combination with an ejector, an

overflow passage, a valve in said passage opening in the direction of flow 0t fluid therethrough and means responsive to variations in pressure ot' the fluids discharged from the ejector tor varying the ctlectiveness oi. the valve.

7. In combination with an ejector, an overflow valve, and a piston responsive to variations in pressure of the fluids passing through the ejector for controlling thevalve.

S. In an ejector, an overflow passage, and means responsive to variations in pressure of the fluids passing through the ejector for varying the resistance to discharge of fluid through the passage.

9. In an ejector, means for delivering motive fluid thereto, an overflow passage, and means responsive to an increase in the pressure of motive fluid delivered to the ejector for increasing the resistance to discharge of fluids through the overflow passage.

10. In combination with an ejector, an overflow passage communicating therewith and with a region of relatively low pressure, means responsive to an increase in pressure or the fluids passing through the ejector for closing the overflow passage, and means for opening the passage when the pressure of the fluids drops below a predetermined amount.

11. In a condenser installation, a con denser, an ejector for withdrawing condensate from the condenser and having an overflow passage communicating therewith, and means responsive to variations in pressure of the fluids passing through the ejector for varying the resistance to discharge of fluids through the overflow passage.

12. An ejector having an overflow passage communicating with a region of relatively low pressure, and means responsive to variations in pressure of the fluids passing through the ejector for preventing said fluids from being subjected to the low pressure when passing the overflow passage during normal operation of the ejector.

13. In a condenser installation, a condenser, an ejector for withdrawing condensate from the condenser, means for delivering motive fluid to the ejector, means responsive to variations in the temperature of condensate to be withdrawn from the condenser for varying the amount of motive fluid delivered to the ejector, and means for separately delivering additional motive fluid to the ejector.

14;. In combination with a condenser, an ejector for withdrawing water of condensation from the condenser, a passage establishing communication between an overflow port of the ejector and the interior of the condenser, a valve for controlling said passage and pressure responsive means including means responsive to the pressure of the motive fluid delivered to the ejector for controlling the operation of said valve.

15. In combination with a condenser, an ejector for withdrawing water of condensation from the condenser, an overflow passage between the ejector and the interior of thecondenser, a valve in said passageand means responsive to the pressure of the motive fluid delivered to the ejector and to the pressure of the fluid delivered by the ejector for controlling the operation of said valve.

16. In an ejector, an overflow valve, one face of which is subjected to the pressure of fluids passing through the ejector in the direction in which the valve opens, a spring stressed to open the valve, and means responsive to pressure of the fluids exerting a closing force upon the valve.

17. The combination with an ejector having a combining tube and a difluser, of overflow ports between the combining tube and diffuser, an overflow passage communicating with said ports, and means responsive to the pressure in said overflow passage and to the pressure at the outlet of said difl'user for controlling the flow of fluid through said overflow passage.

In testimony whereof, I have hereunto subscribed my name this 29th day of September, 1919.

HENRY F. SCHMIDT.

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