US1329549A - Air-ejector - Google Patents

Description

H. F. SCHIVllDT.

AIR EJECTOR.

APPLICATION FILED APR.3. 1918.

1 ,329, 549, Patented Feb. 3, 1920.

, NT WITN 551: /W/ VE 9 ATTORNEYfi.

UNITED STATES PATENT OFFICE.

HENRY F. SCHMIDT, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF EENNSYLVANIA.

AIR-EJECTOR.

Specification of Letters Patent. Patented Feb. 3, 1920.

Application filed April 3, 1918. Serial No. 226,504.

'0 all whom it may concern Be it known that I, HENRY F. SCHMIDT, a citizen oi 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 Air-Ejectors, of which the following is a specification.

This invention relates to air ejectors or similar apparatus for removing air or other non-condensable gases from condensers.

An object of this invention is to produce an improved air ejector apparatus in which means are employed for raising the pressure of the air withdrawn from the condenser in successive steps prior to discharging it into the atmosphere or a region of higher pressure.

A further object is to produce an improved multistage ejector in which improved means are employed for condensing the motive fluid employed in one or more of the stages oi" the ejector and for removing the water Of condensation and the condensing water employed in accomplishing the condensation.

These and other objects are attained by means of apparatus embodying the features herein described and illustrated in the drawings accompanying and forming a part hereof. I

In the drawings: Figure 1 is a diagrammatic illustration of an ejector installation embodying my invention.

Fig. 2 is a diagrammatic illustration of a modification of the apparatus shown in Fig. 1.

Referring to Fig. 1 of the drawings: coi'idensor 3 of any type but illustrated as a surface condenser is provided at a convenient point with an air oi talze port 4-. The inlet port 5 of a two stage ejector 5 is shown in communication with the port 4-. The ejector 5 may be of any type and while I have illustrated a two stage ejector, it will be understood that any number oi stages may be employed. As shown. the first stage of the ejector includes a steam delivery nozzle 6 which receive team 't'roa'i any suitable source and discharges it through a combining chamber 7 with which the inlet port 5 con'ununicates. The combining chamber communicates with a dif fuser 9, which is so arranged that the stream of steam issuing from the nozzle 6 passes therethrough Without substantial change in direction. The outlet of the difiuser 9 is shown in communication with the inlet port 10 of the second stage of the ejector. This stage may be similar in details of construction to the first stage. For the purpose of avoiding the necessity of passing all of the motive fluid delivered to the first stage of the ejector through the second or subsequent stages, I have illustrated means for condensing at least a part of the motive fluid and for delivering the condensate and the condensing water back to the condenser. As shown, a series of water jets 11 are located around the condenser 9 at or near the effective end of the diffuser. These jets receive water from a water chamber 12 and dis charge it into and across the diffuser in the form of a spray. The water so discharged and the resulting water of condensation collects in a U-pipe 18, which "forms a water seal between the ejector andthe condenser and also serves to dischargethe water into the condenser. lVith thisarrangement the seal acts to maintain a predetermined difference in pressure between the interior of the condenser 3 and the outlet of the first stage of the ejector. The connnunication between the first and second stages is so located that it is above the normal water level on the ejector side of the water seal.

In Fig. 2, I have shown a modification ot the invention in. which the separate elements are so arranged as to render it possible to employ the ejector without the necessity of increased head room. As shown, the condenser 3 communicates through piping 14 withthe first stage 15 of the ejector. This stage may be similar in details to the first stage of the apparatus illustrated in Fig.

'1. The discharge piping 16 between the outlet of the first stage 15 and the condenser 3 is arranged to deliver water to the upper portion of the condenser; In condensers of ordinary capacities, the height of the corn denser is sufficient to provide an adequate water seal to maintainthe desired pressure at the outlet of the first stage of the ejector without increasing the head room. The fact thata condensate pump is ordinarily employed immediately below the condenser increases the necessary headroom for the condenser installation per se, and consequently gives greater leeway 1n provldmg the neoessary height for the water seal between the ejector and the condenser.

The second stage 17 of the ejector illustrated in Fig. 2 is so located that its inlet is somewhat above the discharge of the piping 16. While such an arrangement is not absolutely essential it is desirable, because it prevents floodin of the second stage 17 and the attendant osses where moisture or water is delivered to a steam actuated ejector. With the apparatus as illustrated in Fig. 2, a flooding of the first stage at the time of starting the ejector will not detrimentally afi'ect the operation of the apparatus. As soon as steam is delivered to the first stage it operates to create a partial vacuum within the condenser and also eject the water accumulated within the first stage through the piping 16 into the condenser. As soon as the ejector is cleared of water, normal operation follows. The steam issuing from the nozzle of the first stage entrains air and non-condensable gases withdrawn from the condenser and accomplishes a partial compression of these gases. As the expanded motive fluid decreases in velocity in passing through the difl'user it encounters the spray of condensing water issuing from the nozzles 11' and is condensed. The water of condensation and the condensing water collects in the lower portion of the ejector apparatus and in the piping 16 from which it is discharged in a more or less constant stream into the condenser. Air and non-condensable gases are delivered to the inlet of the second stage of the ejector from which they are discharged into the atmosphere or into a region of higher pressure.

The water delivered from the piping 16 to the condenser is discharged from the condenser by the condensate pump 18, which ordinarily discharges the condensate collected within the condenser. The water discharged into the condenser by the pipe 13 of Fig. 1 is also discharged from the condenser by the condensate pump 18. It will, of course, be apparent that the second stage of the ejector may also be provided with a water spray and that a water seal may be provided between it and the first stage or between it and the condenser for discharging the condensing water and the water of condensation. Such an arrangement would only be employed where a triple or a quadruple stage ejector is utilized.

While I have described and illustrated but two modifications of mv invention, it will be apparent to those skilled in the art that various modifications, changes, additions and omissions may be made in the apparatus illustrated without departing from the spirit and scope of the invention, as set forth by the appended claims.

What I claim is:

1. In a condenser installation, a condenser, a multi-stage ejector for withdrawing noncondensable fluid from the condenser, means for condensing the motive fluid employed in the first stage of the ejector, and means including a manometric column forming a liquid seal between the condenser and the outlet of the first stage of the ejector for discharging liquid collected in the ejector into the condenser and preventing e ualization of pressure in the condenser and t e difi'user of the first stage of the ejector.

2. In a condenser installation, acondenser, a multi-stage ejector for withdrawing noncondensable fluid from the condenser, a manometric liquid seal between the outlet of the first stage of the ejector and the condenser for discharging liquid received from said ejector into the condenser and prevent ing equalization of pressure in the condenser and the outlet of the first stage of the ejector, and a condensate pump for withdrawing said liquid and the water of condensation from the condenser.

3. In a condenser installation, a condenser, a multi-stage ejector for withdrawing noncondensable fluid from the condenser. means for delivering condensing liquid to the outlet of the first stage of the ejector, a manometric liquid seal between the outlet of the first stage of the ejector and the condenser for discharging the condensing liquid into the upper portion of the condenser and for preventing equalization of pressure in the condenser and the outlet of the first stage of the ejector, so arranged that the outlet of said liquid seal into the condenser is located below the inlet of the second stage of the ejector.

4. In a condenser installation, a condenser, a stage of. a multi-stage steam actuated ejector for withdrawing non-condensable fluid from the ejector. means for condensing steam issuing from the first stage of the ejector, a manometric liquid seal between the outlet of the first stage and the condenser for discharging water into the upper portion of the condenser and for preventing equalization of pressure in the condenser and the outlet of the first stage of the ejector, and a second stage of the ejector so located that its fluid inlet is above the discharge of said liquid seal.

In testmony whereof I have hereunto subscribed my name this 1st day of April. 1918.

HENRY F. SCHMIDT. Witness:

C. W. MCGHEE.

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