US1611689A - Air ejector - Google Patents

Description

Dec. 21 ,1'926. 1,611,689

4 v J. H. SMITH AIR EJECTOR Filed March 5 1921 2 Sheets-Sheet INVENTOR J Mm H. Smith ATTORNEY Dec. 21 .1926. I 1,611,689

4. H. SMITH AIR EJECTOR Filed March 5 ,1921 2 sheets-sneak 2 A'ITORNEY Patented Dec. 21, 1926.

warren stares Parana JOHN H. SMITH, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNQR T VIESTINGHGUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPQRA'EITQOII Q15 PENNSYLVANIA.

A133, EJECIGR.

Application filed March 3, 1921.

My invention relates to ejectors and par ticularly to that class of ejectors employed for exhausting non-condensable fluids from condensers, and it has for an object the production of a two-stage ejector apparatus of the character designated which shall be simple in construction and which shall operate with a high degree of economy of steam consumption. It is a further object of my invention to provide an ejector apparatus in which the heat of the gases passing therethrough, the heat of the steam op erating the ejectors and the water condensed. from these fluids are conserved and delivered to the power unit.

A still further object of my invention is to produce an efficient air separator which is simple and compact in structure and which cooperates with ejectors of conven tional types to accomplish the above objects.

These and other objects of my invention, which will be manifest in the further description thereof, are set forth in the following specification and illustrated in the accompanying drawing, in which Fig. 1 is a diagrammatic view of a. condenser system constructed in accord with my invention; Fig. 2 is a vertical sectional view of an air separator on the line 2-2 of Fig. 8; Fig. 3 is a similar sectional View on the line 3-3 of Fig. 2; Fig. a is a detailed elevation of the ejector arrangement; and Fig. is a diagrammatic view of a modification of the construction illustrated in Fig. 1.

The marked advantage of operating turhines under high-vacuum exhaust conditions has led to the development of turbine constructions capable of utilizing extremely low exhaust pressures. These conditions of operation have imposed added duties upon the condensing apparatus of power plants utilizing turbines as prime movers, and especially upon the air removal apparatus of such plants, since the vacuum pressures, which it is practicable to utilize in low-pressure turbine plants, are, to a large extent, determined by the efficiency of the air removal apparatus.

By the novel construction of my two-stage ejector, 1 am able to reduce the steam consumptio-n in the operation of my condenser air ejector to approximately one-half of that required for the operation of air ejec tors now in use. This result I accomplish by associating an auxiliary condenser, per- Serial No. 4 19, 365.

forming a dual function of an inter-cooler and an air separator, with each stage of the two-stage ejector. The cooling and the sep aration of the moisture from the air during the process of compression greatly reduces the specfic volume of the air which must be handled by the ejector device, and, conscquently, less energy is required for its removal from the condenser.

My ejector construction also provides means whereby the heat of the motive steam is reclaimed and returned to the plant. The cooling medium for a first stage auxiliary condenser is condensate from the main condenser, which, having absorbed heat from the air and the steam used as a motive fluid in the ejector, is conducted to the feed water tank. An arrangement permitting the return of the condensate from the first-stage condenser unit to the main condenser outlet or hot Well is also provided. The water for the cooling spray of the second stage condenser unit is also condensate from the main condenser, which, together With. the condensed steam of the second stage ejector is delivered to the feed water tank. Further economy in the operation of the air ejectors is thus attained, since the heat and water content both of the motive steam used in the ejectors and of the air removed thereby, is carried from the air removing apparatus to the feed water tank of the power plant.

Referring to the drawing for a more de tailed description of my invention, in Figures 1 to 4, I have indicated at 10 a surface condenser of the conventional type. It is tobe understood, however, that my air ejector apparatus is adapted for use with other types of condensers, as for example, jet condenser-s. Exhaust steam from a prime mover is admitted to the condenser 10 through the inlet opening 11, and any suit able provision for the removal of air from the condenser may be made, as through an air discharge opening 12 from whence it is conducted through a pipe 13 to a manifold 14. Connected to the manifold 14 by conduits 15, preferably provided With shut-oil valves 16, are two or more ejectors 17. The air thus delivered to the ejectors is entrained therein by steam under pressure admitted through inlet pipes 18. The ejectors 17 may be of any conventional type. Each ejector is arranged to discharge through a diffuser 19 and valve 20 into a branch 21 which coma lower chambers.

municates with a manifold 22. A pipe 23 delivers the mixed steam and air from the manifold 22 to a condensing device 25.

The condensing device 25 is composed of a central vertically extending casting 26 having at its upper portion outwardly extending flanges 27, 28, (Figures 2 anti 3). Secured to these flanges are two tube sheets 29, 30 which are arranged to receive tubes 31, 32 which extend througn the central chamber. A horizontally extending partition wall 33 divides the central tube chamber into separated upper and lower compartments. lVater boxes 34 and are secured in any suitable manner to the casting 26 at the edges of each of the tube sheets 29 and 30. The water box 34 is provided with a horizontally extending pdltlbloil 36 in alinement with the partition 33 which divides the water box 35 into separated upper and The water box has a similar horizontal partition wall 3' which likewise divides the water hot; 34 into upper and lower chambers. A vertical partition wall 38 is provided within the water box 35 and serves to further divide the upper and lower water ho chambers into two separated chambers.

The condenser structure thus far described consists of two distinct condenser units separated by partition walls 33, 36 and '3'? and comprising an upper condenser unit 40 and a lower condensing unit 41. The upper condenser unit 40 receives cooling water through the inlet opening 42 and discharges it after traversing in' a double pass through the tubes 31, through an outlet opening 43 Mixed air and steam discharged from the conduit 23 enter the central. condensing chamber of the upper condenser unit 40 through an inlet openinsr 44 and dry and cooled airis discharged th Jetrom through the outlet 45 in the top wall thereof. An outlet 46 is provided for the withdrawal of condensate from the upper condensing chamber. which is preferably led to the hot well of themain condenser by a pipe 47.

Cooling water enters the lower conden er unit 41 through an inlet opening 48 traverses in a double pass through thetubes 32 and is discharged through an outlet opening 49. Situated in the lower portion of the lower condenser unit 41 is a jet condenser apparatus which consists of a water sprav pipe 54 and a perforated air pipe A vertically disposed partition 56 extends between thesides of the lowermost compartment over which the condensate flows to a disc-hargeopening 57. An air dischai outlet 58 is provided near the upper portion of the lower condenser unit 41. It will. thus be seen that the lower condenser unit 41 l composed of two condensing members, an upper surface condenser and a lower 1st condenser.

The air delivered from the outlet 45 of the upper condenser unit 40 is conducted by a pipe 60 to a manifold 61 from which lead two ormore branch pipes 62, provided with valves 63, to ejectors 64. Each ejector is provided with an inlet pipe 65 for the admission of steam under pre ire and with a discharge connection 66 which conducts the mixed air and steam to a "fold (3?. The mixed steam and air V n the manifold 67 through a pipe 69 p provided with a valve 69 to nozzle no of tie lower condenser unit The cooling water for the cond nser units 40, 41 is talten from a hot well T0 oi: the main condenser 10. As illustrated a pipe 71 leads to a pump '?2 which forces the con densate through a p pe 73 to an elevated tank 74. t tondensate delivered through a pipe '75 and branch 76 to the inlet open 42 of the upper condenser unit 40, circulates through the 31 cooling water and is discharged through the outlet and a conduit T7 into a feed water tank 80. The ater for the cooling s ray of the lower condenser unit 41 is also supplied from the tank 7 4 through the conduit '75 and a branch 81 which connected to the spray nozzle The outlet opening 5'? of the lower condenser unit 41 is also connected to the feed water tank through a pipe 82. The heated condensate in the feed water tank 80 may be delivered through a conduit 83 directly to a boiler teed pump. since its tempe ure is sutliciently high to serve as feed either to a boiler or an economizer.

The cooling water for the si denser of the lower condenser ur: be taltcn rom an external source which is a considerably lower tempera ure than the condensate of the In condenser, although under favorable conditions it may be supplied itrom tank T4 as will be hereinafter more fully -described. in relation to 5. As shown, the cooling water is supplied through a concuit to a pump 91 and thence conveyed thro ie'h a pipe 92 to the inlet opening 48 01 the lower condc ser unit 41 and after traversing the ta es 3-2 is discharged through the opening 49 and conduit '95.

Having described the arrangement of an apparatus embodying my inventiom the op eration thereof is follows: Exhaust steam is delivered to the condenser 10 through the inlet opening 11. The steam is condensed and the condensate collected in the hot well 70. The air and non-condensable gases removed through the outlet 12 ant. conduit 13 to the manifold 14. It is preferable to connectto the manifold 14 at least two eiectors. This arrangement provides a spare ejector in case an ejector, which should be suflic-ient for normal service, fails, or in case over-load duty is placed upon the condenser during extended periods. Steam under pressure supplied to the ejector 17 withdraws the air from the manifold 14 and consequently from the condenser 10, and discharges the mixed steam and air at an in creased pressure into the upper condenser unit 40. lVithin this unit, the air is separated from the steam and moisture, and its temperature and specific volume greatly reduced. The dry air is delivered through the conduit to the second stage ejector 64 wherein the pressure of the air is further raised to a little above atmospheric pressure and the combined steam and air discharged into the pipe 55 in the lower portion of the lower condenser unit 41. The steam and air entering through the perforated pipe 55 bubbles up through a body of water and through the water spray from the pipe 54. The steam is thereby eondensed and the air passes upwardly through the tubes 32 of the surface condenser where its temperature and specific volume is further reduced and where it is freed of any moisture content. It is then discharged through the opening 58 to the atmosphere.

The cooling water for the auxiliarv condensers may be supplied from the hot well of the main condenser from which the condensate is preferably forced into a gravity tank 74, from whence it is supplied to the upper condenser unit 40 and to the water spray of the lower unit 41. This condensate from the main condenser having re ceived the heat from the steam and air pass ing through the ejector apparatus is then conducted to the feed water tank 80 from whence it is delivered to a boiler feed pump.

It may be desirable to supply the surface condenser of the lower unit 41 with cooling water at a lower temperature than that of the condensate in the main condenser in order to remove as much of the moisture as possible from the air before it escapes to the atmosphere. This is particularly true in marine installations where it is advantageous to reduce to as great a degree as possible the make-up water which must be added to the power plant. In such installations this external cooling water may well be taken from the sea. As illustrated, cooling water from an external source is forced by a pump 90 through the pipe 92 to the surface condenser of the lower unit 41, where it traverses the cooling tubes 32 and is discharged through pipe 95 to any suit-- able discharge.

It is within the purview of my invention to supply the surface condensers of both the upper and lower condenser units 40, 41 with cooling water either from an external source or from the hot well of the condenser. Referring to Fig. 5 of the drawing 1 have shown an arrangement which is essentially the same as that illustrated in Figs. 1 to 4. Additional provision is made in this embodiment of my invention for supplying the cooling water to the surface condenser units from either an external source or from the condensate tank 74. As shown, a pump 100 receives cooling water from any suitable external source through a pipe 101 and forces it through a pipe 102 and branches 103, 104 to the condenser units 40, 41 from whence it is discharged through pipes 105, 106 to a discharge pipe 107. Cooling water from the condensate tank 74 may be supplied to condenser units through pipe and branches 108 and 109, the former communicating wit-h the pipe. 102 leading to the surface condensers and the latter to the jet condenser 54. The valves 110, 111, and 112 are suitably disposed in the pipes 102 and 104. to permit the cooling water to be supplied to the surface condensers from either the external supply pipe 101, or the condensate tanks 74 through pipe 7 5. The valve arrangement also permits condensate from tank 74 tobe supplied to the surface condensers of the upper unit 40 and water from the supply pipe 101 to the surface condenser 41 in the manner described above in reference to Fig. 1. 1

The operation of the apparatus illustrated in Fig. 5 is in every respect similar to that described above in relation to Figs. 1 to 4. It provides an apparatus which, by the operation of the valves'llO, 111, 112, may be adjusted to meet varying conditions of operation. Where condensate alone is employed for effecting the condensation of the steam and the cooling of the air in my ejector apparatus, all of the water employed for this purpose is conserved and its temperature raised suitably for boiler feed purposes. lVhere water from an external source is employed, in one or both of the surface condensers of the ejector apparatus, some of the heat is dissipated in the discharge water.

Advantages of my system of air removal reside in simplicity and low cost of construction, in economy in steam consumption required to operate the ejectors, in conservation of the heat and water in the air and in the motive steam, and in flexibility of operation, insuring stability and continuity of service under varying conditions.

While I have shown my invention in two forms, it will be obvious to those skilled in the art that it is not so l mited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art. or as are specifically set forth in the appended claims.

What I claim is:

1. In combination with a condenser having means for the removal of air, an ejector connected to the air removal means, an auxiliary condenser for condensing gases from the ejector, means for supplyingcondensate from the main condenser as'cooling water to the auxiliary condenser, and means for delivering the 'ater condensed in the auxiliary condenser to said condensate supplying means.

2. In combination with a condenser having-means for the removal of air, a steamoperated ejector connected to the air removal means, an auxiliary condenser for condensing gases from the ejector, means for supplying condensate from the main condenser as cooling water to the auxiliary condenser, and means for delivering the water condensed in the auxiliary condenser to said condensate supplying means.

In combination with a condenser having means for the removal of air, a plurah ity of ejectors, an auxiliary condenser for each ejector, means connecting the ejectors to the air removal means and in series with each other, means for supplying to each auxiliary condenser condensate from the main condenser as cooling water, and additional means for supplying cooling water from an extraneous source to the auxiliary condenser associated with the ejector last in the series. 7

4. In combination with a condenser having means for the removal of air, a firststage ejector connected to the air removal means, an auxiliary condenser into which the first-stage ejector discharges, a secondstage ejector connected to the outlet of the auxiliary condenser, a second auxiliary con denser into which the second-stage ejector discharges, means for supplying condensate from the main condenser as cooling water to each of the auxiliary condensers, and means for supplying cooling water from an extraneous source to the second auxiliary condenser.

5. Ina pumping apparatus for condensers having air removal means, the combination of a first-stage ejector connected to the air removal means, an auxiliary condenser into which the first-stage ejector discharges, a second-stage ejector connected to the outlet of the auxiliary condenser, a second auxiliary condenser into which the second-stage ejector discharges, means for supplying condensate from the main condenser as cooling water to each of the auxiliary condensers, and means for withdrawing the cooling condensate and the condensate from the auxiliary condensers whereby both the heat and water entering the pumping apparatus are conserved.

6. in combination with a condenser hav ing separate air removal and condensate removal conduits. a steam operated ejector connected to the air removal conduit, an auxiliary condenser into which the ejector discharges, the condensate removal conduit being arranged to supply cooling water to the auxiliary condenser, apump in the condensate removal conduit and means for con ducting condensate formed in the auxiliary condenser to the condensate removal conduit at a point between the pump and the condenser.

7. In combination with a condenser having separate air removal and condensate removal conduits, a steam-operated ejector connected to the air removal conduit, an auxilia I condenser into which the ejector dischar es, :1 second. steam-operated ejector conne ed to said auxiliary condenser, the condensate removal conduit being arranged to supply cooling water to the auxiliary condenser-i; and means for withdrawing the condens-ates whereby both the heat and water involi d in the withdrawal and cooling oi air are conserved.

the

3. in combination with a condenser hava two-stage steam-operated ejector, an ary condenser for the ejector compris 5 a c, n,r,'a horizontal partition dividing casing into two separate chambers, one oi' said chambers having end boxes and conin; tubes constituting a. surface condenser; the other of said chambers having end water boxes and connecting tubes in the up per portion thereof and a water spray nozzle and vapor inlet in the lower portion thereof ant constituting a combined surtace and jet condenser. the first-stage ejector discharging into the said one chamber, and the secondstage ejector withdrawing uncondensed fluids from the said one chamber and discharging into the said other chamber.

9. In combination with two steam-operated ejector pumps connected in series, an air separator comprising a casing. a horizontal partition dividing the easing into two separate chambers, one 0t said-chambers having end water boxes and connecting tubes and constituting a surface condenser. a conduit leading to the lower portion of said chamber and receiving the discharge from one ejector, an outletconduit leading from the top thereof to the second ejector; the other of said chambers having and water boxes and connecting tubes in the upper portion thereof, a water spray pipe in the lower portion thereof, a second spray pipe below the water spray pipe and connectea to receive the discharge from the second ejector, and an outlet in the upper portion of the other chamber.

10. In combination with two steam-operated ejector pumps connected in series an air separator comprising a casing. a horizontal tition dividing the casing into two sepae chambers; one oi? said chambers having end water boxes and connecting tubes and constituting a surface condenser, a conduit leading to the lower portion of said chamber an outlet conduit leading from the top thereof to the second ejector, a condensate discharge leading from the bottom thereof; the other of said chambers having end water boxes and connecting tubes in the upper portion thereof, a water spray pipe in the lower portion thereof, a second spray pipe below the water spray pipe and connected to receive the discharge from the second ejector and an air discharge opening in the upper portion and a water discharge opening in the lower portion of the said other chamber.

11. In combination with a condense-r having means for the removal of air, a firststage ejector connected to the air removal means, an auxiliary surface condenser into which the first-stage ejector discharges, a second-stage ejector connected to the outlet of the auxiliary condenser, and a second auxiliary condenser into which the secondstage ejector discharges, said second auxiliary condenser having tubes through which a cooling fluid is circulated, and a jet by and receiving the discharge from one ejector,

means of which cooling fluid is brought into contact with the fluid to be condensed.

12. In combination with a condenser having means for the removal of air, a firststage ejector connected to the air removal means, an auxiliary surface condenser into which the first-stage ejector discharges, a second-stage ejector connected to the outlet of the auxiliary condenser, a second auxiliary condenser into which the secondstage ejector discharges, said second auxiliary condenser having tubes through which a cooling fluid is circulated and a jet by means of which cooling fluid is brought into contact with the fluid to be condensed, and means for supplying condensate from the main condenser as a cooling fluid to the first auxiliary condenser and to the jet of the second auxiliary condenser.

In testimony whereof, I have hereunto subscribed my name this th day of February, 1921.

JOHN H. SMITH.

Certificate of Correction.

It'is hereby certified that in Letters Patent No. 1,611,689, granted December 21, 1926, upon the application of John H. Smith of Philadelphia, Pennsylvania, for an improvement in Air Ejectors, errors appear in the printed specification requiring correction as follows: Page 1, line 180, claimlO, after the Word chamber insert the Words and receiving the discharge from one ejector; page 5, line 24,

Claim 11,- strike out the Words and receiving the discharge from one ejector; and

hat the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 1st day of February, A. D. 1927. it

[SEAL] M. J. MOORE,

Aeting Commissioner of Patents,

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