US2106362A - Steam jet refrigeration apparatus - Google Patents

Description

2 Sheets-Sheet l E. F. sTALcUP Filed April 24, 1956 HIGH PREssuR EJEcToR ATTORNEY STEAM JET REFRIGERATION APPARATUS Jan. 25, 1938.

Jan. 25, 1938. E. F. sTALcuP STEAM JET REFRIGERATION vAPPARATUS Filed April 24', 1956 2 SheetS-Sheet 2 wlTN EssEs INVENTOR EnNcs-r F'. STALcuP.

BY QJIRIRW ATTORNEY Patented Jan. 25, 1938 UNITED STATUE STEAM .ET BEFRIGERA'IION PPARA'US Ernest F. Stalcup, Rutledge, Pa., assigner to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 24, 1936, Serial No. 76,228

6 Claims.

My invention relates to vapor jet refrigerating apparatus, more particularly to an installation in which a supply of low pressure steam is available and in which a source of high pressure steam is provided for supplementing the low pressure supply, and it has flor an object to provide improved apparatus.

A particular object is to provide apparatus of improved economy of operation.

In accordance with my invention, Iprovide an evaporator, one or more ejectors using steam-of` relatively low pressure, one or more ejectors using steam of relatively high pressure, and means for condensing the vapor exhausted from the ejectors. The latter is divided into a plurality of condensing chambers through which cooling water is circulated in series, a higher vacuum being thereby eiected in the flrstcondensing chamber. The low pressure ejectors are arranged to exhaust into the rst condensing chamber in which the higher vacuum is maintained, and the high pressure ejectors are arranged to exhaust into the second condensing chamber. Thus the better vacuum is utilized to provide most economical operation of the low pressure ejectors. This is desirable as the low pressure steam supplied to such ejectors is usually waste steam, such as exhaust from auxiliaries, and it is economical to use such steam as far as possible. Also, the higher vacuum provides a better heat drop or pressure drop for the low pressure steam.

These and other objects are eiected by my invention, as will be seen from the following description and claims taken in connection with the accompanying drawings, and forming a part of this application, in which: y

Fig. 1 is an end elevation of the apparatus, partly in section, as seen along the line I-I of Fig. 2;

Fig. 2 is a plan view thereof; and,

Fig. 3 is a diagrammatic view of a second embodiment.

Referring in detail to the embodiment shown in Figs. 1 and 2, the apparatus includes an evaporator I0 through which water or other uid to be cooled is circulated. 'I'he evaporator may be of any suitable type known in the art, having either a single chamber or a plurality of chambers through which the water may be circulated either ,in parallel or in series. In the embodiment of Figs. 1 and 2, the evaporator I0 is shown as comprising a single chamber, and it is provided with an inlet connection Il and an outlet connection `I2 for the circulation of water therethrough.

The present invention is applicable to an installation in which there is available a variable or limited supply of motive uid of relatively loW pressure, for example, steam exhausted from aux'- iliaries at a pressure of 2'lbs. per square inch, which exhaust would otherwise `be wasted. There are provided two ejectors I3 which are constructed and designed for operation with such low pressure steam, which is delivered thereto through a main,conduit I4 and branch conduits I5, the latter having valves I6. The suctionl inlets of the ejectors I3 are connected to the evaporator at Il, Valves I8 being preferably interposed in such connections. In order to supplement the action of the low pressure ejectors I3, a number of ejectorsl I9 are provided, which are designed and constructed for economical operationwith motive fluid of higher pressure from a suitable available source. The high pressure motive fluid, usually steam, is conveyed through a main conduit 2| and branch conduits 22 having valves 23. The suction inlets 24, of the ejectors I9 are connected to the evaporator; preferably through valves 25.

A condenser .26 is provided for condensing the exhaust from the ejectors, both the expended motive fluid and the compressed vapor withdrawn from the evaporator. The condenser may be of any suitable type, for example, of the type having water cooled tubes arranged in a plurality of passes, which type is well known in the art. It comprises a shell 21 having a partition 28 dividing the same into first and second chambers 29 and 30, respectively. The tubes are arranged so that the circulating fluid rst passes through tubes in the chamber 29 and then through tubes in the chamber 30. For example, the irst two passes may be in the chamber 29 and four more passes may be arranged in the chamber 30. As the cooling iiuid passes first through the chamber 29, it maintains a lower pressure therein than in the chamber 30. In accordance with the present invention, the outlets of the low pressure ejectors .I3 connected through conduits 3| to the low pressure chamber 29, and the high pressure ejectors I9 are connected through conduits-321m the higher pressure chamber 30.

Suitable air removal apparatus is provided, for example, an ejector 3|' removes air and noncondensible vapor from the chamber 29 and exhausts the same into a higher pressure chamber 30, and another ejector 32', which may comprise aplurallty of stages, is connected to the chamber 30 for removing air and uncondensed vapor therefrom. The suction inlets of the ejectors 3|' and 32' are connected to the chambers at suitable points, preferably remote from the inlets through which the exhaust from the ejectors is admitted.

Suitable provision forsupplying motive uid to' this ejector, is, of course, provided. Suitable provision is made for removing condensate from the chambers 29 and 30, as is well understood in the art.

Automatic control mechanism may be provided for varying the number of ejectors in operation. In Fig. 2, there is shown such an automatic control mechanism for the two low pressure ejectors I3 and for two of the high pressure ejectors I9, the remaining high pressure ejectors being manually controlled. The control mechanism comprises solenoids 33 and 34 for actuating the steam admission valves I6 of the low pressure ejectors I3 and solenoids 35 and 3S for operating the steam admission valves 23 of two of the high pressure ejectors I9. The solenoids 33 to 3S are connected to contacts 33a to 33a respectively. The latter are adapted to be successively engaged by the bridging members 3'I of a thermostatic switch device 38. The latter comprises a bellows 39 for actuating said bridging members 37, a thermostatic bulb Il!) disposed in the chilled water outlet connection I2, containing an expansible uid, and a tube 4I connecting said bulb and bellows.

Operation The operation will rst be described assuming all ejectors to be operating. Low pressure steam is supplied to the low pressure ejectors I3 and high pressure steam is supplied to the high pressure ejectors I9. Water to be cooled is circulated through the evaporator in any suitable known manner, being admitted through the inlet connections II and withdrawn through the outlet connection I2. 'Ihe ejectors withdraw vapor from the evaporator, thereby reducing the pressure therein. Such pressure reduction effects vaporization of a portion of the water with consequent cooling of the remaining portion. The vapor withdrawn from the vaporator, together with the expanded motive fluid, is discharged by the ejectors into the condenser 2S, the low pressure ejectors I3 discharging into the chamber 29 and the high pressure ejectors I9 discharging into the chamber 30. y

The condenser is cooled by means of a supply of cold Water which is circulated, in any suitable known manner, rst through the first and second tube passes in the chamber 29 and then through the third to the sixthv tube passes in the chamber 30. Inasmuch as the water in the tubes in the chamber 39 has absorbed heat from the chamber 29, its temperature is higher than that of the water in the tubes in the chamber 29. Accordingly, a higher vacuum, or lower absolute pressure is maintained in the chamber 29 than in the chamber 30. The provision of 'the best vacuum for the low pressure ejectors I3 provides the maximum heat drop or pressure drop of the low pressure steam supplied toI said ejectors for motivating the'steam. 'Ihe ejectors I9 are provided with higher pressure steam, which is better able to exhaust against the higher absolute pressure in the chamber 30.

During a great portion of the operation of the apparatus, only a limited number of ejectors need be operated. Inasmuch as the low pressure steam is usually steam that is otherwise Wasted, the low pressure ejectors I3 are rst placed in operation and then, as greater cooling action is required, the high pressure ejectors I9 are brought into operation. This may be done manually or, when automatic control is provided as in the illustrated embodiment, it is automatically eiected in the following manner: I

When the temperature of the water flowing through the outlet connection I2 is so low as to indicate that no cooling is required, the bridging members 3l of the thermostatic switch device 38 are moved to the right to disengage all of the contacts. Accordingly, all of the solenoids are deenergized and the steam admission valves are closed. As the cooling load increases, indicated by rise :in temperature of the water flowing through the outlet connect-ion I2, the fluid in the thermostatic bulb III) expands, causing the bellows 39 to move the bridging members 31 to the left. The latter are arranged relative to the contacts 33a to 36a, as will be readily seen from Fig. 2, so as to engage said contacts in the order name-d. Thus, in response to a light load the solenoid 33 will open the steam admission valve I6 of the first low pressure ejector I3, and upon further increase, the solenoid 34 will open the steam admission valve of the other low pressure ejector I3. When the reirigerating load increases beyond the capacity of the two low pressure ejectors, then the solenoid 35 will open the steam admission'valve of the rst high pressure ejector I9 and upon still further increase, the solenoid 36 will open the steam admission valve of a second high pressure ejector I9. Upon decrease in refrigerating load, the ejectors are closed in reverse order.

The remaining high pressure ejectors I9 are provided with manually operated steam admission Valves 23, and may be used to carry base load, the automatically controlled ejectors pro- Viding for the Variations in cooling load in a manner well known in the art.

It will thus be seen that the low pressure steam is first used as far as possible and that the high pressure steam is used only when necessary. During a large portion of the operating period, the refrigerating load will be suiciently low so that the same is carried mainly or entirely by low pressure steam.

It will also be noted that the best vacuum is provided for the low pressure ejectors which are operated the greatest portion of the time and which utilize steam that would otherwise be wasted. f'

In Fig. 3, I show my invention applied to apparatus in which cooling of the water or other liquid to be cooled is effected in a plurality of stages, the evaporator I0 being divided into chambers 42 and 43. The water to be cooled is admitted through a conduit II and admitted into the chamber 42 through a pipe l having spray openings l5 therein. The water collects in the bottom of the chamber 42 and flows by gravity through a conduit 46, formed to provide a loop seal, into an annular pipe 'I in the cham ber 43, which con-duit has spray openings t8 therein. From the chamber 43, the cooled water is withdrawn through an outlet connection 49.

An ejector I9', designed and constructed for operation with high pressure motive iluid has its suction inlet connected to the chamber d2. An ejector I3', designed and constructed to operate with motive fluid of lower pressure has its suction inlet connected to the chamber 43. Bales 5U may be provided in the chambers 42 and 43 adjacent the connections with ejectors, to minimize entrainment of solid particles of water.

The low pressure ejector I3 and the high pres- CII sure ejector I9' discharge into chambers 29' and 30 of a condenser 26. This condenser is also arranged so that cooling fluid flows rst through the chamber 29 and then through the chamber'30', thereby maintaining a higher vacuum in the chamber 29.

In the operation of this embodiment, a portion of the cooling of the Water is eiected in the chamber 42, the vapor being withdrawn therefrom by the high' pressure ejector I9'. The remaining portion of the cooling is effected in the chamber 43, the vapor being withdrawn with the low pressure ejector I3'. Inasmuch as the temperature of the water is lower in the chamber 43, a lower pressure, or higher vacuum, is maintained therein.

At partial load, the high pressure ejector I9' may be shut down and only the low pressure ejector I3 operated. This may be eiected by automatic control mechanism similar to that shown in Fig. 2 and including solenoids 5I and 52 controlling the motive steam supply to the ejectors I3' and I9', respectively, and in turn controlled by contacts 53 and 54, respectively. A thermostat switch device 38, similar to that shown in Fig. 2, engages the contact 53 to effect operation of the low pressure ejector I3', only upon light load, and engages both contacts to effect operlets of the ejectors are opened in any suitablev manner at such times as the'ejecting action of the associated ejectors is established. Also, the ejectors may embody starting nozzles, in which case suitable known forms of control therefor may `-be employed. It will also be apparent that the number of iowpressure ejectors and the number of high pressure ejectors will be such as are most suitable for the particular conditions encountered in each installation.

While' I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, 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 vapor jet refrigerating apparatus, the combination of evaporator means, rst and second `ejectors for withdrawing vapor from said evaporating means to eifect cooling by evaporation of liquid therein, said first and said second ejector being designed and constructed for operation with motive iiuid of relatively low pressure and motive fluid of relatively high pressure, respectively, condensing means comprising first and second condensing chambers for condensing the "respectively, and means for conveying cooling gapor exhausted by said first and second ejectors,

water through said iirst and second condensingI chambers in series in the order named, whereby the first ejector utilizing motive fluid of low pressure exhausts into a region of lower pressure than the second ejector.

2. InV vapor jet refrigerating apparatus, the combination of evaporator means, rst and second ejectors for withdrawing vapor from said evaporator means, said first and said second ejector being designed and constructed for operation with motive fluid of relatively low pressure and motive iiuid of relatively high pressure, respectively, means for supplying motive vapor of relatively low pressure and motive iiuid of relatively high pressure to said first and second ejectors, respectively, means providing first and second condensing chambers connected to said rst and second ejectors, respectively, and means for circulating cooling uid in heat exchange relation with said first and second condensing chambers in'seriesin the order named and for maintaining a lowerpiessure in said rst chamber than in the second chamber, whereby the first ejector utilizing motive iiuid of low pressure exhausts into a region of lower pressure.

3. In vapor jet refrigerating apparatus, the

combination of evaporator means, rst and sec-- ond ejectors for withdrawing vapor -from said k evaporator means, `saidiirst and said second ejector being designed and constructed for operation with motive fluid of relatively low pressure and motive fluid of relatively high pressure, respectively, means for supplying motive vapor of relatively low pressure and motive iiuid of relatively high pressure to said first and second ejectors, respectively,'means providing rst and second condensing chambers connected t6 said Aiirst and second ejectors, respectively, means for conveying cooling uid in heat exchange relation with said first and second chambers in series in the order named, whereby a lower pressure is maintained in said iirst chamber connected to said first ejector utilizing motive iiuid of low pressure, and means for rendering said iirst and second ejectors operative successively in response to successive vincreases in refrigerating load, respectively.

4. In vapor jet refrigerating apparatus, the combination of evaporator means, rst `and second ejectors for withdrawing vapor from said evaporatormeans, said first and said second ejector being designed and constructed for operation with motive iiuidof relatively low pressure and motive uid of relatively high pressure, respectively, means for supplying motive vapor of relatively loW pressure and motive iiuid of relatively high pressure to said iirst and second ejectors, respectively, means providing first and second condensing chambers connected to said first and second ejectors, respectively, means for conveying cooling fluid in heat exchange relation with said rst and second chambers in series in the order named, whereby a lower pressureis maintained in said rst chamber connected to said first ejector utilizing motive iiuid of low pressure,

-designed and constructed for operation with motive uid of relatively high pressure for withdrawing vapor from said first evaporator chambei', condensing means comprising iirst and secing by evaporation of liquid therein, discharging the exhaust uid from said rst and second ejectors into first and second condensing chambers, respectively, and conveying cooling uid into heat exchange relation first with the exhaust uid in said rst condensing chamber and then into heat exchange relation with the exhaust uid in said second condensing chamber, whereby said rst ejectorV utilizing low pressure motive fluid exhausts into a region of lower pressure in the rst 10l condensing chamber.

ERNEST F. STALCUP.

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