US2129098A - Steam jet refrigeration apparatus - Google Patents

Description

Sept. 6, 1938. P. L. FETZER STEAM JET REFRIGERATION APPARATUS 1935 2 shets-sheet 1 Fla Filed MaKrch 2 |NvEN-roR PAUL. L .F'ETZER BY a, fs ATTORNEY Sept. 6, 1938.

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P. L. FETZER 2,129,098

STEAM' JET REFRIGERATIO'N APPARATUS ll." i I l/l 'IZ .fl K 15 l I4 fr l"| FIG. Z.

BY @Jaw ATTOR N EY Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE 2,129,098 STEAM JET REFRIGERATION APPARATUS Vania Application March 2, 1933, Serial No. 659,403

4 Claims.

My invention relates to refrigerating apparatus, more particularly to apparatus of the type known as steam jet refrigerating apparatus, and it has for an object to provide improved apparatus of this type which is adapted for operation at partial load.

Apparatus of this type includes a chamber in which a vacuous or reduced pressured condition is maintained by an ejector or compressor, exhausting usually to a condenser. Liquid to be cooled, usually water, is circulated or conveyed through the chamber, the reduced pressure therein effecting evaporation of a portion of the liquid and consequent cooling of the remaining liquid, which then provides the supply of refrigerated liquid and which may be used as refrigerating medium. A steam ejector is not always sumciently adaptable to change in load, and is usually operatedat full load, that is, with full admission of motivating steam or other fluid.

In order to provide economy of operation at partial load, it has been proposed to provide a plurality of ejectors in parallel and to operate only some of them at partial load. It is necessary With this arrangement, however, to provide a shut-off valve for each ejector which may be shut oli' at partial load, in order to prevent reverse llow therethrough from the condenser to the evaporating chamber, which would destroy the vacuous condition therein. Due to the large .size 0f the vapor connection, such a valve and its operating mechanism represents a considerable item of expense. Such a valve has other objections, such as air leakage into the vacuum system.

It is a particular object of my invention to provide apparatus in which saidvalve ls not required.

In accordance with my invention, I provide a plurality of evaporating chambers or compartments into which liquid to be cooled is admitted. A separate ejector is pro-vided for'l each chamber and a common condenser is provided for the ejectors; Iprovide conduit means for removing cooled liquid from the chambers, and I arrange the conduit means with a manometric connection or loop seal between the chambers, the manometric connection providing a column of liquid whose pressure head opposes the increased pressure, during partialy load operating, in that chamber whose ejector is shut down.

The above and other objects are effected by 'my invention as will be apparent from the f ollowing description and claims taken in accord- Referring now to the drawings more in detail, A

I show steam jet refrigerating apparatus for supplying cooled liquid, such as water, to any apparatus in which it may be required. Such apparatus may be, for example, the air cooler and Washer of air conditioning apparatus, shown on the drawings at 9.

The refrigerating apparatus comprises a primary evaporating chamber I0 and a secondary evaporating chamber tI. In the present ernbodiment, these chambers are formed by separate tanks. Steam ejectors I2 and I3, shown in Fig.,2, have their suction inlets I2 and I3' connected to the chambers I0 and Il, respectively, and effect a vacuous or reduced pressure condition in the respective chambers by withdrawing vapor therefrom. The ejectors I2 and I3 are motivated by steam from a supply conduit I4, the admission thereof being controlled by valves I5 and I6, respectively, the operation of which is described later. The ejectors exhaust into a common condenser II, which is provided with a condensate outlet i8, and air outlet I9 connected to an air ejector 20, a cooling water inlet 2| and a cooling water outlet 22.

For full load operation, both ejectors are operate-d. For partial load operation, only the ejector I2 is operated, the ejector I3 being shut down by closing the valve I6. The condenser pressure is then admitted into the chamber I" through the ejector i3.

The water to be cooled is conveyed, in this case from the air cooler, by a conduit 23 to the evaporating chamber orchambers. The water is divided, one portion being admitted always to spray nozzles 24 in the chamber Ill. The remaining portion is admitted by a valveA 25 either to a second group of spray nozzles 26 in the chamber IIl, for partial load operation, or to spray nozzles 2l in the chamber II, for full load operation. Upon being subjected to the vacuum or decreased pressure in the evaporating chamber, the water is partially evaporated, which action effects cooling of the remaining water, as is well known inthe art.`

The water cooledA ineach evaporating cham- 'ber is discharged therefrom through an outlet -in the bottom, lthe bottom preferably converging toward the outlet. The outlets are connectagainst the higher absolute pressure in the chamber II at partial load operation. This conduit system includes separate branch discharge conduits 28 and 29 communicating with the chambers I0 and II, respectively, and with a common discharge conduit 3|. The conduit 29 is 0I smaller diameter than the conduits 28 and 3|, as it never conveys more than a portion of the water, while-the conduit 28 conveys the full quantity of water at partial load. The conduits 28 and 29 extend iirst downwardly and then communicate at a low level through horizontally extending portions, thereby providing the manometric connection or loop seal between the chambers I0 and II. The conduit 28 is of suilicient height to provide a head of liquid a which opposes the increase in pressurel in the chamber `|I at partial load. The water is then conveyed by the conduit 3|, to a pump 32, by which it is forced through a conduit 33 to the air cooler or other refrigerating load. In the latter, the cooled water is used as refrigerating medium'for any desired purpose, such as air cooling. Its temperature havingA been increased, it is discharged from the air cooler to the conduit 23 and recirculated. Y

Control mechanism for vregulating the operation of the refrigerating apparatus is provided. It includes solenoids 34 and 35 for opening valves I5 and I6, respectively, the latter being biased to closed position by the weight of the core. A

solenoid 36 controls the valve 25, which is biased to the position in which it admits water to the nozzles 26 in the chamber I0, and is operated to admit water to the nozzles 21 in the chamber I I when the solenoid 36 is energized. The solenoid 34 is controlled by contacts 31, and the solenoids 35 and 36 are controlled by contacts 38. The contacts 31 and 38 are controlled by a thermostat 39 in response to the temperature of the liquid to be cooled at any desired point in its circuit or path. Preferably, and as shown, the thermostat includes an expansible bellows 4I connected by a tube 42 to a bulb 43 disposed in the conduit 3|. The thermostat 38 is arranged to close the contacts 31 inv response to a predetermined maximum temperature, to close both contacts 31 and 38 in response to a slightly higher predetermined maximum temperature, and to open both contacts 31 and 38 in response to a temperature lower than the iirst-mentioned predetermined maximum temperature. For the purpose of an example, the first and second predetermined maximum temperatures will be taken as 40 -and 41 F., respectively.

Make-up water to replace the water which is vaporized and removed is supplied through a conduit 44. It 'is preferably ilrst cooled in one of the evaporating chambers, and hence the conduit 44 may be connected to the conduit 23. The admission of make-up water is controlled by a valve 45, which is controlled by a float control 46 in response to the level of water in the chamber I9.

The operation of the above-described apparatus is as follows:

When the air cooler or other refrigerating load requires the maximum amount oi.' refrigeration,

this is evidenced by a temperature of the circuejectors operative, and adjusting the valve 25 to admit water to the chamber II. Approximately one-half oi the water, or any other desired portion, is admitted to the chamber II, and the remaining portion to the chamber I0. The water is cooled or refrigerated in the respective chambers as above described, substantially the same degree of vacuum or pressure being maintained therein. The water is discharged in parallel through the conduits 28 and 29 to the conduit 3I and supplied to the air cooler.

As the requirementfor refrigeration decreases, l

the temperature of the water decreases. However, the contacts 38 will be kept closed and the apparatus maintained at full load operation until the temperature drops below 41 F., indicating that half load operation will supply the needed refrigeration, at least temporarily. The contacts 38 are then opened, deenergizing the solenoids 35 and 36. The ejector I3 is shut down and the valve 25 diverts the water from the chamber II to the chamber I0. Due to the shutting down of the ejector I3, the pressure in the chamber Il will rise to that in the condenser I1, lowering the l level of the Water in the conduit 29, until the difference in head between the column of water in the conduit 28 and the bottom of the chamber I0 and the water inthe conduit 29, indicated by the reference character a, balances the difference between the absolute pressures in the two evaporating chambers. The i'ull quantity of water then ilows through the chamber I0, the branch discharge conduit 28 and the common conduit 3|, while the water in the branch discharge conduit 29 remains stationary. It is to be noted that the higher pressure in the chamber II tends to heat the Water, but as the level of the water is down in the conduit 29, the amount of surface of water subject to heating will ybe negligible.

If the refrigeration requirement is substantially less than full load, and greater than half load, there will be intermittent full load and half load operation, the temperature of the water decreasing during the full load operation and increasing during the half load operation.

If the temperature of the water drops below 40 F., indicating that nofurther refrigeration is presently needed, the contacts 31 are also opened, shutting down the ejector I2. The water is then circulated through the chamber I8 without any cooling except for the action of the air ejector 29 of the condenser, which effects a small amount of evaporation of the water and consequent cooling. Upon subsequent increase in temperature-of the water, the contacts 31 will reclose, and cooling at half load is resumed. Thus, a vload less than half load is taken care of by intermittent haliload operation.

From the above description, it will be seen thatthe ejector I3 and the chamber I I.

While I have shown my invention in one form, 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 tion of the second ejector.

art or as are specically set forth in the appended claims.

What I claim is:

l. Refrigerating apparatus for providing a supply of cooled water comprising rst and second evaporator chambers, means including a discharge conduit for effecting flow of water through said chambers to be cooled therein, for delivering the same to the discharge conduit and for providing a liquid seal between the chambers, rst and second ejectors connected to s-aid first and second chambers for withdrawing vapor therefrom, respectively, means responsive to increase above and decrease vbelow a predetermined temperature of the water iiowing through said discharge conduit for initiating and terminating operation of said rst ejector and responsive to increase above and decrease below a slightly higher predetermined temperature of said water for initiating and terminating low of Water through the second chamber and opera- 2. Refrigerating apparatus comprising a plurality of evaporator chambers, means for conveying water through said chambers in parallel to be cooled therein by partial evaporation and including a common discharge conduit, an ejector associated with each chamber for withdrawing vapor therefrom, and means for initiating operation of an ejector of one chamber in response to a predetermined maximum tempera- 'ture of the water .flowing through said common discharge conduit and of an ejector of a second chamber in response to a slightly higher predetermined temperature thereof.

3. Refrigerating apparatus comprising a plurality of evaporator chambers, means for conveying water through said chambers in parallel to be cooled therein by partial evaporation and including a common discharge conduit, an ejector associated with each chamber for withdrawing vapor therefrom, and means for automatically controlling the operation of the ejectors of a plurality of chambers in response to the temperature of the water owing through said common discharge conduit to maintain said temperature substantially constant, said last-mentioned means operating in the direction to initiate operation of the ejectors in response to increase in said temperature and in the direction to terminate operation of the ejectors in response to decrease in said temperature.

4. Refrigerating apparatus comprising a plurality of evaporator chambers, means for conveying water through said chambers in parallel and including a common water supply conduit, a common discharge conduit, and branch conduits connecting the chambers with the common discharge conduit and arranged to form a liquid seal between the chambers, an ejector connected

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