US2566864A - Multiple stage ejector in refrigeration system - Google Patents

Description

2 sheets-sheet 1 fizz 01 F. WHITNEY MULTIPLE STAGE EJECTOR IN REFRIGERATION SYSTEM Filed Nov. 19, 1948 11.7.1. hwnrl' rm Sept. 4, 1951 2 Sheets-Sheet 2 jizuzzar L. F. WHITNEY MULTIPLE STAGE EJECTOR IN REFRIGERATION SYSTEM Filed NOV. 19, 1948 Sept. 4, 1951 the top of drum 50 is a spill-over duct 55, the

lower part of which provides a trap 56 connected to a mercury return 51 which is connected wit the boiler I.

When sludge accumulates in the cooler II, it

forms a mud-like deposit on the lower walls of" the cooler and since the cooler is provided with downwardly sloping walls, this heavy, mud-like deposit can drain into the drum 50. Since the drum 50 is connected to the low-pressure portion of the system and is in'a relatively Warm location, the more volatile element of the heavy sludge, i. e., the'aqueous refrigerant, is evaporated and drawn into the first stage mixing chamber through the duct, 3,-while the mercury residueflows into the line 52 and thence into the spill-over 55 to the mercury return 51. Since the drum 50 extends a substantial distance below the spill-over connection into the line 55, any sludge in the lower part of the drum is subjected to a substantial liquid head which results in a tendency to squeeze refrigerant out of the sludge so that the mercury may coalesce.

The 'Y 28 which connects the drains and 21 communicates with a small drum or chamber 60 to which the lower end of the inclined pipe 40 is also connected, while an upwardly inclined duct 61 extends from this chamber 66 to a chamber constituting a part of the purger assembly 63. The chamber 64 receives non-condensable gases through the pipe 30 and a drop tube 85 of restricted internal diameter extends downwardly therefrom. Globules ofcondensed mercury spilling over from the duct BI entrain bodies of the non-condensable gases in the tube 65, compressing the gases as they move downwardly through the tube. The lower end of the tube 65 is im- Ine'rsed in a body of mercury in the well 51, the upper surface of this liquid propellant being exposed to atmosphere. A return duct' 6-9 is circumposed about the tube 65 and is connected to the mercury-returnpipe 51, there being a very small pressure-equalizing vent between the upper part ofthe duct 69 and chamber 64. A deflector 68 prevents gas from rising into the duct 69 from the lower end of the drop tube 65. The arrangement of the spill-over connection between the tube SI and chamber 60 determines the level of the mercury in the trap defined by the lower parts of the ducts 34 and 22. The condensed mercury received from the drains I4 and 21 passes into the chamber 60 and from the latter may pass to the spill-over connection, thus being received by the purger. From the purger the mercury flows from the pipe 51 back to the boiler I, the height of the mercury in the pipes 51 and 69 being sufficient to balance the boiler pressure. V

During normal operation of the system the trap defined by the pipes 5i and 40 is constantly receiving condensed mercury from the drains I4 and 21, and the spill-overconnection between pipe BI and chamber 64 definitely limits the height of mercury in the pipe 21. Thus, a mercury column of'constant height is automatically maintained in the leg fil' of the trap while the total static pressure in this leg of the trap is 26, 1939, to which reference may be had for a 4 provided by the mercury column plus the condenser pressure thereabove. This static pressure is balanced in the opposite leg of the trap by the mercury in the tube 40 below its connection with the duct 34, and by the liquid columns in the respective branches 34 and 42 of this leg, as well as thepressures above these respective columns. The liquid heads in the branches 34 and ,42 are provided by bodies of condensed mercury and aqueous reirigerant, as explained more fully in Patent No. 2,174,300 granted to me September more complete description of the operation of the system.

Inaccordance with the present invention, the

first and second stage aspirators and their associated parts constitute a unit which comprises an elongate housing I00 of generally ovoid cross section having a closed rear end IN and a front end I02 formed with vertically spaced openings which receive the first and second stage aspirators I04 and I05, respectively. The floor or'bot-f tom wall I03 slopes slightly from the front -to-; ward the rear so that condensate accumulating therein runs toward the rear wall. The aspirator I04 may be of the samegeneral design as shown in my prior Patent No. 1,756,802 granted April 29, 1930, comprising an elongate funnel III] the enlarged end III of which'isin spaced axial alignment with anozzle II2 connected with the branch 5 of the riser 5 The space betweenthe nozzle and funnel constitutes a mixing chamber surrounded by a perforate casing II4 which is disposed within a dome-like closure or cap II5 which is formed with an en larged opening to receive the" vapor duct '8; Throughout the major portion of its length the funnel I l0.is provided with heat-dissipating us and a jacket II8 surrounds the funnel, this jacket having a plurality of longitudinally extending fin 9 along its lower wall portion 5 and an opening I20 formed in its upper wall outside the housing I00. Opposite the discharge end .of thefunnel H0 is a deflector plate .I2I carried by the end wall IOI of the housing. The lower wall of the housing i provided with a drain opening I24 which is connected with the line I4.

The aspirator I05 is generally similar to the aspirator I04 and comprises an elongate funnel I25 having an intake end I26 in spaced alignment with a nozzle I28 connected tothe branch line 5 of riser 5. A sleeve I30 extends about the space or mixing chamber between the nozzle and funnel, and this sleeve is formed with spaced perforations orinlets so as to provide a corn: munication between the interior of the'housing' and the mixing chamber. A jacket or casing I32 surrounds the funnel and at approximately the 'center of the jacket is a partition I34 (Fig; 2) which divides its interior into two sections I35 and I36.

A series of baflles I38 fit about the outlet end of the funnel within the chamber or section I35 and the lower ends of alternate baflies are cut so as to provide egmental openings I40 (Fig'i l) to permit condensate to run toward the closed end I42 of the jacket. The closed end of this jacket carries a deflector plate I44 and is formed with a drain opening to which the line 2"I,is connected. The upper end of the chamber I35 between partition I34, and the baffles is provided with an opening to which the vapor; line 20 is connected, and the lower end of, the chamber provided with a discharge opening to which the drain pipe 21 is connected.

The intake end of the funnel within the section I36 carrie a series of heat-dissipating fins I45 and the upper part of this chamber is provided with an enlarged opening directly connected with a similar opening in the floor of the jacket I I8 by a short duct I46. The interiors of the jacket H8 and the chamber I36 are filled with alcohol or other similar liquid which receives heat from the gases passing through the funnels and transmits the same by way of a pipe I50 which connects the opening I in the jacket H8 with a condenser I5I located in a hot water supply tank T.

The tank T is provided with a connection I55 leading to the condenser I5I by mean of which the alcohol circuit may be initially evacuated so that the alcohol therein may vaporize at a relatively low temperature (around 176 F.) when the temperature of the water around the condenser I 5| is 170 F. The tank T is also provided with an inlet line I55 for receiving incoming water from the supply main, and a hot water supply line I51 is connected with the upper part of the tank, as in my prior Patent No. 2,174,302 granted September 26, 1939, to which reference may be had for a more complete description of this part of the system.

In operation, mercury vapor discharged from the nozzle 5 aspirates water vapor through the duct 8 and carries it through the funnel IIO, compressing it and discharging the compressed hot vapor into the interior of the housing I00. A substantial amount of heat is absorbed by the alcohol in the jacket H8, and any condensed mercury falls to the bottom of the housing I00 and eventually passes into the drain pipe I 4. The compressed Water vapor and any uncondensed mercury is drawn into the econd stage aspirator and carried through the funnel I which results in further compressing the water vapor which, after passing about the baffies I38, is discharged into the duct 29. The condensed mercury accumulating in the bottom of the chamber I flows through the openings I into the drain '21. Heat from the second stage aspirator is absorbed by the alcohol in the section I36 and circulates upwardly through the jacket H8 and duct I into the condenser I5I where alcohol vapors are condensed and thu give up their heat to the water in the tank T, as is more fully described in my above-mentioned Patent No. 2,174,302.

While I have shown and described one desirable embodiment of the invention, it is to be understood that this disclosure is for the purpose of illustration and that various change and modifications may be made without departing from the spirit and cope of the invention as set forth in the appended claims.

I claim:

1. In a refrigeration system of the type having a refrigerant fluid circuit including a vapor duct and a condenser duct, a propellant fluid circuit including a pressure line and a return line, and a cooling fluid circuit, a multiple stage ejector unit comprising a housing of elongate cross-section, a first stage ejector connected with said vapor duct and with said pressure line and extending within th upper part of said housing, a second stage ejector connected with said. pressure line and extending within the lower part of said housing, jackets about the ejectors having a connection with said cooling fluid circuit, the first stage ejector discharging into the interior of said housing and the second stage ejector having a vapor inlet communicating with the interior of said housing so as to receive vapors discharged by the first stage ejector, a connection between the outlet of the second stage ejector and said condenser duct, and return means from the outlet of said second stage ejector and the interior of said housing to said return line.

2. In a refrigeration system of the type having a refrigerant fluid circuit including a vapor duct and a condenser duct, a propellant fluid circuit including a pressure line and a return line, a multiple stage ejector unit comprising a housing, a first stage ejector connected with said vapor duct and with said pressure line and extending within one part of said housing, a second stage ejector connected with said pressure line and extending within another part of said housing, a casing surrounding the discharge end portion of said second stage ejector, the first stage ejector discharging into the interior of said housing and the second stage ejector having a vapor inlet communicating with the interior of said housing so as to receive vapors discharged by the first stage ejector, a connection between said casing and said condenser duct, and return means from said casing and the interior of said housing to said return line.

3. In a refrigeration system of the type having a refrigerant fluid circuit including a vapor duct and a condenser duct, and a propellant fluid circuit including a pressure line and a return line, a multiple stage ejector unit comprising a housing, a first stage ejector connected with said vapor duct and with said pressure line and extending within one part of said housing, a deflector plate carried by said housing opposite the discharge end of said ejector, a second stage ejector connected with said pressure line and extending within another part of said housing, the first stage ejector discharging into the interior of said housing and the second stage ejector having a vapor inlet communicating with the interior of said housing so as to receive vapors discharged by the first stage ejector, a connection between the outlet of the second stage ejector and said condenser duct, a second deflector plate disposed opposite the discharge end of said second ejector, and return means from the outlet of said second stage ejector and the interior of said housing to said return line.

LYMAN F. WHITNEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENT Number Name Date 1,343,922 Ljungstrom June 22, 1920 1,521,729 Suczek Jan, 6, 1925 1,546,641 Fothergili et a1. July 21, 1925 2,174,302 Whitney Sept. 26, 1939

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