Nov. 11, 1930. A.

EINSTEIN E AL 1,781,541
REFRIGERATION
Filed Dec. 6 l927

//

VENTg S
 Patented Nov. 11, 1930 1,781,541

UNITED STATES PATENT OFFICE

ALBERT EINSTEIN, OF BERLIN, AND LEO SZILARD, of BERLIN-WILMIERSDORF, GER
MANY, ASSIGNORS TO ELECTROLUX SERVEL CORPORATION, of NEw YoRK, N.Y., A.
CORPORATION OF DELAWARE
REFRIGERATION
w
Application filed December 16, 1927, Serial No. 240,566, and in Germany December 16, 1926.
A
Our invention relates to the art of refrig denser 6 where it terminates in a distributor
eration and particularly to an apparatus and head 35. Conduit 37 passes within cooling
method for producing refrigeration wherein Water jacket 12 in order that fluid passing
the refrigerant evaporates in the presence of through this conduit may be cooled. A vent
6 an inert gas and more particularly to the type conduit 34 connects the upper part of con 55
tainer 33 with the upper part of condenser 6.
disclosed in Patent No. 1,685,764 granted Sep
tember 25th, 1928, to Von Platen and Munters The operation of the above described appa
and our British Patent No. 282,428. ratus is as follows: ·
The objects and advantages of our inven A suitable refrigerant, for instance butane,
10 tion will be apparent from the following dein liquid form is contained within evaporator 60
scription considered in connection with the1. An inert gas, for instance ammonia, is in
accompanying drawing which shows, more or troduced into evaporator 1 through conduit
less diagrammatically, a preferred embodi 30 and distributor head 31. The refrigerant
ment of our invention. evaporates in the evaporator in the presence
15 Referring to the drawing, reference charof the inert gas due to the fact that the partial 65
pressure of the refrigerantis reduced thereby
acter 1 designates an evaporator, which is or
and the resulting gaseous mixture passes
dinarily placed within a chamber to be cooled.
through conduit 5 to within condenser 6.
A conduit 5 connects the upper part of evapo
rator 1 with the more intermediate portion Here the mixture comes in intimate contact
20 of the condenser 6. A conduit 11 communi with an absorption liquid, for example water, 70
cates with the bottom of evaporator 1 and ex which is introduced into the condenser
tends within condenser 6 at a level below the through conduit 37 and distributor head 35.
point of communication of conduit 5 with the Inasmuch as the ammonia gas is very soluble
condenser. A cooling water jacket 12 sur in water, while the butane is quite insoluble, 75
25 rounds the condenser and is adapted for the the ammonia gas is absorbed by the water,
passage therethrough of water for the pur thus freeing the butane from the gaseous mix
pose of cooling the condenser. ture. Thus the butane assumes substantially
A conduit 27 communicates with the bottom the entire pressure within the condenser,
of condenser 6 and with the lower part of a which pressure is sufficient to cause its lique
heat exchanger jacket 28. The upper part of faction at the temperature maintained therein 80
jacket 28 is connected to the lower part of by the cooling water.
generator 29. Generator 29 is heated in any The specific grayity of liquid butane is less
suitable manner. A conduit 30 communicates than that of the solution of ammonia in water
with the upper part of generator 29 and ex and hence stratification of the two liquids
tends within evaporator 1 to a point near the occurs, the liquid butane floating upon the 85
bottom thereof where it terminates in a dis ammonia solution. The latter solution is in
tributor head 31. Conduit 30 extends within dicated by reference character 26. The liquid
conduit 5 in order that the fluids passing butane passes from condenser 6 through con
duit 11 and returns to evaporator 1, where
through the respective conduits may be
40 brough into heat exchange relationship with it is again evaporated and the cycle repeated.
90
each other. . The ammonia solution flows by gravity
from condenser 6 through conduit ? and heat
A conduit 32 extends upwardly from with exchanger
in the lower part of generator 29 and com jacket 28 to within generator 29.
municates with a container 33 placed at a level Here the application of heat causes the am 05
45 above that of condenser 6. A source of heat 36 monia to be expelled as a gas from the solu
is provided for heating conduit 32 at a point tion and this ammonia gas passes through
above generator 29. A conduit 37 extends conduit 30 and distributor head 31 to with
downwardly from container 33 and passes in evaporator 1, where it reduces the par
within heat exchanger jacket 28 and thence tial pressure of the butane, wherefore the lat 00
50 upwardly to within the upper part of con ter evaporates as previously described.
 2 1,781,541

Water, containing but little ammonia in duit for conducting weak absorption liquid
solution, passes from generator 29 into con from said container to said condenser by
duit 32 where it is further heated by the gravity, a conduit extending upwardly from
source of heat 36. This heating causes the said generator to said container and means
formation of vapor in conduit 32 which lifts to heat the last-mentioned conduit to lift liq 70
liquid through this conduit to within con uid from the generator to the container.
tainer 33. The liquid thus supplied to con 2. Refrigerating apparatus comprising a
tainer 33 may pass by gravity through con generator, a condenser arranged at a higher
duit 37 to condenser 6. The hot weak liquid level than the generator, an evaporator, a
O passing through conduit 37 is brought into container arranged at a higher level than the 75
heat exchange relationship with the cool condenser, said generator containing an inert
strong liquid passing through heat ex gas dissolved in absorption liquid and
changer jacket 28 and an exchange of heat adapted to expel the inert gas from solution,
between the two liquids takes place. The a conduit for conducting the inert gas from
5 weak liquid is further cooled by being the generator to the evaporator, a conduit 80
brought into heat exchange relation with for conducting liquid refrigerant from the
the cooling water in jacket 12 and is hence condenser to the evaporator, a conduit for
in a condition to rapidly absorb ammonia in conducting mixed vapor of refrigerant and
the condenser. inert gas from the evaporator to the con
20 Vapor entering container 33 from conduit denser in heat exchange relation with inert 85
32 passes therefrom through vent conduit 34 gas passing into the evaporator, a conduit
to the condenser. for conducting rich absorption liquid from
During the operation of the hereinbefore the condenser to the generator by gravity,
described apparatus, the pressure existing in a conduit for conducting weak absorption
25 the varios members is uniform with the ex liquid from said container to said condenser 90
ception of slight pressure differences, suf by gravity, a conduit extending upwardly
ficient to cause flow of fluids, caused by liquid from said generator to said container, means
columns. The pressure existing in generator to heat the last-mentioned conduit to lift
29 must be sufficiently greater than that ex liquid from the generator to the container
30 isting in the upper part of evaporator 1 to and a vent conduit connecting the upper 95
cause the flow of vapor to take place from part of said container with said condenser. .
distributor head 31, or, in other words, to 3. Refrigerating apparatus comprising a
overcome the liquid head designated by h. generator, a condenser arranged at a higher
This excess pressure in the generator is bal level than the generator, an evaporator, a
anced by the head exerted by the column of container arranged at a higher level than the 00
liquid equal to the differences in levels be condenser, said generator containing am
tween the liquid in condenser 6 and genera monia dissolved in water and adapted to ex
tor 29, indicated by hi. It is, of course, nec pel the ammonia from solution, a conduit
essary that the head represented by his less for conducting the ammonia gas from the OS
40 than that represented by h in order that generator to the evaporator, a conduit for
flow shall take place. . . . conducting liquid butane from the condenser
While we have described a preferred em to the evaporator, a conduit for conducting
bodiment for carrying out our invention, it mixed vapor of butane and ammonia from
is to be understood, that modifications there the evaporator to the condenser in heat ex
of fall within the scope of the invention, change relation with ammonia gas passing
which is to be limited only by the appended into the evaporator, a conduit for conducting
claims viewed in the light of the prior art. strong solution of ammonia in water from
What we claim is: the condenser to the generator by gravity,
1. Refrigerating apparatus comprising a a conduit for conducting weak solution of 115
generator, a condenser arranged at a higher ammonia in water from said container to
level than the generator, an evaporator, a. said condenser by gravity, a conduit extend
container arranged at a higher level than the ing upwardly from said generator to said
condenser, said generator containing an inert container and means to heat the last-men
gas dissolved in absorption liquid and adapt tioned conduit to lift liquid from the gen 20
55 ed to expel the inert gas from solution, a erator to the container.
conduit for conducting the inert gas from the 4. Refrigerating apparatus comprising a
generator to the evaporator, a conduit for generator, a condenser arranged at a higher
conducting liquid refrigerant from the con level than the generator, an evaporator, a
denser to the evaporator, a conduit for con container arranged at a higher level than 25
ducting mixed vapor of refrigerant and inert the condenser, said generator containing am
gas from the evaporator to the condenser monia dissolved in water and adapted to
in heat exchange relation with inert gas pass expel the ammonia from solution, a conduit
ing into the evaporator, a conduit for con for conducting the ammonia gas from the
ducting rich absorption liquid from the con generator to the evaporator, a conduit for 30
(5
denserto the generator by gravity, a con conducting liquid butane from the condenser
 1,781,541
to the evaporator, a conduit for conducting
mixed vapor of butane and ammonia from
the evaporator to the condenser in heat ex
change relation with ammonia gas passing
into the evaporator, a conduit for conduct
ing strong solution of ammonia in water from
the condenser to the generator by gravity, a
conduit for conducting weak solution of am
monia in water from said container to said
oO condenser by gravity, a conduit extending
upwardly from said generator to said con
tainer, means to heat the last-mentioned con
duit to lift liquid from the generator to the
container and a vent conduit connecting the
5 upper part of said container with said con
denser. -
5. Method of refrigerating which com
prises evaporating a liquid-cooling agent in
the presence of an inert gas to absorb heat
20, and thus forming a gaseous mixture of cool
ing agent and inert gas, conveying the gase
ous mixture into the presence of an absorp
tion liquid at such condition that the cooling
agent condenses on being deprived of inert
gas in gaseous mixture therewith due to the
introduction of absorption liquid into. the
presence of the inert gas, separating the solu
tion of inert gas in absorption medium from
the condensed cooling agent, returning the
30 condensed cooling agent to the presence of the
inert gas, separating the inert gas and ab
sorption liquid by heat, circulating the ab- .
sorption liquid by means of a separate ource
of heat to the presence of the gaseous mix
33 ture of cooling agent and inert gas and re
turning the inert gas to the presence of the
liquid cooling agent.
In testimony whereof we hereunto affix our
signatures. a
4) ALBERT ENSTEIN.
LEO SZILARD.