IMPROVEMENTS IN REFRIGERATING OR PRODUCING COLD, AND IN APPARATUS EMPLOYED THEREIN
Year: 1877

page_text: LETTERS PATENT to John Gamgee, of Chelsea, in the County of Middlesex,
for the Invention of " IMPROVEMENTS IN REFRIGERATING OR PRODUCING COLD,
AND IN APPARATUS EMPLOYED THEREIN."
Sealed the 29th April 1878, and dated the 1st November 1877.
PROVISIONAL SPECIFICATION left by the said John Gamgee at the Office of
the Commissioners of Patents on the 1st November 1877.
JOHN GAMGEE, of Chelsea, in the County of Middlesex. *IMPROVEMENTS IN
REFRIGERATING OR PRODUCING COLD, AND IN APPARATUS EMPLOYED THEREIN."
The Invention relates to improvements applicable to most of the processes and
apparatus at present in use or known for refrigerating or for cooling air, gases, or
liquids, but is more especially applicable to those processes and apparatus wherein
a gas or vapor is caused to assume the liquid form by compression and cooling, and
is then allowed to return from the liquid to the gaseous state by reduction of
pressure, the absorption of latent heat in the latter physical change effecting the
reduction of temperature of the body it is desired to cool or freeze.
The objects of the Invention are,—
Firstly. To enable liquefiable gases to be condensed or liquified at lower pressures
in the condensers than have been heretofore found necessary, whereby the power
required to work freezing or cooling machines in which such gases are employed,
and the loss of gas by leakage through the joints thereof are materially reduced.
Secondly. To enable various liquefiable gases or volatile liquids to be utilized for
the production of cold, which have either not been applied for that purpose hereto-
fore, or if so applied at all, have not been successfully applied.
In carrying out the first object I combine together, or cause to act in concert, two
or more cooling or freezing machines adapted to each other so as to work together
as a series or cycle, in such a manner that the evaporation of the gas or vapor
in the refrigerator of one machine shall reduce the working temperatures in the
condenser of the next machine, so that the liquefaction of the gas or vapor in the
latter shall take place at the lower pressure proportionate to the reduction of tem-

page_text: perature, and for this purpose it may be convenient to use in the first machine a
gas or vapor, which will liquefy at a comparatively low or moderate pressure, such
as ether, sulphurous acid, chloride of methyle, or the like, and in the next machine
in the series the gas or vapor which requires the greater pressure to liquify it; for
example, such as anhydrous ammonia, carbonic acid, and the like.
Instead of employing gases or vapors in the first machine or machines more
easily liquefied than those employed in the subsequent machines, the more incon-
densible gas or vapour may be employed in both or all the machines. The first
machine or machines in the series or cycle being smaller than the subsequent
machines is or are worked at the normal pressure due to the temperature of the
condensing water.
Instead of employing two or more separate machines as above described, similar
effects may be produced in a single machine by the employment of a supplementary
condenser placed between the main condenser and the refrigerator, such supple-
mentary condenser being cooled by the cold uncongealable liquid flowing from or
returning to the refrigerator.
By these means such gases as anhydrous ammonia and carbonic acid, which at
the temperatures of ordinary condensing water require comparatively high pressure
to condense or liquefy them, may be so reduced in temperature as to liquefy at
comparatively moderate pressures.
In carrying out the second object of the Invention, I employ carbonic acid,
protoxide of nitrogen, ammonia, sulphurous acid, chloride of methyle, formiate of
methyle, methylic or ethylic alcohol, and methylic or ethylic ether combined
together in pairs or groups, or chloride of methyle alone, and utilized by being first
liquefied by mechanical compression and cooling, and then vaporized by reduction
of pressure.
Or I employ the same substances either singly or combined, in pairs or groups,
and utilized by being first absorbed into alcohol, glycerine, or other suitable liquid,
then evaporated therefrom by heat condensed or liquefied by pressure and cooling,
and then vaporized by reduction of pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Gamgee in the Great Seal Patent Office on the 1st May
1878.
JOHN GAMGEE, of Chelsea, in the County of Middlesex. "IMPROVEMENTS IN
REFRIGERATING OR PRODUCING COLD, AND IN APPARATUS EMPLOYED THEREIN."
The Invention relates to improvements applicable to most of the processes and
apparatus at present in use or known for refrigerating or for cooling air, gases, or
liquids, but is more especially applicable to those processes and apparatus wherein
a gas or vapor is caused to assume the liquid form by compression and cooling, and
is then allowed to return from the liquid to the gaseous state by reduction of
pressure, the absorption of latent heat in the latter physical change effecting the
reduction of temperature of the body it is desired to cool or freeze.
The objects of the Invention are,-
Firstly. To enable liquefiable gases to be condensed or liquefied at lower pressures
in the condensers than have been heretofore found necessary, whereby the power
required to work freezing or cooling machines in which such gases are employed,
and the loss of gas by leakage through the joints thereof are materially reduced.
Secondly. To enable various liquefiable gases or volatile liquids to be utilized
for the production of cold, which have either not been applied for that purpose
heretofore, or if so applied at all, have not been successfully applied.
In carrying out my Invention I combine together or cause to act in contact. two
or more cooling or freezing machines adapted to each other, so as to work together
as a series or cycle in such manner that the evaporation of the liquid in the
refrigerator of one machine shall so reduce the temperature in the second machine
that the gas or vapor in the latter shall be liquefied at a lower pressure proportionate
to the said reduction of temperature. For this purpose it is convenient to use in
the first machine an agent, which liquefies at a comparatively low pressure, such as
ether, sulphurous acid, or chloride of methyle, or the like, and in the next machine
in the series, the agent which requires the greater pressure to liquefy it, such as for
example, anhydrous ammonia, carbonic acid, and the like.
The cold produced by the evaporation, for instance, of liquid nitrous oxide is very
great, and, as shown by Faraday, this substance may be used in certain cases to
produce degrees of cold far below those obtained by the evaporation even of liquid
carbonic acid, but the use of nitrous oxide in an ice machine for industrial purposes
is impracticable on account of the enormous pressures which are necessary to
condense it at ordinary temperatures. If even ice were used in the condenser so as
to liquefy the gas at 0° centigrade, the pressure in the machine would amount to
32 atmospheres.
At the boiling point of ammonia, viz., 33-7° centigrade, the liquefaction of nitrous
oxide will take place at between 11 and 12 atmospheres. Further, the more volatile
a body is, the more rapidly does the force of its vapour increase by addition of
heat; thus, for an increase of pressure from 2 to 6 atmospheres, the temperatures
of ammonia and nitrous oxide are increased as follows:-
For ammonia 28.9° centigrade.
"
nitrous oxide 13-1° centigrade.
It is therefore obvious that ammonia, which can be easily liquefied under moderate
pressure at ordinary temperatures, may be made to boil in a receiver, into which
nitrous oxide is being pressed with a view to its liquefaction; on evaporation, very
low temperatures will be produced, and thus a machine obtained combining the
advantages of compactness, safety in operation, and a minimum wear and tear...
In practice in hot countries it may be most advantageous to combine such agents
as sulphurous acid, in the first machine, and ammonia in the second.

page_text: An arrangement of apparatus adapted for the employment of these two agents is
illustrated in the annexed Drawings, wherein,―
Figure 1 represents a sulphurous acid compresser. This forces the gas into a
condenser, Figure 2, where it is liquefied at a pressure depending on the tempera-
ture of the condensing water that is available.
Figure 3 is the vessel in which the sulphurous acid boils or is evaporated,
returning by the tube A to the compresser, Figure 1.
Figure 4 represents the ammonia pumps which force the gas into the condenser,
Figure 5, by the tube B, thence by the tube C into the vessel or liquefier, Figure 3,
where it is subjected to the low temperature of the boiling sulphurous acid.
It is obvious that the two liquids in this chamber are kept separate, the ammonia
being made to pass through a coil surrounded by the boiling acid.
From the liquefier, Figure 3, the ammonia passes through the tube D to the
refrigerator, Figure 6, and thence having done its work, by cooling the material,
the temperature of which it is desired to lower, it returns by the tube E to the
compresser, and so on as long as the machine is worked.
The irregularity in the pressure manifested in working a machine passing on
board a steamer, from one.latitude to another and across the tropics, an irregularity
which has resulted in bursting of joints and pipes when the condensing water was
very hot, suggested the use of a supplementary condenser, whereby the temperature
at which the gas is liquefied can always be under the engineer's control. This is
of special advantage in working with sulphurous acid, ammonia, or chloride of
methyle.
The heat of compression is removed by the water and the gas condensed up to a
safe and economical working pressure, but to limit the latter to a safe point, the
cold liquid returning to the machine after having performed its duty in the ice
moulds, air cooler, ice rink, or elsewhere, is permitted, wholly or in part, to flow over
a coil in which the gas is liquefied, and in this way I succeed in working ammonia
in a machine at 4 or 5 atmospheres' pressure at the outside, whereas the tempera-
ture of the condensing water may vary considerably at different times.
By similar arrangements of apparatus, other agents, such as ammonia and nitrous
oxide, or ammonia and carbonic acid, may be employed together, so that the more
easily condensed agent shall facilitate the condensation of the less easily condensed
agent.
The effectiveness of a machine may be materially increased by using compound
liquids, and the advantage of this depends on facilitating condensation or favoring
contact. Thus chloride of methyle, which I have adopted as a freezing agent
owing to its high latent heat, the moderate pressure at which it condenses and its
stability, may be very usefully employed in the form of a concentrated solution
in methyllic alcohol.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my "Improvements in
Refrigerating or Producing Cold, and in Apparatus employed therein,"-
-
First. The combination substantially as herein-before described of two or more
cooling or freezing machines so as to facilitate the employment of the less con-
densible gases, such as ammonia, carbonic acid, and nitrous oxide, which are capable
of producing very low temperatures by employing the more easily liquefied agents
to condense these gases as herein-before explained.
Second. The mode or manner of working, cooling, or freezing machines as herein-
before described, so that the temperature at which the freezing agents are liquefied
can be regulated at will irrespective of the temperature of the water of condensation,
in order to avoid excessive pressures in the ice machines and excessive wear and
tear.
Third. The employment of supplementary condensers, in the manner and for the

page_text: Fourth. The employment of chloride of methyle alone, or in combination with
the methylic alcohol for the production of artificial cold, as herein-before described.
In witness whereof, I, the said John Gamgee, have hereunto set my hand and
seal, this Thirtieth day of April, One thousand eight hundred and seventy-
eight.
JOHN GAMGEE. (L.S.)