Improvements in Refrigerating and Freezing Apparatus.
Year: 1888

page_text: Date of Application, 18th Feb., 1888
Complete Left, 7th June, 1888
Complete Accepted, 6th July, 1888
PROVISIONAL SPECIFICATION.
Improvements in Refrigerating and Freezing Apparatus.
1, LOFTUS PERKINS of 6 Seaford Street Grays Inn Road in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to refrigerating and freezing apparatus in which the
production of cold is obtained by heating one portion of the apparatus in which is
contained a solution of ammonia or other substance from which gas can be driven off
on the application of heat and liquified in another and cooler portion of the apparatus,
which liquified gas in the heated portion of the apparatus being subsequently allowed
to cool is reabsorbed by the water or other substance remaining in the previously
heated portion of the apparatus.
I form such an apparatus of a system of hermetically closed horizontal pipes or
chambers. One pipe or set of pipes in which the liquid is to be heated is normally
filled or nearly so with the liquid. Above each such pipe is another pipe from the
bottom of which pipes descend into and project downwards a distance say to the
centre of the lower one.
Preferably I heat the lower one by steam or hot water in a pipo passing through or
into it. When the lower one is heated half of its contents are by the consequent
liberation of gas forced into the upper one until gas can enter the lower ends of the
vertical pipes and pass up through them. The gas then bubbles up through the
liquor in the upper pipe and any vapor of water passing up with it will be condensed
leaving the gas only to pass off from the upper pipe to the pipe or pipes forming that
part of the apparatus in which cold is to be produced.
These pipes are always maintained colder than any of the other parts of the apparatus
and consequently when the pressure in the pipes becomes sufficient to liquefy the gas all
liquefaction takes place in them.
When heat is no longer applied to the boiler end and it commences to cool the
pressure in the upper part of the lower pipe will be reduced and the liquid in the
apper one will pass back into it and gas then passing downwards through the
vertical pipes will be kept bubbling through the liquid in the lower pipe and will be
absorbed in it.

page_text: The pipe passing from boiler to refrigerator is kept cooled whilst the boiler is being
heated so that all gas passing to the refrigerator may enter refrigerator in a
comparatively cold state.
Screw plugs may be provided by which any water collected in refrigerator may be
drawn off from time to time. Or I provide the refrigerator with an overflow pipe
which rises up through a small well at its bottom and terminates some little distance
below its centre. The portion of the overflow which projects up into the refrigerator
is surrounded by a tubular guard which is open at the top close to the top of the
refrigerator and has also openings through it at the bottom by which liquid can pass
to the overflow.
Water being heavier than liquid ammonia any water passing over into the
refrigerator will collect at the bottom and may as the refrigerator is filled with
ammonia be made to rise up within the tubular guard and pass off by the overflow.
The outlet pipe from the overflow 1 form with a U bend in it and load it back to
the boiler portion of the apparatus which is placed at a lower level.
When continuous action is required I duplicate the apparatus or use any desired
number of apparatus and keep the refrigerator end of each apparatus immersed in
one bath of an uncongealable liquid or otherwise provide for keeping the refrigerator
end of one when gas is being liquefied in it cooled by the production of cold in
another.
Similarly the gas passing to one may be cooled by gas passing from another.

page_text: COMPLETE SPECIFICATION.
Improvements in Refrigerating and Freezing Apparatus.
I, LOFTUS PERKINS of 6 Seaford Street Grays Inn Road, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement:-
It has before been proposed to construct freezing and refrigerating machines of two
vessels capable of supporting considerable pressure and communicating with one
another at the top through a tube. Into one vessel has been placed a liquid or
substance in which a gas has been absorbed (say an ammoniacal solution) and this
vessel has been heated and the ammonia driven off and liquified under pressure in the
second vessel which is kept cool. Subsequently the heated vessel containing the water
from which ammonia has been driven off has been cooled or allowed to cool and the
pressure being thereby reduced the liquified ammonia in the second vessel has then
again vaporized and been reabsorbed by the water left in the vessel which was pre-
viously heated.
The temperature in the second vessel containing the liquified
ammonia has been thereby reduced.
Freezing apparatus of this kind as heretofore constructed has possessed many
defects and has not come into general use.
When overheated and when consequently not only the ammonia but also the water
has been driven out from the vessel which is being heated it has been liable to
disastrous explosions.
It has also required to be made with pumps and valves or if of small dimensions
has required to be inverted to allow of any water which may have passed over into
the second or cooling vessel being passed back into the first or heating vessel.
The mode of applying heat to the vessel has also been defective, and so also have
been the precautions taken to avoid the passing off of watery vapor from the vessel
that is being heated and to subsequently ensure the ready reabsorption of gas by the
liquid remaining in this vessel have also been defective.
I remove all these objections.
I make the apparatus of a system of hermetically-closed pipes so disposed that any
water or liquid which passes from the portion of the apparatus that is at times heated
may separate itself from liquified gas at the cooler end of the apparatus and pass back
by gravity to the part of the apparatus that is being heated so that no injury can
possibly arise to the apparatus from overheating as any water or liquid distilled over
with the gas from the boiler or beated end will when all ammonia or gas has been
driven from that end flow back again and so a continuous circulation will be kept up
and the only evil that could arise would be that the apparatus would then be working
as a beating apparatus but the apparatus itself would remain uninjured and ready to
act as a cooling apparatus so soon as the heating of the boiler end was stopped and
that end allowed to cool. I also as hereinafter described form the boiler (or that

page_text: portion of the apparatus which is at times heated) in such a manner as to hinder the
passing off of watery vapor from it and to facilitate the reabsorption of ammonia by
the water left in it when it is allowed to cool.
In the drawings annexed I have shewn apparatus constructed as above described.
Figure 1 is a longitudinal section of the apparatus applied to maintain a low
temperature in a room or enclosed chamber.
Figure 2 is a vertical cross section, and
Figure 3 a plan of the same. Figure 4 is an elevation of the heating apparatus.
Figure 5 is a vertical section on a larger scale of one section or division of the cooling
apparatus. Figure 6 is an elevation partly in section of apparatus for cooling liquid
contained in a bath or tank. Figure 7 is a plan view of the same. Figure 8 is a
vertical cross section through the tank and Figure 9 a cross section through a portion
of the boiler or heated end of the apparatus. Figure 10 is a cross section and
Figure 11 a longitudinal section of one of the separators by which any water passing
into the cooling pipes is separated from the liquified ammonia in these pipes and
allowed to flow back to the heated end of the apparatus.
In Figures 1, 2, 3, 4 and 5, A is an enclosed chamber with a door B. Within the
chamber and just below its roof or ceiling are closed horizontal pipes C. From one
end of each of these passes a pipe D to one or other of a series of other horizontal
pipes E which are at a lower level than the pipes C. The pipes E have a number of
short vertical pipes F descending from them and passing into other horizontal pipes G—
their lower ends being about the middle of the pipes G.
Through the pipes G are passed pipes H of smaller diameter the ends of which are
by other pipes H coupled to the two ends of a coil of pipe H³ contained in a stove I.
The pipes H, H¹ and coil H' contain water and form a closed system for conveying
heat from the stove to the liquid contained in the pipes G.
The details of construction of this system of hot water pipes are not shown as they
are well known and the closed system of hot water pipes has been used for applying
heat for a variety of purposes. At H³ (see Figures 3 and 4) are valves by which the
passage through the pipes H' to any of the pipes H can be closed whilst the passage
leading through the pipes H¹ to the other pipes H is opened so that any one of the
pipes may be heated without heating the others--or all the pipes might be heated at
once.
The pipes C which are within the cold chamber have at one end the pipes D passing
into them as above stated and at their opposite ends are formed as shewn in Figure 5
with a short vertical pipe J passing upwards into them. These pipes are closed at the
bottom. At the top they are open and come close to the top of the pipes C they have
also openings J¹ formed through their sides just above the bottom of the pipes C.
Passing up through the closed bottom of the pipes J are vertical pipes K of smaller
diameter the upper end of these pipes which are open terminate about at the level
of the centre of the pipes C-their lower ends are by a descending pipe K' which has
a U bend formed in it connected to the pipes E.
The apparatus is worked in the following manner :-
Each pipe G is filled or nearly so with a saturated solution of ammonia containing
approximately sufficient liquid ammonia to fill the pipe C. To facilitate the filling
of the pipe G this pipe has passing from it at the top a small pipe closed at its end by
a screw cap G. All air can be allowed to pass off from the pipe by unscrewing
this cap.
When a fire has been lighted in the stove I and the coil H2 heated the circulation
of heated water set up through the pipes H H' can be directed through any one or
other of the pipes H. As each pipe H becomes heated it heats the ammonia solution
in the pipe G by which it is surrounded. Slight pressure is thereby generated in this
pipe and one half of the liquid contained in it is forced up into the pipes F and E-
any gas driven off from the liquid in the pipe G then has to pass up through the
vertical pipes F into the pipe E and to bubble up through the liquid in these pipes.
Any steam or watery vapor passing along with the gas will in this way be condensed
and the gas only will pass on to the pipe C.

page_text: As the pressure increases the ammonia liquefies in the pipe C it being kept cold by
reason of its being in the cold chamber.
When all or most of the ammonia has been driven off from the water in the pipe G
the flow of heated water can be shut off from the pipe H which passes through it and
the flow directed through another and so on continuously each one being in turn heated
and so the fire in the stove I may be kept burning continuously. As each pipe G,
after being heated, gradually cools down, the pressure in this pipe decreases and a
vacuum is formed in its upper part the liquid ammonia in the pipe C vaporizes by
degrees, some of it passes downwards through the pipes F into the liquid remaining
in the lower part of the pipes G and bubbles up through the liquid to fill the vacuum
in the upper part of this pipe and keeps this liquid agitated so that the liquid readily
reabsorbs the gas and the vaporisation of the liquid ammonia goes on freely and
consequently the pipe C is cooled down to a low temperature. If it be desired to
accelerate the reabsorption of the ammonia by the water left in the pipes G and
thereby accelerate the cooling down of the pipe C the cooling of this water may be
accelerated by allowing cold water to trickle over the exterior of the pipes G or by
causing a stream of cold water to flow through a pipe passed through them or may be
accelerated in other convenient way.
If when heating any one or other of the pipes G the application of heat
is carried on for too long a time and the water contained in it is vaporised
and condensed in the cold pipe C the liquid level in these pipes will rise above
the top of the pipe K and liquid will rise up from the bottom of the pipe C
through the pipe J and pass away by the descending pipe K₁ and through
the U bend formed in it to the pipe E and from thence to the pipe G-thus if heat be
applied for too long a time to any of the pipes G these pipes will constantly have liquid
passing back to them from the pipes C and this liquid will be composed of water having
ammonia in solution, ammonia solution being of considerably greater specific gravity
than liquid ammonia so that water accumulating in the pipes C will separate itself from
the liquid ammonia and settle to the bottom of these pipes.
Consequently even when the application of heat to the apparatus has been continued
for a long time the apparatus will still remain capable of producing cold in the pipes C
whenever the pipes E and G are allowed to cool.
Another advantage is that if the pipes Gare heated directly by fire heat all chance
is avoided of the pipes being overheated and accidents happening in consequence.
There will always be liquid passing back to the pipes and a circulation of heat will
thereby be maintained through the pipes C.
A solution of ammonia is not the only solution which may be used in the apparatus
other solutions which will act in the same way may be used.
If the solution is of such a nature that the liquid which is the last to distil over is
lighter than the liquid which distils over first then the pipes J, K, need not be used
but the pipe K might be carried up as shewn by dotted lines in Figure 5 to act
simply as an overflow from the upper part of the pipe C.
In order that the ammonia gas passing to the pipes C may be comparatively cool
the pipe D is as shewn surrounded by a water jacket L through which a flow of water
is maintained.
Chambers or rooms cooled by apparatus formed in the above manner may be utilized
for a great variety of purposes-they may for example be used for storing meat or as
cool cellars for breweries or may be used for the manufacture of ice.
In this latter case it is convenient to form the chamber or room with an inner
chamber kept at a considerably lower temperature than the outer room.
In the inner room metallic pails or other vessels containing water may be set to
freeze and when frozen and reduced to a very low temperature may be removed and
stored in the outer clamber.
I have found that when water is in this way submitted to a low temperature when
absolutely at rest and undisturbed in any way blocks of perfectly transparent ice are
obtained as clear as glass and free from all air bubbles.

page_text: In the apparatus shewn at Figures 6 to 11 two pipes C are immersed in brine or
uncongealable liquid in a tank M. Each pipe C is as in the apparatus just described
connected by a pipe D with other pipes E, F, G-similar provision is also made for
heating the pipes they are shewn to be heated by three pipes H passing through them
provision is also made for allowing watery solution which may accumulate. in the
pipe C to pass back into the pipe G.
The action of the apparatus is the same as above described. The brine cooled in M
can be made to circulate through vessels required to be cooled or utilised in a variety
of ways.
In this apparatus also I have shewn part D of the pipe D from one pipe ( made
to surround part of the pipe D from the other pipe C so that at this point there may
be an interchange of temperature between the cold gas passing from one pipe and the
warm gas passing into the other. I do not restrict myself to the use of ammonia
solution other gas solution might be used instead of it.
The apparatus may be used for cooling and refrigerating in a great variety of ways.
For example it may when constructed on a small scale be employed for cooling ordinary
ice safes or refrigerators the cold pipes C being placed within the upper part of the
safe and the remainder on the outside. In this case the heating of the pipes G may
very conveniently be effected by gas burners placed below them so that to keep the
interior of the safe cool it would only be necessary to light these burners for a time
once or twice a day and if desired automatic apparatus might be used to shut off the
gas immediately that the pipes G were sufficiently heated.
Figure 12 shows a simple form in which the apparatus may be constructed—in this
'ease the apparatus is formed of one tube closed at its ends set up vertically and having
two bends in it. The end of the pipe descending from the upper bend is the part C
to be cooled-it has inserted into it pipes J and K to separate saturated solution from
liquid ammonia and to convey any solution in the lower extremity of the pipe back to
the lower bend which is the part of pipe to which the heat is applied.
:
The lower bend is filled with ammonia solution and when heat is applied to the bend
the ammonia vaporises and is liquified in the part C. When the lower bend is allowed
to cool the water remaining in it is drawn up into the end of the pipe which rises
from the bend by reason of a vacuum being then formed in this end-the liquid
ammonia vaporises and bubbles up through the water and is rapidly absorbed by it-
the vaporisation of the ammonia therefore goes on rapidly and intense cold is produced
at the extremity C of the pipe where the liquid ammonia is contained.
If when applying heat to the lower bend of the pipe the application of heat be
continued for too long a time the water contained in it will be vaporised and condensed
in the end C and will pass back again through the separator pipes J and K as in the
forms of apparatus previously described to the point at which heat is being applied so
that at this time a continuous circulation is kept up and all danger from overheating of
the apparatus is avoided.
When the solution vaporised in the part G of the apparatus is of such a nature that
the more readily vaporisable liquid is of greater specific gravity than the liquid which
is last vaporised then the pipe J and K is unnecessary for conveying back this liquid
from the part C to the part G but can be led back through an overflow pipe whenever
the liquid in the part Crises to too high a level as previously explained."
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what 1 claim is :-
1. A freezing or refrigerating apparatus consisting of a system of hermetically
closed pipes or chambers in part of which a solution of ammonia or like solution may
be heated and the ammonia or other gas or vapor so driven off and condensed and
liquified in another part of the apparatus at a higher level and an overflow pipe from
this higher part to the heated part by means of which if the application of heat be too
long continued water or other liquid last evaporated by the heat and condensed in
the cooler part may flow back to the heated portion of the apparatus.

page_text: 2. Heating the solution of ammonia or other solution contained in the apparatus by
means of hot water pipes.
3. The construction of the apparatus in two or more similar divisions and in such
manner that the cool gases passing from the cool end of one division of the apparatus
are employed to cool the warm gases passing to the cool end of another division of the
apparatus.
4. The construction of the apparatus in two or more similar divisions so that
heat may be applied to one or more whilst another or others are being allowed to
cool.
5. The construction of freezing and refrigerating apparatus substantially in the
ways herein before described and illustrated in the drawings annexed.
LOFTUS PERKINS.

page_text: Date of Application, 18th Feb., 1888
Complete Specification Left, 7th June, 1888-Accepted, 6th July 1888
PROVISIONAL SPECIFICATION.
Improvements in Refrigerating and Freezing Apparatus.
I, LOFTUS PERKINS of 6 Seaford Street Grays Inn Road in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to refrigerating and freezing apparatus in which the
production of cold is obtained by heating one portion of the apparatus in which is
contained a solution of ammonia or other substance from which gas can be driven off
on the application of heat and liquified in another and cooler portion of the apparatus,
which liquified gas in the heated portion of the apparatus being subsequently allowed
to cool is reabsorbed by the water or other substance remaining in the previously
heated portion of the apparatus.
I form such an apparatus of a system of hermetically closed horizontal pipes or
chambers. One pipe or set of pipes in which the liquid is to be heated is normally
filled or nearly so with the liquid. Above each such pipe is another pipe from the
bottom of which pipes descend into and project downwards a distance say to the
centre of the lower one.
Preferably I heat the lower one by steam or hot water in a pipe passing through or
into it. When the lower one is heated half of its contents are by the consequent
liberation of gas forced into the upper one until gas can enter the lower ends of the
The gas then bubbles up through the
vertical pipes and pass up through them.
liquor in the upper pipe and any vapor of water passing up with it will be condensed
leaving the gas only to pass off from the upper pipe to the pipe or pipes forming that
part of the apparatus in which cold is to be produced.
These pipes are always maintained colder than any of the other parts of the apparatus
gas all
and consequently when the pressure in the pipes becomes sufficient to liquefy the
liquefaction takes place in them.
When heat is no longer applied to the boiler end and it commences to cool the
pressure in the upper part of the lower pipe will be reduced and the liquid in the
upper one will pass back into it and gas then passing downwards through the
vertical pipes will be kept bubbling through the liquid in the lower pipe and will be
absorbed in it.

page_text: The pipe passing from boiler to refrigerator is kept cooled whilst the boiler is being
heated so that all gas passing to the refrigerator may enter refrigerator in a
comparatively cold state.
Screw plugs may be provided by which any water collected in refrigerator may be
drawn off from time to time. Or I provide the refrigerator with an overflow pipe
which rises up through a small well at its bottom and terminates some little distance
below its centre. The portion of the overflow which projects up into the refrigerator
is surrounded by a tubular guard which is open at the top close to the top of the
refrigerator and has also openings through it at the bottom by which liquid can pass
to the overflow.
'
Water being heavier than liquid ammonia any water passing over into the
refrigerator will collect at the bottom and may as the refrigerator is filled with
ammonia be made to rise up within the tubular guard and pass off by the overflow.
The outlet pipe from the overflow I form with a U bend in it and lead it back to
the boiler portion of the apparatus which is placed at a lower level.
When continuous action is required I duplicate the apparatus or use any desired
number of apparatus and keep the refrigerator end of each apparatus immersed in
one bath of an uncongealable liquid or otherwise provide for keeping the refrigerator
end of one when gas is being liquefied in it cooled by the production of cold in
another.
Similarly the gas passing to one may be cooled by gas passing from another.

page_text: 1, LOFTUS PERKINS of 6 Seaford Street Grays Inn Road, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
It has before been proposed to construct freezing and refrigerating machines of two
vessels capable of supporting considerable pressure and communicating with one
another at the top through a tube. Into one vessel has been placed a liquid or
substance in which a gas has been absorbed (say an ammoniacal solution) and this
vessel has been heated and the aminonia driven off and liquified under pressure in the
second vessel which is kept cool. Subsequently the heated vessel containing the water
from which ammonia has been driven off has been cooled or allowed to cool and the
pressure being thereby reduced the liquified ammonia in the second vessel has then
again vaporized and been reabsorbed by the water left in the vessel which was pre-
viously heated. The temperature in the second vessel containing the liquified
ammonia has been thereby reduced.
Freezing apparatus of this kind as heretofore constructed has possessed many
defects and has not come into general use.
When overheated and when consequently not only the ammonia but also the water
has been driven out from the vessel which is being heated it has been liable to
disastrous explosions.
.
It has also required to be made with pumps and valves or if of small dimensions
has required to, he inverted to allow of any water which may have passed over into
the second or cooling vessel being passed back into the first or heating vessel.
The mode of applying heat to the vessel has also been defective, and so also bave
been the precautions taken to avoid the passing off of watery vapor from the vessel
that is being heated and to subsequently ensure the ready reabsorption of gas by the
liquid remaining in this vessel have also been defective.
I remove all these objections.
I make the apparatus of a system of hermetically-closed pipes so disposed that any
water or liquid which passes from the portion of the apparatus that is at times heated
may. separate itself from liquified gas at the cooler end of the apparatus and pass back
by gravity to the part of the apparatus that is being heated so that no injury can
possibly arise to the apparatus from overheating as any water or liquid distilled over
with the gas from the boiler or heated end will when all ammonia or gas has been
driven from that end flow back again and so a continuous circulation will be kept up
and the only evil that could arise would be that the apparatus would then be working
as a heating apparatus but the apparatus itself would remain uninjured and ready to
áct as a cooling apparatus so soon as the heating of the boiler end was stopped and
that end allowed to cool. I also as hereinafter described form the boiler (or that

page_text: portion of the apparatus which is at times heated) in such a manner as to hinder the
passing off of watery vapor from it and to facilitate the reabsorption of ammonia by
the water left in it when it is allowed to cool.
In the drawings annexed I have shewn apparatus constructed as above described.
Figure 1 is a longitudinal section of the apparatus applied to maintain a low
temperature in a room or enclosed chamber.
Figure 2 is a vertical cross section, and
Figure 3 a plan of the same. Figure 4 is an elevation of the heating apparatus.
Figure 5 is a vertical section on a larger scale of one section or division of the cooling
apparatus. Figure 6 is an elevation partly in section of apparatus for cooling liquid
contained in a bath or tank. Figure 7 is a plan view of the same. Figure 8 is a
vertical cross section through the tank and Figure 9 a cross section through a portion
of the boiler or heated end of the apparatus. Figure 10 is a cross section and
Figure 11 a longitudinal section of one of the separators by which any water passing
into the cooling pipes is separated from the liquified ammonia in these pipes and
allowed to flow back to the heated end of the apparatus.
In Figures 1, 2, 3, 4 and 5, A is an enclosed chamber with a door B. Within the
chamber and just below its roof or ceiling are closed horizontal pipes C.
From one
end of each of these passes a pipe D to one or other of a series of other horizontal
pipes E which are at a lower level than the pipes C. The pipes E have a number of
short vertical pipes F descending from them and passing into other horizontal pipes G-
their lower ends being about the middle of the pipes G.
Through the pipes G are passed pipes H of smaller diameter the ends of which are
by other pipes Hi coupled to the two ends of a coil of pipe H2 contained in a stove I.
The pipes H, H' and coil H³ contain water and form a closed system for conveying
heat from the stove to the liquid contained in the pipes G.
The details of construction of this system of hot water pipes are not shown as they
are well known and the closed system of hot water pipes has been used for applying
heat for a variety of purposes. At H³ (see Figures 3 and 4) are valves by which the
passage through the pipes H¹ to any of the pipes H can be closed whilst the passage
leading through the pipes H¹ to the other pipes H is opened so that any one of the
pipes may be heated without heating the others—or all the pipes might be heated at
once,
The pipes which are within the cold chamber have at one end the pipes D passing
into them as above stated and at their opposite ends are formed as shewn in Figure
with a short vertical pipe J passing upwards into them. These pipes are closed at the
bottom. At the top they are open and come close to the top of the pipes C they have
also openings J formed through their sides just above the bottom of the pipes C.
Passing up through the closed bottom of the pipes J are vertical pipes K of smaller
diameter the upper end of these pipes which are open terminate about at the level
of the centre of the pipe C-their lower ends are by a descending pipe K' which has
a U bend formed in it connected to the pipes E.
'
The apparatus is worked in the following manner :-
Each pipe G is filled or nearly so with a saturated solution of ammonia containing
approximately sufficient liquid ammonia to fill the pipe C. To facilitate the filling
of the pipe G this pipe has passing from it at the top a small pipe closed at its end by
a screw cap G. All air can be allowed to pass off from the pipe by unscrewing
this cap.
When a fire has been lighted in the stove I and the coil H2 heated-the circulation
of heated water set up through the pipes H H' can be directed through any one or
other of the pipes H. As each pipe H becomes heated it heats the ammonia solution
in the pipe G by which it is surrounded. Slight pressure is thereby generated in this
pipe and one half of the liquid contained in it is forced up into the pipes F and E-
any gas driven off from the liquid in the pipe G then has to pass up through the
vertical pipes F into the pipe and to bubble up through the liquid in these pipes.
Any steam or watery vapor passing along with the gas will in this way be condensed
and the gas only will pass on to the pipe C.

page_text: As the pressure increases the ammonia liquefies in the pipe it being kept cold by
reason of its being in the cold chamber.
When all or most of the ammonia has been driven off from the water in the pipe G
the flow of heated water can be shut off from the pipe H which passes through it and
the flow directed through another and so on continuously each one being in turn heated
and so the fire in the stove I may be kept burning continuously. As each pipe G,
after being heated, gradually cools down, the pressure in this pipe decreases and a
vacuum is formed in its upper part the liquid ammonia in the pipe C vaporizes by
degrees, some of it passes downwards through the pipes F into the liquid remaining
in the lower part of the pipes G and bubbles up through the liquid to fill the vacuum
in the upper part of this pipe and keeps this liquid agitated so that the liquid readily
reabsorbs the gas and the vaporisation of the liquid ammonia goes on freely and
consequently the pipe C is cooled down to a low temperature. If it be desired to
accelerate the reabsorption of the ammonia by the water left. in the pipes G and
thereby accelerate the cooling down of the pipe the cooling of this water may be
accelerated by allowing cold water to trickle over the exterior of the pipes G or by
causing a stream of cold water to flow through a pipe passed through them or may be
accelerated in other convenient way.
If when heating any one or other of the pipes G the application of heat
is carried on for too long a time and the water contained in it is vaporised
and condensed in the cold pipe C the liquid level in these pipes will rise above
the top of the pipe K and liquid will rise up from the bottom of the pipe C
through the pipe J and pass away by the descending pipe K and through
the U bend formed in it to the pipe E and from thence to the pipe G-thus if heat be
applied for too long a time to any of the pipes G these pipes will constantly have liquid
passing back to them from the pipes C and this liquid will be composed of water having
ammonia in solution, ammonia solution being of considerably greater specific gravity
than liquid ammonia so that water accumulating in the pipes C will separate itself from
the liquid ammonia and settle to the bottom of these pipes.
Consequently even when the application of heat to the apparatus has been continued
for a long time the apparatus will still remain capable of producing cold in the pipes C
whenever the pipes E and G are allowed to cool.
Another advantage is that if the pipes G are heated directly by fire heat all chance
is avoided of the pipes being overheated and accidents happening in consequence.
There will always be liquid passing back to the pipes and a circulation of heat will
thereby be maintained throngh the pipes C.
A solution of ammonia is not the only solution which may be used in the apparatus
other solutions which will act in the same way may be used.
If the solution is of such a nature that the liquid which is the last to distil over is
lighter than the liquid which distils over first then the pipes J, K, need not be used
but the pipe K might be carried up as shewn by dotted lines in Figure 5 to act
simply as an overflow from the upper part of the pipe C.
In order that the ammonia gas passing to the pipes C may be comparatively cool
the pipe D is as shewn surrounded by a water jacket L through which a flow of water
is maintained.
Chambers or rooms cooled by apparatus formed in the above manner may be utilized
for a great variety of purposes-they may for example he used for storing meat or as
cool cellars for breweries or may be used for the manufacture of ice.
In this latter case it is convenient to form the chamber or room with an inner
chamber kept at a considerably lower temperature than the outer room.
In the inner room metallic pails or other vessels containing water may be set to
freeze and when frozen and reduced to a very low temperature may be removed and
stored in the outer chamber.
I have found that when water is in this way submitted to a low temperature when
absolutely at rest and undisturbed in any way blocks of perfectly transparent ice are
obtained as clear as glass and free from all air bubbles,

page_text: In the apparatus shewn at Figures 6 to 11.two pipes Care immersed in brine or
uncongealable liquid in a tank M. Each pipe C is as in the apparatus just described
connected by a pipe D with other pipes E, F, G-similar provision also made for
heating the pipes they are shewn to be heated by three pipes H passing through them
-provision is also made for allowing watery solution which may accumulate in the 5
pipe C to pass back into the pipe G.
•
The action of the apparatus is the same as above described. The brine cooled in M
can be made to circulate through vessels required to be cooled or utilised in a variety
of ways.
In this apparatus also I have shewn part D× of the pipe D from one pipe C made
to surround part of the pipe D from the other pipe C so that at this point there may
be an interchange of temperature between the cold gas passing from one pipe and the
warm gas passing into the other. I do not restrict myself to the use of ammonia
solution-other gas solution might be used instead of it."
The apparatus may be used for cooling and refrigerating in a great variety of ways.
For example it may when constructed on a small scale be employed for cooling ordinary
ice safes or refrigerators-the cold pipes being placed within the upper part of the
safe and the remainder on the outside. In this case the heating of the pipes G may
very conveniently be effected by gas burners placed below them so that to keep the
interior of the safe cool it would only be necessary to light these burners for a time
once or twice a day and if desired automatic apparatus might be used to shut off the
gas immediately that the pipes G were sufficiently heated.
Figure 12 shews a simple form in which the apparatus may be constructed-in this
case the apparatus is formed of one tube closed at its ends set up vertically and having
two bends in it. The end of the pipe descending from the upper bend is the part C
to be cooled-it has inserted into it pipes J and K to separate saturated solution from
liquid ammonia and to convey any solution in the lower extremity of the pipe back to
the lower bend which is the part of pipe to which the heat is applied.
The lower bend is filled with ammonia solution and when heat is applied to the bend
the ammonia vaporises and is liquified in the part C. When the lower bend is allowed
to cool the water remaining in it is drawn up into the end of the pipe which rises
from the bend by reason of a vacuum being then formed in this end-the liquid
ammonia vaporises and bubbles up through the water and is rapidly absorbed by it-
the vaporisation of the ammonia therefore goes on rapidly and intense cold is produced
at the extremity C of the pipe where the liquid ammonia is contained.
If when applying heat to the lower bend of the pipe the application of heat be
continued for too long a time the water contained in it will be vaporised and condensed
in the end C and will pass back again through the separator pipes J and K as in the
forms of apparatus previously described to the point at which heat is being applied so
that at this time a continuous circulation is kept up and all danger from overheating of
the apparatus is avoided.
When the solution vaporised in the part G of the apparatus is of such a nature that
the more readily vaporisable liquid is of greater specific gravity than the liquid which
is last vaporised then the pipe J and K is unnecessary for conveying back this liquid
from the part C to the part G but can be led back through an overflow pipe whenever
the liquid in the part Crises to too high a level as previously explained.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. A freezing or refrigerating apparatus consisting of a system of hermetically
closed pipes or chambers in part of which a solution of ammonia or like solution may
be heated and the ammonia or other gas or vapor so driven off and condensed and
liquified in another part of the apparatus at a higher level and an overflow pipe from
this higher part to the heated part by means of which if the application of heat be too
long continued, water, or other liquid last evaporated by the heat and condensed in
the cooler part may flow back to the heated portion of the apparatus.

page_text: 2. Heating the solution of ammonia or other solution contained in the apparatus by
means of hot water pipes.
3. 2. The construction of the apparatus in two or more similar divisions and in such
manner that the cool gases passing from the cool end of one division of the apparatus
are employed to cool the warm gases passing to the cool end of another division of the
apparatus.
4. The construction of the apparatus in two or more similar divisions so that
heat may be applied to one or more whilst another or others are being allowed to
cool.
3. The construction of freezing and refrigerating apparatus substantially in the
ways herein before described and illustrated in the drawings annexed.
Dated thin at 1
T1000
LOFTUS PERKINS.