IMPROVEMENTS IN THE PRODUCTION OF ICE, AND IN APPARATUS EMPLOYED THEREFOR OR CON- NECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER SIMILAR PURPOSES
Year: 1877

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
THE PRODUCTION OF ICE, AND IN APPARATUS EMPLOYED THEREFOR OR CON-
NECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER
SIMILAR PURPOSES." A communication from abroad by Georges Dubern, of
Paris, in the Republic of France.
Sealed the 18th January 1878, and dated the 18th August 1877.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 18th August 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE PRODUCTION OF ICE, AND IN APPARATUS
EMPLOYED THEREFOR OR CONNECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE TO OTHER SIMILAR PURPOSES." A communication from abroad by
Georges Dubern, of Paris, in the Republic of France.
This Invention relates to improved apparatus for the production of ice, whereby.
important advantages are obtained.
În carrying out this Invention a strong boiler is employed, placed in communica-
tion with a receptacle by means of a curved pipe making a complete circumvolution.,
This pipe is made of such a shape that when the machine is turned over, as herein-
after mentioned, no liquid and gas at the same time may continuously flow in either
direction. The capacity of the receptacle is, say, about one-third or one-fourth of that
of the boiler, and all the parts of the apparatus are either welded, brazed, or soldered;
they should be capable of withstanding safely a working pressure of, say, 150 lbs. to
the square inch. The boiler is filled about two-thirds or three-fourths with a solution
of ammonia at no higher temperature than O centigrade, or a few degrees below O
centigrade when being saturated. The boiler is placed over a brisk fire and the
receptacle in sufficient cold water to prevent a sensible rise of its temperature. In
a few minutes, the boiler, being as yet but very little heated, some, but very
Posice 871

page_text: moderately, warm gas distils over, and from the fact of its rather cool condition
readily liquefies at the lower part of the receptacle, and soon intercepts the free
communication between that and the boiler; hence as the temperature rises, any hot
ammonia coming afterwards from the boiler to the receptacle has to bubble through
the liquefied and altogether cold ammonia; this cools it and liquefies it very rapidly,
in addition to which the bubbling causes agitation, which greatly assists the
liquefied ammonia in parting with the heat abstracted from the gaseous ammonia,
and convey it quickly to the outside water through the métallic sides of the
receptacle.
"
This method of cooling and washing the gaseous ammonia constitutes an important
feature of the Invention; it also secures the great superiority with regard to economy
of fuel and rapidity of working of the improved ice machines over others of the
same class, in which the ammonia has to be condensed and liquefied by additional
pressure on account of its hot condition, or when very imperfectly, cooled, whilst as
yet in a state of a gas by mere contact with the cold sides of the pipes or receptacle.
Injecting cold liquid aminonia by means of a pump would produce equally good
results if forced into a receptacle containing gaseous ammonia, especially if the
injection were made in the form of a shower. The injection may also be produced
by causing the liquid to flow from a higher receptacle by means of pipes in com-
munication with both of them.
When the bubbling is heard to diminish or cease, the machine is taken from the
fire, turned over half round, end for end, in the direction from the boiler to the
receptacle, and the boiler placed in cold water. The above described process now
takes place in a similar manner in the opposite direction, the ammonia distills from
the receptacle into the boiler, and produces very intense cold; any liquid placed
about around the receptacle being also cooled in the same degree.
In the above described machine the proper flow of gas is secured without the
assistance of valves, cocks, and the like. This constitutes the second important
advantage of these machines, as there is no leakage anywhere, nor any loss of
ammonia.
The receptacle may be made so as to produce a solid cylinder of ice by con-
structing it with an annular space of greater diameter at the top than at the
bottom. On account of its peculiar shape the greater part of the liquid ammonia
contained at the top in the wide annular space evaporates with a relatively small
fall of level, at least up to the moment that level reaches the smaller annular space.
In this manner a large evaporating surface is preserved during almost the whole
process. After heating and turning over the machine, a metallic vessel, holding the
liquid to be cooled, is placed around the receptacle or within it when constructed
with a cylindrical internal space, and proper contact with the sides of the receptacle
is secured by filling the remaining empty space with some incongealable liquid, such,
as for example, water and salt, water and glycerine, alcohol, and the like; the
external parts should be well protected by some non-conductor of heat.
The machine above described, if made large to produce a considerable quantity of
icc, would be incommodious from the fact of its requiring to be turned completely
round after each successive heating, and in addition to which, as the quantity of
fuel required for the manufacture of small supplies of ice is not taken into con-
sideration, no special means are applied to it to utilize to the utmost the caloric
evolved by the combustion of coal.
In order to produce a machine having all the above-mentioned qualities, and,
moreover, calculated for the economical manufacture of ice, systematically and in
large quantity the following modification is adopted :-A strong boiler is employed,
preferably cylindrical, and with hemispherical ends; a pipe closed at one end &
open at the other passes through the top of the boiler, in which pipe is placed certain
safety apparatus, herein-after described.
Above the boiler is arranged a vapour chamber having a narrow neck, to which
is fixed a pipe having a flange water-tight in the neck of the chamber; the pipe at
the top has its sides perforated with a number of holes, the total area of which

page_text: should be equal to the sectional area of the pipe. Over the pipe is placed a bell
or receiver, which reaches to within a short distance of the bottom of the chamber;
an overflow pipe is fixed air-tight to the top of the bell or receiver, and passes
through it; the lower part of this pipe reaches to about the centre of the boiler.
Over the first combination of pipes and receiver there is placed a second one,
similar to the first, with the exception that it has its overflow bent, so as to reach
nearly to the bottom of the vapour chamber; above is provided a valve witli its valvo
box, from which springs a vertical coiled boiler pipe, making a few ascending con-
volutions of a quick pitch; and around the coil and the chamber is a reservoir to hold
water, in order to maintain the temperature of the chamber and of the coil at, say,
about 50° centigrade; in smaller machines a piece of wet cloth twisted about the
chamber is sufficient. The boiler pipe is continued over to a receptacle, through the
top of which it passes, and thence descends to the bottom, where it discharges
the ammonia from the boiler.
Above the receptacle is a valve box and valve opening upwards, similarly to the
valve herein-before described. From the top of the valve box springs a pipe,
which after being carried upwards turns down and forms a coil with many convolu-
tions. At the place where the coil commences the receptacle pipe may advantageously
be subdivided into several pipes running parallel to each other; then collecting again
into a single one it passes through the top of the boiler, and descends to within a
short distance of the bottom of the same. A rigid arm connects the boiler. to the
receptacle. Around the coil are two or more cylindrical vessels, each well
protected by a heat non-conductor, and furnished with two taps, one at the top for
filling, and the other at the bottom for emptying. The boiler is also made with
a central passage, the receptacle being either made in a plain cylindrical shape or
having also a central passage.
Where very rapid evaporation is required the modification of receptacle secondly.
herein-before described is most suitable. The receptacle may also be made with a
conical internal passage, or with an internal chamber and descending pipes. By
this construction a large portion of the surface of the sides of the receptacle is
maintained in contact with the liquefied ammonia, for the greater part of the time
of the duration of the process. An aperture is also provided for filling the boiler
with the ammonia solution; it is composed of an ordinary lead joint, jamming by
means of a screw. There is also an ordinary fusible boiler plug, the fusible part of
which melts between, say, 180° centigrade and 200° centigrade.
The boiler between 2/3rds and 3/4ths filled with a concentrated solution of ammonia is
placed over a fire, and the receptacle in cold water. Some nearly anhydrous
ammonia is immediately evolved; it passes into the chamber through the first and'
second receivers, through the valve above the coil and pipe into the receptacle; at
the same time, the valve of the receptacle closes, and if it should leak or not work
at all, the ammonia solution rising in the pipe and coil from the receptacle acts as
a valve, the moment it has reached a sufficient head to counterbalance the flow
through the boiler pipe; thus whatever be the case no flow can take place through
the receptacle pipe at this stage.
When the temperature of the boiler has attained to, say, about 40° or 45° centigrade,
some liquefied ammonia has already condensed in the receptacle, and fresh gas'
entering the bubbling is perceptible, and the process then rapidly proceeds.
As the temperature of the boiler increases some steam passes up through the
receivers, and, condensing, accumulates at the lower part of the partitions; any
steam that may have escaped from the chamber has to pass through the boiler coil,
and is further condensed there, so that following the incline of the coil it falls back
into the vapour chamber. When the pipe is found to get hot cold water is poured
into the reservoir. About this stage of the process steam has acquired sufficient
tension to distil in such a quantity as would prove injurious to the efficient pro-
duction of cold, this steam however, having to bubble through the cool water
accumulated at the lower part of the receivers, it is there retained in the form of
water, whereas ammonia distils over towards the receptacle; any excess of water in

page_text: the second receiver flows back to the first one through its overflow pipe, and from
this one to the boiler through the other overflow pipe. As the lower part of the
overflow pipes are always below the surface of liquids no regular flow of gas can
take place through them.
When the bubbling is heard to become slower the machine is withdrawn from the
fire, the boiler placed in cold water, and the receptacle in the liquid from which
heat is to be abstracted; the vessels surrounding the coil of pipe from the receptacle
are also filled with cold clean water. On the temperature lowering in the boiler the
pressure also diminishes rapidly, and becomes less than that of the receptacle, the
valve closes, and if it leaks or does not work the liquefied ammonia ascends to a
certain height in the boiler pipe, and therefore answers the purpose of a valve, as
far as the flow of gas is concerned, at the same time also the valve of the receptacle
opens, and the ammonia gas returns to the boiler through the receptacle pipe and
coil, and finally through the other lower end of the pipe, there causing a bubbling,
assisting in the reabsorption of ammonia by its solvent. As the ammonia distills
towards the boiler intense cold is produced in the receptacle; this cold is either
employed to cool directly anything desired, or it first cools a circulating liquid,
holding in solution salts, glycerine, and the like, which liquid in its turn cools
water or other body to be converted into ice, the same being contained in suitable
moulds. The gaseous ammonia flowing through the receptacle pipe and the coiled
pipe or pipes has a temperature several degrees below 0 centigrade, the water con-
tained in the vessels before mentioned is therefore cooled by the coil; this water
being afterwards drawn out is put into the moulds, where finally it has to be made
into ice.
The advantage of several separate vessels over a single one of the same collective
capacity is that by this means nearly the whole of the refrigerating capacity of the
ammonia is utilized before it returns to the boiler.
When the bubbling is heard to diminish in the boiler the machine is to be turned
Whilst in that
only a quarter round, so that the refrigerator becomes at the top.
position the free access of external air to the receptacle, by warming it, causes
additional pressure within, which forces back to the boiler through the receptacle
pipe any liquid remaining in it, and which might prevent the thorough success of
the next operation. For the sake of cheapness of construction certain of the parts
of the apparatus herein-before described may be dispensed with.
In machines where the metallic valves are dispensed with, it is absolutely
necessary that the boiler pipes and receptacle pipes should rise to a certain
height above the heighest level to which the fluids to be contained therein can ever.
attain.
In some cases, as for example, in India, where the ice machines may have to be
handled by natives, it is necessary to have some reliable safety apparatus employed
in connection with them. The construction of the safety apparatus employed
according to this Invention is based on the fusion of alloys having low melting
points. The pipe, which extends down to the bottom of the boiler, as before
mentioned, is half or two-thirds filled with fusible metal melting at a temperature
of, say, about 10 centigrade, above the proper one necessary for regular working;
over the alloy is placed a heavy metallic rod plunger projecting upwards above the
boiler, say, by about half its length, its upper end being hooked or furnished with a
notch. When the alloy melts the rod descends and releases the catch of an alarm,
this being effected by some of the well-known plans adopted in clock-making.
According to another modification, which is especially adapted for apparatus for
domestic use, a connecting rod turning downwards is fixed to the top of the plunger,
the end of which connecting rod is furnished with a small projecting piece or hook,
and reaches as low as the furnace fire-grate. This grate is hinged at one of its sides;
the opposite side is made very heavy, and has a small arm projecting a little outside
the furnace through a vertical groove directed downwards, and allowing free motion
to the small arm and grate about its hinge from a horizontal position downwards
until it reaches a vertical one under the grate; and sufficiently below it to allow free

page_text: motion, is placed a vessel containing water; the extremity of the arm above
mentioned is hooked to the connecting rod outside the furnace. It is evident that
as long as the alloy is solid the grate will remain up, supported by the plunger and
connecting rod, and that the moment the plunger sinks down freely into the safety
pipe, the fire on the grate is necessarily dropped into water.
When the grate is of large dimensions the whole weight of the plunger may be
arranged to bear on the handle of a water cock, the moment it is no longer
supported by the fusible alloy. One of the passages of the cock is in communication
with a water reservoir, and the other with a pipe entering the furnace and per-
forated with small holes so as to spread the water about the whole surface of the
grate. Before a dangerous temperature in the boiler is reached the water will flow
into the furnace and extinguish the fire.
.
If the machine does not give sufficiently distinct indication of the moment when
all the ammonia is evaporated from its solution, this defect is due to the excessive
area of the tube connecting the boiler to the refrigerator. A simple diaphragm
perforated with a small hole, and placed at the extremity of the tube leading to the
refrigerator will be sufficient to give the gas the requisite velocity to produce a
sufficient sound.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 18th
February 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE PRODUCTION OF ICE, AND IN APPARATUS
EMPLOYED THEREFOR OR CONNECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE TO OTHER SIMILAR PURPOSES." A communication from abroad by
Georges Dubern, of Paris, in the Republic of France.
The said Invention relates to improvements having for their object the production
of ice in a more economical and expeditious manner than heretofore, as herein-after
described with reference to the accompanying Sheet of Drawings.
Figure 1 of the Drawings represents a sectional elevation of an apparatus con-
structed according to one modification of the said Invention, and Figure 1ª is a
corresponding horizontal section taken along the line 1-2, Figure 1.
Figure 2 represents a vertical section of a modified form of receptacle constituting
a portion of the improved apparatus, and Figures 2a and 2b are corresponding
horizontal sections of the same taken along the lines 3, 4, and 5, 6, respectively, in
Figure 2.
Figure 3 represents a sectional elevation of an apparatus constructed according to
another modification of the said Invention.
Figures 4 and 4ª are respectively a vertical section and plan illustrating a modi-.
fied form of boiler, or of receptacle.
Figures 5 and 6 are vertical sections illustrating respectively two other modifica-
tions of the receptacle.
Figures 50 and 5b are respectively a plan and horizontal section corresponding to
Figure 5, and Figure 6a is a horizontal section corresponding to Figure.6.

page_text: Figures 7 and 7a are sectional elevations taken, the one at right angles to
the other, of an apparatus for maintaining a constant circulation of the water to
be frozen.
Referring to Figures 1 and 1ª, A is a strong boiler which is placed in communication
with a receptacle B by means of a curved or coiled pipe C, making one complete
circumvolution at D. This pipe is so constructed that when the apparatus is turned
over, as herein-after mentioned, liquid and gas together will not be able to flow simul-
taneously and continuously from A to B, or vice versa. The capacity of the
receptacle B is, say, about one one-third or one-fourth of that of the boiler A, and
all the parts of the apparatus are united by being either welded, brazed, or sol-
dered; they should be capable of resisting a working pressure of, say, 150 lbs. to the
square inch. The boiler A is filled to about two-thirds or three-fourths of its
capacity with a solution of ammonia saturated at a temperature not higher than 0°
centigrade, or a few degrees below 0° centigrade; water or salt water may be employed
as a solvent. The boiler A is placed over a brisk fire, and the receptacle B is immerged
in sufficient cold water in order that it may not become heated. In a few
minutes, while the boiler is as yet but slightly heated, some moderately warm
gas distils over,
and from the fact of its rather cool condition readily liquefies
at the lower part of the receptacle B, where it accumulates and soon intercepts the
free communication between the said receptacle and the boiler, so that any hot
gaseous ammonia subsequently distilled over from the boiler to the receptacle, as the
temperature rises, is compelled to bubble through the liquefied and completely cooled
ammonia, being thereby rapidly cooled and liquefied in its turn, in addition to which
the passage of the gas causes an agitation which greatly assists the liquefied
ammonia in parting with the heat abstracted from the gascous ammonia, and
conveying it quickly to water in contact with the metallic sides of the receptacle.
When the bubbling diminishes or ceases the apparatus is taken from the fire,
turned over half round, end for end, in the direction indicated by the arrows, the
receptacle B being placed in contact with the liquid to be cooled as herein-after
explained, and the boiler A immerged in cold water. The herein-before described
action now takes place in a similar manner in an inverse direction, the ammonia
distils over from the receptacle B into the boiler A, and produces very intense cold
in the receptacle B, the liquid in contact with the said receptacle being also
cooled in the same degree by the extraction of its caloric by the evaporization
of the ammonia.
This method of cooling and washing the gaseous ammonia constitutes an important
feature of the Invention, and to it is mainly due the great superiority with regard
to economy of fuel and rapidity of working of the improved ice machines over
others of the same class in which the ammonia has to be condensed and liquefied by
additional pressure on account of its being imperfectly cooled whilst still in a 4
gaseous state by not being brought properly into contact with the cold slides of
the pipes or receptacles. Equally good results may be obtained by injecting cold
liquid ammonia by means of a pump into a receptacle containing gaseous aminonia,
especially if the injection is made in the form of spray; the injection may also be
produced by causing the liquid to flow from a higher receptacle to a lower by means
of pipes suitably arranged.
In the above-described apparatus the proper flow of gas is secured without the
assistance of valves, cocks, and the like; this constitutes another important advan-
tage of these machines, as there is no leakage anywhere, nor any loss of ammonia.
The receptacle may be made so as to produce a solid cylinder of ice by constructing
it (as shown in Figures 2, 2ª, and 2b,) with an annular space A, B, of greater
diameter at the top than at the bottom. On account of its peculiar shape the
greater part of the liquid ammonia contained at the top in the wide annular space
A, A, evaporates with a relatively small fall of level, at least up to the moment
when that level falls to the smaller annular space B, B. In this manner a large 5
evaporating surface is preserved during nearly the whole process. After heating
and turning over the apparatus in the manner herein-before described, the receptacle

page_text: when constructed, as shown in Figures 1 and 1ª, is placed in a metallic vessel con-
taining the, liquid to be cooled or congealed, or when constructed as shown in
Figures 2, 2a, and 2b, the vessel containing the liquid to be cooled or congealed is
placed in the cylindrical internal space C, and the space between it and the inner
sides of the annular space A, B, filled up with some uncongealable liquid, such for
example, as salt and water, glycerine and water, alcohol, and the like. The external
parts should be well protected by some non-conductor of heat.
This form of the apparatus, if made of sufficient size to produce a considerable
quantity of ice, would be inconvenient, as the operation of turning round after each
successive heating an apparatus of such large dimensions would be attended with
difficulty; moreover, as the quantity of fuel required for the manufacture of small
supplies of ice is of little importance, no special means are provided for utilizing to
the utmost the caloric evolved by the combustion of the fuel.
In order to produce an apparatus combining all the advantages herein-before
described, with a capacity for the economical manufacture of ice on a commercial scale,
the modification illustrated in Figure 3 is adopted. A is a strong boiler, preferably
cylindrical, and with hemispherical ends, in which boiler is fitted a pipe B, closed at
its lower end, and open at its upper end, which protudes from the top of the
boiler, the said pipe being intended for the reception of certain safety apparatus
herein-after described.
Above the boiler is arranged a steam chamber C, having a narrow neck a, to
which is fixed a tube b connected by a flange c, forming a tight joint to the neck a
of the chamber C; the tube b at the top has its sides perforated with a number of
holes, the area of which should be equal to the sectional area of the tube. Over
the tube is placed a bell or receiver O, which extends down to within a short
distance of the bottom of the chamber C, and an overflow pipe e is fixed air-tight to
the top of the bell or receiver, and passes through it, the lower part of this pipe
terminating at about or below the centre of the depth of the boiler A. Over the
tube and bell O there is placed another tube b¹ with a bell O¹ similar to the first,
with the exception that it has its overflow pipe e¹ bent so as to reach nearly to the
bottom of the steam chamber C.
The upper part of the steam chamber is provided with a valve D in a valve box
D', from which springs a pipe E coiled upwards in the form of a worm, which, with
the steam chamber C, is placed in a tank F for containing water in order to maintain
the chamber C and the coil E at a temperature of, say, about 50° centigrade. In
small apparatus a piece of wet cloth twisted about the chamber is sufficient for the
purpose. The worm E communicates with a pipe E¹, which passes through the
cover of a receptacle G, and thence descends to the bottom of the same, where it
discharges the amonia from the boiler.
The receptacle G is provided at its upper part with a valve box and valve H,
opening upwards similarly to the valve D, and communicating with a chamber H',
connected to a pipe I', which after being carried upwards turns down and forms a
worm I of a number of coils or convalutions.
The pipe I may advantageously be subdivided at this part into several pipes
running parallel to each other in the form of a worm, and then re-united again into
a single pipe. The worm I communicates with a pipe I¹¹, passing through the top
of the boiler A, and descending to within a short distance of the bottom of the
same.
The boiler A and receptacle G are connected together by a rigid arm J, and the
worin I is placed in two cylindrical vessels K containing liquid, each well protected
by a suitable non-conductor of heat, and also furnished with two cocks (not shewn
in the Drawing), one being placed at the top for filling, and the other at the bottom
for emptying. The boiler A may, if desired, be made with a central passage A¹, as
shewn in Figures 4 and 4ª, and the receptacle G may either be made of a plain
cylindrical shape, or with a central passage similar to the boiler, Figures 4 and 4a.
Where very rapid evaporation is required the modification of receptacle herein-
before described with reference to Figures 2; 2a, and 2b, is most suitable. The

page_text: receptacle may also be made with a conical internal passage G², as shewn in
Figs. 5, 5ª and 5b, or with an internal chamber G³, as shewn in Figures 6 and 6*.
By this construction a large portion of the surface of the sides of the receptacle is
maintained in contact with the liquefied ammonia for the greater part of the time of
the duration of the process. An aperture (closed with an ordinary lead joint and
screw) is to be provided for the facility of filling the boiler with the ammonia
solution. The boiler may also be provided with an ordinary fusible boiler plug, the
fusible part of which melts at a temperature between, say, 180 degrees and
200 degrees centigrade.
The sectional area of the pipes E, E¹, I, I, I", and of the valves should be in the
proportion of about one square inch to every two cubic feet of ammoniacal solution
contained in the boiler. In small apparatus it is especially necessary to preserve
this proportion.
The boiler A, with the pipes and the receptacle G, should be capable of resisting
a pressure of one hundred and fifty pounds per square inch without the slightest
distortion. The proportion between the dimensions of the receptacle G and of the
boiler A should be the same as described with reference to the apparatus shewn in
Figure 1.
The apparatus (Figure 3) operates in the following manner :-The boiler A
between two-thirds and three-fourths filled with a concentrated solution of ammonia
is placed over a fire, and the receptacle G in cold water. Some nearly anhydrous
ammonia is immediately evolved, which passes into the chamber C through the first
and second bells 0, 0¹, then through the valve D, above, through the coil E and pipe
E¹ into the receptacle G; at the same time the valve H of the receptacle closes, or if
it should leak or not work at all the ammonia solution rising in the pipe I and
worm I from the boiler acts as a valve the moment it has reached a sufficient height
to counterbalance the flow through the pipe E, thus in any case no flow can take
place through the receptacle pipe I at this stage. When the temperature of the
boiler has attained say about 40° or 45° centigrade, some ammonia will already have
been condensed in the receptacle (through which the gas distilled over from the
boiler is compelled to bubble or pass, the sound produced by the same being audible,)
and the process then rapidly proceeds.
In order to render the passage of the gas more distinctly perceptible it is
necessary or desirable to contract the end of the pipe E'.
As the temperature of the boiler increases, some steam passes up through the
bells or receivers O, O', and is condensed in the chamber C, in which the water of
condensation accumulates, any steam that may have escaped from the chamber C
will be condensed in the worm E, and the water of condensation will fall back by
its own gravity into the chamber C.
When the worm E is found to have become heated, cold water is introduced into
the tank F; about this stage of the process steam is generated in such a quantity
as would prove injurious to the efficient production of cold if it were not compelled
to bubble through the cold water, accumulate about the lower part of the bells or
receivers O, O₁, in the chamber C, where it is condensed, whilst the gaseous
ammonia passes on towards the receptacle G ; any excess of water in the second bell
or receiver O¹ flows back to the first bell O, through its overflow pipe e¹, and thence
to the boiler through the overflow pipe e; as the lower extremities of the overflow
pipes are always immersed in liquid, no objectionable flow of gas can take place
through them.
When it is ascertained that the bubbling has become less rapid the apparatus is
withdrawn from the fire, the boiler A placed in cold water, and the receptacle G in
the liquid from which beat is to be abstracted; the vessels K, K, surrounding the
worms I are also filled with cold water.
On the temperature lowing in the boiler the pressure also diminishes rapidly
and becomes less than that in the receptacle G; the valve D closes, or if it leaks or
does not work, the liquefied ammonia ascends to a certain height in the pipe E', and
therefore answers the purpose of a valve in so far as the flow of gas is concerned.

page_text: At the same time also the valve H opens and the gaseous ammonia returns to the
boiler through the pipe I' and worm I, and finally escapes through the pipe I",
causing agitation in the boiler, which assist in the re-absorption of ammonia by the
water or other liquid employed as a solvent.
Gi
As the ammonia returns to the boiler A. intense cold is produced in the receptacle
this cold is either employed direct for the purpose of refrigerating or cooling any-
thing desired, or it is caused to abstract heat from a circulating liquid, holding in
solution, salts, glycerine, and the like, which liquid in its turn abstracts heat from
water or other body to be converted into ice, the same. • being contained in suitable
moulds. The gaseous ammonia flowing through the pipe I' and the worms I is of a
temperature of, say, several degrees below 0° centigrade, the water contained in the
vessels K is therefore cooled by the worm; this water is employed to fill the moulds
in which the ice is produced.
The advantage of employing several separate vessels K in lieu of a single one of
the same total capacity, is that by this means nearly the whole of the refrigerative
power of the ammonia is utilised before it returns to the boiler. In my Drawings
I have shewn two of such vessels, but the number may be increased. For example, if
only one vessel were employed the temperature of the water contained in it would be
lowered to a uniform temperature of about 5° centigrade, so that the ammonia would
reach the boiler while still very cold, and consequently still possessing considerable
refrigerative capacity. On the other hand, if a series of vessels are employed,
arranged about the worm I, the temperature of the first may be lowered to about 0°,
that of the second to 10°, that of the third to 20°, and so on, so that the ammonia
will reach the boiler at a temperature approximating to that of the surrounding
atmosphere after the greater part of its refrigerating power has been utilised.
When the bubbling is heard to diminish in the boiler A, the apparatus is turned a
quarter round, so that the refrigerator becomes situate at the top. Whilst in that
position exposure of the sides of the receptacle G to the external atmosphere by
raising the temperature increases the internal pressure, and forces back into the
boiler through the pipe I any remaining liquid which might otherwise interfere with
the success of the next operation.
This apparatus
constructed to produce the greatest possible quantity of ice by
the consumption of a given quantity of fuel, but for the sake of economy of con-
struction certain parts of the apparatus herein-before described may be dispensed
with. For example, the vessels K may be omitted and a straight pipe substituted
for the worm I, and the chamber C, with the bells O, O', and the valves may be
dispensed with, the worm E being made to serve the same purpose as the chamber
C for preventing the passage of steam.
In apparatus in which no metal valves are employed it is absolutely necessary
that the pipes E¹ and I should be carried to a certain height above the highest
level which the liquids contained in the boiler or in the receptacle are ever allowed
to attain. Let q, 7, Figure 3, be the highest level of the aminonaical solution in the
boiler, and s, t, the highest level of the liquified ammonia in the receptacle G, then
the length of the pipe E', when the apparatus is inverted above the level s, t, should
be equal to x, y, plus an additional piece to compensate for the difference of density
between a column of an ammonaical solution and a column of liquid ammonia, and
plus another additional piece to provide sufficient draft to cause the gas to flow at a
given velocity through the pipe I, I. This latter property will depend in a great
measure upon the sectional area of the pipe I, and also on the length of the worm I
(the required section may be calculated according to the formula for the flow of gas
in pipes). As the level in the receptacle G is at its maximum, when that in the
boiler A is at its minimum, it will be found that the data herein-before given imply a
supplementary length to prevent all flow of ammonaical liquid to the boiler over
the upper part of the pipe E. Moreover, as the density of liquid ammonia is always
less than that of a solution of ammonia, if the pipe in the boiler and that in the
receptacle G were of the same height, this height would be more than sufficient for
the pipe I. I.

page_text: In some cases, as for example in India, where the ice apparatus may have to be
manipulated by natives, it is necessary to employ a reliable safety apparatus in
combination with them. It is preferred to employ one, the construction of which
is based on the fusion of alloys having low melting points. The pipe B, Figure 3,
which extends down to the bottom of the boiler, is filled to one-half or two-thirds
of its height, with fusible metal melting, at a temperature of, say, about ten degrees
centigrades above the temperature necessary for regular working; over the alloy
is placed a heavy metallic rod or plunger not shown, the drawing projecting upwards
above the boiler for, say, about half its length, its upper end being hooked or fur-
nished with a notch engaging with the catch of an alarum device. When the alloy
melts, the rod descending releases the catch, and the alarum is sounded, this being
effected by any one of the well-known methods adopted in clock-making.
Or the following modification of safety apparátus which is especially suitable for
ice or refrigerating apparatus for domestic use may be adopted. To the top of the
plunger is fixed a connecting rod which is turned downwards, and provided at its
lower end, which terminates at the level of the furnace fire-grate, with a small pro-
jecting piece or hook. The grate is hinged at one of its sides and its opposite side
is made to preponderate, and is provided with a small arm to which the end of the
connecting rod is hooked, the said arm projecting slightly outside the furnace
through a vertical groove directed downwards, and allowing free motion to the arm
and grate about its hinge from a horizontal position downwards until it reaches a
vertical one. Under the grate, and sufficiently below it to allow free motion, is
placed a vessel containing water. It will be evident that so long as the alloy is
solid the grate will remain elevated, being supported by the plunger and connecting
rod, and that the moment the plunger sinks down freely into the safety pipe the
fire on the grate will necessarily be dropped into water.
This arrangement of safety apparatus provides the most perfect security, but it
is somewhat inconvenient in the case of apparatus of large size. When therefore
the grate is of large dimensions, and, consequently unwieldy, it will be desirable in
lieu of moving the grate to utilize the weight of the falling plunger to act upon the
handle of a water-cock, which is in communication with a water reservoir and with
a pipe entering the furnace, and perforated with small holes so as to direct water
on to and to distribute it over the whole surface of the grate. Before a dangerous
temperature is attained in the boiler the water will flow into the furnace and
extinguish the fire.
If the machine does not give sufficiently distinct indication of the moment when
all the ammonia is evaporated from its solution this defect is due to the excessive
area of the tube connecting the boiler to the refrigerator; in this case the addition
of a simple diaphragm, perforated with a small hole and placed at the extremity of
the tube leading to the refrigerator, will be sufficient to give the gas the requisite
velocity to produce a sufficient sound.
As ice is a bad conductor of heat the water to be frozen is placed in narrow
vertical moulds, of a width not exceeding one inch, and of any convenient length
and breadth, the freezing circulating liquid passes completely round them, and
hence the heat has never to be abstracted through more than half an inch thickness
of ice.
In order to produce ice as free as possible from air bubbles the water to be frozen
may be kept in constant motion by the following arrangement, reference being had
to Figures 7 and 7ª of the Drawings:-A is an ice mould; B is a square pipe,
having at the top a small funnel and an overflow C; this pipe is enclosed in another
pipe which leaves a free space on each of the four sides; both these pipes are connected
water-tight to each other at their lower end, so that no water may gain access
between them; the central pipe is open throughout, and by reason of the external
pipe water can never become frozen in it, so as to prevent the flow which it is
intended to maintain; D is the ice mould overflow; E and F are two longitudinal
pipes collecting the overflow water of all the moulds, placed side by side, and con-
ducting it into the reservoir of a pump or scoop wheel; G is another longitudinal

page_text: pipe, conducting the water from the pump and distributing it to each of the
moulds; H is one of the flexible pipes (india-rubber, canvas, or the like), delivering.
the water of the pipe G to to the moulds through the funnel and pipe B.
The moulds are placed parallel to each other, and contained in large wood boxes
divided by a number of partitions, each containing a mould with a space of, say,
about three-eighth inch; on each side of it the two narrow sides of the moulds are
fitted in grooves formed in the sides of the box, and the end of the moulds are
about a quarter inch clear from the bottom of the box. The circulation water is.
admitted between each mould and its partition by means of a narrow pipe,
extending along the whole width of the mould close to the top part of it in an
horizontal position, and slotted underneath throughout its whole length; through
this slot the refrigerating liquid falls in the form of a wide sheet; in the same
partition on the other side of the mould, and one inch below the level of the feed pipe,
is placed an overflow pipe similar to the feed pipe. Any liquid from the feed pipe
descends one side of the mould and rises along the other side, as represented by the
arrows.
The overflow pipes of the several compartments all discharge the circulating
liquid into the longitudinal pipe J; this pipe conveys it to a pump or scoop wheel
which raises it to a reservoir, from which it flows round the receptacles of the ice
machine, thence returns to the longitudinal pipe J; this pipe acts as a reservoir;
it is furnished with flap valves K, which regulate the supply to smaller pipes or
channels L, from which finally, say, eight or ten, small supply pipes O take the
circulation liquid and deliver it in the shape of a wide sheet of water on one side
of every mould.
The circulation in each of the ice moulds takes place in the following manner :—
The water having been raised by the pump or scoop wheel into the pipe or
channel G, extending along the whole of the moulds, it flows through H, and similar
pipes to H, into a funnel pipe B, through it to the bottom of the moulds A, and
away through the overflow D at the top of them into the longitudinal pipe F,
which latter discharges it into the pump or scoop wheel reservoir, and so on in
succession, repeating the former course. When on account of ice being formed
throughout the whole of the mould no water can pass through the pipe B, the
funnel overflow C discharges it into the channel E, and thence it flows back to the
said reservoir. The size of the pipes or channels E, F, G, and others depend entirely
on the number of ice moulds. The section of the pipes E, F, G, B, as also their
relative level above each other, should be such as to admit of the renewal of the
water.contained in the ice moulds once every minute or two minutes; it is sufficient
if the refrigerating liquid in the mould compartments is completely renewed every
four or five minutes. When the ice is formed in a set of, say, eight or ten moulds,
the valve K of the corresponding set is closed, the pipe H placed as represented by
dotted lines, the moulds withdrawn, others inserted, and the valve K opens again,
and so on, repeating the operations. The ice plates of a set of moulds are piled on
each other and placed in a large mould where they form a solid block. The whole
of the refrigerator, pipes, pumps, and the like, are to be well protected by a non-
conductor of heat, such, for example, as alternate layers of felt, wood, or air.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion, that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, -
First. The peculiar method and arrangement by which the cooling and con-
densation of the heated gaseous ammonia is effected by washing it in liquefield and
cool ammonia, substantially as herein-before described.
Secondly. The peculiar arrangement of separate boiler and receptacle pipes, or
of a single S shaped or coiled pipe, for ensuring the proper flow of the gases with
or without the co-operation of valves, substantially as herein-before described.

page_text: Thirdly. The washing bell or receiver with its overflow pipe, substantially as
and for the purpose herein-before described.
Fourthly. The management of the boiler pipe, delivering the gaseous ammonia
at the bottom of the receptacle, for the purpose of ensuring the complete agitation
of the liquid, and giving audible indication of the progress of the operation, sub-
stantially as herein-before described.
Fifthly. The employment of two or more separate cylinders about the coil of the
receptacle pipe so as to abstract from the ammonia nearly the whole of its frigorific
capacity, substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, the Eighteenth day of February, One
thousand eight hundred and seventy-eight.
J. HENRY JOHNSON.
JOHNSON. (L.S.)