IMPROVEMENTS IN REFRIGERATING APPARATUS
Year: 1862

page_text: LETTERS PATENT to Alexander Carnegie Kirk, of Bathgate, North
Britain, Engineer, for the Invention of "IMPROVEMENTS IN REFRIGERATING
APPARATUS."
Scaled the 25th September 1862, and dated the 25th April 1862.
PROVISIONAL SPECIFICATION left by the said Alexander Carnegie Kirk
at the Office of the Commissioners of Patents, with his Petition, on
the 25th April 1862.
I, ALEXANDER CARNEGIE KIRK, of Bathgate, North Britain, Engineer, do
hereby declare the nature of my said Invention for "IMPROVEMENTS IN REFRI-
GERATING APPARATUS," to be as follows:-
This Invention relates to a peculiar arrangement and combination of
apparatus for producing cold by the alternate compression and expansion of
air or any incondensible and elastic gas, and consists in alternately compressing
and expanding the air or gas in a vessel having a moveable piston and pro-
vided with a suitable regenerator through which, on the piston being moved
to one end of the vessel, the enclosed air may pass freely to the other end,
giving out its heat to or absorbing heat from the regenerator as it passes
through it. The piston is caused to move in such a manner that the air
while being compressed will always be at one end of the vessel, and whilst
being expanded be always at the opposite end of the same, the regenerator
preventing the conveyance of heat or cold by the air from one end of the
vessel to the other. The heat generated during compression is removed by

page_text: exposing that part of the vessel to a current of cold air, water, or other
cooling medium, whilst the cold produced at the other end by expansion is
used to refrigerate any liquid or substance which may be brought in contact
therewith.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Carnegie Kirk in the Great Seal Patent Office
on the 24th October 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CARNEGIE KIRK, of Bathgate, North Britain, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of April, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alexander Carnegie Kirk, Her special license that I, the said Alexander
Carnegie Kirk, my executors, administrators, and assigns, or such others as I,
the said Alexander Carnegie Kirk, my executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN REFRIGERATING APPARATUS," upon the condition (amongst others)
that I, the said, Alexander Carnegie Kirk, my executors or administrators,
by an instrument in writing under my hand and seal, or under the hand and
seal of one of them, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Carnegie Kirk, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates to a peculiar arrangement and combination of
apparatus for producing cold by the alternate compression and expansion of
air or any incondensible and elastic gas, and consists in alternately compressing
and expanding the air or gas in a vessel having a moveable piston and pro-

page_text: vided with a suitable regenerator through which, on the piston being moved
to one end of the vessel, the enclosed air may pass freely to the other end,
giving out its heat to or absorbing heat from the regenerator as it passes
through it. The piston is caused to move in such a manner that the air
whilst being compressed will always be at one end of the vessel, which I call
the hot end, and whilst being expanded will be always at the opposite or
cold end of the same, the regenerator preventing the conveyance of heat or
cold by the air from one end of the vessel to the other. The beat generated
during compression is removed by exposing that part of the vessel to a current
of cold air, water, or other cooling medium, whilst the cold produced at the
other end by expansion is used to refrigerate any liquid or substance which
may be brought in contact therewith.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
corresponding Figures.
Figure 1 of the Drawings is a vertical section of a cylinder A, A, with
piston B, B, and regenerator C. To gain heating and cooling surface the
ends D and E are made conical, D being the cold end, and E the hot end. By
removing the cover the substance to be cooled may be put into the conical
end D by the pipe F, F, cold water may be admitted to the conical end D, and
will overflow by the pipe G, G, the expansion of the air between the outside
of the cone D and the piston B, cooling any substance contained inside D,
while the heat generated during compression of the air (when the piston B
has been shifted to the end D of the cylinder) contained between the cone. E
and the piston B, is removed by the water flowing from the pipe G, G, ; H, H,
is the passage connecting the interior of the cylinder A, A, with whatever
expanding and compressing apparatus may be employed, free communication
between the hot and cold ends being maintained through the regenerator and
the holes k, k, in the plate by which the rod I is attached to the piston. At its
lower end the rod I passes through an air-tight packing, thus allowing the
piston B to be moved from one end of the cylinder to the other without escape
of air. The piston may be of thin metal, air-tight, and filled. with sawdust.or
other non-conductor.
Figure 2 is a vertical section of a cylinder arranged to cool'a continuous
current of a saturated solution of common salt in water, spirit, air, or other
convenient fluid not liable to freeze at the lowest temperature used, which
current may be employed to cool any other-substance at a greater or less

page_text: distance from the machine. A, A, is the cylinder; B, B, the piston; C, the
regenerator; D, D, the cold end; E, E, the hot end of the cylinder; F, the
inlet pipe for cold water; G, the outlet pipe; f, the inlet pipe for salt water
or other fluid as may be used; y, the outlet, and I, the piston rod. The
covers at both ends of the cylinder are stout castings h and i, and the cooling
surface is formed of a corrugated plate d, d, at the cold end, and c, e, at the
hot end, formed with circular V grooves on both sides, and as thin as prac-
ticable, supported against the pressure of the compressed air by the covers
h and i, and against the pressure of the water by small studs and nuts a, a,
(Figures 2, 3, and 4,) and forming an air-tight joint with the cylinder outside
by being bolted between the flanges and covers, and in the case of e, by being
jointed to the cover at b, b, (Figures 2 and 4).
Figures 3 and 4 are plans respectively of the plates d, d, and e, e, shewing
the course of the water. The water after flowing round in one groove
between the corrugated plate and its cover is stopped by the pieces u, n, (cast
or fixed in,) and made to pass by the shallow aperture m, m, (Figures 3, 4,
and 5,) into the next groove, and so on backwards and forwards till it reaches
the outlet pipe. In the case of c, e, small pipes p, p, open throughout, are
inserted through the cover to the top of the groove, so as by letting any air
escape to ensure the water filling the grooves to the top. To cool the air
more effectually, thin fins q, q, may be cast or soldered inside the hole in the
centre of the plate e, e. The piston B, B, is formed at both ends into conical
ridges fitting the plates d and e pretty nearly; the inside is filled with some
non-conductor, such as sawdust; the arms h, k, which serve for the attach-
ment of the piston rod with the annular passage o, o, allow a free passage
for air passing through the regenerator from one end of the cylinder to the
other. These corrugated plates d and c, if of cast-iron, I prefer in all cases to
galvanize, and if of brass to coat with tin, as without these precautions there
is great risk of moisture passing through the metal, closing up the small air
passages in the regenerator, and causing a break down in some part of the
machine. The rod T at its lower end works through an air-tight packing.
Figures 6, 7, 8, 9, shew in plan, front elevation, back elevation, and vertical
section at A, B, (Figure 6) respectively a machine adapted to the purpose, in
which a tubular arrangement of heating and cooling surface is adopted, and
the compression and expansion is produced by a cylinder and piston actuated
by any convenient prime mover. M is a cylinder containing a piston of the
usual construction actuated through the medium of a piston rod, cross head,
guide, and connecting rod by a crank P, which is driven by a belt on the
drum N. A loose pulley O is provided for stopping the machine, and a fly

page_text: wheel to equalize the strain on the belt. A, A, are the cooling cylinders
communicating one with cach cnd of the cylinder M by the passages H, H.
The piston B, B, B, B, (Figure 9) shewn in plan in Figure 10, is formed in
two parts, and contains the regenerator between them, which nearly fills the
diameter of the cylinder. The parts are held together by the rod I, by which
(working through an air-tight packing) the piston is moved up and down.
Each part of the piston is made hollow of cast iron, and fitted with iron tubes
extending through it, which tubes may be screwed or otherwise fixed; but
I prefer merely to fix them slightly by drifting the ends, and to make all air-
tight by galvanizing the whole piston and tubes. The space inside the piston
between the tubes may, in this form, be left empty, or, (which is preferable,)
filled with sawdust. The pistons in this case may be made solid of cast iron,
and the holes bored or cast; but I prefer to construct them as above. To
prevent the regenerator from contracting the air passage by closing on the
ends of the pistou tubes, rings a, a, of wire lying between the rows of tubes are
interposed. The tube plate D at the cold end, and E at the hot end, which
may be of cast iron, have tubes b, c, fixed into them, composed by preference
of thin brass or copper closed at the end c, so that they may stand inside the
tubes in the piston, leaving between them and the piston tubes a narrow space
for the air to pass from one end of the cylinder to the other. The method I
prefer for fixing the tubes is to insert them tightly into carefully bored holes in
the tube plate, which, if of cast iron, should be previously galvanised, and
make all air-tight by floating a good body of soft solder round the ends of the
tubes outside. Tube plates e, c, of wood are employed to guide the flow of the
cold water at the hot end, and of the saturated solution of salt in water, spirit,
or other substance used to convey the cold from the cold end; these tube plates
having fixed in them small tubes d, d, open at both ends, and reaching nearly
to the bottom of the tubes b, c, so that at the cold end the salt water entering.
by the pipe may descend the spaces between the small tubes d and the tubes
b, c, and ascending the small tubes & may escape by the pipe g, and at the hot
end the cold water may enter by the pipe F, ascend the space between the
tubes b, c, and the small tubes d, and descending the small tubes d may
escape by the pipe G. The pistons B, B, B, which are alike in both the
cylinders A, A, arc supported in equilibrium on opposite ends of the lever Q,.
(Figures 8 and 9,) the third end of which is connected by the rod S to the
eccentric R, so that on the crank shaft being caused to revolve the pistons B, B,
may be moved, the one up and the other down alternately. This eccentric is
placed at right angles or nearly so to the crank. A cam motion may be sub-
stituted, allowing the pistons B, B, to remain quite stationary during the

page_text: greater part of the compression and expansion strokes, with a slight advantage
as regards the cold produced; but the superior smoothness of motion and
durability of an eccentric cause me to prefer it. By the inlet valves U, U,
(Figures 6 and 7,) and the pipe V opening to the atmosphere, if the air be
expanded to the atmospheric pressure, air will be sucked in at the end of the
expansion stroke to supply loss by leakage; but when a higher pressure is
used I cause air to be forced in by a compressing pump connected to the pipe
V. In every case it is necessary that the air admitted by the pipe V be
thoroughly dried by being passed over concentrated sulphuric acid, or other
suitable substance, as if moisture be present in the machine it will collect in
the cold end of the regenerator, block up the air passage, and perhaps cause
a break down.
The regenerator shewn in all these Drawings is the ordinary one, composed
of wire gauze about 25 to 30 meshes per inch. To allow the machine to be
casily started a valve T (Figures 6 and 7) is provided, by opening which the air
may be allowed to pass from one end of the cylinder M to the other. So soon
as the fly wheel has acquired sufficicut momentum the valve T is to be shut,
when the machine will continue to move quite easily.
In all arrangements the cold end of the cylinders and pipes containing the
cold salt water, spirit, or other fluid used to convey the cold to a distance
must be carefully protected by hair, felt, sawdust, or some good non-
conductor.
The regenerator, which may be of any of the ordinary constructions may,
if preferred, be situate outside the cylinder in a passage communicating with
cach end thereof, or in an annular space left between the piston and the
cylinder; but I prefer that the regenerator move with the piston, as shown in
my Drawings. In cases where the regenerator docs not fill up the entire
diameter of the cylinder the piston should be a good non-conductor of heat;
but in all cases it is important that the piston and cylinder be composed of
some material which will not absorb air during compression. Several forms
of compressing and expanding apparatus may be used according to the degree
of pressure required, such as for example, (if for slight pressure,) an ordinary
bellows. In some cases Stirling's air engine might be directly employed for
compressing and expanding the air by connecting by a pipe the hot end of the
cylinder A, herein-before referred to, with the cold end of the heating vessel
of the engine; the alternate expansion and contraction of the air producing
respectively the requisite compression and expansion in the cooling cylinder A;
but I generally employ an ordinary double-acting cylinder and piston, as
shewn in my Drawings.

page_text: Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion, that I am well aware that it has
been already proposed to produce cold by the expansion of air, and therefore
I lay no claim to such in principle, neither do I claim any special form of
apparatus for effecting the compression and expansion of the air; neither do
I claim any of the parts of my combined apparatus separately; but what I
consider to be novel and original, and therefore claim as the Invention secured
to me by the hercin-before in part recited Letters Patent is,
1st, the general constructions, arrangements, and combinations of apparatus
for producing cold, substantially as hercin-before described and illustrated by
my Drawings.
2nd, the application and use to and in the production of cold of a vessel
containing air or other clastic fluid or gas alternately in a state of com-
pression and expansion, and provided with a piston and regenerator operating
in the manner herein-before described.
In witness whereof, I, the said Alexander Carnegie Kirk, have hereunto
set my hand and scal, the Fourteenth day of October One thousand
eight hundred and sixty-two.
ALEXANDER CARNEGIE KIRK. (L.S.)