IMPROVEMENTS IN THE PRODUCTION OF ICE
Year: 1856

page_text: LETTERS PATENT to Giovanni Battista Piatti, of Genoa, in the Kingdom
of Sardinia, for the Invention of "IMPROVEMENTS IN THE PRODUCTION OF
ICE."
Sealed the 20th March 1857, and dated the 13th October 1856.
PROVISIONAL SPECIFICATION left by the said Giovanni Battista Piatti
at the Office of the Commissioners of Patents, with his Petition, on the
13th October 1856.
I, GIOVANNI BATTISTA PIATTI, of Genoa, in the. Kingdom of Sardinia, do
hereby declare the nature of the said Invention for "IMPROVEMENTS. IN THE
PRODUCTION OF ICE," to be as follows:-
My system of congelation is based principally upon the following con-
ditions:-
First, that when the temperature of the water has been; by the dilatation of
the compressed air, lowered to a certain degree, the compressed air, while con-
tinuing to abstract caloric from the water, no longer agitates it, as the water
requires to be at rest for its proper congelation.
Second, that at the moment of the congelation of the water, the effect of the
dilatation of the compressed air takes place in such manner that the tension
of that air shall not compress the water, and shall not, therefore, prevent.it
from dilating.

page_text: Third, that the compressed air in dilating cannot abstract caloric from any
other bodies besides the water, and that this latter, while giving up its caloric
to the expanding compressed air, cannot receive any from the exterior.
In carrying out this Invention, I provide a large pipe, which I shall call the
cooling well, placed in a vertical position and partially filled with water. I con-
struct the bottom of this well in such a manner as to allow of the compressed
air passing through it, and by means of force pumps I introduce under the
column of water in the well a constant and uniform current of compressed air
at a given pressure, which will, by reason of its levity and tension, pass up
through the column of water, dilate as it rises, and absorb from the water a
great portion of its caloric.
.
It will be seen that as the dilatation of the air takes place in the water this
latter body alone will be thereby deprived of a portion of its caloric; and in
order that the water may not receive from the external atmosphere any portion
of the caloric which it, gives, up to the expanding air, the sides of the cooling
well are surrounded by a jacket of pulverized charcoal or other bad conductor
of heat.
When the temperature of the water, in the cooling, well has been sufficiently
lowered, it is emptied therefrom, and by suitable arrangements of apparatus
caused to pass into a chamber, which I shall call the freezing chamber, and in
which are arranged a certain number of boxes for its reception. These boxes
are made double all round,, and in this stage of the operation the, dilatation of
the compressed air does not, take place in contact, with the the water as before,
but all round it, that is to say, in the space forming an air jacket around
the boxes.
In the well the water could not readily freeze, being continually agitated
by the compressed air in the above-mentioned boxes, the water being, on the
contrary, in a state of perfect repose (as the air no longer acts directly upon it)
will-readily freeze. The freezing chamber must, as well as the cooling well,
be provided with a jacket of charcoal, or other non-conductor of heat.
When it is desirable to use rarefied air instead of compressed air, the cool-
ing well must be made low and wide, and completely closed, and the, air-will
áct above the water, being caused to enter by a cock above, and making its
exit by another cock also above. The arrangement of the freezing. chamber
need not be altered:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Giovanni Battista Piatti in the Great Seal Patent Office on.
the 13th April 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GIOVANNI
BATTISTA PIATTI, of Genoa, in the Kingdom of Sardinia, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of October, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Giovanni Battista Piatti, Her special license that I, the said Giovanni
Battista Piatti, my executors, administrators, and assigns, or such others as
I, the said Giovanni Battista Piatti, my executors, administrators, and
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 "IMPROVEMENTS IN THE PRODUCTION OF ICE," upon the condition (amongst
others) that I, the said Giovanni Battista Piatti, by an instrument in writing
under my hand and seal, 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 Giovanni Battista Piatti, 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 Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):
It is a well-known scientific fact, and which has even been applied to
industrial purposes, that when gases are by any means caused to dilate they
will absorb caloric from any bodies with which they are in contact or in com-
munication, thus producing a decrease of temperature in bodies which are
near them.
Many attempts have been made. to apply this principle of the absorption of
caloric by the dilatation of gases to the extraction from water of a great
portion of its caloric, and thus to produce ice in any season, but the arrange-
ments of apparatus hitherto adopted have not been found to produce practically
a favorable result.

page_text: In order to carry on the manufacture of artificial ice in a profitable manner
it is necessary to fulfil two conditions; the first of which is, that the dilatation
of the gases employed must be produced in such a manner that it shall only
extract from the water the required quantity of caloric; the second consists in
entirely preventing the water, while giving up its caloric to the expanding
gases, from receiving any from the sides of the apparatus in which the lowering
of the temperature is effected.
In the apparatus hitherto employed these two fundamental conditions have
not been realized in a satisfactory manner, which may be confidently stated to
be the principal cause of ice not having been hitherto successfully manufactured
commercially by the dilatation of gases. By my improved process, however, the
above-mentioned conditions are successfully maintained in practice, as, in order
to obtain the lowering of the temperature of the water, to be converted into
ice, I first cause the gases to dilate in the midst of the water. and in immediate
contact with .it I also make the sides of my apparatus double, and fill the
space between the inner and outer ones with powdered charcoal, ashes, or
other substances which are bad conductors of heat, which bad conductor causes
the gases to absorb more readily and in greater quantity the caloric from the
water in which they are dilated, and prevents the caloric from passing from
the exterior to the interior of the apparatus to supply that absorbed from the
water by the dilatation of the gases.
Having now pointed out the improvements forming the basis of my Inven-
tion, I will proceed to describe the apparatus which I employ for carrying the
same into effect, and its mode of operation.
with water,
Below this
The Figures in the accompanying Drawing represent the principal parts of
an apparatus for manufacturing ice on a large scale, the upper part of the
freezing chamber being broken away the better to shew the interior. Fig. 1
is a plan or birds'-eye view of the apparatus; Fig. 2 is a longitudinal vertical
section of the same; Fig. 3 is a transverse vertical section, taken in the line
a, b, of Fig. 2; and Figures 4, 5, 6 represent some of the parts detached.
At A, A, (Figures 1 and 2) is represented a well nearly filled
and provided at its lower extremity with openings or valves B.
well is a chamber C, which communicates by means of a pipe D
force pump (not shewn in the Drawing). In this well A, which I shall call
the cooling well, the lowering of the temperature of the water to be congealed
is first effected in the following manner:-I first, by means of the air pump,
introduce a current of compressed atmospheric air through the pipe D into
the chamber C at a degree of tension sufficient to overcome the resistance of
the valves B, and the pressure exerted upon them by the weight of the
with an air

page_text: column of water in the well. The compressed air will open the valves, enter
the water, and partially expand, in order to establish an equilibrium with the
pressure of the water at the bottom of the well, then ascending by reason of
its lightness it will pass through the whole height of the column of water in
the well, always dilating more in proportion as the pressure of the water upon
it diminishes, and the air finally makes its escape at the upper part of the
column of water into the atmosphere at a very slight degree of pressure,
having while in the water almost expanded to its natural state, and having
absorbed from the water the caloric necessary for that purpose. By thus
continuing for some time the passage of compressed air through the water in
the well A, A, the temperature of that water will be very speedily lowered,
and for the purpose of preventing the water from again absorbing caloric
from the atmosphere, I surround the well at m, m, with a jacket filled with
charcoal or other bad conductor of heat, and for the same purpose, when the
compressed air bas ceased to pass through the water in the well, I protect
the mouth of this latter with a cover or lid made of wood covered with straw
or charcoal.
As it is absolutely necessary for the success of the operation that the air
shall be compressed before entering the chamber C, the air pump is provided
with a reservoir in which the air is previously compressed, and passes thence
in a continuous and uniform current into the chamber C, the valves D being.
so disposed and constructed as not to open until the compressed air in the
chamber C has reached the required degree of tension.
The valves B consist of a number of orifices made in the bottom plate a
of the well A, which may be closed by means of a disc of leather, india-
rubber, or gutta percha b, also pierced with holes, so arranged that the holes
in the disc and the bottom of the well shall not be opposite to each other,-
consequently the disc will when pressed down upon; the bottom of the well
close the apertures therein. This arrangement is the one represented at
Fig. 2.
Fig. 4 represents (in vertical section on an enlarged scale) another con-
struction or arrangement of valves for closing the bottom of the well. In this
arrangement the valves consist of pistons a, a, a, which work in cylinders b, b, b,
pierced with holes at their sides, the pistons severally covering the holes c in
the bottom of the well. It will be readily understood that until the com-
pressed air impinges upon the apertures a in the bottom of the well in Fig. 2, .
the leather or other disc b, or, in the case of Fig. 4, pistons a, will bear upon
the apertures B, and consequently the entrance to the well A will be closed;
but on the compressed air in the chamber c acquiring a sufficient degree

page_text: of tension to enable it to overcome the pressure of the water, the disc b, of
Fig. 2, will be raised, and the air will pass through the apertures 6; or, if. the
arrangement represented at Fig. 4 be employed, the pistons a will be caused,
to rise, and the air will pass through the apertures in the sides of the cylinders b
into the well A, A. Should the pressure exerted upon the valves B by their
own weight and that of the column of water not be sufficient to keep them.
closed until the compressed air in the chamber C has acquired the required.
tension, increased pressure may be put upon them by the application of
weights, care being taken to distribute the weight equally over the whole
surface.
As the water is not intended to be converted into ice in the well A, A, it
being desired merely to lower the temperature therein, I cause it when it has
become sufficiently cold to pass into a chamber G, G, which I shall call the
congealing or freezing chamber, as it is in this chamber that the conversion of.
the water into ice takes place. For this purpose the well A is made to
communicate with the chamber G by means of a pipe F, which runs right
through the middle of the chamber G. Boxes H, H, are set on each side of
the pipe in the freezing chamber, and communicate with that pipe by
means of orifices o. On opening the cock E on the pipe F by pushing for-
ward the rod n, the water will be caused to flow through that pipe and pass
out at the orifices o into the boxes H, H, and when these latter have received
the necessary quantity of water the flow is stopped by shutting the cock E,
and the cock J is opened for the purpose of discharging any water that may.
remain in the pipe F, F.
The water from the well A, A, being thus distributed in the freezing boxes
H, H, the dilatation of gases is again employed for finishing the operation of
lowering the temperature of the water and converting it into ice. For this
purpose the compressed air is not brought into direct contact with the water,
but is caused to act on the outside of the freezing chambers H, HI, which are
made to dip into the chamber I, I, underneath in such manner as to allow
of the free circulation of the gases between and around them. The freezing
boxes are fixed, and the under chamber J, I, is hermetically closed, but is
capable of communicating with the exterior by means of two pipes K and L
(Fig. 1), which are closed by means of cocks. The under chamber I, I, is
first put into communication with an exhaust air pump applied to the outer
extremity of the pipe L, and a vacuum thereby produced in that chamber.
Currents of compressed air are then from time to time introduced therein
through the pipe K, which air, after having expanded in the under chamber I,
is drawn off through the pipe L by means of an exhaust air pump.

page_text: In order that the effect of the dilatation of the compressed air introduced
into the chamber I may be equally distributed throughout the whole extent
of the freezing chamber, a pipe M, M, is made to run along its bed, having
several branch pipes r, r, (Figures 2 and 3) on each side. The compressed
air fed in through, the pipe K passes through the pipe M, M,. into the small
branch pipes ; and as these, pipes M and rare pierced with small holes at
their upper part, the compressed air will pass through these holes into the
chamber I, where it will expand, and by absorbing caloric from the water in
the boxes H, H, will convert it into ice.
In order to accelerate the freezing operation, instead of compressed air a
current of vaporized ether, or, by preference, carbonic acid gas, might be
employed. In this case, instead of discharging into the atmosphere the gases
drawn out by the air pump adapted outside the pipe L, as is practised when
compressed air is employed, the gases drawn out are submitted to a high
degree of pressure by means of the force pump, and again injected through
the pipe K into the chamber I, I.
The freezing chamber and also its under chamber must be provided in the
same manner as the well A, A, with a layer or jacket of charcoal, or other
bad conductors of heat. The boxes H, H, are also severally provided with
covers s, and over these covers must be laid straw, bags of sawdust, or other
suitable material (see Fig. 5); or these covers may be of iron, and be made
hollow (as shewn at Fig. 6), and the gases may be caused to dilate within
them as well as in the chamber I, I.
When the freezing of the water has been completely effected, the pieces
of ice are to be removed from inside the boxes H, H, in the following
manner:-A current of hot air is first introduced into the chamber I, I,
through an orifice communicating with the pipe K, which will, detach the
pieces of ice from the sides of the boxes H, H, then on removing the covers s
the pieces of ice may be removed adhering to the rods u, u, with which the
covers are provided.
By means of this apparatus not only fresh water but also sea water and
other liquids may be converted into ice.
Having now described my Invention of "Improvements in the Production
of Ice," I wish it to be understood that under the above in part recited Letters
Patent I claim,-.
Firstly, the dilatation of compressed air in direct contact with and in
passing through the water to be subsequently converted into ice.
Secondly, the employment of double casings provided inside with charcoal

page_text: or other material which is a bad conductor of heat, for the purpose of pre-
venting the reabsorption of caloric by the water.
Thirdly, the peculiar and novel arrangenient of apparatus for cooling and
freezing, above shewn and described, or any mere modification thereof.
"In witness whereof, I, the said Giovanni Battista Piatti, have hereunto
set my hand and seal, the Thirtieth day of March, in the year of our.
Lord One thousand eight hundred and fifty-seven.