Improved Refrigerating Process and Apparatus therefor.
Year: 1899

page_text: Date of Application, 1st Aug., 1899-Accepted, 2nd Sept., 1899
Improved Refrigerating Process and Apparatus therefor.
A communication from CARL KRAUSSE, Merchant, of Neumarkt 9, Dresden-A,
in the Empire of Germany.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
It is well-known that ice can be produced by the rapid evaporation of liquid
carbonic acid and the consequent absorption of heat produced by the expansion
of the gas. For this purpose the carbonic acid is passed through a saline solution
in the refrigerator through serpentine tubing in which the liquid carbonic acid
is allowed to expand. Cells filled with water are suspended in the salt solution
which water being cooled below the freezing point by the expansion becomes
converted into ice. The carbonic acid gasified in this manner is cooled in a
condenser where it is again liquefied by pressure. In this manner by the alter-
nate gasifying and liquefying of the carbonic acid a continuous process is main-
tained in such machine for the production of ice. The principle of the "Wind-
hausen carbonic acid ice apparatus is chiefly employed in ice and refrigerating
machines in which carbonic acid is employed, whatever modification and changes
may be introduced in the various modifications in construction.
"
According to this invention, however, the recovery or at any rate the relique-
fying of the carbonic acid is not aimed at, the liquid carbonic acid being directly
introduced into the solution of salt where it becomes gasified expanding and
finally escapes in the form of gas. This process is less adapted for the production
of ice in great quantities but is very suitable for the production of ice for the
purpose of households, small trades, hospitals and the like, and especially for
the production of ice creams and the like. Of course the loss of the carbonic
acid gas is involved in the process (unless another use is found for the employ-
ment of the carbonic acid gas), hence it would be less economical than the
regenerative process on a large scale, but, on the other hand, taking into con-
sideration the moderate price at which liquid carbonic acid can be acquired and
used for the production of ice, and that it can be obtained almost at any time
and in any place, and as the production of ice can be independent of any particular
kind of machine plant or freezing mixtures in which raw ice is used, and must
be provided before it can be used for the production of artificial ice, and that
such production is independent of the use of dangerous chemicals (such as
sulphuric acid) and that the vessel required for carrying out the process is of
the simplest construction, the process offers great advantages.
But the invention can be further modified by excluding from the cycle of
operations the use of a saline solution, the liquid carbonic acid being introduced
directly into the liquid to be frozen thereby producing ice, either raw ice, ice
mixtures or ice for household purposes and the like containing carbonic acid
gas. Ice produced in this manner from water taken from the ordinary water
supply, contains, according to the investigation of a chemical analyser of articles

page_text: of food, on an average 1 gr. of carbonic acid per kg. of ice, about 14 times as
much as water taken at the same time from the water supply which contains
only 0-07 gr. of carbonic acid per kg. of water. With a much smaller percentage
of carbonic acid such ice as contains it will be superior in many cases to other
raw ice, for instance in the case of cooling drinks. The advantage becomes even
more pronounced when for sanitary reasons sterilized water has to be used, in
this case the loss of the carbonic acid gas naturally contained in the water is
more than amply replaced and consequently the tastiness of the thus cooled drink
is increased, by the employment of ice produced in this manner. At any rate
the admixture of ice thus produced from sterilised water will not interfere with
the quality of the substances for the freezing or cooling of which it is used. The
employment of ice containing carbonic acid gas for the production of iced goods,
creams &c. is more important still as it is not advisable from a hygienic point
of view to enter carbonic acid gas directly into such preparations.
For the production on a small scale the apparatus shown in Figures 1 and 2
in which a saline solution is used will be found convenient. It consists of a
vessel, say of sheet iron, with double walls a b, the interior of which is isolated
against heat either by a layer of air contained between the two walls a and b
or by filling that space with non-heat conducting material.
At c the vessel is connected in the ordinary manner with the valve of a liquid
carbonic acid bottle d by means of a tube e which extends into and close to the
bottom of the vessel which is partly filled with the saline solution. Inasmuch
as the freezing up of the pipes arranged in the saline solution is not to be
apprehended, it is advisable, especially in vessels of larger dimensions, to allow
the carbonic acid to pass out through an annular perforated spray tube f upwards,
the carbonic acid gas being thus conveniently distributed. The upper part of
the inner vessel is provided with a discharge tube g through which passes the
gasified. carbonic acid into a chimney or through the wall or the window of the
house. When working inside a room, but if the apparatus is close to an open
window such a tube will hardly be necessary or only in the form of a short cylinder
by which the escaping gas is guided in a certain direction (say to the open
window). Inasmuch as the saline solution is violently agitated by the passing
of the carbonic acid it is advisable to protect the water or substance to be
refrigerated or frozen against any part of the saline solution being projected
into it. For this purpose a tubular ring provided with holes directed upwards
may be constructed in front of the escape pipe g. Any liquid that may have
been carried into the ring flows back through an opening i or openings (Fig. 1)
in the underside of said ring, which is protected by an arched part or plate
against the entrance of water. The freezing cell or vessel 7 is placed in the
vessel a b. This vessel is intended to contain the water ice cream preparations
or the like which is to be frozen and is rotated in the vessel which is closed in
at the top by a flange m fitting on to the edge n of the vessel a b. To prevent any
danger of the vessel being blown upwards by the pressure of gas it is kept in
its position by means of any suitable device. The packing represented in the
drawing between the parts m and n is intended more to provide against the escape
of the saline solution than against the escape of carbonic acid gas.
The apparatus as represented in Figs. 3 and 4 is intended for the production
of ice and ice preparations containing carbonic acid, and consequently the
vessel is dispensed with inasmuch as the vessel a b is directly charged with
the liquid to be refrigerated.
The admission pipe e by which the carbonic acid enters is inclined towards
the bottom of the vessel; for it has been proved by experience that when arranged
in this manner the freezing up of the orifice of the tube is prevented. The level
of the liquid may vary say between HW and NW (Fig. 3). It should however
not be allowed to fall below NW in order to prevent too much carbonic acid gas
escaping.
The carbonic acid passes directly towards the bottom of the vessel and then

page_text: rises passing through the liquid. The contact with the bottom and the change
of direction thus produced effects a satisfactory distribution of the gas. The
cover o carrying the escape tube g, is kept closed by lever catches such as p
(see Fig. 5) or the like. At least two overlapping shields and r, are preferably
arranged before the mouth of the escape tube, which shields are perforated one
at the edge (g) and the other at the centre (r). A small hole in the centre of
the shield allows any accumulated water to flow back. These shields are
required to prevent part of the liquid from being carried away by the escaping
gas.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondent, and in what
manner the same is to be performed, I declare that what I claim is:-
1. A refrigerating process in which liquid carbonic acid is used, consisting
in directly introducing carbonic acid gas under pressure into a saline solution
to be cooled so as to serve as the freezing means for the material to be refrigerated,
substantially as described.
2. The refrigeration of liquid or fluid substances by directly introducing
carbonic acid gas under pressure into the material to be refrigerated, substantially
as described.
3. Refrigerating apparatus for carrying out the process described comprising
a closed vessel intended to contain the saline solution, a spray tube at the bottom
of said vessel for admitting the carbonic acid gas under pressure and an exit
pipe for the discharge of the used carbonic acid gas at the top an inner vessel
for the material to be refrigerated substantially as described.
4. In apparatus of the kind described in Claim 3 a ring shaped tube such as h,
with perforations in its upper surface provided before the exit tube, as g, to
prevent any of the saline solution being carried away by the escaping carbonic
acid gas, substantially as described.
5. Apparatus for the production of ice and refrigerated materials containing
carbonic acid comprising a vessel with an admission pipe for the compressed
carbonic acid gas entering the vessel obliquely in a downward direction a remov-
able cover and a gas discharge pipe, substantially as described.
6. In apparatus of the kind described in Claim 5 superposed shields such
as qr arranged before the exit opening for the used carbonic acid gas said shields
being provided at the edges and at the centre respectively with perforations to
prevent particles of the liquid being carried away by the escaping carbonic acid
gas, substantially as described.
7. The complete refrigerating apparatus substantially as described or illustrated
in Figure 1 or in Figure 3 of the accompanying drawings.
Dated this 1st day of August 1899.
BOULT & WADE,
Agents for the Applicant.