Apparatus for the Production of Ice, and for Cooling Liquids by the Expansion of Compressed Air.
Year: 1897

page_text: Date of Application, 12th Jan., 1897-Accepted, 13th Feb., 1897
COMPLETE SPECIFICATION.
Apparatus for the Production of Ice, and for Cooling Liquids by the
Expansion of Compressed Air.
1, THOMAS BELL LIGHTFOOT, of 35 Queen Victoria Street, in the City of
London Engineer, do hereby declare the nature of this invention (as communicated
to me from abroad by Gesellschaft für Linde's Eismaschinen, of Wiesbaden,
Germany) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to apparatus for the production of ice or cold water by
the expansion of compressed air such as is readily available in many localities, such
for instance as in torpedo-boats, iron-clads &c.
The action of the apparatus is based on the employment of a counter current
apparatus such as was described in the Specification to Linde's Patent No. 12528
of 1895, compressed air being made to flow through a coiled pipe contained within
a second coiled pipe or chaunel, communicating at one end with the chamber into
which the compressed air, issuing through a restricted opening of the first named
coil is allowed to expand thereby producing cold which is utilised in freezing water
contained in a vessel placed in the said chamber, the expanded air being then made
to pass through the outer coil on its way to the atmosphere so as to impart the
remainder of its cold to the compressed air passing through the inner coil to the
freezing chamber.
The accompanying drawing shews an ice making machine constructed according
to the above described invention. Figure 1 shews a vertical section and Figure 2
a cross section at X X.
Within a casing A of wood or other bad conductor of heat is placed a counter-
current cooler B consisting of an outer tube coil b and an inner one b', and in the
central space within this double coil is fixed a cylindrical double wall C formed of
two concentric shells e c', having a closed annular space between them. This
annular space is connected at its lower end by a tubular branch e, with the, lower
end of the outer tube coil b, while the upper end of the space communicates_by
holes with the central cylindrical chamber D within the double wall C. The
lower end of this central chamber communicates by a tubular branch d with a
tubular chamber E, into which enters the lower end of the inner pipe coil b', the
end of which is closed with the exception of a very small opening. Lastly, into
the central space D is inserted a cylindrical vessel F filled with the water required
to be frozen, and made of such a diameter as to leave an annular space between
and the cylindrical wall C, the upper end of the vessel F being however formed
so as to fit against the wall C, and thus close the upper end of the said space.
The annular space containing the double coil B is carefully packed with a bad
conductor of heat, care being taken that the coil does not touch the casing A and
that the separate convolutions of the coil do not touch each other.
The top of the casing is closed by a double cover G.
The action of this apparatus is as follows. A supply of cold compressed air
being admitted to the upper end of the inner pipe coil b', it flows down the same
and issuing through the restricted opening at the lower end it expands into the
chamber E and into the annular space D which is at about atmospheric pressure.
By such expansion the air becomes colder and in flowing upward through D it
takes up heat from the water in the vessel F', and passes from the top of D through

page_text: the holes into the annular space between c and c¹; in this space it flows
downwards again and enters the lower end of the outer pipe coil b still in a cold
condition.
In this coil it flows upward, imparting its remaining cold to the compressed air
flowing downward in the coil b', so that it eventually issues at the upper end of b
into the atmosphere at the temperature at which the compressed air enters b', the
whole of the cold produced by the expansion of the latter being thus utilised.
The temperature of the compressed air being reduced by the above means as it
flows down the coil ', it will in expanding produce a greater reduction of tem-
perature than before, and this decrease of temperature will continue until the
freezing point of the water in F is reached, or until the water has been cooled to
required low temperature, when the vessel F is removed and another one is
introduced, or the action of the apparatus is stopped.
A spring needle H is provided for clearing the small hole of the pipe 6' in case
it should become clogged with frozen moisture from the air.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In an apparatus for producing ice or cooling liquids by the expansion of
compressed air, the combination of a counter-current cooler consisting of a coiled
pipe through which compressed air is made to flow and situated within a second
coiled pipe or channel through which air at atmospheric pressure is made to flow
in the contrary direction to the compressed air, and a chamber enclosed by a double
casing and adapted to contain a vessel with the water to be frozen or cooled, the
lower end of which chamber communicates with a small opening in the compressed
air coil so that the issuing compressed air expands into the chamber so as to
produce cold therein and then passes at the upper end of the chamber into the
double casing and thence through the outer coiled pipe or channel of the counter
current cooler so that the cold expanded air escaping through such outer coil will
cool the incoming compressed air, substantially as described.
2. In an apparatus for producing ice or cooling liquids by the expansion of
compressed air, the combination within a non-conducting casing A, of a counter-
current cooler B packed with non-conducting material, and a cylindrical double
wall C within the coil B enclosing a central chamber D, and containing a vessel F
with the water to be frozen or cooled, the compressed air coil being made to
communicate by a small opening with the chamber D at bottom, while the
expanded air coil 6 communicates with the bottom of the space in the double wall C,
the upper end of which communicates with the central chamber D substantially as
described.
ABEL & IMRAY,
Agents for the Applicant.