An Improved Method of and Apparatus for Cooling and Refrigerating.
Year: 1895

page_text: Date of Application, 11th June, 1895-Accepted, 13th July, 1895
COMPLETE SPECIFICATION,
An Improved Method of and Apparatus for Cooling and
Refrigerating.
I, BERNHARD ALEXANDER SMITH, of Collins Street, Melbourne, in the Colony
of Victoria, Civil Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
1
This invention has been devised to provide improvements in the method or
process of cooling and refrigerating any fluid medium such as air, or suitable
liquids for the preservation of perishable produce and in general for cooling and
refrigerating for other requirements and consists―
Firstly in the method or process hereinafter to be described, and-
Secondly in the apparatus to carry such method or process into practical effect.
The invention is based upon the fact that atmospheric air when compressed and
then cooled will upon such air being made to perform mechanical work during its
expansion have its temperature lowered and will consequently lower the temperature
of bodies in contact with it owing to the absorption by such expanded air of heat
from bodies in its particular locality. By the employment of my invention a
greater efficiency in working and economy is effected than by existing systems or
appliances, the greater efficiency is due to the fact that at no period during the
process does the temperature of the working air rise much above that of the
cooling water nor fall much below that of the refrigerating room.
In order that my invention may be the more easily understood reference may be
made to the accompanying drawings consisting of a plan view (partly in section) of
a two step plant embodying my improvements and in which-
"A"
is a stop valve of any approved design and "B" an air inlet valve set
within the pipe "B" leading into a double action air compression cylinder "C."
"D" is a tube or pipe leading from the compression cylinder "C" into a horizontal
surface condenser "E." This condenser "E" is preferably constructed of longi-
tudinal horizontal tubes as "E" secured into the end plates "E" and enclosed in
a sealed cell or chamber of staunch construction.
From this condenser "E" a return pipe or duct "F" is led to another high
pressure double action compression cylinder "G" from whence another lead away
pipe "H" proceeds to and enters the end of another cylindrical horizontal surface
condenser "K," this latter is preferably similar in construction to the 'con-
denser "E" bereinbefore described.
"E" is a tank or cistern in which the condensers "E" and "K" are submerged,
this tank or cistern is kept filled with water for the purposes of cooling the con-
densers "E-K." In this tank or cistern "E" and through the condensers "E"
and "K" the circulation of the water is maintained by a pump or analogous
mechanism drawing the liquid preferably from the lower and injecting it into the
upper portion of such tank.
"L" is another return pipe or duct joining "K" with a double acting expansion
cylinder "M."
The cylinders "M" and "G" are placed in line and provided with a through
piston rod connecting them direct with the steam engine Gi" and on this piston
rod are mounted pistons of any suitable design.
M" to a
"N" is a lead away pipe from the aforesaid expansion cylinder "
horizontal cylindrical refrigerator or condenser "O" this latter is similarly

page_text: constructed to the condensers "E" and "K" herein before referred to.
"P" is a
return tube or duct leading back to another double action expansion cylinder "Q."
This cylinder "Q" is similar in its construction and working to the cylinder "M"
before described and its piston rod "Q" likewise proceeds through the cylinder "C"
and steam cylinder of engine "C¹."
"R" is also a leadaway tube connecting the cylinder "Q" with the refrigerator
or condenser "S" whilst "T" is the terminal return tube leading towards the
cylinder "C" first hereinbefore described and in and to the latter portion of which
is set the cock "A" air valve "B" and final connecting pipe "B'."
"U'-U³," "U³-U" are appliances such as fans or blowers for circulating the
air used as a refrigerating medium through the tubes of the condensers "O-S"
in such a manner that such refrigerating medium when chilled will uniformly and
efficiently circulate around or through the produce rooms or chambers "V"
preferably in the direction shewn by the arrows.
"V, V" are chambers constructed of any approved material, in which the
produce or other matters requiring cooling or refrigeration are placed and although
I have shewn an open air passage between such said chambers "V, V" and the
outer walls "W, W "I would have it distinctly understood that I do not confine
myself to any arbitrary adherence to such arrangement as for instance I may in
some cases cause main trunk tubes to convey the refrigerating medium through the
building and, from such main trunk, I may lead branch pipes provided with shutters
stop cocks or the like for turning on and off the supply of such refrigerating medium
in accordance with requirements at the discretion of the operator.
With reference to the steam engine cylinders "C" and "G" I would have it
distinctly understood that whilst preferring the piston rods "M" and "Q" to
proceed through the cylinders placed in line therewith I may alternatively employ
other operating gear, such as a pulley shaft for instance on which may be mounted
cranks with connecting rods in lieu of the direct motion of the steam pistons, and
further expansion cylinders may be connected by any suitable gear from a shaft in
connection with the compression cylinders.
The modus operand of my invention may be described as follows-
1
Referring to the drawings herewith of a two step plant the same has been
designed to pump up 3,000,000 heat units per day (pound degree Centigrade) from
a refrigerator at a temperature of 14 degrees Centigrade (260 degrees absolute)
to a source viz. the tank of cooling water "E3" at a temperature of 21 degrees
Centigrade (295 degrees absolute) I am presuming that a tank of cooling water
be employed in connection with the condensers "E-K" but in the case of plants
on board ship the source referred to is the sea water at the depth at which it is
drawn into the circulating pumps herein before referred to.
To charge the plant with air the stop valve "A" is closed and the air inlet
valve at " B" is opened. If thought necessary or desirable the air may be dried
by any approved apparatus (such as asbestos soaked in sulphuric acid) on its
way to the inlet valve "B."
Steam is turned on in the cylinders "C" and "G₁" and the plant set working
and continued at work till the gauge pressure on the condenser side of the stop
valve "A" has reached the initial pressure at which the plant is required to work,
(about 40 lbs. per square inch absolute).
When the plant has been charged with air up to the initial pressure the inlet
valve "B" is closed the stop valve "A" opened and the engines "C-G" work
at the required speed to maintain the temperature necessary. When the tempera-
tures at the various parts of the cycle bave reached their working values the
temperature of the air just before entering the first compression cylinder "C" is a
little below the température of the refrigerating room namely 252 degrees
absolute as against a temperature of 260 degrees absolute in the refrigerating room.
The air is compressed in the cylinder "C" till it reaches a pressure of about 87 lbs.
per square inch absolute, and temperature of 315 degrees absolute when the
outlet valves open and the air is forced out of the low pressure compressor "C"

page_text: through the exhaust pipe "D" into the surface condenser "E." The air is then'
cooled to a temperature of about 299 degrees absolute by means of the water
circulating through the tubes "E" in the condenser "E" while on its passage to
pipe "F" the air thus cooled passes thence through the pipe "F" and is admitted
to the second compressor "G" through suitable inlet valves, it is there compressed
to a higher pressure, in this case amounting to 104 lbs. per square inch absolute
and temperature of 315 degrees absolute thence it passes through pipe "H" to the
second surface condenser "K" where again the circulation of water through the
pipes "E" in the condenser "K" cools the air to a temperature of about
299 degrees absolute during its passage from pipe "H" to pipe "L
the air thus
having been cooled after each compression is reduced down to a temperature
nearly equal to that of the cooling water, which is supposed to be at a temperature
of 295 degrees absolute.
From the pipe "L" the compressed air at a pressure of 104 lbs. per square
inch absolute is passed into the first expanding cylinder "M" where it expands
till its pressure falls to 48 lbs. per square inch absolute the expansion being
regulated by suitable expansion valves, and the exhaust taking place through
separate valves. During the expansion in the cylinder "M" the air does work in
assisting to compress the air in cylinders "G" and "C" and during this practically
adiabatic expansion the working air becomes cooled to a temperature depending
on the initial pressure and temperature, and the amount of expansion is so regulated
that the air is cooled to a temperature a little lower than that of the refrigerating
room, say to a temperature of 36 degrees C. or 238 degrees absolute. The air then
passes by the pipe "N" to the surface condenser "0."
-
The air of the refrigerating chamber is driven and delivered by blowers "U¹—Ù³”
through the tubes in the surface condenser "0"; the temperature of the working
air on its passage through the condenser "0" to pipe "P" is thus raised nearly
to that of the refrigerating room say from a temperature of 238 degrees absolute
to a temperature of 252 degrees absolute. The air is drawn off through the
pipe "P" to the second expanding cylinder "Q" where it is again allowed to
expand till its pressure falls to about 40 lbs. per square inch absolute and do work
in assisting to drive the compressors "C" and "G," the expansion being regulated
by means of any approved expansion valve, and the temperature of the air falling
to 238 degrees absolute.
The expanded air then exhausts from the cylinder "Q" through pipe "R" at a
lower temperature than that of the cooling chamber namely 238 degrees absolute
into the surface condenser "S." By the circulation of air by blowers "UBU*"
through and from the tubes in the surface condenser the temperature of the air is
again raised during its passage from the pipe "R" through the condenser to the
pipe "T" to the temperature 252 degrees absolute.
The air having completed the cycle is reduced to its initial pressure and
temperature and is consequently ready to go through the same process again. It
must be distinctly understood that the pressures and temperatures given above are
subject to alteration according to circumstances, the efficiency of the plant becoming
greater as the range of temperature is reduced; the compressors and expanders
are double acting and may be constructed of any suitable material, whilst the walls
and covering or roofing of the cool chambers "V-V" and the outer walls "W-W"
may be insulated with any suitable non-conductor.
I would also have it understood that I may employ any suitable fluid in lieu of
air as hereinbefore referred to to fulfil the functions of the working medium i.e. the
medium employed in the closed cycle which is to be compressed cooled and expanded
as aforesaid.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
-
1. My herein before described method of cooling and refrigerating. consisting

page_text: essentially in the employment of air under an initial pressure greater than that of
the atmosphere and working in a closed cycle the air being compressed in one or
more steps and being cooled after each compression in suitable condensers and the
expansion of the compressed air in one, two or more steps in cylinders in such a
manner as to assist in the working of the mechanism the expanded air being passed
after each expansion through surface condensers through which air from the
refrigerating chamber or such other refrigerating medium as may be used is
propelled by suitable mechanism the amount of compression and expansion being
so regulated that the temperature of the working air during the compression
does not rise much above that of the cooling water, nor fall during expansion
much below that of the refrigerating room, substantially as and for the purposes
set forth.
2. In methods of cooling and refrigerating-The employment of surface condensers
for raising the temperature of the working air and consequently lowering the
temperature of the air of the refrigerating chamber, the working air being admitted
into receivers through the tubes of which the air of the refrigerating chamber is
driven by suitable blowers substantially as and for the purposes set forth and in
manner illustrated.
3. In apparatus for cooling and refrigerating-The combination of a compression
cylinder as "C" condenser as "E" and tank as "E" with a second compression
cylinder as "G" and condensers as "K" substantially as and for the purposes
set forth.
4. In apparatus for cooling and refrigerating-The combination of an expansion
"P" with a
cylinder as "M" pipe as "N" condenser as "()" and return tube as
second expansion cylinder as "Q" and condenser as "S" in both of which the
expansion of the air assists in the work of compression substantially as and for the
purposes set forth.
"
5. In apparatus for cooling and refrigerating-The combination of a stop cock
as "A
air inlet valve as "B" pipe as "B" and compression cylinder as "C"
substantially as and for the purposes set forth.
6. In apparatus for cooling and refrigerating-The general combination and
arrangement of the whole of the parts illustrated on the accompanying drawings
constituting my improved apparatus for cooling and refrigerating.
Dated this 10th day of June 1895.
HENRY F. TALBOT,
7 Cherry Street, Birmingham, Agent for the Applicant.
HENRY F. TALBOT,
7 Cherry Street, Birmingham, Agent for the Applicant.