Improvements relating to the Progressive Refrigeration of Gases.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to the Progressive Refrigeration of Gases.
I, WILLIAM HAMPSON (no occupation) Bryn, Nannerch Mold Chester, do
hereby declare the nature of this invention to be as follows:-
The usual cycle of compression, cooling, and expansion is modified by using all
the gas, after its expansion, to reduce as nearly as possible to its own temperature
the compressed gas which is on its way to be expanded; with this object all the
expanded gas surrounds the pipe or pipes of compressed gas through all their length
from the point of expansion to the point of normal temperature, and this length of
pipe is sufficient to allow of the fullest possible interchange of temperatures between
the compressed and expanded gas.
Dated this 21st day of May 1895.
Improvements relating to the Progressive Refrigeration
I, WILLIAM HAMPSON, M.A. Oxford, L.S.A. London, at present lodging at
No. 334 City Road, E.C., of Nannerch. Mold, North Wales, 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:—
This invention relates to producing refrigeration of air or gas to a high degree
of intensity.
The essential feature in my invention is that the usual cycle of compression,
cooling and expansion is modified by using all the gas after its expansion to reduce
as nearly as possible to its own temperature the compressed gas which is on its way
to be expanded; with this object all the expanded gas surrounds the pipe or pipes of
compressed gas through all their length from the point of expansion to the point
of normal temperature, and this length of pipe is sufficient to allow of the fullest
possible interchange of temperatures between the compressed and expanded gas.
As a consequence of continuously applying all the expanded gas to cool the
compressed gas whilst on its way to be expanded it results that the cold is intensified
until liquifaction of the gas ensues provided the apparatus is adequately protected
from external heat. Hence in my original application to the Patent Office I styled
my invention "The Self-intensive Refrigerator of Gases."
The annexed drawings show one form in which my apparatus may be made.
Figure 1 is a vertical section.
Figures 2 and 3 are horizontal sections taken respectively on the lines 2, 2 and
3, 3 in Figure 1.
I take for granted, as part of the apparatus employed in the usual cycle of
refrigeration, a good compressor, with all its appliances, also a good cooler, whether
by means of water, or, if it be desired to start with a lower temperature, some other
well-known refrigerating agent.

page_text: The gas, compressed to as high a pressure as is practicable or convenient, and
cooled, is delivered to my apparatus, by the pipe A, Figure 1.
the apparatus it is divided by a branch pipe B, into a suitable number of smailer
In passing down
pipes C, preferably of copper. The pipes are united at the bottom by another
branch pipe D, to the bottom of which is fixed a delivery pipe, with an orifice E,
which can be diminished to any desired extent by a point controlled by a rod F,
which passes through the top of the apparatus and near its lower end has a screw
upon it.
The contracted orifice E forms the obstacle, against which the
and as soon as it has passed this point it is free to expand.
gas is compressed,
The gas, after expansion in the cold chamber G is cooler than it was before. The
cooled, expanded gas issues into the bottom of the chamber K L M N.
chamber is divided by shelves O, into a number of channels, which oblige the
This
expanded gas to follow a course similar to, and enclosing, that of the compressed
gas, which is flowing in the opposite direction. The compressed gas, which is on
its way to be expanded is cooled by the contact of its pipes with the enclosing
expanded gas, and it reaches the expansion point at a lower temperature than that
of the gas which preceded it. It is therefore colder after expansion than the
preceding gas was, and as it passes upwards again reduces the compressed gas to
a lower temperature than it had itself while compressed. Therefore the compressed
gas which it has cooled nearly to its own temperature becomes after expansion
colder than it did itself. This coldest gas, in the same way, on passing upwards,
cools the compressed gas to a lower point than ever, and in this way the
intensification of cooling goes on till the gas begins to liquify in the cold chamber.
As the process of cooling goes on, the position of normal temperature rises
higher in the chamber till it is near the top, and from that point to the bottom
there is a gradual descent of temperature in both compressed and expanded gas.
The length of tubes is such as to effect as complete an interchange of temperatures
as possible.
The expanded gas leaves the chamber by the pipe P, and may be either discharged,
or led to the compressor to be pumped over again. The gas which is used must
be thoroughly dried, to avoid blocking the pipes with snow and ice, and therefore,
even in using air, it will usually be best to keep the expanded gas and make it
circulate again.
As refrigeration goes on, the cold causes the gas in the apparatus,
to occupy much less space, and this is especially the case when liquifaction begins.
More gas will have to be admitted to the circulation to make up the volume.
Supposing that the lower pressure in the apparatus is atmospheric, which for most
purposes will be most convenient, there must be an arrangement for admitting dry
gas at atmospheric pressure to the pipe P before it reaches the compressor.
The casing KQ RN is in horizontal section square, with corners cut off.
fits easily into a cylindrical cavity ST UV within a double casing or jacket. This
It
casing or jacket serves to isolate the apparatus and prevent it from absorbing heat
from its surroundings.
The space within the jacket is filled lightly with wool, animal or cotton, and a
pump will be used to exhaust the space of air as completely as possible through the
tap W. For the most intense_cold a thickness of lagging amounting to eighteen
inches will not be excessive. The spaces Y, Z, between the square and cylindrical
cases can also be packed.
Others of the many methods of lagging may be employed.
air jacketing to protect the cold chamber.
H is an additional
When a sufficiency of gas has been liquified and collected in the chamber G, it can
be drawn off by the pipe X which should be of non-conducting material and used
for any desired purpose.
A continuous supply of cold, of any desired intensity may be obtained by letting
the liquified gas flow slowly through the tap X along a well lagged pipe to an J
observatory chamber which is well lagged externally, and which contains a vessel
in which any object can be subjected to cooling as in drawing Figure 4.

page_text: Or as is illustrated by Figure 5 a continuous supply of cold air may be obtained
by substituting for the observatory chamber a chamber through which air can pass
downwards in cooling while the vaporising gas passes upwards, through it in a coil
or coils of pipe, finally going to the pipe P.
Or, see Figure 6, a quantity of cold can be stored for use after the apparatus has
ceased working, by passing the coils of vaporising gas through a cistern of water
or solution of suitable freezing point, which can be cooled or frozen by the cold gas,
and can subsequently give up its cold gradually over long periods by means of coils
in which air to be cooled can circulate through it.
The choice of the gas employed in the circulation will depend upon the degree of
cooling required.
When it is desired to go below the temperature of liquifaction of the circulating
gas, the operation must be continued until a fair amount of liquid has collected.
The pipe from the reservoir is then turned off and the continuation of the pumping
produces a partial vacuum over the liquid. This promotes rapid evaporation and
cooling.
Thus it will be seen that with my self intensive refrigerator of gas, in whatever
form it may be made, the method of working consists in compressing the gas, then
cooling it to the temperature of some available cooling agent, then allowing it to
become cooler still by expansion in any suitable way and the novel feature consists
in concentrating in the compressed gas as nearly as possible, all the cold in the
expanded gas, so that the additional effect of continuing the work appears as
additional intensity in the cooling of the circulating gas.. The means for attaining
this end, is to cause the stream of gas, after it has been cooled by expansion, to
closely surround the pipe or pipes which contain the compressed gas on its way to
expansion, so as to enclose them substantially throughout their whole length froin
the point of expansion to the point at which they enter the apparatus at the
temperature of the cooling agent, which will usually be common water, but may be
some freezing mixture, or other preliminary process of refrigeration. And the length
of the pipes must be sufficient to allow the compressed gas to reach, as nearly as
possible, the lowest temperature reached by the expanded gas; and to allow the
expanded gas to reach as nearly as possible, before leaving the apparatus, the
temperature at which the compressed gas enters. And the material and relative
proportions of the pipes must be such as to allow of the quickest possible interchange
of temperatures, consistently with strength and safety. And to prevent external
heat interfering with the above process, the most effective system of lagging, with
the best nonconductive materials, must be employed, and as few parts as possible
must be in any way exposed or placed in situations where they could receive or
conduct inwards the external heat; and the form of the whole apparatus must be
as compact as possible, and must present the smallest possible proportion of surface,
relatively to its bulk, that is consistent with a form convenient for working. And
none of the expanded gas must be used or allowed to refrigerate in any avoidable
way any object other than the gas itself which is undergoing the operation, so that
excepting unavoidable leakage all the cold contained in the expanded gas, shall
before it leaves the apparatus be transferred to the compressed gas.
I am well aware that the principle of regeneratively interchanging temperatures
between currents of gases has long been familiar in multitudes of devices for
evaporating and condensing heating and cooling, but never before has refrigerating
apparatus been designed with a view to the transfer (unavoidable leakage excepted)
of all the cold of the expanded gas to the compressed gas which is going to be
expanded. On the contrary where heretofore the cold expanded gas has been
employed at all to cool the compressed gas it has been in conjunction with the use
also of the cold expanded gas to cool objects external to the apparatus. Such use
of the expanded gas to cool anything besides the gas itself and the containing
apparatus is fatal to the attainment of low temperatures by self intensive
refrigeration.

page_text: 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 :-
My self intensive refrigerator of gases wherein all the expanded gas is applied
directly to continuously lower the temperature of the compressed gas before 5
expansion, and therefore also that of the gas after expansion; and so to continuously
increase the intensity of the cooling.
Dated this 19th day of February 1896.
WILLIAM HAMPSON, M.A., L.S.A.