Improvements in Refrigerating Apparatus.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Refrigerating Apparatus.
I, HANS HENRIK SCHOU, of Pilealle 27, Copenhagen, in the Kingdom of Denmark,
Engineer, do hereby declare the nature of this invention to be as follows:-
_w
In the methods hitherto employed for the production of artificial cold the
lowering of the temperature is almost exclusively produced by allowing a liquid,
whose boiling-point is sufficiently low, to evaporate in a system of tubes, the neces-
sary heat for this evaporation being taken from the air, water or the like
surrounding the tube-system, and which are thereby more or less cooled.
This method in itself does not necessitate the use of a refrigerating machine and
it is only important that the pressure of the vapours when these are exhausted
into the atmosphere should not increase so much as to prevent the complete cooling.
The use of a refrigerating machine however becomes imperative when the
substances, that are used for the production of the artificial cold, are too valuable
to be allowed to escape in the form of vapours. It will then be necessary to
condense these vapours in order that they may be used over and over again.
In all refrigerating machines hitherto employed, whose mode of working is based
on the evaporation and consequent condensation of liquids, these two operations
are intimately connected so that the one does not take place without it being
immediately followed by the other.
As however every refrigerating machine requires motive power and sometimes
heat for the recovering of the substance employed, it has up to the present been
impracticable to use artificial cold in places where a refrigerating machine could not
easily be placed, for instance in railway cars, and at times when it would not be
desirable to keep the motor at work.
The object of my invention is to divide the process of evaporation, i.e: the pro-
duction of cold and the process of condensation, i.e. the recovering of the cooling
liquid in such a manner, that each of these processes may take place independently
of the other, as regards time as well as place.
This result is obtained by allowing the vapours produced in the cooling appar-
atus to be absorbed by a suitable substance in a closed receiver, that is connected
with the tube system, in which the evaporation takes place. If afterwards this
receiver is connected with the suction pipe of an ordinary refrigerating machine
and the vapours are separated from the substance, that had absorbed these, the
refrigerating machine will draw the vapours away and the recovering of these
vapours in a liquid form will not present any difficulty.
The present invention therefore solves the problem of producing artificial cold
without interruption, whilst the recovering of the cooling liquid may be effected
at any suitable time.
By using an absorbing-receiver in refrigerating apparatus in the manner herein-
before described, or if necessary several such receivers, that may be used alternately,
an advantage obtained, amongst others, is that the motor may be stopped at any
time, for instance, if this motor is also driving other machinery and it should be
desirable to stop the machinery for a time, without it being necessary to interrupt
the cooling process.

page_text: The water contained in the absorbing receiver or any other substance that may
be used for absorbing the vapours of the cooling liquid will of course be heated
by the absorption and it is necessary to get rid of this heat. In cases where the
cold produced is not very intense the heat may, by giving a suitable shape to the
absorbing receiver, be given off directly to the surrounding air, if the temperature
of this air be not too high. This way of getting rid of the heat will often be
sufficient, especially in railway cars where the absorbing receiver is exposed to a
constant draught.
If however the heat cannot be sufficiently transmitted to the surrounding air
in the above described manner, it may be removed, for instance by providing the
absorbing receiver with a water jacket, that may either be constantly provided with
cold water or for example in railway cars filled with cold water at the stations.
Another way to cool the absorbing receiver is simply to allow water to evaporate
on its surface, which method is a very good one for receivers on railway cars when
the weather is very warm, because the strong draught will help the evaporation.
The water for evaporation can either be arranged so as to drip on
to the surface of the absorbing receiver from another receiver or the
absorbing receiver may be provided with a jacket of suitable material over which
water is now and then poured, for instance, at the stations. Or the said jacket
may be arranged to suck up the water from another receiver placed underneath.
In most cases it will be advisable to use ammonia as the cooling liquid and water
as the absorbing agent. The following are a few examples of the manner in which
the present invention can be applied for the production of artificial cold.
The cooling of a railway car may for instance, be effected as follows:-
Underneath the ceiling of a car or in some other suitable place a system of tubes
is arranged, which may consist of one long tube bent several times. One end of
the tube system or of the above mentioned single tube is placed in connection with
a receiver containing ammonia in a liquid state, in such a manner that the admis-
sion of the ammonia into the tube can be regulated according to the consumption,
whilst the other end of the tube or tube system is connected with an absorbing
receiver filled with water. As one kilogram of water will absorb about kilogram
of ammonia at the ordinary atmospheric pressure, or more at higher pressures, and
as ammonia by its evaporation absorbs about 300 units of heat per kilogram the
quantities of ammonia and water, that it will be necessary to carry even for long
journeys will be proportionately small and of small importance.
Further, the ammonia and absorbing receivers can easily be changed on the
road. The absorbing receivers can after the water has absorbed a sufficient
quantity of ammonia, be brought to a central station where the recovery of the
ammonia in a liquid state may be effected, or be emptied and only the ammonia
water brought to the central station.
In a similar manner the cooling or other chambers whether fixed or portable may
be effected, such for instance as small cooling chambers for meat and other victuals,
situated in places, where motive power is not available or where the installation
of motive power would be too costly. By taking liquid ammonia only once a day
to the cooling chamber and fetching away the ammonia water it will be possible
without any motive power and with a minimum amount of attendance to use
artificial cooling, which in so many respects is preferable to the use of ice.
A great drawback with many of the existing smaller refrigerating apparatus
provided with a machine for the recovery of the cooling vapours in a liquid state,
is that as soon as the motive power is stopped the refrigerating apparatus ceases to
work such as during the night, when the cost of a special attendant would probably
be too great.
This disadvantage is obviated by the present invention wherein an absorbing
receiver is used in connection with the tube system, in which the cold is produced,
when the motor is not at work. When the motor is at work the absorbing receiver
is disconnected from the tube system and placed in connection with the machine,
which will then draw the vapours from the absorbing receiver as well as from

page_text: the tube system. The absorbing receiver may if necessary be heated by the exhaust
from the motor.
As already mentioned the present invention is specially adapted for the cooling
of railway cars for conveying goods, that must be kept cold and the following is
an example of a refrigerating arrangement for such a car.
On the outside of one of the end walls of the car one or two tanks are arranged,
containing the liquid which has been chosen as a cooling agent; in most cases
ammonia will be preferred. At the bottom of each tank is arranged a pipe pro-
vided with a valve and both these pipes unite in a branch pipe.
From this pipe a main pipe is carried through the end-wall of the carriage into
the interior of the carriage as near the ceiling as circumstances will allow. This
main pipe is provided with a regulating valve.
Inside the carriage the main pipe is bent a sufficient number of times to give
the requisite amount of surface, after which it is carried through the other end-wall
of the carriage and is provided with a stop cock. It then passes into a receiver
attached to the carriage. The receiver is partly filled with a liquid or other
suitable substance for the absorption of the cooling vapours. In cases where
ammonia is used as a cooling agent water is generally used for absorbing purposes.
The receiver is provided with an outlet cock and a pressure gauge. A pressure
gauge is also placed on the main pipe. For measuring the temperature in the
car thermometers are arranged in such a manner, that they can be seen from the
outside, so that it is not necessary to open the car for the purpose.
The operation of the apparatus is as follows:--
An
After having partly filled the tank and receiver with ammonia and water
respectively the ammonia is admitted into the main pipe connecting the same.
energetic evaporation of the ammonia will immediately begin and after the vapours
have passed through the main pipe in the car they will immediately become
absorbed by the water in the receiver. The evaporation therefore will continue
and the main pipe become cooled. The temperature in the car will thereby be
caused to drop and the desired result is obtained. By means of the regulated
valve the quantity of liquid conducted into the main pipe can be regulated
according to the degree of cold required. The quantity of cooling liquid will of
course vary according to the difference between the temperature outside the car
and the temperature required inside the same. The air that may be in the main
pipe when the apparatus is started, can easily be blown out by means of ammonia.
It may further be mentioned that the tube or tubes in the car during the cooling
process will be covered with white frost on account of the moisture in the air
inside the car. Whilst this circumstance will cause the air inside the car to be
comparatively dry, the white frost, when the cooling process ceases, will melt and
the water would drop down onto the goods in the car which would be very unde-
sirable. In order to avoid this the tubes inside the car may be provided underneath
with strings or strips of water absorbing material or with small water catchers,
which moreover help to promote the circulation of the air thus making the tempera-
ture in the car more uniform. When the cooling apparatus is not at work the
water catchers may be shut up underneath the tubes, whereby they will only occupy
a very small space.
.
100x
COMPLETE DI BUIFICATION
Improvements in Refrigerating Apparatus.
I, HANS HENRIK SCHOU, of Pilealle 27, Copenhagen, in the Kingdom of Denmark,
Engineer, do hereby declare the nature of this invention and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to improvements in refrigerating apparatus.
In the methods hithereto employed for the production of artificial cold the
lowering of the temperature is almost exclusively effected by allowing a liquid,
the boiling-point of which is sufficiently low, to evaporate in an arrangement of
tubes, the heat necessary for the evaporation being extracted from the air, water
or the like surrounding the tubes which are thereby more or less cooled.
This method in itself does not necessitate the use of a refrigerating machine,
the only essential being that the pressure of the vapour formed when exhausted
into the atmosphere shall not increase sufficiently to prevent complete cooling.
The use of a refrigerating machine, however, becomes imperative when the
substances employed for the production of artificial cold, are too valuable to be
allowed to escape in the form of vapour. It will then be necessary to condense the
vapour in order that the substance may be repeatedly used.
In all refrigerating machines hitherto employed, the mode of working of which
is based upon the evaporation and subsequent condensation of liquids, these two
operations are intimately connected so that the one does not take place without it
being immediately followed by the other.
As, however, every refrigerating machine requires motive power and sometimes
heat for the recovery of the substance employed-it has up to the present been
impracticable to produce artificial cold in places where a refrigerating machine
could not easily be placed, for instance in railway cars, and at times when it would
not be desirable to keep the motor at work.
The object of my invention is to divide the process of evaporation, i.e., the pro-
duction of cold and the process of condensation, i.e., the recovery of the cooling
liquid in such a manner, that each of these processes may take place independently
of the other, both as regards time and place.
This result is obtained by allowing the vapours produced in the cooling apparatus
to be absorbed by a suitable substance in a closed receiver connected with the tube
system in which the evaporation takes place. If afterwards this receiver be con-
nected with the suction pipe of an ordinary refrigerating machine and the vapours
separated from the substance by which they had been absorbed the refrigerating
machine will draw the vapours away and they can without difficulty be recovered in
a liquid form.
By my invention, therefore, I effect the production of cold without interruption,
the recovery of the cooling liquid being effected at any suitable time.
By using an absorbing-receiver in refrigerating apparatus in the manner herein-
before described, or if necessary several such receivers, which may be used in turn,
amongst other advantages obtained, it may be mentioned that the motor can be
stopped at any time, for instance, if the said motor is also driving other machinery
and it should be desirable to stop the machinery for a time, without it being
necessary to interrupt the cooling process.
The water contained in the absorbing-receiver, or any other substance that may
be used for absorbing the vapours of the cooling liquid, will of course be heated
by the absorption and it is necessary to get rid of this heat. In cases where the
cold produced is not very intense the heat may, by giving a suitable shape to the
absorbing receiver, be given off directly to the surrounding air, if the temperature
of this air be not too high. This way of getting rid of the heat will often be
sufficient, especially in railway cars where the absorbing-receiver is exposed to a
constant draught.
If, however, the heat cannot be imparted to the surrounding air in the above
described manner to a sufficient degree, it may be extracted, for instance by pro-
viding the absorbing-receiver with a water jacket, which may either be constantly
provided with cold water or, for example in railway cars, filled with cold water at
the stations. Another way to cool the absorbing-receiver is simply to allow water
to evaporate on its surface, which method is a very good one for receivers on

page_text: -
railway cars when the weather is very warm, because the strong draught will
help the evaporation. The water for evaporation can either be arranged so as to
drip on to the surface of the absorbing-receiver from another receiver or the
absorbing-receiver may be provided with a jacket of suitable material over which
water is now and then poured, for instance, at the stations. Or the said jacket
may be arranged to suck up water from another receiver or tank placed underneath.
In most cases it will be advisable to use ammonia as the cooling liquid and water
as the absorbing agent. The following are a few examples of the manner in
which the present invention can be applied for the production of artificial cold.
The cooling of a railway car may for instance, be effected as follows:-
Underneath the roof of a car or in some other suitable place therein a system of
tubes is arranged, which may consist of one long tube bent several times. One
end of the tube system or of the above mentioned single tube is placed in connection
with a receiver containing liquid ammonia, in such a manner that the admission
of the ammonia into the tube can be regulated according to the consumption, whilst
the other end of the tube or tube system is connected with an absorbing-receiver
filled with water. As one kilogramine of water will absorb about ½ kilogramme of
ammonia at the ordinary atmospheric pressure, or more at higher pressures, and
as ammonia by its evaporation absorbs about 300 units of heat per kilogramme the
quantities of ammonia and water, which it will be necessary to carry even for
long journeys, will be proportionately low and of small importance.
Further, the ammonia and absorbing-receivers can easily be changed on the
road. The absorbing-receivers can, after the water has absorbed a sufficient
quantity of ammonia, be brought to a central station where the recovery of the
ammonia in a liquid state may be effected, or be emptied and only the ammonia
solution brought to the central station.
In a similar manner the cooling of other chambers whether fixed or portable
may be effected, such for instance as small cooling chambers for meat and other
victuals, situated in places, where motive power is not available or where the
installation of motive power would be too costly. By taking liquid ammonia
only once a day to the cooling chamber and fetching away the ammonia solution
it is possible without any motive power and with a minimum amount of attendance
to employ means for artificially cooling, which in many respects is preferable to
the use of ice.
A great drawback to many of the existing smaller refrigerating apparatus pro-
vided with a machine for the recovery of the cooling vapours in a liquid state, is
that as soon as the motive power is stopped the refrigerating apparatus ceases to
work, for instance during the night, when the cost of a special attendant would
probably be too great.
This disadvantage is obviated by the present invention wherein an absorbing-
receiver is used in connection with the tube system, in which the low temperature
When the motor is at work the
is obtained, when the motor is not at work.
absorbing-receiver is disconnected from the tube system and placed in connection
with the machine, which will then draw the vapours from the absorbing-receiver
as well as from the tube system. The absorbing-receiver may, if necessary, be
heated by the exhaust from the motor.
As already mentioned the present invention is specially adapted for the cooling
of railway cars for conveying goods, that must be kept cold and in the accom-
panying drawings I have illustrated an example of a refrigerating arrangement
for such a car.
In the said drawings,
Figure 1 is a longitudinal section of a railway car having my refrigerating
apparatus applied thereto :
Figure 2 is a plan with the roof removed; and,
Figure 3 is a vertical transverse section thereof.
On the outside of one of the ends of the car one or two tanks A is or are arranged,
containing the liquid which has been chosen as the cooling agent; in most cases

page_text: ammonia will be preferred. At the bottom of each tank A is arranged a pipe B
provided with a valve C both these pipes B uniting in a branch pipe D.
From this pipe a main pipe E is carried through the end of the car into the
interior thereof as near the roof as circumstances will allow. This main pipe is
provided with a regulating valve F.
Inside the car the main pipe E is bent a sufficient number of times to give the
requisite amount of surface, after which it is carried through the other end of the
car and is provided with a stop cock G. It then passes into a receiver H attached
to the car. The receiver H is partly filled with a liquid or other suitable substance
for the absorption of the vapour. In cases where ammonia is used as a cooling
agent water is generally used for absorbing purposes.
A
The receiver H is provided with an outlet cock I and a pressure gauge.
pressure gauge is also fitted to the main pipe E. For measuring the temperature
in the car thermometers are arranged in such a manner, that they can be seen
from the outside, so that it is not necessary to open the car for the purpose.
The operation of the apparatus is as follows:-
After having partly filled the tank A and receiver H with ammonia and water
respectively the ammonia is admitted into the main pipe E connecting the same.
An energetic evaporation of the ammonia will immediately begin and after the
vapours have passed through the main pipe in the car they will immediately become
absorbed by the water in the receiver. The evaporation, therefore, will continue
and the main pipe become cooled. The temperature in the car will thereby be
caused to drop and the desired result is obtained. By means of the regulating
valve Fthe, quantity of liquid conducted into the main pipe can be regulated
according to the degree of cold required. The quantity of cooling liquid will of
course vary according to the difference between the temperature outside the car
and the temperature required inside the same. The air that may be in the main
pipe when the apparatus is started, can easily be blown out by means of ammonia.
It may further be mentioned that the tube or tubes in the car during the cooling
process will be covered with white frost on account of the moisture in the air inside
the car.
Whilst this will cause the air inside the car to be comparatively dry, the
frost, when the cooling process ceases, will melt and the water would drop down
on to the goods in the car which would be very undesirable. In order to avoid this
the tubes inside the car may be provided underneath with strings or strips of water
absorbing material or with small water catchers K, which moreover help to promote
the circulation of the air, thus making the temperature in the car more uniform.
When the cooling apparatus is not at work the water catchers K may be shut up
underneath the tubes, whereby they will only occupy a very small space.
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. In refrigerating apparatus wherein the production of cold is effected by the
evaporation of a liquid, the employment of a receiver containing a suitable sub-
stance for the absorption of the cooling-vapours, the said receiver being connected
with the end of the evaporation-main, opposite the end communicating with the
tank containing the cooling liquid for the purpose of rendering the cooling process,
i.e. the evaporation, and the recovery of the cooling liquid, i.e., the condensation
of the cooling vapours independent of each other, substantially as, and for the
purposes, hereinbefore described.
2. In apparatus of the kind claimed in the preceding claiming clause and
especially applicable to railway cars, the arrangement of the tank or tanks con-
taining the cooling liquid and of the absorbing receiver or receivers outside the car
or in a space separate apart from the cooling chamber, in combination with a tube
system arranged inside the car and underneath the roof thereof, the ends of said
tube system being suitably connected with the tank for the cooling liquid and the
absorbing receiver respectively, substantially as herein before described.

page_text: 3. In refrigerating apparatus of the kind claimed in Claim 2 the arrangement of
water absorbing strings or strips or of small water-catchers underneath the cooling
tubes for the purpose of absorbing or carrying away the moisture, which is deposited
upon the surfaces of the said tubes, substantially as, and for the purpose, herein-
before described.
4. In refrigerating apparatus of the kind claimed in Claim 1, the arrangement of
a water jacket surrounding the absorbing receiver for the purpose of conveying
away the heat produced by the condensation of the cooling vapours, substantially
as set forth.
5. In refrigerating apparatus of the kind claimed in Claim 1 the arrangement of a
jacket surrounding the absorbing receiver for the purpose of effecting the evapora-
tion of water on the surface of the absorbing tank and extracting the heat therefrom
by either letting water drip upon the said jacket or arranging the latter to suck
water up from a tank, substantially as described.
6. The combination and arrangement of parts forming the improved apparatus
for the production of cold hereinbefore described and illustrated in the accompanying
drawing.
Dated the 21st dow of Dacamber 1897
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.