IMPROVEMENTS IN REFRIGERATING AND FREEZING APPARATUS
Year: 1876

page_text: LETTERS PATENT to Carl Linde, of Munich, in the Kingdom of Bavaria, but at
present of No. 20, Southampton Buildings, Chancery Lane, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN REFRIGERATING AND
FREEZING APPARATUS."
Sealed the 8th August 1876, and dated the 5th April 1876.
PROVISIONAL SPECIFICATION left by the said Carl Linde at the Office of
the Commissioners of Patents on the 5th April 1876.
"
CARL LINDE, of Munich, in the Kingdom of Bavaria, but at present of No. 20,
Southampton Buildings, Chancery Lane, in the County of Middlesex. IMPROVE-
MENTS IN REFRIGERATING AND FREEZING APPARATUS."
My Invention relates to that description of refrigerating apparatus wherein cold
is produced by the volatilization of liquids such as ether or ammonia in a closed
vessel, the vapours produced being condensed in a second vessel by means of a force
pump.
My Invention has firstly for its object to prevent the loss of volatile liquid that
occurs in machines of present construction through the leakage of the vapour past
the surfaces of the moving parts of the pumping machinery, such as the pump
piston and stuffing box of the piston rod. According to my Invention, I prevent
any such leakage by the interposition of a body or layer of glycerine or other
suitable liquid, subjected to a somewhat greater pressure than the pressure to which
the vapour is subjected inside the pump, so that should the moving parts referred to
allow of any leakage past them, it would be the glycerine which would leak into the
pump and not the vapours leaking out of the same. My said Invention can be
carried into practice in various ways. Thus according to one arrangement I employ
two pump cylinders side by side, the pistons being arranged to move in opposite
directions. The cylinders are made to communicate with each other at the stuffing
box ends, and also with an air vessel containing glycerine under a somewhat greater
pressure than that to which the ether or ammonia vapour is subjected in the pump.
Thus the stuffing box ends of the cylinders will always be charged with such
glycerine under pressure while the vapour is being drawn in and forced at the
other ends of the cylinders. Any glycerine that may leak past the piston into this
end of the cylinder will firstly serve to fill any dead space in the pump, and will
then flow through the delivery valves and be collected in a well or chamber formed
[Price 6d]

page_text: on the pipe through which the ether vapour is forced into the condenser. From
this chamber the accumulated glycerine may be forced from time to time by a small
hand pump back into the before-mentioned air vessel. By preference I construct
the pistons with cup leather packing, so arranged that the glycerine under pressure
will press the leather against the cylinder and thus make the piston fluid tight.
According to another arrangement instead of applying the glycerine to the piston
as above described I apply it to the stuffing box in the following manner :-
divide the stuffing box into two compartments, and in the one nearest the cylinder
cover I provide two cup leathers embracing the piston rod, and having between
them and the sides of the stuffing box a circular perforated shield, behind which is
a cavity containing glycerine, subjected to greater pressure than that to which the
ether vapour inside the pump is subjected, so that the cup leathers will be pressed
against the piston rod by the glycerine, and should any leakage take place between
the two the glycerine will leak into the cylinder, thus preventing the ether vapour
from leaking out of it. The pressure upon the glycerine may be maintained by
a column of mercury made to act upon a closed reservoir of glycerine communi-
cating with the stuffing box by a pipe, the upper end of the column of mercury
being made to communicate with the pipe through which the vapour under pressure
passes to the condenser, so that the mercury acts upon the glycerine with its own
pressure plus that of the compressed vapour. The said reservoir of glycerine may
communicate by a pipe provided with a cock with the end of the cylinder so as to
admit a small quantity of glycerine on to the piston to act as a lubricant.
According to another arrangement I provide in the middle of the length of the
pump cylinder an annular recess, in which I place a similar arrangement of cup
leathers and perforated shield, and which is charged with glycerine under pressure,
thus acting as a stationary packing to the piston, which in this case is made of a
length somewhat exceeding that of its stroke. I construct the evaporating and
condensing vessels of the apparatus by preference each of a vertical coil of pipes,
the one containing the liquid to be volatilized and the other the vapour to be
condensed, which coils are contained in corresponding helical passages, through
which in the one case the liquid or fluid to be refrigerated is made to flow, and in
the other case the cold water for condensing the ether vapour, the liquids in the
passages being made to flow in the contrary directions to that of the vapour in the
coils. In order to prevent leakage of ether or ammonia vapour through the various
cocks or valves of the apparatus I enclose them in casings having screwed caps
provided with caoutchouc or soft metal packing so as to close air tight.
For making good any sinall loss of the volatile liquid that may still occur
through leakage I connect a closed vessel charged with such liquid by a tube
provided with a stop-cock with the pipe connecting the pump with the evaporating
vessel, so that by opening the communication when required any desired quantity
of the vapour may be drawn off from the said vessel by the pump and forced into
the condensing apparatus. When the apparatus is intended to produce ice I effect
this by the following arrangement: In a closed chamber containing water is a
horizontal revolving drum or cylinder, the periphery of which dips into the water.
Concentrically within the drum is, firstly, a cylindrical core filling the central part
of the drum, and, secondly, between this and the inner surface of the drum is a
cylindrical partition, by which the space inside the drum is divided into two
annular compartments which communicate with each other at each end of the
drum. A pipe conducting the refrigerated brine from the refrigerator is made to
open into the inner one of the two compartments, while the pipe for con-
ducting the brine away again communicates with the outer compartment. Thus
a circulation of cold brine is kept up in the lower part of the drum which dips into
the water in the chamber, the consequence of which will be that as the drum
revolves a coating of ice will be formed on its outer surface, which will increase in
thickness by the formation of a fresh coating at every revolution. When a sufli-
cient thickness of ice has been obtained the supply of brine is stopped and warm
water is introduced through the pipes into the drum so as to cause the ice to

page_text: separate therefrom, and allow it to be removed. If it be desired to produce ice in
the shape of flat slabs the drum may be made polygonal instead of cylindrical, or it
may be of a star shaped cross section. The ends of the drum are open at the centre
and a revolving fan is provided in the casing, whereby the cold air is made to
circulate through the drum and over the outer surface thereof, so as to render the
temperature uniformly cold throughout the chamber and thereby greatly accelerate
the formation of the ice.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Linde in the Great Seal Patent Office on the 29th August 1876.
CARL LINDE, of Munich, in the Kingdom of Bavaria, but at present of No. 20,
Southampton Buildings, Chancery Lane, in the County of Middlesex. "IMPROVE-
MENTS IN REFRIGERATING AND FREEZING APPARATUS."
My Invention relates to that description of refrigerating apparatus wherein cold
is produced by the volatilization of liquids, such as ether or ammonia in a closed
vessel, the vapours produced being condensed in a second vessel by means of a
force pump.
My Invention has firstly for its object to prevent the loss of volatile liquid that
occurs in machines of present construction through the leakage of the vapour past
the surfaces of the moving parts of the pumping machinery, such as the pump,
piston, and stuffing box of the piston rod. According to my Invention I prevent
any such leakage by the interposition of a body or layer of glycerine, or other
suitable liquid, subjected to a somewhat greater pressure than the pressure to
which the vapour is subjected inside the pump, so that should the moving parts
referred to allow of any leakage past them it would be the glycerine that would
leak into the pump and not the vapours leaking out of the same. My said Invention
can be carried into practice in various ways. Thus according to one arrangement
I employ two pump cylinders side by side, the pistons being arranged to nove in
opposite directions. The cylinders are made to communicate with each other at
the stuffing box ends, and also with an air vessel containing glycerine under a
somewhat greater pressure than that to which the ether or ammonia vapour is
subjected in the pump. Thus the stuffing box ends of the cylinders will always be
charged with such glycerine under pressure while the vapour is being drawn in
and forced out at the other ends of the cylinders. Any glyceriue that may leak
past the piston into this end of the cylinder will firstly serve to fill any dead space
in the pump, and will then flow through the delivery valves and be collected in a
well or chamber formed on the pipe through which the ether vapour is forced into
the condenser. From this chamber the accumulated glycerine may be forced from
time to time by a small hand pump back into the before-mentioned air vessel. By
preference I construct the pistons with cup leather packing, so arranged that the
glycerine under pressure will press the leather against the cylinder and thus make
the piston fluid tight.
According to another arrangement instead of applying the glycerine to the piston
as above described I apply it to the stufling box in the following manner :-I divide
the stuffing box into two compartments, and in the one nearest the cylinder cover
I provide two cup leathers embracing the piston rod, and having between them and
the sides of the stuffing box a circular perforated shield, behind which is a cavity
containing glycerine, subjected to greater pressure than that to which the ether
vapour inside the pump is subjected, so that the cup leathers will be pressed against
the piston rod by the glycerine, and should any leakage take place between the
two the glycerine will leak into the cylinder, thus preventing the ether vapour
from leaking out of it. The pressure upon the glycerine may be maintained by a
column of mercury made to act upon a closed reservoir of glycerine communicating
with the stuffing box by a pipe, the upper end of the column of mercury being made

page_text: to communicate with the pipe through which the vapour under pressure passes to the
condenser, so that the mercury acts upon the glycerine with its own pressure plus
that of the compressed vapour. The said reservoir of glycerine may communicate
by a pipe provided with a cock with the end of the cylinder so as to admit a small
quantity of glycerine on to the piston to act as a lubricant.
According to another arrangement I provide in the middle of the length of the
pump cylinder an annular recess, in which I place a similar arrangement of cup
İcatliers and perforated shield, and which is charged with glycerine under pressure,
thus acting as a stationary packing to the piston which in this case is made of a
length somewhat exceeding that of its stroke. I construct the evaporating and
condensing vessels of the apparatus by preference each of a vertical coil of pipes,
the one containing the liquid to be volatilized and the other the vapour to be
condensed, which coils are contained in corresponding helical passages, through
which in the one case the liquid or fluid to be refrigerated is made to flow, and in
the other case the cold water for condensing the ether vapour, the liquids in the
passages being made to flow in the contrary direction to that of the vapour in the
coils. In order to prevent leakage of ether or ammonia vapour through the various
cocks or valves of the apparatus, I enclose them in casings having screwed caps
provided with caoutchouc or soft metal packing so as to close air-tight.
For making good any small loss of the volatile liquid that may still occur
through leakage I connect a closed vessel charged with such liquid by a tube
provided with a stop-cock with the pipe connecting the pump with the evaporating
vessel, so that by opening the communication when required any desired quantity
of the vapour may be drawn off from the said vessel by the pump and forced into
the condensing apparatus. When the apparatus is intended to produce ice I effect
this by the following arrangement-In a closed chamber containing water is a
horizontal revolving drum or cylinder, the periphery of which dips into the water.
Concentrically within the drum is, firstly, a cylindrical core filling the central part
of the drum, and, secondly, between this and the inner surface of the drum is a
cylindrical partition by which the space inside the drum is divided into two annular
compartments which communicate with each other at each end of the drum. A
pipe conducting the refrigerated brine from the refrigerator is made to open into
the inner one of the two compartments, while the pipe for conducting the brine
away again communicates with the outer compartment. Thus a circulation of cold
brine is kept up in the lower part of the drum which dips into the water in the
chamber, the consequence of which will be that as the drum revolves a coating of
ice will be formed on its outer surface, which will increase in thickness by the
formation of a fresh coating at every revolution. When a sufficient thickness
of ice has been obtained the supply of brine is stopped and warm water is intro-
duced through the pipes into the drum so as to cause the ice to separate therefrom,
and allow it to be removed. If it be desired to produce ice in the shape of flat
slabs the drum may be made polygonal instead of cylindrical, or it may be of a star
shaped cross section. The ends of the drum are open at the centre and a revolving
fan is provided in the casing, whereby the cold air is made to circulate through the
drum and over the outer surface thereof, so as to render the temperature uniformly
cold throughout the chamber and thereby greatly accelerate the formation of the
ice.

page_text: of the vapour discharged from the pump. The liquid condensed in B flows by
a regulating valve D into A, to be again volatilised. The heat developed by the
condensation in B is taken up by water or air circulating through the passages
around the pipes, and the heat required for volatilisation in A is derived from
air circulating in like manner, when the apparatus is used for cooling air, or from
brine when it is used for freezing.
In order to supply volatile liquid, a vessel K, charged therewith, is made to
communicate by a pipe with the suction of the pump, so that the volatile liquid
is drawn from K in the form of vapour, the heat necessary for its evaporation
being derived from water in which K is immersed.
Fig. 2 represents, partly in elevation and partly in section, the two single
acting cylinders of the pump, with the air vessel W partly charged with glycerine
between them. It will be seen that the stuffing boxes of the pumps are entirely
covered by the glycerine, which also lubricates the cylinders and prevents leakage
of the volatile fluid past the pistons, the pressure in the air vessel W being some-
what greater than that of the vapour when compressed by the pump.
For a
double acting pump, such as is shewn mostly in section in Fig. 3, the glycerine
is applied to pack the stuffing box in a manner shewn to an enlarged scale in
Fig. 4, which is a section of one side of the stufling box of the pump shewn in
Fig. 3.
at
One part of the cavity of the stuffing box is occupied by two cup leathers a, a,
which are pressed against the piston rod by glycerine admitted by a pipe
higher pressure than that to which the pump compresses the vapour. A perforated
ring & keeps the cup leathers in position. Means of supplying the glycerine at
the required excess of pressure are shewn in Fig. 3. The discharge pipe of the
pump dips into a vessel at G, in which is collected any glycerine that may have
leaked into the pump, and that has accompanied the fluid discharged from the
pump. The same vessel G communicates by a small pipe c with a vessel 9, at
a higher level, containing mercury, which by a pipe communicates with a
vessel y, containing glycerine. From this vessel the pipe is led to the stuffing
boxes or pistons, where it may be required. The glycerine in g is thus subjected
to the pressure of the discharge of the pump, as well as that due to the column
of mercury from q down to g. The glycerine collected in G is from time to time
drawn therefrom by a small pump and forced into g, an equal volume of mercury
being thus forced back into q.
Fig. 5 shews a section of a cylinder in which the packing of an elongated piston
or plunger is effected by cup leathers and glycérine in a mauner similar to that
of the piston rod in Figs. 3 and 4.
Fig. 6 represents a longitudinal, and Fig. 7 a transverse section of an ice
forming druin T, operating as described above. The drum is made with au
annular chamber, divided into two annular compartments.
Into the one com-
partment the cold brine flows by a pipe a, and from the other it is withdrawn
by a pump through the pipe b. The drum T being made to revolve slowly with
part of its periphery immersed in water, a crust of ice is formed on its circumference
which is gradually thickened as layer after layer is deposited.
The refrigeration may be promoted by causing, by means of a fan, a current of
air to pass through the casing within which the drum is mounted.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, 1 claim in respect of refrigerating or ice making machines
in which cold is produced by the evaporation of a volatile liquid and the vapour
thereof is again condensed by compressing pumps —
First. The method, substantially as herein described, of preventing leakage of
the volatile liquid or its vapour past the pistons or the piston rods of the pumps
employed by applying to the packings glycerine at a greater pressure than that
produced by the action of the pump.
Second. The construction of a stufling box or packing to which glycerine is
applied, for the purpose referred to in the preceding claim, substantially in the

page_text: manner herein described in reference to Figs. 3, 4, and 5 of the accompanying
Drawings.
Third Giving the glycerine the required excess of pressure, for the purpose
above referred to, by subjecting it to the pressure of a column of mercury, which
is itself subjected to the pressure of the pump discharge, substantially as herein
described with reference to Fig. 3 of the accompanying Drawings.
Fourth. The use, for producing ice, of a drum partly immersed and revolving
in water, the interior of the drum next to its periphery being charged with cold
brine or other refrigerating liquid, substantially as herein described with reference
to Figs. 6 and 7 of the accompanying Drawings.
In witness whereof, I, the said Carl Linde, have hereunto set my hand and
seal, this Seventeenth day of July, in the year of our Lord One thousand
eight hundred and seventy-six.
CARL LINDE. (L.S.)