IMPROVEMENTS IN PNEUMATIC REFRIGERATING MACHINES
Year: 1881

page_text: LETTERS PATENT to Mathias Josef Klein, of New York City, 'in the State of
New York, in the United States of America, Engineer, for an Invention of
COMPLETE SPECIFICATION filed by the said Mathias Josef Klein at the
Office of the Commissioners of Patents on the 4th May 1881.
MATHIAS JOSEF KLEIN, of New York City, in the State of New York, in
the United States of America, Engineer. "IMPROVEMENTS IN PNEUMATIC
REFRIGERATING MACHINES."
This Invention relates to that class of pneumatic refrigerating machines in
which cold is produced by the compression and expansion of one and the same
body of atmospheric air. In such machines the minimum pressure of the cold
producing air has heretofore been one atmosphere or less, in consequence of which
they were of large dimensions, requiring great power to operate them, and are
subject to many objections principally on account of the moisture of the air.
The object of this Invention is to overcome these objections, and my Invention
consists in the production of cold by the compression and expansion of a confined
body of atmospheric air, which I call "working-air," under a minimum pressure at
all times higher than one atmosphere, that is to say, this "working-air" remains in
a compressed and concentrated state. The waste through joints, stuffing boxes, &c.,
of this working air in its circulating course is supplied by other atmospheric-air,
which I call "feed-air."
The "working-air" which is compressed and expanded reaches on its circulating
course a certain maximum pressure, and a minimum pressure always higher than
one atmosphere, and the higher this minimum pressure will be retained the more
cold can be produced. The compression and expansion of the "working-air"
between the maximum and minimum pressure may be produced in various ways,
either by one or inore compressors or by one or more expanders of suitable
construction.
For instance, the minimum pressure being 5 and the maximum pressure
20 atmospheres, this "working-air" may be alternately compressed from 5 to 20,
and then expanded from 20 to 5 atmospheres, or it may be compressed from 5 to

page_text: 12 atmos. in one compressor, and from 12 to 20 in another, and then expanded
from 20 to 5 atmos.; or it may be compressed in one compressor from 5 to 15, then
expanded in an expander from 15 to 8, then again compressed in a second com-
pressor from 8 to 13, and in a third compressor from 13 to 20, and then expanded
in a second expander from 20 to 10, and in a third from 10 to 5 atmosph. By
this arrangement it would require for the working-air, in the first case, one
compressor and one expander, in the second case two compressors and one expander,
and in the third case three compressors and three expanders. It will readily be
understood that these proportions may be varied at will. By every compression
"heat" is produced, and by every expansion the production is "cold." The heat
may be abstracted during the process of compression or after, or both during and
after compression, and the cold produced by the expansion may be transferred to
any other medium in the same manner. This abstraction of the heat and trans-
ferring of the cold may be accomplished either by suitable surface coolers or by
liquids either injected or permanently combined with the "working-air," or in any
other manner. Whatever the construction and arrangement of the apparatus in
which the "working-air" operates, the same must be provided with an air-feeder
to compress the usual atmospheric air to the minimum pressure of the "working-
air," or higher, and deliver the same ("feed-air") to the "working-air." My
Invention further consists in a new method of perfectly drying or abstracting the
aqueous parts of the "feed-air" without the use of chemicals before admitting the
same to the "working-air." It consists also in purifying the "feed-air," and in
the automatic regulation of the minimum and maximum pressure of the "working-
air," as well as in the combination of parts, and means designed to reduce the
motive power for this production of cold.
By these several improvements I am able to produce a pneumatic refrigerating
machine of small dimensions in comparison to the quantity of cold to be produced,
second, the quantity of cold to be produced in a certain time will be variable
within extended limits; third, the internal parts of the machine remain uninjured
by the purified dry "working-air," and remain free from dust, dirt, snow, and
hoar-frost, in consequence of which the same will be easily managed and of great
durability; fourth, the motive power to operate the machine is comparatively
small, in consequence of which the machine works economically, no matter for
what purpose the same may be used. It will readily be understood that the
construction and arrangement of a machine containing my improvement may be
manifold.
In order to explain this Invention as completely as possible I now proceed to
describe the best means I am acquainted with for carrying the same into practical
effect, reference being had to the illustrative Sheet of Drawing hereunto annexed,
and to the numeral figures and letters of reference marked thereon, and where a
machine is represented with one compressor and one expander for the "working-air,"
and in which
Fig. I. represents a front elevation of the machine; Fig. II. is a vertical section,
and Fig. III. a plan of the same; Fig. IV. shows a vertical section of the air-
purifier.
Similar letters refer to similar parts in all the several views.
Upon a suitable frame X is mounted the steam cylinder S of any desired
construction, the compressor C, and the expander E, which latter is provided with
a variable cut-off. For the air-feeder a small air-compressor C¹ attached at the
side of cylinder E is arranged. The piston rods of the cylinders are connected to
a cross-head T, which by means of suitable pitmans G drive the fly wheels F on
the main shaft B turning in suitable bearings in the frame X. By this arrange-
ment the pistons of the cylinders S, C, E, and C³, move up and down at the same
time. The expansion cylinder E and the steam cylinder S have slide and cut-off
valves, which are operated by the excentric Z attached to the shaft B.
The slide valves receive their motion from the shaft B' and the cut off valves
from the shaft B². The compressors C and C¹ are surrounded by jackets, through which

page_text: "
The
cooling water or any other cooling medium is circulated by means of the supply
pipes c, c² and discharge pipes c¹, c³, to abstract a part of the heat developed in
these cylinders by the compression of the " working air" and "feed-air."
expander E has a surrounding jacket, through which, by means of the supply pipe e
and discharge pipe e¹, any substance or substances are allowed to circulate to
abstract the heat from said substances and at the same time heating the
working-air" during its expansion in E. The air-cooler K, in which the heated
"working-air," after coming from the compressor C, is cooled, is a surface cooler of
any suitable construction, and is connected with the valve-boxes V, V₁, of the
compressor C and with the expander E by means of the pipes L and M; it is
provided with supply and discharge pipes k, k', for the circulation of the cooling
medium, which may be water, air, or any other substance. The refrigerator R,
which may be of similar construction as the cooler K, is connected with the
compressor C and the small surface cooler H by means of pipes and O, and is
provided with supply and discharge pipes W and for the circulation of any
substance from which heat shall be abstracted. The air-feeder C¹ is connected with
the feed-air purifier A and the feed-air reservoir Y by means of pipes a and U.
The small surface-cooler H, with the water-chamber H2 at its bottom and the
pressure reducing valve J at its upper end, is connected with the air-reservoir Y by
pipe U2, with the expander E by pipe N, and with the refrigerator R.by the
pipe O. The purpose of this cooler H is to cool off the compressed "feed-air" to.
or nearly to the lowest temperature which exists in the machine.
P is a pump to set in circulation the non-congealing liquid, or the water or other
medium which is designed to congeal, and is connected at one side with the jacket
of the cylinder E and at the other side by means of pipe p with the ice-making
apparatus or the apartment to be cooled, or any other apparatus (not shewn in the
Drawing). The expander E, the refrigerator R, the small cooler H, the pump P,
the pipes N, O, Q, r, W, and p, are all covered with a nonconducting material.
"
The purified, concentrated, and perfectly dry "working-air," alone or combined
with a lubricating or non congealing liquid, is enclosed in N, H, O, R, Q, C, L, K, M,
and E, and during its circulating course therein is compressed by the compressor
to its maximum pressure and expanded by the expander E to its minimum pressure.
This " working-air" is supplied by the air feeder C, which takes the air from the
atmosphere and conducts it through z, A, a, U, Y, U2, H', and the ports x, x, to the
working-air," purified, compressed, and perfectly dried. The expression "the
working-air is perfectly dry" in this description means deprived of almost all its
aqueous parts, although it may contain at the same time more or less of some non
congealing lubricating liquid. The feed-air purifier A is a small chamber provided
at its bottom with an orifice z for the entrance of the atmospheric air, and is
provided with a zigzag channel formed through it from a to z by means of a series
of horizontal partitions d, d. Water is admitted through a pipe b at top of the
chamber, escaping at z. The atmospheric or "feed-air" enters at 2, and being
delivered at a comes in contact with this water and is deprived of dust and other
impurities, and being thus purified and impregnated with water passes into the
air-feeder C, in which it is compressed to the minimum pressure of the "working-
air" or to a higher pressure if desired. The heat generated during this compression
is partially absorbed in the evaporation of the water carried along from the
purifier A, and which has nearly the same effect as a spray of cooling water thrown
into the compressing cylinder C¹ during the compression of the air; a further
portion of the heat is removed by the circulation of the cooling water in the jacket
of the cylinder C'. This water with which the "feed-air" is impregnated fills out
the waste spaces of the compressor C₁ and renders any lubrication of its piston
unnecessary, while the valves and pistons of the cylinders E and C, into which only
the dry "working-air" enters, must be perfectly lubricated.
The moist "feed-air" in a compressed state, and a little heated, passes from C¹
through the pipe U into the feed-air reservoir Y. Against the large surfaces of
this reservoir this compressed "feed-air" will be cooled off to nearly the temperature

page_text: "
of the surrounding atmosphere, and a part of its moisture will be condensed in
this reservoir and pass with the "feed-air" through the discharge pipe U2 into the
chamber H. If the "feed-air" is not cool enough the pipe Us may be cooled by a
stream of cooling water. The upright tube H¹ is surrounded by the dry
"working-air," which, coming directly from the expander E, is at its lowest degree
of temperature and at the minimum pressure. It enters near the top of H through
pipe N and escapes at O. From H2 this now partially dry "feed-air" passes up
into the tube Hi and through the ports x, x, and mingles with the "working-air."
While passing through the tube H¹ this air has been cooled off by the
'working-air," which passes downward outside said tube H to the same or nearly
the same temperature of the "working-air" or the lowest temperature which exists
in the machine. -Now, since the "feed-air" in the tube H¹ has the minimum
pressure of the "working-air," or a higher pressure, and in consequence of the
above mentioned cooling in this tube nearly all the moisture or aqueous parts
still remaining in said "feed-air" is condensed and drawn into the chamber Ĥ2 in
the form of condensed water and snow. This water collected in the chamber H
may be removed by a stop cock or by a self-acting stop-valve m (as shown), or it
may remain in said chamber for some time if of sufficient size and be removed at
any time desired.
The "feed-air" at the time of mingling with the "working-air," as well as the
working air itself, is perfectly dry, that is to say, it is in such a degree or condition
of dryness that not the least portion of the very small quantity of water-vapor still
contained in it can become further condensed at any point of its course, and it is
quite obvious that this dry "working-air" will remain in this dry state indepen-
dently of the length of time the operation of the machine is continued.
The ports x, x, in tube H are regulated by a pressure reducing valve J of any
desired construction. The "working-air" in its minimum pressure acts against the
diaphragm or piston of said valve which .closed the tube H at its top. Said
diaphragm is balanced by means of a weight J2 and lever Jo (see Fig. II). If said
minimum pressure of the " working-air is falling, the weight J2 moves the
diaphragm downward as well as the ring al and opens the several ports x, x, and
the dry "feed-air" is allowed to escape through said ports and combine itself with
the "working-air." When the minimum pressure of the "working-air" rises, the
weight J together with the diaphragm and valve ring a moves upward and closed
the ports x.
The "feed-air" coming from the air-feeder C¹ remains then in the
reservoir Y, and the pressure in the same rises.
By the continual escape of the "working-air" through the stuffing boxes and
other leakages the pressure of the working air decreases; this causes the valve J to
open the ports and new "feed-air" to enter and mix with the "working air." It
is obvious that by this arrangement the minimum pressure of the "working-air" is
automatically regulated. Said minimum pressure may be varied by the position of
the weight J upon the lever J¹. The proportion of the maximum pressure to the
minimum pressure of the "working-air" is relative to the proportion of the volume
of the compressor C to that of the expander E and the position of the cut off of the
latter. If said cut off is variable, the said proportions will be variable. The greater
the ratio of said proportion the lower will be the temperature reached by the
machine.
The operation of the machine is as follows:-The necessary power for driving
the machine is obtained from the steam cylinder S or from any other motor. When
the machine is started the pressure of the air in the several parts of the machine is
of course one atmosphere. The stop valve U¹is opened and the stop valve in the
pipe U2 is closed. The air feeder C₁first fills the reservoir Y with purified com-
pressed atmospheric air until the pressure therein is a certain degree higher than the
required minimum pressure of the "working-air," when the stop valve in the pipe U2
is gradually opened. During this operation all the moisture of the "feed-air" has
time to condense in the tube H¹ before the "feed-air" enters through,, into the
working-air." Having thus filled the machine with purified and perfectly dry

page_text: 27
"working-air," and the required minimum and maximum pressures of the " working-
air" being reached these pressures of the "working air" will remain constant
because they will be automatically regulated by means of the air-feeder C¹, the
reservoir Y, and pressure-reducing valve J, as above described. Should the air-
feeder C¹ furnish more air than required to counterbalance the loss by leakages, &c.,
the surplus will remain in the reservoir Y, and the pressure in the same will
continue to rise until a portion of the same will escape through a suitable safety-
valve placed on top of reservoir Y (not shown in Drawing). The same result
may be obtained by stopping the air-feeder C' from time to time similar to the feed
water pump of a steam-engine, or the amount of "feed air" delivered may be
reduced by enlarging the amount of waste space of the air feeder, or by reducing
its stroke, or by pressing the suction-valves by means of springs or screws, or in any
other way. By stopping the machine for several hours or a longer time the stop-
valve U and the stop valve in the pipe U2 may be closed, and the "feed-air
remaining in the reservoir Y may be stored for filling the machine with concentrated
working air for its next operation. The working air makes the following circuit:―
From the refrigerator R it passes at its minimum pressure through the pipe Q to the
compressor C, where it is compressed to its maximum pressure and consequently
heated. It next passes through pipe L and enters the surface-cooler K, in which by
the aid of a cooling medium (usually water) its temperature is reduced. It then passes
through the pipe M to the expander E, in which it is expanded from its then
maximum to the minimum pressure, and as a resultant cold and power are produced.
The latter is utilized in compressing the working air in C, and at the same time
affords very great assistance to the steam cylinder S. The "working-air" as it
emanates from the expander E through pipe N has reached its lowest degree of cold
and is in the minimum pressure state; it next passes into the upper portion of the
jacket between the tubes H' and H, thence downward, cooling off the feed-air
contained in the tube H¹ to its lowest temperature, as described. From this jacket
the cold "working-air" passes through pipe O to the refrigerator R, in which it
abstracts heat from any substance or substances which are circulating or resting
within R, the "working-air" in the meantime rising in temperature. From the
refrigerator R said "working-air" passes through pipe Q to the compressor C, where
it is again compressed from the minimum to the maximum pressure, and repeats the
circuit already described. This operation is continuous.
The more perfect the expansion of the "working air" in E the greater the
reduction in the amount of power required to drive the machine, and also the
greater the cold produced. In order to obtain a perfect expansion in the expander E
through the different fillings of the latter, it is preferable to make the capacity of
the compressor C variable. This may be obtained by varying its waste-spaces. To
effect this two small cylinders D, D, are attached at the top and bottom of the
cylinder C, each provided with a tight piston fand regulating screw (see Fig. II.).
By increasing the degree of filling in E by means of the variable cut-off, the pistons
ff, of the cylinders D, D, must be moved to the outside and vice-versa. The same
effect may be obtained by other means. The motive power for driving the machine
will also be reduced by circulating the non-congealing liquid or the water which is
designed to freeze to ice, or any other liquid or medium to be congealed in the
jacket and cylinder heads of the expanding cylinder E. If it is designed to use
the refrigerating capacity of the machine for the production of ice, the water
intended to be frozen will be allowed to circulate in the said jacket where it is
cooled off to nearly its freezing point, and then it is allowed to escape into the ice
producing apparatus, wherein it freezes to ice by means of a non congealing liquid
which is circulated in said apparatus and the refrigerator R. In the production of
ice the said non-congealing liquid may be avoided if the refrigerator R is made of a
suitable construction as an ice apparatus in which the water after coming from the
jacket in E enters and freezes to ice by the direct action of the concentrated cold
"working-air."
When the machine is not designed for the production of ice the non congealable

page_text: liquid is allowed in lieu of water to circulate in the jacket of the cylinder. E.
Having here being cooled off to a certain degree passes through the pipe W into
the refrigerator R, where it is still further reduced in temperature, then it is
allowed to pass through the pipe r to the apparatus or apartment where its cold is
to be utilized. Having performed its refrigerating function it next goes back to
the pump P to repeat the circuit described.
When the machine is designed to produce cold. water for any purpose, common
water, in lieu of a non congealable liquid, is allowed to make the circuit just
described, and it may be used over and over again or not. In the latter case a
continued stream of fresh water is allowed to circulate through the jacket of the
cylinder E and then through R. And if the machine is designed to cool off any
liquid or gas these latter substances are made to pass through the jacket E and
then through R.
The effect of said jacket on E will be increased if the substance circulating
through the same also circulates through the piston of cylinder E, and in the same
manner the cooling effect of the jacket in the compressor C will be increased if
the cooling medium is also allowed to circulate through the piston of the same.
If the machine has more than one compressor and expander for the "working-
air" each of them should be provided with such a jacket.
"
The motive power for driving the machine can be further reduced by combining
the dry, concentrated, "working-air" with a surplus of a lubricating liquid. The
latter may be any lubricant which does not freeze at the lowest temperature of
the "working-air," or it may be a non-congealing liquid of any kind or com-
position which can serve as a lubricant, such as glycerine. The introduction of
these liquids into the "working-air" may be done during the working of the
machine by means of suitable oil-cups, or by other means, or it may be done before
starting by filling the same at one or more parts with a sufficient quantity of said
liquid. After starting the "working-air comes in contact with this liquid, and.
will be highly impregnated with it, and a part of said liquid is therefore compelled
to make the same circuit as the "working-air." Said liquid lubricates the pistons,
valves, and stuffing boxes of the cylinders E and C, fills out the waste spaces of
the same, absorbs a part of the heat developed in the compressor C, and gives off
some heat to the expanding "working. air" in the expander E. Its effect in the
compressor C is the same, or nearly the same, as a spray of cooling liquid injected
into it during the compression of the "working-air," and therefore the power for
this compression is reduced. The effect of said.liquid in the expander E is, first,
a higher power obtained from the expanding working-air, and, secondly, a
temperature of the latter, which is not too low for the economical working of the
machine. The presence of such a lubricating liquid in the "working-air" reduces
therefore considerably the motive power for driving the machine.
The "feed-air" in drying, as above described, is cooled off in H¹ to, or nearly to
the lowest degree of cold which exists in the machine by the direct operation of
the cold "working-air." The same effect may also be obtained in H₁ by means
of a non-congealable liquid. In order to do this the cold "working-air" is allowed
to pass from the expander E first to a small surface-cooler, in which it reduces said
non-congealable liquid to, or nearly to, its own degree of cold, and passes then
directly into the refrigerator R, and not into H, while the cooled liquid goes from
this cooler into the jacket between the tubes H and H, reducing the temperature
of the "feed-air," and returns (its temperature having in the meantime become
slightly raised) to said small surface-cooler to be cooled off again by the cold
working-air," and then repeats the circuit described. If this modification is used
the upper portion of the jacket between the tubes H and H¹ where the "feed-air"
passes the ports x, x, must be separated from its lower portion by an air tight
partition, and a pipe conducts the "feed-air" from the ports x, x, to the pipe N, or
to any other place where the working air circulates. If it is designed that the
'feed-air" after passing the ports x, x, shall enter into the "working-air" at any
point where the same is in its maximum pressure, the air-feeder C₁ must in this
"

page_text: case compress the "feed-air" to the said maximum or a higher pressure, and
then the maximum pressure of the working air will be directly and automatically
regulated.
Instead of a separate non-congealable liquid which transfers the low temperature
from the cold " working-air" to the "feed-air" in H', the non-congealable liquid
circulating in R may do this work. To effect this the said liquid coming from the
refrigerator R passes into the jacket between the tubes H and H¹, and then to the
ice-apparatus or other apartment, or the whole tube H³ may be enclosed in the
ice-box where the non-congealable liquid coming from R enters the same.
these modifications are equivalent with the small cooler H.
All
It is not necessary to cool the "feed-air" before it enters into the vessel H2, as
the whole cooling of the feed-air can be done in H¹ alone by the cold "working-air"
or by said non-congealable liquid, but in such case, as will readily be seen, a part
of the "cold" produced by the machine would be wasted, and it is therefore
preferable to cool the "feed-air," as above described, before it enters into the
chamber H2.
If the partial dry "feed-air" after coming from Y and U2 would enter directly
into the circular course of the "working-air" without passing the small cooler H
or its equivalent, said "working-air" would in this case only be partially dry, a
part of its aqueous parts would be precipitated during its circular course to water
or water and snow, and mingle with the lubricating or non-congealable liquid.
The latter may be contained in the "working-air" in a surplus or not. The
composition of said liquid would thereby change continually, and more or less
trouble during the working operation of the machine would be the consequence.
Such trouble would take place to a higher degree if the compressed "feed-air"
after coming from the air-feeder C¹ would enter directly into the " working-air."
In this case the "working-air" would receive all the moisture of the "feed-air."
By nearly absolute dryness of the atmosphere only could cooler H alone or Y,
H, and H be omitted without having trouble by the operation of the machine.
In this case of course the impregnation of the "feed-air" with water in the
purifyer A. must be omitted, and the "feed-air" purified by filtering the same
by means of cotton or other material.
My Invention is not restricted to the arrangement shown in the Drawing.
The several parts of the machine may be arranged in any other position than
shown. My Invention is furthermore not confined to the special kind of con-
struction of the several parts; any kind of a single or double-acting air compressor,
of a single or double acting air-expander; any kind of a cooler, refrigerator, air
purifyer, or pressure reducing-valve; and any kind of an air-receiver may be used.
The compressor C and expander E may also be arranged in one cylinder, in one
end of which the "working-air" shall be compressed, and in the other end of
which it shall be expanded. And instead of one compressor and one expander,.two
or more compressors and two or more expanders may be employed in which the
"working-air" is compressed and expanded between the maximum and minimum
pressure in any manner. Instead of one cooler K and one refrigerator R, two or
more of each may be used. The refrigerator R may serve for several purposes at
the same time; one part of it may be used for the production of ice, and another
for the production of cold air, &c.
When the machine is designed cool a room or apartment the cold " working-
air "in its minimum pressure state may transfer its cold directly to the air of said
room by passing the same, after coming from expander E, through pipes in said
room or apartment, and then to the compressor C. In this case said room or
apartment is the equivalent of refrigerator R. In lieu of the feed-air purifyer A
an equivalent apparatus may be employed, in which the feed-air " may pass
through a body or spray of water, or through a mass of cotton or other fibrous
material, which is kept constantly impregnated with fresh water. The air feeder
C' may be a double or single-acting air-compressor; it may consist of one
compressor, in which the "feed-air "is compressed from the atmospheric pressure

page_text: directly to the minimum pressure of the working-air, or a higher pressure; or it
may consist of two or more compressors, in which the "feed-air " is first compressed
from the atmospheric pressure to a medium pressure, and then further until the
pressure required in the air-receiver Y is reached. As an equivalent apparatus for
the air-feeder C there may be substituted a pulsometer, an injector, or any
other apparatus or arrangement which is able to furnish compressed air of any
desired degree of pressure. Also several of the apparatuses or arangements just
mentioned may be employed at the same time; for instance, the "feed-air" may
be first compressed by a pulsometer; and then further compressed by means of a
piston compressor to the required minimum pressure of the "working-air," or a.
higher pressure. The air feeder may also be driven by a separate motor; in this
case the air-reservoir Y may be filled with compressed air of the required pressure
before the whole machine is started.
Having now fully described and set forth my said Invention, and the manner of
operating the same, I wish it understood that I claim,-
1.) In a pneumatic refrigerating machine the continuous use of a confined body
of atmospheric air called "working-air," which is compressed and expanded, and
the minimum pressure of which is higher than one atmosphere, substantially as and
for the purpose described.
2.) In a pneumatic refrigerating machine the combination of a small air-
compressor, or an equivalent apparatus or arrangement, which serves as air-feeder,
with one or more air-compressors and one or more expanders, in which the enclosed
"working-air" operates, designed to maintain the " working-air at a higher
minimum pressure than one atmosphere, substantially as and for the purpose
described.
"'
3.) In a pneumatic cold producing apparatus or refrigerating machine the air-
feeder C or its equivalent, in combination with the compressor C, cooler K,
expander E, and refrigerator R, or with their respective equivalents, substantially
as and for the purpose described.
4.) The air-purifyer A or its equivalent, designed to purify the "feed-air," and
impregnate it with water, in combination with the air-feeder C¹ or its equivalent,
substantially as described.
5.) The combination of the air-feeder C₁ or its equivalent, the small surface
cooler H or an equivalent apparatus, and the chamber H, designed in conjunction
with the cold "working-air or a non-congealable liquid to reduce the "feed-air,"
while in its compressed state, to or nearly to the lowest temperature which exists
in the machine, and by these means to dry the "feed-air" perfectly, substantially
as described.
6.) The method of drying the "feed-air " before it enters into the circular course
and mixes with the enclosed working-air consisting in compressing the "feed-air" to
the minimum pressure of the "working-air" or higher, and then cooling it off while
in this condition to or nearly to the lowest temperature which exists in the
machine, and by these means so far as possible to condense all the water vapours
contained in the said "feed-air" to, water or to water and snow, and remove the
same, substantially as set forth.
7.) In a pneumatic refrigerating machine the compressor C for the enclosed
working-air," in combination with the small cylinders D, D, having air-tight
pistons ff, with regulating screws or their equivalent, substantially as and for the
purpose described.
8.) In a pneumatic refrigerating machine the expander E, or expanders, for the
enclosed" working-air" in combination with jackets provided with supply and
discharge pipes designed to circulate the water or any other liquid or gas to be
congealed, substantially as and for the purpose described.
9.) The air-feeder C' or its equivalent, in combination with the feed-air reservoir
Y and pressure reducing-valve J, designed to regulate automatically the minimum
or maximum pressure of the enclosed "working-air," substantially as and in the
manner specified.
.

page_text: 10.) In a pneumatic refrigerating machine the combination of the air-feeder C'
or its equivalent, the feed air purifyer A or its equivalent, the feed-air reservoir Y,
the small surface cooler H. or its equivalent, the chamber H, the pressure reducing
valve J, the compressor C, the cooler K, the expander E, and the refrigerator R, the
working-air being impregnated or combined with a lubricating or non-congealing
liquid, designed and arranged to operate substantially as and in the manner and
for the purpose set forth.
In witness whereof, I, the said Mathias Josef Klein, have hereunto set my
hand and seal, this Nineteenth day of April, in the year of our Lord One
thousand eight hundred and eighty one.
Witness,
HENRY E. ROEDER,
314, Broadway, New York,
America.
MATHIAS JOSEF KLEIN. (L.S.)