IMPROVEMENTS IN AND APPERTAINING TO MACHINERY AND APPARATUS FOR COOLING, DRYING, AND PURIFYING ATMOSPHERIC AIR FOR REFRIGERATING PURPOSES
Year: 1877

page_text: LETTERS PATENT to John Sturgeon, of Crosby, near Liverpool, in the County
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN AND
APPERTAINING TO MACHINERY AND APPARATUS FOR COOLING, DRYING, AND
PURIFYING ATMOSPHERIC AIR FOR REFRIGERATING PURPOSES."
Sealed the 18th June 1878, and dated the 21st December 1877.
PROVISIONAL SPECIFICATION left by the said John Sturgeon at the Office
of the Commissioners of Patents on the 21st December 1877.
JOHN STURGEON, of Crosby, near Liverpool, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN AND APPERTAINING TO MACHINERY AND APPARATUS FOR
COOLING, DRYING, AND PURIFYING ATMOSPHERIC AIR FOR REFRIGERATING PURPOSES'
My Invention has for its object improvements in and appertaining to machinery
and apparatus for cooling, drying, and purifying atmospheric air for refrigerating
purposes.
It is well known that when a volume of air occupying a certain space at its
normal temperature and presure is compressed into a smaller space, the same
quantity of heat that was distributed through its original volume, and forming its
natural temperature, being concentrated into less space, the air must show a riso in
temperature above that of the surrounding atmosphere. If the heat thus generated
by the compression of the air be absorbed and carried off, so as to reduce the air
in its compressed state to the same temperature as the surrounding atmosphere, or
nearly so, and the compressed air thus cooled be then allowed to expand back into
its original space or volume, but with so much less quality of heat left to fill such
space or volume, a considerable lowering of the temperature will result. This well-
known principle is applied in all descriptions of machinery for refrigerating by the
compression, cooling down, and expansion of atmospheric air. The compression
and expansion being generally effected by means of two cylinders, one for com-

page_text: pressing and the other for expanding, having their pistons and rods geared together,
so that the compressed air while expanding in the one cylinder is returning a portion
of the power employed in compressing it by assisting to drive the machine, to
cool the air while compressed by extracting the concentrated heat it has hitherto
been the practice before passing the compressed air into and through the receiver
and cooling tank to inject water into the compressing cylinder, thus bringing the air
and water into direct contact, and in fact mixing them. The objection to this place
is that the expanded cold air is charged with moisture, which rapidly forms large
quantities of ice and snow, rendering the cold air unfit for direct application for most
refrigerating purposes. Heat is also abstracted from the compressed air by surface
contact with cold surfaces, such as metal pipes and water filled vessels.
The objection to cooling by the outside application of water only, is that in such
case the air cylinders require lubrication by oil rendering the air impure and unfit
for the purpose required.
According to my Invention instead of the ordinary piston and cylinder used in
the cases herein-before referred to. I make both the compressing and expanding
cylinders of greator length than the stroke of the engine, and instead of one piston
I use two pistons on the same piston rod fixed thereon, thus dividing the cylinder
into three paits, namely, the top, and bottom, and centre.
The compressing cylinder is surrounded with a water jacket, through which a
constant circulation of water is maintained, the water being first admitted into the
interior of the compressing cylinder between the two pistons, being the centre of
the cylinder, through an opening on the top and about the middle of the cylinder,
and passing out through another opening or openings into the water jacket or
elsewhere, such water in no case coming into direct contact or mixing with the air
in the top or bottom of the cylinder. The expanding cylinder is supplied with
water in a similar manner, but in this case in place of the water jacket the expanding
cylinder is covered with a non-conducting lagging, and in order to prevent the
water between the pistons in the cylinder from being frozen, its temperature may
be regulated and kept above freezing point by mixing with the water used a
sufficient quantity of the water heated by the compressing cylinder; or instead of
water in the expanding cylinder I use glycerine or chloride of calcium (Ca° C)
dissolved in water, the proportions being fourteen parts of chloride of calcium to
eighty-six parts of water, or thirty parts of chloride of calcium to seventy parts of
water or chloride of magnesium (Mg. Co. 1₂) in the same proportions dissolved in
water as the chloride of calcium.
My Invention further consists in and may be carried out by using compression
and expansion cylinders of the ordinary dimensions with a piston of the following
construction-I nake the piston hollow, with openings carried entirely through its
periphery between the packing or piston rings. Into the hollow piston I fix a pipe
turned on the outside, and long enough to pass through a stuffing box in the
cylinder cover, and into a circulating pump cylinder, which is fixed outside in such
a manner that at each stroke of the engine tho pipe works a single-acting ram pump,
and forces the water or its substitute through into the hollow piston, and through
the openings in its periphery, and coming into contact with the interior surface of the
cylinder, the water afterwards escaping through another pipe passing through the
same; or the opposite cylinder cover or the pipes may be applied as ram pumps at
both ends of the cylinder.
In lieu of a single hollow piston the same object may be attained by using a
duplex piston, separated so as to form a chamber into which the water can pass, and
at the same time be in contact with the inside surface of the cylinder.
In connection with these arrangements I employ the water pressure between the
pistons, or in the hollow piston to press the piston rings or packing outwards by
leaving openings under the piston rings or packing communicating with the water
space, and regultating the pressure of the water or its substitute to the extent
requisite for tightening the rings.
In lieu of the pines before referred to for supplying the interior of the piston the

page_text: water, or its substitute, may be taken in through the piston rod, which is made
hollow for the purpose.
My Invention further consists in constructing the cylinder covers and water-
containing piston of the compressing cylinder with concentric projecting water
spaces, the water spaces or projections on the piston fitting into the female spaces
forward by the concentric water spaces or projections on the cylinder covers
By the means herein-before described the cylinders will be lubricated by water
or its substitute, and the compression cylinder cooled, avoiding the necessity of
using oil, and the objectionable practice of using water in direct contact with the
compressed air for extracting the heat, thereby combining the advantages of the
external water cooling with those of the internal water-cooling systems, and avoiding
the disadvantages of either.
In further carrying out my Invention I fix the compression and expanding
cylinders horizontally, the one behind the other, and geared together by con-
tinuation of the piston rod from the one to the other. The cylinders are set upon
an iron bed, forming at the same time the cooling tank or receiver for the air
heated by compression. On either side of the air cylinders I fix steain cylinders,
forming a pair of engines, geared in any suitable manner to the crank shaft, which
is carried in bearings on the crank or receiver and geared direct to the air cylinders
by crank and connecting rod, or their equivalent. The bed being the cooling tank
or receiver is formed into three compartments, the two end compartments forming
compressed air chambers, and the centre compartment being the cooling tank,
which is constructed with a number of tubes passing through it, connecting the air
chambers, and round which a circulation of cold water is inaintained The
receiving air chamber is divided in two separate portions by a central ring, so that
the air when compressed into the internal or central division has to pass through
the inner set of tubes to the front air chainber, returning through the outer set of
tubes to the exterior sub-division of the first air chamber, or vice versa. The
circulation of the compressed air is thus effected through the cooling tubes, and
the heat generated by compression is thus further absorbed and carried off
The air, being kept from direct contact with the water used for cooling, will be
free from moisture, except that generally contained in the atmosphere in the form
of watery vapour
The combined action of compression and of the discharge of heat from the air
will tend to condense this watery vapour, and when all is thus discharged I cairy
off by means of a tiap or traps applied to the lowest parts of the compressed air
chambers where this condensed moisture accumulate in the form of water.
The trap consists of a tube hanging vertically downwards, and closed at the
bottom by a valve weighted to open only when the pressure upon it exceeds the
proposed pressure in the air chambers. When sufficient water is collected in the
tube or trap to overcome by its additional weight the spring or otherwise retained
valve, the valve will open and allow the water to run out until the weight is
relieved sufficiently to allow the valve to close again.
To get rid of the remaining moisture in the air as far as possible I apply in one
of the compressed air chambers, by preference the second receiving chamber, a wire-
work cradle, or other equivalent contrivance filled with carbon or baffle plates,
tubes, or plugs composed of carbon, which besides absorbing any noxious particles
in the air by purifying the air, also absorbs the moisture from the air while still
under pressure, and consequently before such moisture can be precipitated in snow
or ice by the cold produced when the air is expanded. Coke, pummice stone,
cinders, peat, charcoal, animal charcoal, vegetable charcoal, or other suitable sub-
stance, may be used for absorbing the moisture; and I apply a door to the
chamber in which the absorbing substance is placed for convenience of removing
and renewing it when fully charged.
To apply this my Invention to, say, a meat safe or refrigerator, I convey a pipe
from the refrigerator to the inlet valves of the compressing cylinder, with a branch
and valve for the admission of external air as required. As the air iş drawn from

page_text: the refrigerator, or from the outside, it is compressed into the receiving air chamber,
passing through the tubes in the cooling tank, and through the absorbing apparatus
in the 2nd air chamber, and back to the first air chamber, from which the
expanding cylinder is supplied; and from the expanding cylinder air is discharged
to the refrigerator in a cold dry state. After passing the air contained in the
refrigerator through and through the apparatus until it is sufficiently cooled down,
the outer are is then taken in and dealt with in similar manner; the old air con-
tained in the refrigerator being allowed to pass out as the new cold air is passed
in. By means of a valve or tap, or simple disengaging and engaging arrangement,
the expanding cylinder can be kept out of action until the required compression of
.air is obtained in the receiver.
By these means a continuous supply of pure cold air can be delivered in a
sufficient dry state, and at a temperature which can be regulated at will by
regulating the speed of the apparatus and the circulation of the water in the
cooling tank.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Sturgeon in the Great Seal Patent Office on the 21st June
1878.
John Sturgeon, of Crosby, near Liverpool, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN AND APPERTAINING TO MACHINERY AND APPARATUS FOR
COOLING, DRYING, AND PURIFYING ATMOSPHERIC AIR FOR REFRIGERATING
PURPOSES."
My Invention has for its object improvements in and appertaining to machinery
and apparatus for cooling, drying, and purifying atmospheric air for refrigerating
purposes.
It is well known that when a volume of air occupying a certain space at its
normal temperature and pressure is compressed into a smaller space, the same
quantity of heat that was distributed through its original volume and forming its
natural temperature being concentrated into less space, the air must show a rise in
temperature above that of the surrounding atmosphere. If the heat thus generated
by the compression of the air be absorbed and carried off so as to reduce the air in
its compressed state to the same temperature as the surrounding atmosphere, or
nearly so, and the compressed air thus cooled be then allowed to expand back into
its original space or volume, but with so much less quantity of heat left to fill such
space or volume, a considerable lowering of the temperature will result. This well-
known principle is applied in all descriptions of machinery for refrigerating by the
compression, cooling down, and expansion of atmospheric air. The compression and
expansion being generally effected by means of two cylinders, one for compressing,
and the other for expanding, having their pistons and rods geared together, so that
the compressed air while expanding in the one cylinder is returning a portion of the
power employed in compressing it by assisting to drive the machine. To cool the

page_text: air while compressed by extracting the concentrated heat, it has hitherto been the
practice before passing the compressed air into and through the receiver and cooling
tank to inject water into the compressing cylinder, thus bringing the air and water
into direct contact, and in fact mixing them. The objection to this plan is that
the expanded cold air is charged with moisture which rapidly forms large quantities
of ice and snow, rendering the cold air unfit for direct application for most
refrigerating purposes. Heat is also abstracted from the compressed air by surface
contact with cold surfaces, such as metal pipes and water-filled vessels.
The objection to cooling by the outside application of water only is that in such
case, the air cylinders require lubrication by oil, rendering the air impure and unfit
for the purpose required.
According to my Invention, instead of the ordinary piston and cylinder used in
the cases herein-before referred to, I make both the compressing and expanding
cylinders of greater length than the stroke of the engine, and instead of one piston
I use two pistons on the same piston rod fixed thereon, thus dividing the cylinder
into thee parts, namely, the top, and bottom, and centre.
The compressing cylinder is surrounded with a water jacket, through which a
constant circulation of water is maintained, the water being first admitted into the
interior of the compressing cylinder between the two pistons, being the centre of
the cylinder through an opening on the top and about the middle of the cylinder,
and passing out through another opening or openings into the water jacket, or
elsewhere, such water in no case coming in direct contact, or mixing with the air in
the top or bottom of the cylinder. The expanding cylinder is supplied with water
in a similar manner; but in this case in place of the water jacket the expanding
cylinder is covered with a non-conducting lagging, and in order to prevent the
.water between the pistons in the cylinder from being frozen, its temperature may
be regulated and kept above freezing point by mixing with the water used a
sufficient quantity of the water heated by the compressing cylinder, or instead of
water in the expanding cylinder I use glycerine or chloride of calcium (Cao Clo)
dissolved in water, the proportions being fourteen parts of chloride of calcium to
eighty-six parts of water, or thirty parts of chloride of calcium to seventy parts of
water, or chloride of magnesium (Mg C¹, C¹, in the same proportions dissolved in
water as the chloride of calcium
My Invention further consists in and may be carried out by using compression
and expansion cylinders of the ordinary dimensions with a piston of the following
construction-I make the piston hollow with openings carried entirely through its
periphery between the packing or piston rings. Into the hollow piston I fix a pipe
turned on the outside and long enough to pass through a stuffing box in the
cylinder cover, and into a circulating pump cylinder which is fixed outside in such
a manner that at each stroke of the engine, the pipe works a single-acting ram
pump and forces the water or its substitute through into the hollow piston and
through the openings in its periphery, and coming into contact with the interior
surface of the cylinder, the water afterwards escaping through another pipe passing
through the same, or the opposite cylinder cover, or the pipes may be applied as
ram pumps at both ends of the cylinder.
In lieu of a single hollow piston the same object may be attained by using a
duplex piston separated so as to form a chamber into which the water can pass, and
at the same time be in contact with the inside surface of the cylinder.
In connection with these arrangements I employ the water pressure between the
pistons, or in the hollow piston to press the piston rings or packing outwards by
leaving openings under the piston rings or packing communicating with the water
space and regulating the pressure of the water or its substitute to the extent
requisite for tightening the rings
In lieu of the pipes before leterred to for supplying the interior of the piston, the
water or its substitute may be taken in through the piston rod which is made
hollow for the purpose.
.My.Invention further .consists in constructing the cylinder covers and water-.

page_text: containing piston of the compressing cylinder with concentric projecting water
spaces, the water spaces or projections on the piston fitting into the female spaces
formed by the concentric water spaces or projections on the cylinder covers.
By the means herein-before described the cylinders will be lubricated by water or
its substituto, and the compression cylinder cooled, avoiding the necessity of using
oil and the objectionable practice of using water in direct contact with the com-
pressed air for extracting the beat, thereby combining the advantages of the external
water cooling with those of the internal water cooling systems, and avoiding the
disadvantages of either.
In further carrying out my Invention I fix the compression and expanding
cylinder horizontally the one behind the other, and geared together by continuation
of the piston rod from the one to the other. The cylinders are set upon an iron
bed, forming at the same time the cooling tank or receiver for the air heated by
compression. On either side of the air cylinders I fix steam cylinders, forming a
pair of engines, geared in any suitable manner to the crank shaft, which is carried
in bearings on the bed or receiver, and geared direct to the air cylinders by crank and
connecting rod, or their equivalent The bed, being the cooling tank or receiver, is
formed into three compartments, the two end compartments formning compressed air
chambers, and the centre compartiment being the cooling tank, which is constructed
with a number of tubes passing through it connecting the air chambers, and round
which a circulation of cold water is maintained. The receiving air chamber is
divided in two separate portions by a central ring, so that the air when compressed
into the internal or central division has to pass through the inner set of tubes to the
front air chamber, returning through the outer set of tubes to the exterior sub-
division of the first air chamber, or vice versa. The circulation of the compressed
air is thus effected through the cooling tubes, and the heat generated by compression
is thus further absorbed and carried off.
The air being kept from direct contact with the water used for cooling, will be
free from moisture, except that generally contained in the atmosphere in the form of
watery vapour.
The combined action of compression and of the discharge of heat from the air will
tend to condense this watery vapour, and when all is thus discharged I carry off by
means of a trap or traps applied to the lowest parts of the compressed air chambers,
where this condensed moisture accumulates in the form of water.
The trap consists of a tube hanging vertically downwards, and closed at the
bottom by a valve weighted to open only when the pressure upon it exceeds the
proposed pressure in the air chambers. When sufficient water is collected in
the tube or trap to overcome by its additional weight the spring or otherwise
retained valve, the valve will open and allow the water to run out until the weight
is relieved sufficiently to allow the valve to close again.
To get rid of the remaining moisture in the air as far as possible, I apply in one
of the compressed air chambers, by preference the second receiving chamber, a wire-
work cradle, or other equivalent contrivance, filled with carbon, or baffle plates,
tubes, or plugs composed of carbon, which, besides absorbing any noxious particles
in the air by purifying the air, also absorbs the moisture from the air while still
under pressure, and consequently before such moisture can be precipitated in snow
or ice by the cold produced when the air is expanded, coke, pummice stone, cinders,
peat, charcoal, animal charcoal, vegetable charcoal, or other suitablo substance may
be used for absorbing the moisture; and I apply a door to the chamber in which
the absorbing substance is placed for convenience of removing and renewing it when
fully charged.
To apply this my Invention to, say, a meat safe or refrigerator, I convey a pipe
from the refrigerator to the inlet valves of the compressing cylinder, with a branch
and valve for the admission of external air as required. As the air is drawn from
the refrigerator, or from the outside, it is compressed into the receiving air chamber,
passing through the tubes in the cooling tank and through the absorbing apparatus
in. the second. air chamber, and back to the first air chamber, from which the

page_text: expanding cylinder is supplied, and from the expanding cylinder air is discharged to
the refrigerator in a cold dry state. After passing the air contained in the refri-
gerator through and through the apparatus until it is sufficiently cooled down, the
outer air is then taken in and dealt with in similar manner, the old air contained in
the refrigerator being allowed to pass out as the new cold air is passed in. By
means of a valve, or tap, or simple disengaging and engaging arrangement, the
expanding cylinder can be kept out of action until the required compression of air
is obtained in the receiver
By these means a continuous supply of pure cold air can be delivered in a suffi-
ciently dry state, and at a temperature which can be regulated at will by
regulating the speed of the apparatus and the circulation of the water in the
cooling tank.
That my Invention may be clearly understood I have hereunto annexed a Sheet
of Drawings illustrative thereof, marked with letters and figures of reference cor-
responding with those in the following explanation. In all the Figures the same
letters of reference where they occur indicate the same or corresponding parts.
Figure 1 represents a side elevation of a refrigerating or cold-producing machine
constructed in accordance with iny Invention, showing the cooling tank and the
two end chambers in section; Figure 2 is a plan of the same.
Figure 3 is a cross section through the cooling tank, and Figure 4 a cross section
through one of the end chambers A is the compressing cylinder, into which the
air passes from the refrigerator chamber through the pipe B, which has a valve
attached at C for the admission of the external atmospheric air whenever required.:
The compressed air passes through the pipe D to the chamber E, where it moots
the baffle plate E, at which point much of the water contained in the air will be
discharged and is drained off through the pipe and trap F, the air passing round to
the other side of the baffle plate E' in a much drier state, and thence through the
inner set of tubes G, G, to the chamber H. Here it impinges on the baffle plate H¹,
and any water discharged is drained off by a similar trap to that shown at F
placed at the point marked ✗. The compressed air, thus further dried, then passes
to the other side of the baffle plate H', then through the wirework cage I, filled
with carcoal or other suitable substance, which further absorbs the damp, and
any other deleterious particles in the air. From thence it passes over the baffle
plates H² to the outer annular space of the chamber, meeting the baffle plates H³, and
the wire gauze or perforated covering H, all of which assist in still further drying the
air and preventing the admission of dust to the outer range of pipes or tubes G¹, G¹,
through which the air returns to the chamber E², where it is received, dried, and
purified and cooled by the water surrounding the tubes G, G', in the tank G. When
the required pressure is obtained the air is admitted to the expansion cylinder J
(through the stop valve J¹) from the exhaust branch of which the expanded air
returns in an intensely cold, dry, and pure state, back to the refrigerator chamber.
The drain tubes above referred to may be placed at all the low points where the
moisture discharged from the compressed air is likely to collect.
The chamber H is provided with a hinged door K to enable the wirework cage
I to be readily removed and replaced when the carbon or other absorbing and puri-
fying material with which it is filled requires renewal, the compressed air in the
pipes and chambers being previously let off.
The air cylinders are driven by means of a pair of steam cylinders L, L¹, through
the crank shaft M, and the whole mounted on and carried by the cooling tank G³.
Figure 5 is a longitudinal section on an enlarged scale of the compression
cylinder, and Figure 6 a cross section of the end covers showing the inlet and
delivery valves. The valve chamber is divided by a central rib N, the inlet valves
being on the side N and the delivery valves on the side N'. These valve chambers
open into corresponding pockets on the top of the cylinder, which form a communi-
cation between the front and back valve chambers, and are provided with branches,
that on the side N being for the inlet and that on the side N₁ being for the delivery..
For convenience of illustration the section of the valve chamber at the side N, in

page_text: Figure 5, is taken through the bent dotted line a, b, in Figure 6, and the section
through the valve chamber at N' is taken through the line c, d. Through the
hollow pistons O a constant circulation of cold water is maintained by means of the
pump P, the check valve P¹, the pipe P2, through which the water passes to the
piston of the expansion cylinder Ps, and the discharge pipe P', Figures 1, 5, and 6.
By means of the cock on the end of the pipe P4, the pressure of the water may be
regulated so as to give any required outward pressure to the piston rings. The
water or non-freezing liquid circulating through the hollow pistons comes in
contact with the interior surface of the cylinders through the openings p, p, and
effects the necessary lubrication without coming into direct contact with the air
(with the exception of the thin surface film left by the traverse of the piston), and
without the use of oily or fatty lubricants.
Figure 9 shows another mode of internal cooling and water circulation without
pumping, the water being admitted through openings in the middle of the cylinder
between two pistons fastened to the same rod at sufficient distance apart to allow of
the full piston travel without over-running the openings through which the water
enters and passes out.
The cooling surface may be further increased by arranging the piston and covers
in the form shown by the dotted lines or by the corrugated surfaces shown in
Figure 10, or by a variety of other forms, the object of this part of my Invention
being to effect internal cooling and lubrication, while at the same time intercepting
the water or other lubricant from direct contact and mixture with the air as much
as possible.
Figures 7 and 8 are enlarged views of one end of the expansion cylinder, showing
the arrangement of the air admission and exhaust valves
In this part of my
Invention I have adopted the principle of a valve rising and falling upon a seating
in preference to any of the forms of sliding valves, which require much lubrication
not needed in the rising and falling valve. Qis the inlet valve, which is raised
and lowered by the action of the cams R, R¹, on the shaft S, driven by the gearing
S' (Figure 2). The cams R, R¹, are loose on the shaft, and so arranged that by
partly turning them on the shaft, so as to lengthen or shorten the raised portion of
the cam, the inlet valve Q may be made to shut and cut off the admission of air to
the expansion cylinder at any required point in the stroke.
The grade of cut-off and expansion for which the expansion cylinder is set, will,
by regulating the rate at which the compressed air is used, also tend to regulate the
degree of pressure attained in the compression cylinder.
The exhaust valve T is opened by means of the cam T¹, on the same shaft S, and
returned to its seat by the spring T2. The other end of the cylinder is governed by
a similar pair of valves actuated in the same manner by means of cams on the same
shaft.
"
In witness whereof, I, the said John Sturgeon, have hereunto set my hand
and seal, this Nineteenth day of June, in the year of our Lord One
Witness,
FREDERICK JOHN CHEESBROUGH,
Of 15, Water Street,
Liverpool,
Consulting Engineer and Patent Agent.
JOHN STURGEON. (L.S.)