IMPROVEMENTS IN REFRIGERATING MACHINES, AND IN PART APPLICABLE TO AIR COMPRESSORS, PUMPS, AND GAS MOTORS."
Year: 1881

page_text: LETTERS PATENT to Louis Sterne, Dugald Clerk, and James Baird Handyside,
'
all of Glasgow, in the County of Lanark, North Britain, Engineers, for an
Invention of "IMPROVEMENTS IN REFRIGERATING MACHINES, AND IN PART
APPLICABLE TO AIR COMPRESSORS, PUMPS, AND GAS MOTORS."
PROVISIONAL SPECIFICATION left by the said Louis Sterne, Dugald Clerk,
and James Baird Handyside at the Office of the Commissioners of Patents on
the 15th August 1881.
LOUIS STERNE, DUGALD CLERK, and JAMES BAIRD HANDYSIDE, all of Glasgow,
in the County of Lanark, North Britain, Engineers. "IMPROVEMENTS IN
REFRIGERATING MACHINES, AND IN PART APPLICABLE TO AIR COMPRESSORS,
PUMPS, AND GAS MOTORS."
This Invention relates to refrigerating machines of the kind in which air is
compressed, cooled in the compressed state, and reexpanded in a manner to return
part of the power employed for compressing it, and a part of the improvements is
advantageously applicable to air compressors, pumps, and gas motors.
In carrying out the Invention in the case of a refrigerating machine the cooling
of the compressed air is effected by means of conduction through metallic shells or
partitions which are themselves cooled by water. The air is compressed at two or
more stages, and is to some extent cooled between the stages. The compression is.
carried to a higher pressure than has hitherto been adopted in refrigerating machines,
and a kind of cooling apparatus is employed which, owing to its very efficient
action combined with the high pressure of the compressed air, can be made of a
very moderate size. The cooling apparatus also removes so much of the moisture
from the compressed air that no trouble is experienced from ice or excess of snow or
frozen particles when the air is reexpanded.
In one general arrangement or modification of the refrigerating engine as designed
for moderate sizes four horizontal double-acting cylinders are placed in a line, their.

page_text: several pistons being on one rod which is connected to a crank shaft carrying one
or two flywheels. The cylinder at one end is a steam cylinder, by means of which
the power for working the machine is obtained; and the cylinder at the other end
is that in which the air is reexpanded and a part of the power returned. The two
intermediate cylinders are for compressing the air, and this air after being
compressed to a certain extent in one cylinder passes through a large pipe, or vessel,
or passage to the other cylinder, in which it is further compressed, for example, to
a pressure of 90 pounds or upwards to the square inch. The compressing cylinders
and the 'pipe or passage between them are surrounded by jacket spaces, through
which water is made to flow continuously for the purpose of removing some of the
heat due to the compression. The inlet and outlet check valves of the compressing
cylinder are conical-seated disc valves, and in order to make them close quickly
springs are applied to them, whilst to prevent them from striking injuriously and
making a noise or rattling when closing they are provided with dash-pots or air-
cushion appliances. The stem or spindle of each valve passes into a small chamber
and has a piston fixed on it which works in the, chamber, in which also the spring
is applied. When the valve closes the piston on its stem approaches one end of
the chamber, which part is turned cylindrical to nearly fit the piston, but at a short
distance from the end 'the sides are recessed, narrow cylindrical strips being
however left to guide the piston. When the valve opens the piston is moved out
of the confined cylindrical part into which air gets, and this air acts as a cushion
when the piston moves back into that part on the closing of the valve. These
cushioning appliances are in immediate connection with the valves, and have no
connection with external working parts.
The various rubbing surfaces in the machine, or those of them for which it is
important to have more complete and well regulated lubrication, are lubricated by
The
means of apparatus arranged so that its manner of working is always seen.
lubricant is contained in a cup, having at its bottom a valve leading to a spout, and
it drops from this spout so as to be seen into a passage leading down to the rubbing
surfaces. The valve is opened intermittently by a cam movement due to the
moving part itself, and the extent of opening can be regulated by a screw.
The cooling apparatus is arranged so that the compressed air may pass through
a lengthened course and over an extensive surface, whilst the cooling water is passed
through a similar course, but in an opposite direction. In one modification the
cooling apparatus consists of a combination of vessels, which may be of castiron, and
each of which is in the form of a cylinder, with one end closed and with a flange on
the other end. The cylinders are of graduated sizes, and are placed one within
the other, being fixed together by their flanged ends, and being shaped to leave
thin spaces between each other. Ribs are also formed on the cylinders to cause the
air and water to flow in tortuous directions through the spaces, and so increase the
length of course. In the space between the outermost vessel and the next there is
water which has passed through the other water spaces, and the compressed air
enters by a central pipe at one end into the second or next inner space. The water
and air are directed by suitable passages so as to pass through alternate spaces, and
the cooled air finally passes off by a central pipe at the end of the apparatus
opposite to that at which it entered. As the compressed air becomes cooled in
passing through the apparatus, moisture is deposited from it as water for which a
suitable outlet or outlets are provided. It may either be blown out through a
small regulated stop cock, or it may be separated by means of a trap valve, or a
chamber may be provided in which it may be slowly collected.
After the compressed air has passed through the cooler, hereinbefore described, it
may in some cases be advantageously passed in contact with metallic surfaces cooled
on their other sides by what may be termed the waste cold air returning from
the chamber in which the cooled air is distributed. This supplementary process is
not however required for abstracting more moisture from the air, as the moisture
is sufficiently abstracted by the water-cooled apparatus hereinbefore described.

page_text: In a second general arrangement or modification of the engine, and suitable for
larger sizes, a shaft with cranks at right angles is employed, and the cylinders are
arranged in two parallel lines, the pistons of the steam cylinder and one of the
compressing cylinders being on one rod and the other rod having on it the pistons
of the other compressing cylinder and the reexpansion cylinder. In this arrange-
ment the various cylinders may be proportioned so as to make the strains on the
machinery comparatively small.
The parts of the hereinbefore described apparatus which are applicable to air
compressors, pumps, and gas motors are the check valves combined with their
springs and cushioning appliances, and also the lubricating apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Louis Sterne, Dugald Clerk, and James Baird Handyside in the
Great Seal Patent Office on the 14th February 1882.
LOUIS STERNE, DUGALD CLERK, and JAMES BAIRD HANDYSIDE, all of Glasgow,
in the County of Lanark, North Britain, Engineers. "IMPROVEMENTS IN
REFRIGERATING MACHINES, AND IN PART APPLICABLE TO AIR COMPRESSORS,
PUMPS, AND GAS MOTORS."
Our said Invention relates to refrigerating machines of the kind in which air is
compressed, cooled in the compressed state, and reexpanded in a manner to return
part part of the power employed for compressing it, and a part of our improvements
is advantageously applicable to air compressors, pumps, and gas motors.
In carrying out our Invention in the case of a refrigerating machine the cooling
of the compressed air is effected by means of conduction through metallic shells or
partitions which are themselves cooled by water. The air is compressed at two or
more stages, and is to some extent cooled between the stages. The compression is
carried to a higher pressure than has hitherto been adopted in refrigerating
machines, and a kind of cooling apparatus is employed which owing to its very
efficient action combined with the high pressure of the compressed air can be made
of a very moderate size. The cooling apparatus also removes so much of the
moisture from the compressed air that no trouble is experienced from ice or excess
of snow or frozen particles when the air is reexpanded.
The inlet and outlet check valves of the compressing cylinders are conical-seated
disc valves, and in order to make them close quickly springs are applied to them,
whilst to prevent them from striking injuriously and making a noise or rattling
when closing they are provided with dash-pots or air-cushion appliances.
The
The various rubbing surfaces in the machine, or those of them for which it is
important to have more complete and well regulated lubrication, are lubricated by
means of apparatus arranged so that its manner of working is always seen.
lubricant is contained in a cup having at its bottom a valve leading to a spout,
and it drops from this spout, so as to be seen, into a passage leading down to the
rubbing surfaces. The valve is opened intermittently by a cam movement due to
the moving part itself, and the extent of opening can be regulated by a screw.
The parts of our improved apparatus which are applicable to air compressors,
pumps, and gas motors are the check valves combined with their springs and
cushioning appliances, and also the lubricating apparatus.
And in order that our said Invention and the manner of performing the same
may be properly understood, we hereunto append four Sheets of explanatory
Drawings to be hereinafter referred to and representing a modification of our
improved refrigerating machines.
Figure 1 on Sheet 1 of the accompanying Drawings is a side elevation; Figure 2
on Sheet 2 is a horizontal section; and Figure 3 on Sheet 3 is a transverse vertical
section; Figures 4 and 5 on Sheet 4 are a longitudinal section and an end view of
the apparatus for cooling the compressed air; Figures 6 and 7 are enlarged sections
of the inlet and outlet check valves; and Figure 8 shows such valves as arranged
for a gas motor, whilst Figure 9 is an enlarged section of the lubricator. In these
Drawings the same reference numerals are used to mark the same or like parts
wherever they are repeated.
In one general arrangement or modification of our improved refrigerating engine,
as designed for moderate sizes, four horizontal double-acting cylinders are placed in
a line, their several pistons being on one rod which is connected to a crank shaft
carrying one or two flywheels. A second general arrangement or modification of
the engine, and which is the one shown by way of example in the accompanying
Drawings, is suitable for larger sizes, and in this modification a shaft 10 with
cranks at right angles to each other is employed, and the cylinders 11, 12, 13, 14,
are arranged in two parallel lines, the pistons of the steam cylinder 11 and one of

page_text: the compressing cylinders 12 being on one rod 15, and the other rod 16 having on
it the pistons of the other compressing cylinder 13 and the reexpansion cylinder 14.
The crank shaft 10 carries a single flywheel 17 on it between its two cranks, and
the various cylinders are by preference proportioned so as to make the strains
nearly balance each other.
One 11 of the two cylinders near the crank shaft is a steam cylinder, by means
of which the power for working the machine is obtained, and the other cylinder 14
near the crank shaft is that in which the air is reexpanded and a part of the power
returned. The two other cylinders 12, 13, are for compressing the air, and this air
after being compressed to a certain extent in one cylinder 12 passes through a
large pipe 18, or it might be a vessel or passage, to the other cylinder 13, in which
it is further compressed, for example, to a pressure of 90 pounds or upwards on the
square inch. The compressing cylinders 12, 13, are surrounded by jacket spaces 19,
through which cold water is made to flow continuously for the purpose of removing
some of the heat due to compression, and the intermediate pipe 18, or vessel or
passage, may be cooled in a similar way. The air from the cold room (or from any.
other space) is led by a pipe 20 to a passage 21 formed along the bottom of the first
compressing cylinder 12, and communicating with inlet valves 22 at each end of
the cylinder, and the outlet valves 23, also at the ends of the cylinder, communicate
with a passage 24 formed along the top of the cylinder and communicating with
the pipe 18, by which the partly compressed air passes to the second compressing
cylinder 13. The second compressing cylinder 13 has a similar arrangement of
passages and valves, an upper passage 25 communicating with inlet valves 22 and
a lower passage 26 leading the air from outlet valves 23 to a pipe 27, which conveys
the air to the first 28 of two coolers. From the first cooler 28 the air passes by a
pipe 29 to the second cooler 30, and from this it proceeds by a pipe 31 to the
admission valve chest 32 of the reexpansion cylinder 14.
In the horizontal section, Figure 2, one inlet valve 22 and one outlet valve 23 is
shown at one end of each of the compressing cylinders 12, 13, whilst at the other
ends of these cylinders are shown the sockets into which the inlet and outlet valves,
each in its box, are fixed by screwing, and the valves in their boxes are shown
enlarged in Figures 6 and 7. Each inlet valve 22 is contained in a box 33 having the
valve seat formed on it, and the stem or spindle 34 of the valve passes into a small
chamber 35 formed in the box, and has a piston 36 fixed on it, which works in the
chamber 35 in which also the spring is applied. When the valve 22 closes the piston
36 on its stem 34 approaches one end of the chamber 35, which part is turned
cylindrical to nearly fit the piston, but at a short distance from the end the sides are
recessed, narrow cylindrical strips being however left to guide the piston. When
the valve 22 is opened the piston 36 is moved out of the confined cylindrical
part, into which air gets, and this air acts as a cushion when the piston moves
back into that part on the closing of the valve. A cover 37 is screwed upon the
outer end of the box 33 and affords convenient access to the piston and spring. In
the case of the outlet valve 23, Figure 7, the valve having to reach its seat from
the inside, the chamber 35 for the piston 36, and the spring is formed in a separate.
piece 38, which is screwed into the box 33; the other parts are substantially the
same as in the case of the inlet valve 22. Figure 8 shows both an inlet valve 22
and an outlet valve 23 of our improved construction as applied to a gas motor of
the kind described in the Specification of Letters Patent granted to Dugald Clerk,
one of us, and numbered 1089 of 1881. In this application however of the inlet
valve 22 the spring is not required, the weight of the valve 22 and piston 36 being
sufficient. Our improved arrangement of check valves is applicable to pumps of
various kinds, the improved construction allowing of a high speed of working
without rattling or uncertainty of action. It is important to notice that the
cushioning appliances are in immediate connection with the valves and have no
connection with external working parts.
The two coolers 28, 30, are alike in construction, one of them being shown.
enlarged in Figures 4 and 5. This cooling apparatus is arranged so that the:

page_text: compressed air may pass through a lengthened course and over an extensive
surface, whilst the cooling water is passed through a similar course but in an
opposite direction. The apparatus consists of a combination of vessels 41, 42, 43,
44, 45, 46, which may be of castiron, and each of which is in the form of a cylinder
with one end closed and with a flange on the other end. The cylinders are of
graduated sizes and are placed one within the other, being fixed together by their
flanged ends and being shaped to leave thin spaces between each other. Ribs are
also formed on the cylinders or on some of them, as at 47, 48, to cause the air and
water to flow in tortuous directions through the.spaces and so increase the length
of course. In the space between the outermost vessel 41 and the next 42 there
is water, which has passed through the other water spaces, namely, that between
the vessels 43 and 44 and between the vessels 45 and 46, having entered by a
pipe 49, and leaving by a pipe 50. The compressed air enters by a central inlet
51 at one end into the second space between the vessels 42 and 43, next passes
through the space between the vessels 44 and 45, and afterwards through the
innermost vessel 46. In this last vessel 46 a midfeather 52 causes the air to go
to the inner end of the vessel and return thence to the outlet 54. The water and
air thus pass through alternate spaces, being directed from space to space by
suitable passages, those for the air being seen in section at 55 and 56 in Figure 4
and indicated by dotted lines in Figure 5, whilst those for the water consist of
channels formed in suitable positions across the flange joints, as indicated by dotted
lines at 56 and 57 in Figure 4. As the compressed air becomes cooled in passing
through the apparatus moisture is deposited from it as water, for which a suitable
outlet or outlets are provided. It. may either be blown out through a small
regulated stop cock, or it may be separated by means of a trap valve; or a chamber
may be provided in which it may be slowly collected.
After the compressed air has passed through the cooling apparatns hereinbefore
described it may in some cases be advantageously passed in contact with metallic
surfaces, cooled on their other sides by what may be termed the waste cold air
returning from the chamber in which the cooled air is distributed. This supple-
mentary process is not however required for abstracting more moisture from the
air, as the moisture is sufficiently abstracted by the water-cooled apparatus herein-
before described.
The reexpansion cylinder 14 is by preference provided, as shown, with separate
admission and exhaust valves, and the admission valves 58 have adjustable cut-off
valves 59 working on their backs to admit of the degree of expansion being
regulated or varied. The exhaust valves 60 are simple slides or plates which are
kept against their ports by fixed outer guides 61. The exhaust ports 62 are made
as direct and short as possible, and have a slightly increasing width towards their
outer parts, which renders them less liable to be obstructed by snow or frozen
particles.
Our improved lubricator, which is shown separately in vertical section in
Figure 9 on Sheet 4 of the accompanying Drawings, comprises a cup 63 to contain
a liquid lubricant and parts for adjusting and working a valve 64, which controls
an outlet in the bottom of the cup. The outlet at the bottom of the cup 63 com-
municates with a spout 65, from which the lubricant drops in a visible manner, and
a passage or channel is provided to receive the drops and lead them to the surface
to be lubricated. The valve 64 is formed on a spindle 66, the bottom end of which
is screwed into a small block 67 fitted so that it can slide vertically without turning
in the bottom end of a hollow tube 68, forming the stem or support of the lubricator.
A. helical spring is applied within the tube 68, so as by pressing down on the
block 67 to tend to keep the valve 64 closed; and the valve is opened inter-
mittently by the action of any suitable reciprocating or rotating cam-like part on
the block 67. For example, if the lubricator is applied to the guide for the slide
block of the piston-rod crosshead, the tubular stem 68 may be inserted in a socket
formed for it through the top of the guide, and the slide block may be formed with
a slight depression at a part passing to and fro under the block 67. When the

page_text: depression is immediately under the block 67 the spring will force that block down
into it and the valve 64 will be closed, but when the higher parts of the slide block
are passing they will raise the block 67 and open the valve 64. The valve
spindle 66 extends up to the cover 69 of the lubricator cup 63, and its upper end is
squared and works in a square hole in the cover. The cover 69 is fixed by means
of an outer ring 70, which is screwed on the top edge of the lubricator cup; and
when this ring 70 is loosened the cover 69 can be turned round, and when turned
will turn the spindle 66. In this way the spindle 66 may be screwed to a greater
or less extent into the block 67, and the further the spindle is screwed into the
block the less will be the effective action of any cam surface on the block, and the
smaller the extent of opening of the valve 64, and vice versa. The quantity of
lubricant supplied can thus be regulated with great nicety, and will be proportional
to the speed of working, as the valve 64 is opened intermittently by the moving
part.
Having thus particularly described our said Invention and the manner of per-
forming the same, we have the state that we do not restrict ourselves to the precise
details herein described or delineated, but that what we believe to be novel and
original, and claim as the Invention secured to us by and in terms of the herein-
before in part recited Letters Patent is,―
1. The arrangement or combination of parts forming a refrigerating machine in
which air is compressed at two or more successive stages with or without cooling
between the stages, and is cooled by passing in a single stream or small number of
streams through an elongated course in contact with metallic surfaces cooled by
water passing in the opposite direction, substantially as hereinbefore described.
2. The general arrangement or combination of parts, hereinbefore described with
reference to Figures 1, 2, and 3 of the accompanying Drawings.
3. The combination in a refrigerating machine of one or more cylinders for com-
pressing air at one or more stages to a pressure of 90 pounds per square inch or
upwards with cooling apparatus in which the compressed air passes in a single
stream or small number of streams through an elongated course in contact with
metallic surfaces cooled by water passing in the opposite direction, substantially as
hereinbefore described.
4. The arranging or combining together of the parts of apparatus for cooling
compressed air, substantially in the improved manner hereinbefore described with
reference to Figures 4 and 5 of the accompanying Drawings.
5. The combination with check valves for air compressors, pumps, or gas motors,
of springs tending to close them, and of pistons and air-cushion chambers to prevent
concussion when closing, substantially as hereinbefore described.
6. The arranging or combining together of the parts of lubricators, substantially
in the improved manner hereinbefore described with reference to Figure 9 of the
accompanying Drawings.
In witness whereof, I, the said Dugald Clerk, on behalf of the said Louis
Sterne, myself, and James Baird Handyside, have hereunto set my hand
and seal, this Thirteenth day of February, in the year of our Lord One
thonsand eight hundred and eighty-two
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
DUGALD CLERK. (L.S.)