IMPROVEMENTS IN AND RELATING TO APPARATUS FOR COMPRESSING AND COOLING AIR FOR REFRIGERATING AND OTHER PURPOSES
Year: 1884

page_text: I, GEORGE THOMAS HARRAP of 35 Upper Tollington Park in the Parish of
Hornsey in the County of Middlesex, Engineer, do hereby declare the nature
of my invention for IMPROVEMENTS IN AND RELATING TO APPARATUS FOR
COMPRESSING AND COOLING AIR FOR REFRIGERATING AND OTHER PURPOSES; to
be as follows:-
In mechanical refrigerators for ships or vessels carrying perishable articles, or for
cooling air on shipboard, or in any other places, the question of economy of space
and weight is an important feature.
'
.
In the manufacture of these refrigerators it is also necessary to produce strong
and simple parts of light weight, and easily understood by ordinary mechanics. It
is also best to pass the strains from one cylinder (or cylinders) to the other
(or others) through as few parts as possible; both for wear and for the production
of a light machine.
.
By my invention I propose to greatly reduce the space usually occupied by this
class of machinery, and to make it simple and easily understood.
I place the air compressing cylinder (with its valve boxes preverably on one,
or both sides) above the air expansion cylinder and steam, or motor, cylinder ;
the expansion cylinder preferably with its valve box underneath; and the steam
cylinder the same as the air expansion cylinder, or arranged the same as an
ordinary steam cylinder, with its valve chest in any convenient position.
The air compression cylinder (which may be water jacketed and have water
jacket covers of any suitable design) I prefer to place sloping down towards the
crankshaft, and the two other cylinders sloping up towards the shaft. All the
cylinders are bolted to the end-of one frame, which is made up of two side
members running direct from the cylinders to the crank shaft bearings, suitably
tied to one another, and may carry the guide bars, valve gear, pumps &c. This
frame is bolted to the cooler boxes which take none of the working strains.
All the cylinders work on to one crank pin, and at such an angle as to give a
good resultant turning effort. I prefer to have a connecting rod single at both

page_text: ends for the air compression cylinder; and to have the steam (or motor) and air
expansion cylinder piston ro is connected to one crosshead, and have a connecting
rod double at both ends (working on this) so as to take the strains from close to
the slide blocks to that part of the crank pin on each side of the compression
connecting rod.
The crank may be a "closed" or sweep crank, built up or forged with the shaft,
and carrying the flywheels between or outside the frame; or the flywheels may be
fixed to two separate pieces of shaft, and carry the crank pin in suitable bosses
formed in them.
In one arrangement of valves I use plate valves to both sets of valves for the air
compression cylinder, which may be adjustable for length if necessary. The plate
valves for the outlet of the air from the compression cylinder are two in number,
a main valve having a port near each end, with a plain plate on the back to open
the ports of the former at the right time; the main valve closing the cylinder port
when the air is being drawn into the cylinder at the beginning of the stroke. For
the inlet valve in the compression cylinder I use a plain plate which allows the air
to pass by the ends of it into the cylinder ports.
These valves are held to their places by means of truncated lightened pistons
fitted with packing rings, and carried from the valve box, and having, if necessary,
a flange at the outer end to increase the bearing surface on them and the back of
the valve. Pressure may be admitted to them (by air or steam) by small pipes
from any convenient position; they may be fitted with coil or flat springs, with or
without screw adjustment. The spring and screw adjustment may be used by
themselves. I do not use these pistons as air or steam passages thus getting a
greater wearing surface on their faces than otherwise. The piston may also be
placed on the "cut-off" valve of the compression cylinder, working against the
valve box cover.
In another arrangement of valves for the inlet and outlet of the air compression
and expansion cylinders, I use a main valve without an "exhaust" chamber, but
with an inlet (or outlet) port near each end, the exhaust (or inlet) air passing by
the end of this valve from (or into) the cylinders. On the back of the main valve
I place an ordinary D shaped valve for distributing (or receiving) the air to (or
from) the main valve, and which receives (or discharges) from (or into) the branch
pipe on one side. This side is left open for this purpose, and forms also a bearing
surface around the branch pipe aperture to prevent escape of air to or from
the same.
The back and top side of this auxillary valve may contain, or work against,
truncated pistons as previously described, or any of the valve arrangements may
be balanced by suitable means; or any suitable arrangement of auxillary valve
may be used.
In another arrangement of valves for the air expansion cylinder, I use a main
valve having an inlet port at each end, with a ported chamber between them
working over a port similar to an ordinary "exhaust port" communicating with
the branch pipe. The air is distributed from this centre port to the end ports (and
so to the cylinder) by means of a hollow valve on the back of the main valve.
The exhaust from the cylinder passes the ends of the main valve.
.
By the last arrangement of air compression cylinder valves there is no actual
necessity for springs or plates to the valves, the pressure being in the valve box
and so keeping the valves on their faces. In all the arrangements however,
I make the outlet ports of the said expansion cylinder so that they cannot easily
choke (as they look downwards, and are straight and short) and are easily cleaned.
If an air compressing machine only is required I place another motor cylinder in
the place of the air expansion cylinder. This second cylinder may compound with
the first.
The refrigerator machine may also be compounded by putting one or more steam
(or motor) cylinders alongside, underneath or over the other steam, motor, or air
cylinders, and coupled to the same crosshead as any of the other cylinders, or

page_text: working on to a separate crank (or cranks) at any suitable angle to the first crank,
to obtain a better turning effort. Or this cylinder, or cylinders, may be put at the
back of any of the other cylinders, and worked from the same piston rod.
For the valve arrangements herein described I can use two or more eccentrics.
These arrangements of compression cylinder valves may be used for a hot-air
engine or any other motor, or machine, requiring the compression of air.
I, GEORGE THOMAS HARRAP, Engineer, of 35 Upper Tollington Park in the
parish of Horusey in the County of Middlesex do hereby declare the nature of my
invention for IMPROVEMENTS IN AND RELATING TO APPARATUS FOR COMPRESSING
AND EXPANDING AIR FOR REFRIGERATING AND OTHER PURPOSES and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
In mechanical refrigerators for ships or vessels carrying perishable articles, or for
cooling air on shipboard, or in any other places, the question of economy of space,
and weight is an important feature.
In the manufacture of these refrigerators it is also necessary to produce strong
and simple parts of light weight easily understood by ordinary mechanics. It is
also best to pass the strains from one cylinder (or cylinders) to the other (or others)
through as few parts as possible; both for wear and for the production of a light
machine.
By my invention I propose to greatly reduce the space usually occupied by this
class of machinery, and to make it simpler and easier understood.
And in order that my said invention may be understood and carried into
practical effect, I have caused to be annexed to this specification the accompanying
sheets of drawings, to the figures and letters of reference thereon indicated I now
refer.
Fig. 1. is an end view, Fig. 2. a side view, and Fig. 3. a plan of my refrigerating
machine. Fig. 4. is a section of a compression cylinder, or pump, and valves, and
Fig. 5. is a plan of the same; Figs. 9. and 10. are sections of another arrangement
of valves for the same purpose. Fig. 6. is a section of valves for an expansion
cylinder; and Figs. 7. and 8. are sections of another form of valves for the same
purpose.
I place the air compressing cylinder A (Figs 1. 2. 3.) [with its valve box, or
boxes, preferably on one or both sides] above the air expansion cylinder B and
steam (or motor) cylinder C; the expansion cylinder preferably with its valve box
underneath; and the steam cylinder the same as the air expansion cylinder, or
arranged the same as an ordinary steam cylinder, with its valve chest in any
convenient position.
The air compression cylinder A (which may be water jacketed and have water
jacket covers of any suitable design) I prefer to place sloping down towards the

page_text: ·
crankshaft, and the two other cylinders B, C, sloping up towards the shaft. All the
cylinders are bolted to the end of one frame E, which is made up of two side
members running direct from the cylinders to the crank shaft bearings, suitably
tied to one another, and may carry the guide bars H, valve gear, pump &o. This
frame is bolted to the cooler boxes F which take none of the working strains. D is
a snow box of suitable construction. .
->
All the cylinders work on to one crank pin I, and at such an angle as to give a
good resultant turning effort. I prefer to have a connecting rod J single at both
ends for the air compression cylinder; and to have the steam (or motor) and air
expansion cylinder piston rods connected to one crosshead K*, and have a con-
necting rod K double at both ends (working on this) so as to take the strains from
close to the slide blocks to that part of the crank pin on each side of the compression
cylinder connecting rod J.
The crank may be a "closed" or "sweep crank," built up or forged with the
shaft, and carrying the flywheels G between, or outside, the frame; or the
flywheels G may be fixed to two separate pieces of shaft, and carry the crank pin
in suitable bosses formed in them.
"
Figs. 4 and 5, show one arrangement of valves, where I use plate valves A. A. A
to both sets of valves for the air compressing cylinder, or pump, A, which can be
made adjustable for length if necessary. The plate valves A. A³. for the outlet of
the air from the compression cylinder are two in number, a main valve A* having
a port A³ near each end, with a plain plate A³ on the back to open the ports of the
former (A) at the right time; the main valve A closing the cylinder port A¹ when
air is being drawn into the cylinder (or at the beginning of the stroke). For the
inlet valve A, to the compression cylinder, I use a plain plate also, which allows
the air to pass by the ends of it into the cylinder ports A.
These valves may be held to their places by means of springs A6 or A8, the latter
in conjunction with the tightening screw A carried by a plate A10 bolted to the
valve box; or any other suitable arrangement may be used for the same purpose.
Figs 9 and 10, are anotlier arrangement of valves for the inlet and outlet of
the air compression cylinder or pump, where I use a main valve A without an
"exhaust "chamber, but having the centre cut away to form one large inlet
port A, and having an outlet port A³ near each end. A is the cylinder port.
On the back of the main valve A' I place an ordinary D shaped valve A³ for
distributing the air to the main valve A from the branch pipe A¹ on one side.
This side is left open for this purpose, and forms also a bearing surface arround the
branch pipe aperture A¹ to prevent escape of air into the same from valve box or
chamber.
Figs 7 and 8, show an arrangement of valves for the inlet and outlet of the air
expansion cylinder where I use a main valve B7 without an "exhaust" chamber,
but with a lightening chamber B10, and having an air inlet port B³ near each end,
the outlet air passing by the end of this valve from the cylinder ports B'. On the
back of this main valve B' I place an ordinary D shaped valve B8, having a central
chamber B, and (preferably) two ports B³ for distributing the air to the ports B³
of the main valve B', and which receives the air from the branch pipe B2 on one
side. This side is left open for this purpose, and forms also a bearing surface
arround the branch pipe aperture B9 to prevent escape of air from the same into
the valve box, or chamber.
In the arrangements described with reference to Figs 7, 8, 9. and 10, the
auxillary valves A and B may be kept to their places, or be balanced, by means of
the plates U. T. and screws, and openings as at B6, as shown in Figs 7 and 8, or by
any other suitable arrangement.
Fig 6 is another arrangement of valves for the air expansion cylinder, where I
use a main valve B7 having an inlet port B³ at each end, with a ported
chamber B between them, working over a port B2 similar to an ordinary
." exhaust port," communicating with the inlet branch pipe. The air is dis-
tributed from the centre ports B₁ to the end ports B³ (and so to the cylinder

page_text: the ma
ports B') by means of a noшow valve D on the back oL
exhaust from the cylinder ports B₁ passes the ends of the main valve B'. The
auxillary valve B' may be kept to its place, or balanced, by means of a truncated
lightened piston O, fitted with a packing ring P, and carried from the valve box by
means of the bossed plate N, and having (if necessary) a flange at the outer end o
to increase the bearing surface on the back of the valve. Pressure may be
admitted to the piston O (by air or steam) by a small pipe entering at Q from any
convenient position, the piston may be fitted with a coil spring R, or a flat spring;
with or without screw adjustment as shown in Fig 4 A8 A9 A10. The spring and
screw adjustment may be used by themselves. I do not use these pistons as air or
steam passages thus getting a greater wearing surface on their faces than otherwise.
The piston may also be placed on the "cut off" or auxillary valve and work
against the valve box cover. Any of the arrangements of valves herein described
may be fitted with this piston arrangement, or with any other suitable arrangement
for the same purpose.
By the arrangement of valves for the air compression cylinder described herein
with reference to Figs 9 and 10, there is no actual necessity for springs or plates to
the valve A, the pressure being in the valve box and so keeping the valves to their
faces.
In both the arrangements of valves for the air expansion cylinder, described
herein with reference to Figs 6. 7 and 8, the cylinder ports B', which are the outlet
and inlet ports alternately, I make straight and short and place the cylinder pre-
ferably for them to look downward, so that they cannot easily choke, and are easily
cleaned.
If an air compressing machine only is required, I place another motor cylinder
in the place of the air expansion cylinder. This second cylinder may compound
with the first.
The refrigerator machine may also be compounded by putting one or more steam
(or motor) cylinders, under, at the side of, or over the other steam, motor, or air
cylinders, and coupled to the same crosshead as any of the other cylinders, or
working on to a separate crank, or cranks, at any suitable angle to the first
crank, to obtain a better turning effort. Or this cylinder, or cylinders, may be
put at the back of any of the other cylinders, and work on the same piston rod
extended.
For the valve arrangements herein described I can use two or more eccentrics to
the machine.
These arrangements of air compression cylinder (or pump) valves may be used
for a Hot-air engine or any other motor, or machine, requiring the compression of
air with or without gas.
The action of the combined apparatus herein described as a refrigerating machine
in its capacity of compressing, expanding and cooling air is similar to that of such
varieties of apparatus now in use.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
Firstly-In apparatus for compressing, or expanding, air (or both), the arrange-
ment of three cylinders (supplemented as described), one above and two below (or
vice versa), at the end of a frame, and sloping towards the crank shaft, and
working on one crank pin, substantially as and for the purposes herein described
with reference to Figs 1. 2. and 3.
Secondly. In apparatus for compressing air the arrangement of slide valves
operating substantially as and for the purposes herein described with reference to
Figs 4 and 5.
Thirdly In apparatus for compressing air the arrangement of slide valves
operating substantially as and for the purposes herein described with reference to
Figs 9 and 10.

page_text: Fourthly In apparatus for expanding air the arrangement of slide valves
operating substantially as and for the purposes herein described with reference to
Figs 7 and 8.
Fifthly In apparatus for expanding air the arrangement of slide valves
operating substantially as and for the purposes herein described with reference
Fig 6.
Sixthly -In apparatus for compressing, or expanding, air (or both), the
truncated piston with, or without, packing ring, spring and screw adjustment,
applied to the auxillary valves which truncated piston may be stationary or
carried by the auxillary valve and operating substantially as and for the purposes
herein described with reference to Fig. 6.
In witness whereof I the said George Thomas Harrap have hereunto set my
hand and seal this twenty-second day of October in the year of our Lord
one thousand eight hundred and eighty four.