Year: 1886

page_text: Date of Application, 31st Aug., 1886.
Complete Left, 25th May, 1887.
Complete Accepted, 28th June, 1887.
I DAVID GREIG of Leeds in the County of York Engineer do hereby declare
nature of this invention to be as follows:-
ΑΠ
These improvements relate in the first place to the cooling of the air during
compression, and are specially applicable to vertical air compressors of the single
acting type.
Heretofore it has been customary to cool the air during compression either by
injection of water into the cylinder, or by water circulation through a jacket
surrounding the cylinder, or through a hollow piston and rod, working in a horizontal
double acting cylinder. Water injection is, however, objectionable as the air becomes
saturated and this increases the tendency to freezing in the motor engines driven by
the compressed air. A jacket surrounding the cylinder only cools the outer film of
air in the cylinder immediately in contact therewith and hardly affects the interior
body of the air. Moreover the cooling surface in contact with the air continually
diminishes as the piston advances, at the very time that the heat of compression
increases and cooling is most needed. A hollow water jacketted piston and rod is
objectionable on account of complication, and the increased diameter of rod required.
The horizontal position is unfavorable for inducing a proper circulation of the
heated air.
According to my improvements I place the air cylinder vertical, the single acting
piston or ram compressing the air upwards and expelling it through a delivery valve
at the top of the cylinder with its face downwards and so constructed as to cover the
entire end of the cylinder, such valve containing a water jacket exposed to the contact
of the compressed air as it is driven upwards. The air as it is being compressed is
thus compelled to pass over the whole water jacketted surface of the valve. A natural
circulation of the air is thus induced, the colder particles descending and the heated
particles ascending and being thus brought in contact with the cool surface. The
whole body of the air being compressed is thus brought in contact with the cold
surface of the valve.

page_text: Another improvement consists of a special arrangement of the single acting ram
by which the outer air can be taken in through a covered way or casing, so as to
enable it to be treated with a washing or filtering process, or drawn in from a purer
or cooler source than that of the engine house. For this purpose I place the intake
valves in the head of the ram or plunger piston in the side of which I arrange a long
opening or slot of sufficient length to draw the air in during the whole stroke through
an opening made about midway in the side of the cylinder the interior of which is
otherwise shut out from the outer air by the main body of the long piston or ram.
To this side opening in the cylinder a pipe or casing may be attached by which the
air can be drawn from the desired point.
Dated this 31st day of August 1886.

page_text: I, DAVID GREIG, of Leeds, in the County of York, Engineer, do hereby declare
the nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
These improvements relate in the first place to the cooling of the air during
compression, and are specially applicable to vertical air compressors of the single
acting type.
Heretofore it has been customary to cool the air during compression either by
injection of water into the cylinder, or by water circulation through a jacket
surrounding the cylinder, or through a hollow piston and rod working in a horizontal
double acting cylinder. Water injection is however objectionable as the air becomes
saturated and this increases the tendency to freezing in the motor engines driven by
the compressed air. A jacket surrounding the cylinder only cools the outer film of
air in the cylinder immediately. in contact therewith and hardly affects the interior
body of the air. Moreover the cooling surface in contact with the air continually
diminishes as the piston advances at the very time that the heat of compression
increases and cooling is most needed. A hollow water jacketted piston and rod is
objectionable on account of complication and the increased diameter of rod required.
The horizontal position is unfavourable for inducing a proper circulation of the
heated air.
According to my improvements I place the air cylinder vertical, the single acting
piston or ram compressing the air upwards and expelling it through a delivery
valve at the top of the cylinder with its face downwards and so constructed as to
cover the entire end of the cylinder such valve containing a water jacket exposed to.
the contact of the compressed air as it is driven upwards. The air as it is being
compressed is thus compelled to pass over the whole water jacketted surface of the
valve. A natural circulation of the air is thus induced, the colder particles descending
and the heated particles ascending and being thus brought in contact with the cool
surface. The whole body of the air being compressed is thus brought in contact with
the cold surface of the valve.
Another improvement consists of a special arrangement of the single acting ram
by which the outer air can be taken in through a covered way or casing, so as to
enable it to be treated with a washing or filtering process, or drawn in from a purer
or cooler source than that of the engine house. For this purpose I place the intake
valves in the head of the ram or plunger piston in the side of which I arrange a long
opening or slot of sufficient length to draw the air in during the whole stroke through
an opening made about midway in the side of the cylinder the interior of which is
otherwise shut out from the outer air by the main body of the long piston or ram.
To this side opening in the cylinder a pipe or casing may be attached by which the
air can be drawn from the desired point.

page_text: Figure 1 is a side elevation partly in section and Figure 2 a vertical section of
the cylinder and ram of air compressing machinery formed to work in the manner
above described.
Figure 3 is a section on the line A B, Figure 4 a section on the line C D and
Figure 5 a section on the line E F.
A is the cylinder with a jacket B around it through which a circulation of water
is maintained as usual. C is a hollow ram working upwards through the bottom of
the cylinder. D is the delivery valve covering over the top of the cylinder it is made
hollow and a circulation of water is maintained through it. The stem E of the valve
is for this purpose made hollow and is carried out through a stuffing as shown at
Figure 2. Within the interior of the valve is a horizontal disc F. Water is supplied
into the space below this disc through a pipe G which passes down centrally through
the hollow valve stem E-the water passes upwards from this space around the edge
of the disc into the space above the disc and passes away through the hollow stem.
Flexible pipe connections allow the valve stem E and pipe G to rise and fall
freely HH are the intake valves on the top of the ram. A section on a larger scale
through one of the valves is shown at Figure 6. I is a slit or opening down one side
of the ram through which air can pass to its interior through an opening J in the
side of the cylinder which as before stated may have a pipe leading from it to any
desired point.
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 :-
1. The arrangement of the cylinder or cylinders of engines for compressing air in
vertical position with a piston or hollow ram working upwards through the bottom of
each cylinder and with a delivery valve over the upper end of the cylinder having
circulation of water maintained through it substantially as described.
a
2. The arrangement of the intake valves in the head of the ram with air admission
to the valves through a slot in the ram opposite to an opening in the side of the
cylinder substantially as described.
.
3. The construction of engines for compressing air substantially in the manner
herein before described and illustrated in the drawings annexed.
Dated this 9th day of May 1887