Improvements in Pumps for Compressing Air and Gases.
Year: 1885

page_text: Improvements in Pumps for Compressing Air and Gases.
We GEORGE EDWARD BELLISS and ALFRED MORCOM both of Ledsam Street
Works Ledsam" Street Birmingham in the County of Warwick Engineers do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN PUMPS FOR
COMPRESSING AIR AND GASES" to be as follows:-
--
Our invention consists in constructing and combining or arranging in the manner
hereinafter described the parts of pumps for compressing air and gases our
improvements embodying the ordinary principle of compressing by stages.
We will describe our improvements as applied to an air compressing pump. The
essential parts of the pump as arranged according to our invention consist first of
a large outer cylinder constituting the body of the pump in which cylinder an
annular plunger having a trunk at its bottom works second of a smaller annular
plunger attached to the bottom of a fixed trunk constituting the inner cylinder
and third of a central plunger working in the said inner cylinder or trunk of the
fixed plunger. The central plunger and the outer annual plunger are connected
together and move simultaneously The parts described are surrounded by a water
tank and annular water passages for keeping them cool. In the said tank are
cooling coils into which the compressed air is forced. The annular water passage
in the fixed trunk supplies water to the moveable trunk of the large outer plunger
(or the direction of the current of the water may be reversed) and the top of the
inner cylinder is in communication with the air cooling coils in the water tank.
The large outer plunger is furnished with valves opening inwards and the inner
plunger with a valve opening outwards.
The air to be compressed is drawn into the large or outer cylinder by the
advance stroke of the plunger in the said cylinder the air entering through valves
in the cover of the cylinder. In the return stroke of this plunger the air undergoes
a first compression by being forced into an annular space formed between the trunk
of the large plunger and the fixed plunger trunk. This compressed air is on the
next forward stroke of the large plunger forced into the inner or central cylinder
thereby undergoing a second compression and a third compression is obtained by
forcing the air by means of the central plunger into the cooling coils in the water

page_text: tank. The plungers are kept cool during their operation by the water in the tank
surrounding the air cooling coils and the water passages which water is pumped
through the closed tank by the differential pumping action of the large outer
plunger carrying the moveable trunk and the plunger on the bottom of the fixed
trunk the proportions of which plungers may be modified according to the amount
of water required to be pumped through the tank or if necessary to change the
direction of the pumping. As the three compressing portions of the pump are kept
cool by annular water spaces the cooling of the air is very efficiently effected and
the amount of water pumped through the tank can be readily regulated.
Dated this sixteenth day of February 1885.

page_text: Improvements in Pumps for Compressing Air and Gases.
We GEORGE EDWARD BELLISS and ALFRED MORCOM both of Ledsam Street
Works, Ledsam Street, Birmingham in the County of Warwick, Engineers, do
hereby declare the nature of our invention for "IMPROVEMENTS IN PUMPS FOR
COMPRESSING AIR AND GASES" and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
Our invention consists in arranging in the manner herein after described the
parts of pumps for compressing air and gases, our improvements embodying the
ordinary principle of compressing by stages.
We will describe our improvements as applied to an air compressing pump.
The essential parts of the pump or compressor, as arranged according to our-
invention, consist first, of a large outer cylinder constituting the body of the pump,
in which cylinder an annular plunger having a trunk at its bottom works; second
of a smaller annular plunger attached to the bottom of a fixed trunk constituting
the inner cylinder; and third of a central plunger working in the said inner cylinder
or trunk of the fixed plunger. The central plunger and the outer annual plunger
are connected together and move simultaneously. The parts described are sur-
rounded by a water tank and annular water passages for keeping them cool. In
the said tank are the ordinary cooling coils into which the compressed air is forced.
The annular water passage in the fixed trunk supplies water to the lower side of
the fixed plunger which forms a water pump on that side with the moving trunk.
The water is then forced into the annular space in the trunk of the annular
plunger and by means of the said trunk and the necessary valves a differential
pumping action is set up which by altering the diameter of the trunk can be varied
to any extent; or the current may be reversed.
The air to be compressed is drawn into the outer cylinder by the forward stroke
of the plunger in the said cylinder the air entering through valves in the cover of
the cylinder. In the return stroke of the plunger the air undergoes a first
compression by being forced into the annular space formed between the trunk of
the large plunger and the fixed plunger trunk. This compressed air is on the next
forward stroke forced into the inner or central cylinder thereby undergoing a second
compression and a third compression is obtained by forcing the air by means of the
central plunger into the cooling coils in the water tank. The plungers are kept
cool during their operation by the passage of water from an outside water supply
through the annular spaces and the tank surrounding the air cooling coils which
water is circulated through the system by the differential pumping action already
described.
The accompanying Drawing represents in vertical section a pump or compressor.
for compressing air and gases the parts of which pump or compressor are arranged
according to our invention.
A is the large outer cylinder constituting the body of the pump in which cylinder
the annular plunger B having a trunk Cat its bottom works; D is the smaller
annular plunger attached to the bottom of the fixed trunk E constituting the inner
cylinder and F is the central plunger working in the said inner cylin ler or trunk E
of the fixed plunger. The central plunger F and the outer annular plunger B are

page_text: connected together and move simultaneously. The outer cylinder A is surrounded
by a water tank I and the working and fixed parts within the said cylinder A are
furnished with annular water passages for keeping them cool. In the said tank I
are the ordinary cooling coils J into which the compressed air is forced as herein-
after described. The annular water passage a in the fixed trunk E and fixed
plunger D supplies water to the lower side of the said fixed plunger D, which lower
side of the fixed plunger D forms with the moving trunk Ca water pump. The
water below the plunger D is forced into the annular space G and by means of the
trunk H and the necessary valves a differential pumping action is set up which by
altering the diameter of the trunk H can be varied to any extent or the current
may be reversed.
The air to be compressed is drawn into the cylinder A by the forward stroke of
the plunger B in the said cylinder; that is to say, when the plunger B is moving
in the direction of the arrows c, the air entering through valves T in the cover of
the cylinder.
In the return stroke of the plunger B the air undergoes a first compression by
being forced into the aunular space K. This compressed air is on the next forward
stroke forced into the inner or central cylinder L thereby undergoing a second
compression and a third compression is obtained by forcing the air by means of
the central plunger F moving in the cylinder Linto the cooling coils J in the water
tank with which coils the top of the cylinder L is in communication by means of
the pipe L² and the valve represented. The cylinders are kept cool during the
compressing operation by the passage of water from an outside water supply
through the annular spaces represented and the tank I surrounding the air cooling
coils which water is circulated through the system by the differential pumping
action already described.
As the three compressing portions of the pump are kept cool by the water in
direct contact with the sides of the compressing cylinders and plunger as well as by
conduction through the metal of all the cylinders, the cooling of the air is very
efficiently performed.
By this arrangement the surfaces liable to leakage and wear at the higher
pressures are kept as small as possible and the compression of air at high pressures
is quickly effected without undue heat and wear and leakage of the parts.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim as our invention of "Improvements in pumps for compressing air and
gases'
"J
First The arrangement or combination of the parts of a three stage pump or
compressor hereinbefore described and illustrated in the accompanying Drawing,
whereby the air or gas is first compressed in a large cylinder and from thence passes
to a smaller cylinder for the second compression and from thence to a still smaller
cylinder for the last compression substantially as described.
Secondly The arrangement of parts described and illustrated in the accom-
panying Drawing for causing a circulation of water through the pump or compressor
without the aid of a separate pump and without throwing an undue load on the
pump or compressor.
T
CCL 1
1007
GEORGE EDWARD BELLISS.
ALFRED MORCOM.