Year: 1898

page_text: I, FRANCIS WINDSOR GRAHAM SNOOK, Mechanical Engineer, of 83, Park Road,
Newcastle-upon-Tyne, in the County of Northumberland, do hereby declare the
nature of this invention to be as follows:-
My improvements relate to the arrangement of parts hereinafter described, of
a two stage air or gas compressing pump and of a circulating water pump form-
ing part of the said air or gas compressing pump, as hereinafter described, for
cooling the air or gas during the compressing process.
Constructed in accordance with my invention a two stage air or gas compressing
pump consists essentially of a large pump, the chamber of which is annular,
and of a smaller pump, the chamber or cylinder of which is surrounded by the
said annular chamber of the large pump.
Both pump chambers are enclosed in a tank containing cooling water, and are
furnished with pistons or plungers secured to reciprocating piston rods, which may
be worked by a steam cylinder or other motor. The plunger of the large pump
is fitted with a valve or valves through which the air or gas is admitted, on the
upstroke of the piston rods, to the space beneath the said plunger, in the body
of the large pump, from the upper part of the said large pump chamber, which is
open at the top to the source or supply of air or gas to be compressed.
+
On the said plunger making its downstroke, the air or gas is compressed and
discharged into the top of the inner or small pump cylinder, through a pipe or
coil which traverses the cooling water tank and is fitted at each end with non-
return valves.
On the upstroke of the pump rods the air or gas, now in the upper part of
the inner or small pump, is further compressed by the action of the plunger of
the said pump, and is forced or pumped out past a non-return valve, through
another cooling coil in the tank, to a receiver.
A two stage compression of the air or gas is thus effected.
A constant circulation of cooling water through the tank is maintained by the
differential displacement of the piston of the inner or small pump, the cylinder
of which is connected at the bottom by passages with the source of the cooling
water and with the tank.
By this arrangement a compact and efficient two stage air or gas compressing
pump, with large immersed surfaces for effectively cooling, combined with a
reliable circulating pump for the cooling water, is obtained.
Dated this Eighth day of August 1898.

page_text: Improvements in Two-stage Air or Gas Compressing Pumps.
I, FRANCIS WINDSOR GRAHAM SNOOK, of 83, Park Road, Newcastle-on-Tyne,
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:-
My improvements relate to the arrangement of parts, hereinafter described, of
a two-stage air or gas compressing pump and of a circulating water pump
forming part of the said air or gas compressing pump, as hereinafter described,
for cooling the air or gas during the compressing process.
A two-stage air or gas compressing pump, constructed in accordance with my
invention, consists essentially of a large pump, the chamber or working cylinder
of which is annular, and of a smaller pump the chamber or working cylinder
of which is surrounded by the said annular chamber or cylinder of the larger
pump.
Both pump cylinders are enclosed in a tank containing cooling water, and are
furnished with pistons or plungers secured to reciprocating piston rods which may
be worked by a steam cylinder or other motor.
The piston or plunger of the larger pump is fitted with a valve or valves
through which the air or gas is admitted, during the up-stroke of the piston, to
the space beneath the said piston or plunger in the body of the larger pump from
the upper part of the said larger pump cylinder which is open at the top to the
source or supply of air or gas to be compressed.
is
When the said piston or plunger makes its downward stroke the air or gas
compressed and discharged into the top of the inner or smaller pump cylinder
through a pipe or coil contained in the cooling water tank and which is fitted at
each end with a non-return valve.
When the piston of the smaller pump makes its upward stroke the air or gas,
now in the upper part of the inner or smaller pump, is further compressed by
the action of the said piston and is forced or pumped out, through a non-return
valve and another cooling coil in the cooling tank, to a receiver.
A two-stage compression of the air or gas is thus effected.
A constant circulation of cooling water through the tank may be maintained
by the differential displacement of the piston of the inner or smaller pump, the
cylinder of which is connected at the bottom by passages with the source of
supply of the cooling water and with the cooling tank.
And in order that the said invention may be fully understood I will now
proceed to describe the same with the aid of the accompanying two sheets of
drawings, in which Figure 1 is a sectional elevation, taken on the line X-X of
Figure 3, of an air or gas compression pump constructed in accordance with my
invention, Figure 2 a sectional elevation of same taken on the line Z-Z of
Figure 2, and Figure 3 a plan view of same.
1 represents the annular cylinder of the larger pump fixed by the flange 2 in
a tank 3 containing cooling water. 4 is the annular piston working in the annular
cylinder 1 and operated by the piston rods 5 passing through stuffing-boxes 6
at the lower end of the cylinder 1. The said stuffing-boxes are arranged to
pass through the bottom of the water tank 3, water-tight joints being made
therewith by means of the glands 7. The two piston rods 5 are connected to a
cross-head 8 to which reciprocatory motion may be imparted from a steam engine
or other motor by means of the rod 9. 10 are valves in the annular piston 4,
arranged to open downwards. The upper end of the annular cylinder 1 is more or

page_text: less open to the atmosphere if the apparatus is intended to be employed for the
compression of air; but if the apparatus is to be employed for the compression
of a gas the upper end of the said annular cylinder may be closed by a suitable
cover one or more openings through which is or are connected by a pipe or pipes
with the source of supply of such gas. In either case the air or gas, as the case
may be, may be admitted to the valves 10 in the piston 4 through openings 11.
12 is the cylinder of the inner or smaller pump, 13 the piston of same and 14 the
corresponding piston rod connected to the same cross-head S as the piston rods 5
of the annular piston 4. The piston rod 14 passes through a stuffing-box 15 formed
in the bottom of the water tank 3, the lower end of the cylinder 12 being jointed
to the bottom of the cylinder 1 by suitable jointing devices at 16 against which it
is pressed by the cap 16* screwed on to the central part 1 of the annular cylinder 1.
17 is the inlet or suction valve of the smaller pump 12, and 18 the delivery valve
of same.
19 is the delivery valve at the bottom of the annular cylinder 1. This valve
is connected to one end of a coil of pipe 20 immersed in the cooling water in the
tank 3; the other end of the coil of pipe 20 is connected with the box of the inlet
or suction valve 17 of the smaller pump cylinder 12.
The box of the delivery valve 18 of the smaller pump has connected to it one
end of a coil of pipe 21 which is also immersed in the cooling water in the
tank, the other end 21 of the coil 21 being led to the receiver of compressed
air.
The circulation of the cooling water through the tank 3 may be effected by
the piston 13 of the smaller pump 12 in the following manner:-22 is a valve-box
containing a suction valve 23 and a delivery valve 24. 25 is the inlet passage
to the valve box 22, which passage is connected with the source of supply of cold
water. 26 is a suction passage leading from the suction valve 23 to the space in
the pump cylinder 12 below the piston 13. 27 is a delivery passage icading from
the delivery valve 24 to the space 28 surrounding the pump cylinder 12. This
space 28 communicates by a passage 29 with the tank 3. 30 is an overflow pipe
for taking the heated water from the tank 3 and conveying it away to waste or
otherwise. In order to shut-off or regulate the supply of cooling water to the
pump 12 and tank 3 the suction valve 23 may be prevented altogether from opening,
or its lift may be regulated as required by means of the screwed spindle 31 passing
through the stuffing-box 32 of the valve box 22, and raised or lowered by turning
it by means of the handle 33.
It will now be understood that when reciprocating motion is imparted to the
pistons 4 and 13 by means of the rods 5 and 14, the upward movement of the
piston 4 causes air or gas, as the case may be, to pass through the valves 10 to
the space below the said piston, and the downward movement of the said piston.
compresses such air to a certain extent and forces it through valve 19, coil of
pipe 20, and suction valve 17 into the space above the piston 13. Then during
the next upward stroke of said piston 13 the said air is further compressed thereby
and forced through delivery valve 18 and coil of pipe 21 into the pipe 21 leading
to the compressed air receiver, not shown in the drawings.
It will be understood that the air in passing through the coils 20 and 21 will be
cooled by the contact of the water in the tank 3 with the outer surfaces of the
said coils.
It will further be understood that the upward movement of the piston 13 will
draw water through the suction valve 23 and passage 26 into the space in the
cylinder 12 below the piston 13, and that the downward movement of the piston 13
will force that water out through the delivery valve 24, and passage 27 into
the space 28 surrounding the cylinder 12 so as to keep the latter cool, the water
then passes from space 28 through passage 29 into the lower part of tank 3 and
rising in the latter comes in contact, as before described, with the cooling coils 20
and 21 and finally flows away through the overflow pipe 30.
By the above described arrangements a compact and efficient two-stage air
or gas compressing pump is obtained with a minimum of height, great accessi-

page_text: bility of the pistons or plungers, large surfaces for cooling and a reliable circu-
lating pump for the cooling water.
It will be obvious that the pump cylinder 12 and piston 13 can only be used
for circulating the cooling water in cases where the gas being compressed, such
as atmospheric air for example, is not injuriously affected by the presence of
water but in other cases, such as in the compression of ammonia or sulphurous
acid gas for the production of anhydrous ammonia or sulphurous acid, for example,
the circulation of cooling water must be effected by means which do not involve
the entrance of water into the pump cylinder 12.1
Having now particularly described and ascertained the nature of the said in-
vention, and in what manner the same is to be performed, I declare that what
I claim is
First. In a two-stage air or gas compressing pump the arrangement of the smaller
pump cylinder and piston within and concentric to the larger pump cylinder
which said larger pump cylinder is annular with respect to the smaller pump
cylinder, and is provided with an annular piston, substantially as described.
Second. In a two-stage air or gas compressing pump, constructing the water
passage leading from the inlet valve to the lower part of the smaller pump
cylinder, and the water passage leading from the delivery valve to the annular
space or jacket surrounding the smaller pump cylinder, in or connected with the
cooling water tank, substantially as described.
Third. In connection with the water passages constructed in or connected with
the cooling water tank, in accordance with the second claiming clause hereof, the
combination with such passages of the inlet and outlet valves and valve-box
substantially as described.
1
1011 J. 1900