Improved Apparatus for Pumping or Compressing and Mixing Gas and Air.
Year: 1898

page_text: Date of Application, 12th July, 1898
Complete Specification Left, 29th Dec., 1898-Accepted, 8th Apr., 1899
PROVISIONAL SPECIFICATION.
Improved Apparatus for Pumping or Compressing and Mixing Gas
and Air.
I, JAMES KEITH, Assoc. M. Inst. C.E., of 27, Farringdon Avenue, in the City
of London, Gas, Hydraulic, Heating and Ventilating Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention is a development of the improvements in gas pumps or com-
pressors described in the Specification of Letters Patent granted to me No. 14057
of. 1897, and it has for its object to simplify and improve the construction of the
apparatus and to adapt it for compressing and mixing gas and air for illumina-
ting and other purposes.
The improved apparatus, under one modification in which gas only is com-
pressed, comprises a pump which consists of a pump cylinder provided with an
annular water space formed between the pump cylinder and an inner open ended
cylinder secured upon the same sole plate as the pump cylinder. Into this water
spaco a small gas holder dips, which holder constitutes the plunger of the pump,
the water acting as a seal when the plunger is moved up and down by means of
a water motor such as described in the Specification of Letters Patent above re-
ferred to, or of the construction hereinafter described. The gas to be compressed
is alternately drawn in and expelled both above and below the plunger, the gas
being drawn in through pipes communicating one with the interior or lower side
and the other with the exterior or upper end of the plunger, the other ends of
each of these pipes being connected to an inlet chamber or chambers in a valve
box provided with valves adapted to open on the suction stroke of the plunger.
A second set of valves are provided which are adapted to open on the expulsion
stroke of the plunger and permit the gas previously drawn in to be forced into
a gas receiver which surrounds the pump portion of the apparatus. This receiver
or regulator which is weighted at the bottom to give the desired pressure to the
gas or air contained within it dips into a water space contained between the pump
cylinder and an outer open ended cylinder or casing provided with an overflow,
and is adapted to control a cock on the water supply of the motor by means of
a lever actuated by the rising and falling of the receiver.
The motor preferably used consists of a piston connected to the pump plunger
and working in a cylinder situated within the innermost cylinder of the pump, a
main valve and an auxiliary valve, the latter being adapted to be moved by the
piston of the motor. The pressure water from the supply pipe enters an orifice
in the auxiliary valve casing and is led to the upper side of the motor piston
on which side it acts constantly. When the motor piston is at the innermost part
of its stroke the main valve which has a large and a small end, (the latter being
always acted upon by the pressure water,) reverses and admits pressure water by
a series of ports to the under side of the piston which is of greater area than the
upper side, whereby the motor is caused to make an upward stroke and draws in
gas or air on the under side of the plunger whilst expelling the air or gas on the

page_text: upper side of the plunger. The auxiliary valve is, at about the outer end of the
stroke of the motor piston, acted upon by the piston so as to admit pressure water
to the large end of the main valve and to reverse it in order to effect the reversal
of the plunger stroke, by allowing the water on the under side of the piston to
escape by way of an exhaust port to the interior of the inner, cylinder of the
pump apparatus. The exhaust water flows up into and over the top of the inner
cylinder and fills the annular space into which the pump plunger dips and passes
out near the bottom of outer cylinder to form a seal for the receiver, finally over-
flowing near the upper open end of the outer cylinder.
In a modification of the invention in which the apparatus is designed to draw
in a proportion of air with the gas and compress, both for use particularly in in-
candescent gas lighting, an additional annular or double cylinder open at its
upper end is provide which, is fixed to or forms, part of the plunger and dips
into the water contained in the inner cylinder secured to the sole plate, and
referred to in the previous modification as the inner cylinder of the. pumping
apparatus. This annular cylinder is provided with a valve which allows the
water to enter the annular space on the downward stroke of the plunger but pre-
vents its returning on the upper stroke the surplus water overflowing at the open
end of the double cylinder over the top of the plunger into the water seal formed
between the inner and outer cylinders of the pump apparatus. Into this annular
or double cylinder dips a cylinder secured to and suspended from the cover of the
outer cylinder, These two cylinders form inner chambers into the insides of
which air is drawn and into outer chambers formed between their outer peri-
pheries and their adjacent cylinders gas is drawn at the same time, the gas and
air being discharged from their respective chambers simultaneously and at the
same pressure. The drawing in and discharging of air and gas, is accomplished
by the addition to the previously described modification of an air valve box
having two separate ports connecting to the top and bottom sides of the plunger,
the delivery chamber of the air valve box being connected to the delivery chamber
of the gas valve box so that the air and gas mix regularly in fixed proportions.
In order to prevent any possible escape of gas through the air inlet valves which
might happen should the valves leak when the apparatus is not working, the air
inlet to air valve box is connected to a water seal valve which will effectually
prevent any such leakage escaping to the outside. This water seal valve consists
of a closed box, which is bolted to the side of the outermost cylinder or casing
The waste water. is carried down from the overflow on the outer casing into the
water seal box by a pipe, and then overflows through a deep trap. The air inlet
pipe dips about 1" into the water in this box, which is of such capacity that the
water will rise up both the air inlet and overflow pipes, considerably more than
the height due to the working pressure of the gas before the water level gets
below the bottom of the air inlet pipe. This arrangement of water seal box pre-
vents the gas escaping through the trap. so that in the event of the air suction
valves leaking back when the apparatus is not in motion the water simply rises
in the pipes according to the pressure, and also effectually washes the air which
is. compelled to pass through the seal before reaching the air valve box, thus pre-
venting dust collecting in the valves, and other parts of the apparatus.
The mixed air and gas can either be taken direct from the delivery end of valve
box or taken from the holder by a separate stand pipe in order that they may be
more thoroughly mixed..
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Pumping or Compressing and Mixing Gas
and Air,
I, JAMES KEITH, Assoc. M. Inst. C.E., of 27, Farringdon Avenue, in the City
of London, Gas, Hydraulic, Heating and Ventilating 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;
1
This invention is a development of the improvements in gas pumps or com-
pressors described in the Specification of Letters Patent granted to me No. 14,057
of 1897 and it has for its object to simplify and improve the construction of the
apparatus and to adapt it for compressing and mixing gas and air for illuminating
and other purposes.
The invention is illustrated by the accompanying drawings, Figure 1 being a
vertical section, Figure 2 a plan, and Figures 3 to 6 inclusive, details hereinafter
particularly referred to. Figure 7 is a vertical section and Figure 8 a plan of a
modified form of apparatus in which gas and air are compressed and mixed, and
Figures 9 to 11 inclusive are details connected therewith.
The improved apparatus, illustrated by Figures 1 to 6, in which gas only is
compressed, comprises a double-acting pump which consists of a pump cylinder A
provided with an annular water space B formed between the pump cylinder A
and an inner open ended cylinder C secured upon the same sole plate D as the
pump cylinder A. Into this water space B a small gas holder E dips, which
holder constitutes the plunger of the pump, the water acting as a seal when the
plunger E is moved up and down by means of a water motor such as described
in the Specification of Letters Patent above referred to, or of the construction
hereinafter described. The gas to be compressed is alternately drawn in and
expelled both above and below the plunger E, the gas being drawn in through
pipes F, G, communicating one F with the interior or lower side, and the other G
with the exterior or upper end of the plunger E, the other ends of each of these
pipes being connected to an inlet chamber or chambers H, I, in a valve box J
connected to the gas supply by an orifice J¹ and provided with valves H¹, I',
adap'ed to open on the suction stroke of the plunger E. A second set of valves H2,
12, are provided which are adapted to open on the expulsion stroke of the plunger E
and permit the gas previously drawn in to be forced by way of a delivery
chamber 13 into a gas receiver K which surrounds the pump portion of the appar-
atus. This receiver or regulator K which is weighted at the bottom by means
of a ring K to give the desired pressure to the gas or air contained within it
dips into a water space L contained between the pump cylinder A and an outer
open ended cylinder or casing M provided with an overflow N, and is adapted to
control a cock on the water supply of the motor by means of a lever, not shown,
but connected to the receiver at r, actuated by the rising and falling of the
receiver.
The motor preferably used consists, as shown particularly at Figure 3, of a
piston a connected to the pump plunger E and working in a cylinder b situated
within the innermost cylinder C of the pump, a main valve c and an auxiliary
valve d, the latter being adapted to be moved by the piston a of the motor. The
pressure water from the supply pipe el enters an orifice e in the auxiliary valve
casing and is led by a pipe g to the upper side of the motor piston a on which
side it acts constantly. When the motor piston a is at the innermost part of
its stroke the main valve c which has a large and a small end C¹, .C³, respectively
(the latter being always acted upon by the pressure water), reverses and by way
of a series of ports f¹ formed in a liner in the auxiliary valve casing f admits

page_text: pressure water to the under side a² of the piston a which is of greater area than
the upper side a', whereby the motor is caused to make an upward stroke and
draws in gas or air on the under side of the plunger E whilst
expelling the air or gas on the upper side of the plunger. The auxiliary
valve d is, at about the outer end of the stroke of the motor piston a, acted upon
by the piston to place two series of ports d', , in a liner D in communication
with each other (the former port being always in communication with the pres-
sure water by means of a pipe e²) and thus admit pressure water to the large
end of the main valve c and so reverse it to effect the reversal of the stroke of
the plunger E, by allowing the water acting on the under side a² of the piston a
to escape by way of the ports f¹ and ports as in the liner 1) and the water behind
the piston to escape by way of the ports d², d, and an exhaust port f³ to the
interior of the inner cylinder Ŭ of the pump apparatus. The exhaust water flows
up into and over the top of the inner cylinder C and fills the annular space B
into which the pump plunger E dips and passes out near the bottom of the
outer or pump cylinder A to form a seal for the receiver K finally overflowing
at N near the upper open end of the outermost cylinder M.
In the modification of the invention illustrated by Figures to 11 in which
the apparatus is designed to draw in a proportion of air with the gas and com-
press both for use particularly in incandescent gas lighting, an additional annular
or double cylinder E' open at its upper end as shown particularly at Figure 7, is
provided which is fixed to or forms part of the plunger E and dips into the water
contained in the inner cylinder C secured to the sole plate 1), and referred to
in the previous modification as the inner cylinder of the pumping apparatus. This
annular cylinder E¹ is provided with a valve E2 which allows the water to enter
the annular space on the downward stroke of the plunger but prevents its return-
ing on the upper stroke, the surplus water overflowing at the open end of the
double cylinder E₁ over the top of the plunger E into the water seal B formed
between the inner and outer cylinders C, A, of the pump apparatus. Into this
annular or double cylinder E¹ dips a cylinder A' secured to and suspended from
the cover of the outer cylinder A. These two cylinders E, A, form inner cham-
.bers into the insides of which air is drawn and into outer chambers formed between
their outer peripheries and their adjacent cylinders gas is drawn at the same
time, the gas and air being discharged from their respective chambers simulta-
neously and at the same pressure. The drawing in and discharging of air and
gas is accomplished by the addition to the previously described modifications of
an air valve box O, particularly shown at Figures 8 to 11, having two separate
pipes P, Q, connecting to the top and bottom sides of the plunger E, and suction
and delivery valves 02, 03, 04, 05, as described with reference to Figures 1 to
10, the delivery chamber R of the air valve box O being connected to the delivery
chamber 13 of the gas valve box J by a passage 07 so that the air and gas mix
regularly in fixed proportions.
In order to prevent any possible escape of gas through the air inlet valves
which might happen should the valves leak when the apparatus is not working,
the air inlet O' to the air valve box O is connected to a water seal valve S which
will effectually prevent any such leakage escaping to the outside. This water
seal valve S consists of a closed box, which is bolted to the side of the outermost
cylinder or casing M, and is provided with a pipe 06 open to the atmosphere. The
waste water is carried down from the overflow N on the outer casing into the
water seal box by a pipe T, and then overflows through a deep trap U. The air
inlet pipe O dips about 1" into the water in this box S, which is of such capacity
that in the case of back pressure through the air valves the water will rise up
both the air inlet and overflow pipes 0º, T, respectively, considerably more than
the height due to the working pressure of the gas before the water level gets below
the bottom of the air inlet pipe 06. This arrangement of water seal box S prevents
the gas escaping through the trap U, so that in the event of the air suction
valves 03, 03, leaking back when the apparatus is not in motion the water simply

page_text: rises in the pipes according to the pressure, and also effectually washes the air
which is compelled to pass through the seal before reaching the air valve box 0,
thus preventing dust collecting in the valves, and other parts of the apparatus.
The mixed air and gas can either be taken for use direct from the delivery end
of the valve box J or taken from the holder by a separate stand pipe in order
that they may be more thoroughly mixed.
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 combination of parts constituting the improved double-acting gas pump
or compressor hereinbefore described as arranged for compressing gas alone or
for compressing and mixing gas and air.
2. A double-acting gas compressing pump directly actuated by a water motor
and arranged to compress gas alone or to compress and mix gas and air, in com-
bination with a loaded gas holder or receiver surrounding the pump plunger and
connected to a cock or valve to control the water supply to the motor substan-
tially as described.
3. A double-acting gas and air compressing and mixing apparatus composed
of a motor and a pump plunger formed with a double cylinder dipping into an
annular water space having water automatically admitted thereto, and an open
ended cylinder dipping into the annular cylinder, in combination with a loaded
gas holder or receiver surrounding the pump and controlling the water supply
to the motor substantially as described.
4. In gas and air compressing and mixing apparatus the arrangement of a
water seal to prevent the escape of gas through the air inlet valves said water
scal consisting of a valve box connected to the outer casing to the air valve box
and to the atmosphere substantially as described.
1000
December 1808.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow,
Agent for the Applicant.