Improvements in and relating to Apparatus for the Production of Oxygen Gas.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883) as required by
the decision of the Chief Examiner of the 29th day of June 1897.
Date of Application, 29th Feb., 1896
Complete Specification Left, 26th Nov., 1896-Accepted, 23rd Jan., 1897
PROVISIONAL SPECIFICATION.
Improvements in and relating to Apparatus for the Production of
Oxygen Gas.
I, FREDERICK JOSEPH STEDMAN of 147 Strand in the County of London,
Electrician do hereby declare the nature of this invention to he as follows:-
This invention relates to apparatus for the production of oxygen gas, and is
especially applicable for use by lecturers and others requiring a portable and
compact oxygen producing apparatus.
In carrying out my invention I employ a series of retorts, capable of being
hermetically closed, connected to a main pipe, preferably closed at one end and
connected at the other end with a wash-bottle or gas purifier provided preferably
at the gas inlet side with a non-return valve. This wash-bottle is connected by
a tube to a gas bag or gas container, whence a tube extends to the lime light jet
or place where the gas is to be used.
In order to obtain the necessary pressure upon the gas bag or container I provide
a weight or weights on the upper board or part so arranged as to give as constant
pressure as possible whether the container be full or almost empty. I find it con-
venient for this purpose to use one or more tanks containing water shot or other
self moving body upon the pressure board or the gas bag.
A lamp or burner may be placed beneath say the first retort to heat it and when
the gas produced has been used or partly used, the burner is transferred
automatically or otherwise to the second retort and so on through the series.
The operation of the apparatus is as follows;-
The retorts having been filled with the gas producing mixture-say chlorate of
potash and oxide of manganese-and heat applied to the first retort by means of
the lamp, oxygen is given off and passes by the pipe to the wash-bottle thence
into the gas bag where it is stored, being drawn off as required, through the
delivery tube.
In order to render the action automatic I provide mechanism operated preferably
by the rise or fall of the gas bag or container whereby the burner is transferred
automatically from one retort to the next. One method by which this may be
effected is by forming an adjustable projection or device on the gas bag pressure
board which, on the collapse or partial collapse of the bag as the gas is drawn off
operates an escapement mechanism to release a stand upon which the heater is
placed and allow it under the influence of a spring to move according to the
operation of the gas bag from one retort to the next.
In some cases the traverse of the heater may be effected by electrical means
operated by the rise or fall of the gas container or other moving part. By

page_text: this arrangement the heater or burner heats the first retort which delivers its
gas into the gas reservoir, which as it first rises and then falls as the gas is used,
operates the escapement mechanism and allows the heater to travel to the next
retort, and so on throughout the series. Instead of the operation of the gas bag
gasometer or other reservoir merely allowing the heater to travel, it may itself
effect the movement of the heater.
The gas container or other moving part may be adapted to regulate or cut off
the supply of heat to the retorts.
The details may be varied without departing from the spirit of the invention.
Dated this 28th day of February 1896.
FREDERICK J. STEDMAN.
Boult & Wade,
Agents for the Applicant.
Improvements in and relating to Apparatus for the Production of
Oxygen Gas.
1. FREDERICK JOSEPH STEDMAN of 147 Strand, in the County of London,
Electrician, 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:-
This invention relates to apparatus for the production of oxygen gas, and is
especially applicable for use by lecturers and others requiring a portable and
compact oxygen-producing apparatus.
In carrying out my invention 1 employ a series of retorts, capable of being
hermetically closed, connected to a main pipe, preferably closed at one end and
connected at the other end with a gas-purifier provided preferably at the gas-inlet
side with a non-return valve. This gas-purifier is connected by a tube to a gas
container, whence a tube extends to the lime light jet or place where the gas is
to be used. Below the series of retorts is a device for heating them, the latter
heing movable automatically or otherwise from one retort to another in succession
or otherwise controlled to effect the generation of gas at a rate proportional to
that at which it is withdrawn from the gas-container for use.
In order to obtain the necessary pressure upon the gas-container I provide a
weight or weights on the upper board or part thereof so arranged as to give as constant
a pressure as possible. I find it convenient for this purpose to use one or more
tanks containing water for instance upon the gas-container; which tank or tanks
may be used as gas purifiers, the rest of the apparatus may be placed on the
upper part thereof to weight it for the purpose described.
The operation of the apparatus is as follows:-
The retorts having been filled with the gas producing mixture-say chlorate of
potash and oxide of manganese-and heat applied to the first retort by means of
the heating device, oxygen is given off and passes by the pipe to the gas-purifier
and thence into the gas-container where it is stored, being drawn off us required,
through the delivery tube, the heating-device shifting automatically to the second
retort, and so on, when the gas-container needs replenishment.
In the accompanying drawings-
Figure is a perspective view of one construction of apparatus according to
this invention, parts being broken away to illustrate the construction of details
where necessary.

page_text: Figures 2 and 3 are elevations of the apparatus, at right angles to each other
and partly in section, to show the appliances by which the movable heating-device,
hereinafter referred to, is controlled and operated.
Like letters indicate like parts throughout the drawings.
A is a box in which the apparatus is transportable, and which forms a base for
it when in use.
A' is the box lid. B is a cylindrical collapsable oontainer for
storing the oxygen; it consists of a flexible collapsable tube B₁ of gas-proof
fabric, closed at its upper and lower ends by discs B, having grooves 13 at their
edges, into which the fabric is tightly drawn by windings B of cord or wire so as
to secure a gas-tight joint between the flexible tube and the discs aforesaid. As an
alternative, a steel band with a tightening device at its ends may be substituted for
the wire or cord binding. The lower one of the two discs 13 is fixed inside the
box A to the bottom thereof.
B is a plate which supports the generating apparatus, and is carried upon the
upper disc B. Care guide rods, which, when the apparatus is being used for
generating oxygen, are screwed, as shown, into sockets A at the bottom of the
interior of the box, and extend upwards through tubular guides B6 attached to the
plate 15 in the expansion and contraction of the container B, the plate 15 and
the generating apparatus carried upon it as hereinafter described, rise and fall,
being guided in their rising and falling movement by the rods C. The weight of
the disc B plate B5 and the generating apparatus on the latter serves to maintain
the necessary pressure upon the gas in the container B. B is an elastic band
encircling the middle of the reservoir so that when it collapses it may fold inward
compactly.
The tubular guides 13 extend for a sufficient distance downward from the
underside of the plate B5 to prevent it from descending too close to the bottom of
the box, and thus the collapsable container B is protected against being crushed
or compressed into too small a compass. A are elastic loops provided upon the
box-lid A to receive the guide rods C and other parts of the apparatus when it is
dismantled and packed for transport.
the
A is a plate which operates in conjunction with apparatus carried on
moving plate 135 to release the movable heating-device, as will hereinafter be
explained.
On the plate 135 is a fixed framing D which comprises guides D on which
travels a lamp-carriage E running upon rollers (Figures 2 and 3): Fis a spring
attached at one end to the framing D and at its other end 3 coiled about and
attached to a pin E carried in a bracket E extending from the underside of the
carriage; this spring tends always to draw the carriage from that end of its guides
at which it is shown in Figure 1 of the drawings, to the opposite end, for a purpose
to be hereinafter explained.
Gis a lamp, screwed into the carriage E.
Above the guides D' is a frame 12 carrying a series of retorts H. Above each
retort is a cover II, these covers being connected together by a tubular con-
nection which communicates with the interior of each retort, and delivers gas
from the retorts by way of a pipe J through a non-return valve K into a purifier
or washer L, carried. like the rest of the apparatus, upon the plate B. The
lids Hare not intended to be removed from the retorts, but conversely, when the
retorts have to be re-charged, each is removed from beneath its lid; this enables
the construction of the apparatus to be simplified. Each retort is provided with
a flange H, by which it rests, beneath its lid, upon the side bars of the frame D².
Above each lid is a cross bar or bridge D³ through which passes a screw ])'
whereby cach lid can be forced close down upon the corresponding retort: the lids
are flanged at H3, and the edges of the retorts grooved as at H, the flange fitting,
if desired, into asbestos or other packing in the groove, so as to maintain a gas-
tight joint between them. It will be seen from Figure 1 that the side bars of the
frame 12 are cut away at D in proximity to each retort, so that if the screws D³
be slackened back to enable the lids H to be raised, any retort can be moved
..

page_text: along in the frame until it comes over the cut-away portions D³ of the bars,
when it can be readily lowered downward and out of the apparatus.
The purifier L is a box into which, as aforesaid, the gas from the retorts H
is delivered at one end through a non-return valve K: the inlet pipe L by
which the gas passes from the non-return valve into the purifier, is led down to
the bottom thereof, and along it, as shown in Figs. 1 and 3, being perforated
along the whole of its length with a number of minute perforations as at L
(Fig. 1), through which the gas issues into the liquid contents of the purifier,
rising to the surface thereof, and being withdrawn from the space L above the
liquid by a pipe I communicating with the interior of the container B by way
of the nozzle B carried on the top of the plate B
I is an overflow-orifice provided in one wall of the purifier near the top, and
having a screw plug L; this orifice is provided, in order that when the purifier is
being charged with liquid through one of the other openings it may be allowed to
overflow at the orifice 1 to ensure that an excess of liquid shall not be supplied to
the purifier; otherwise there would be a risk of overcharging it with liquid, which
night he forced by the pressure of the incoming oxygen, out by the pipo L and
into the gas-container.
fairly uniform
The purifier L and the rest of the apparatus carried upon the plate B³ are so
disposed that when the purifier is filled with liquid. there will be a
distribution of weight upon the top of the container B.
The means whereby the lamp G which effects the generation of gas, is caused
to shift from one retort. If to another automatically as soon as any one retort censes
to maintain the desired conditions of pressure and volume in the container B will
now he described:-
M is a rod pivoted to the framing D and extending centrally beneath the
guides in a direction parallel thereto; it is free to have a slight endwise move-
ment in the frame 1) against the resistance of a spring M' in compression between
the shoulder Al" and the frame. Fixed to one end of this pivotted rod is an arm Ma
aforesaid carrying at its outer end a roller M. The rod M has transverse levers M³
fixed to it each provided with two pins M, M7, the pins M being a little further
advanced than the pins Me in the direction of the travel of the carriage E away
from the end, of the guides at which it is shown in the drawings. On the
carriage E is a hinged depending flap E having two projections and E: one
of these projections is adapted to come into engagement with the pin Me the
other being adapted to come into engagement with the pin M. The flap E is
hinged in order that when the carriage has to be moved from the right-hand to
the left-hand end of the guides as viewed in the drawings, the flap will pass freely
and without hindrance over the pins M6 M7, which are not required to affect it
until it commences its return journey. From the drawing (Figure 3) it will he
seen that when the arm M³ is up the flap and carriage will be engaged by
one or other of the pins M, but when the arm M is down the flap will be engaged by
one of the pins M7.
The position of the parts when the apparatus is to he started is as follows:-
The container B, which is assumed to be empty, will consequently he collapsed,
and therefore the plate B5 will be at the bottom of its vertical travel in the box A.
the arm M then resting by means of its roller M against the plate A on the
inside of the box, so as to be held up. The earringe is placed. against the
resistance of the spring F. under the first retort 11, ie. that at the left-hand end of
Figure 2, say, which is charged with the proper agents. With the carriage in
this position the projection of the flap is engaged and retained by the pin M
on the first of the levers M. The lamp G should then be lighted, whereupon
oxygen will be generated from the contents of the first retort, and will flow through
the pipes and non-return valve K into the liquid at the bottom of the
purifier L by way of the perforations in the pipe L. ascending through the liquid
into the space and out into the container by way of the pipe L: by this
influx of gas the container will be expanded and the plate B and apparatus carried

page_text: upon it will consequently rise. As soon as the plate 13 has risen to its full extent,
the free end of the arm M will pass clear to the upper end of the plate A'; and
will descend under the influence of gravity: thus moving the pin M6 of the
arm M (Fig. 3) clear of the projection on the carriage flap, and almost simul-
taneously bringing the other pin M on the same arm M into the path of the
other projection E of the flap, so that the carriage E is able to make but a very
slight movement, not sufficient to take the lamp G from beneath the first retort.
Thereafter no change in the position of the parts takes place until gas is withdrawn
from the container B this will have the effect of partly collapsing it, and bringing
the plate 1 down again towards the bottom of the box A. As soon as the plate
has descended sufficiently far to bring the outer end of the arm M into contact
with the top of the plate A, the latter will begin to raise the arm, and a
small further descent of the plate 13 will raise the arm so far as to remove
the pin M² out of contact with the flap E", and allow the carriage E to fly
forward under the influence of its spring F; but the operation of removing the
pin M on the first of the arms M out of the path of the projection E on the flap
effected simultaneously the insertion in the path of the carriage of the pin M6 on
the succeeding arm M by which the carriage will be stopped as soon as it has moved
sufficiently far to bring the lamp under the second retort it. This retort in turn will
deliver its oxygen into the purifier L and container 1, and restore the desired
conditions of pressure and volume in the latter, after which the operations similar
to those described with reference to the generation of gas from the first and second
retorts, will be repeated, until the contents of the series of retorts have been
utilised.
The non-return valve K enables the retorts II to be removed from beneath their
covers for re-charging whenever desired, without risk of the return of gas or
liquid into the retorts by way of the pipes J J.
The capacity of each retort is preferably so related to that of the container B that
just sufficient gas is given off by the contents of one retort to completely fill the
reservoir. If desired springs D may be provided upon the guides D to check the
movement of the carriage at the end of its travel. When the pins M M are
struck by the projections EE from the carriage E spring M allows the rod M
to yield in order that the motion of the carriage and the lamp G may not be too
suddenly checked.
The whole apparatus is preferably so constructed that the various portions can bo
readily taken apart and stowed compactly in the box A for transport.
Nare studs secured at opposite ends of the plate B at the same distanco
apart as that of the pillars 17 upon which the frame D³ is supported, so that the
said frame when the apparatus has to be moved from place to place, can be
taken from the pillars 17 and secured upon the studs N by the screws D
which ordinarily hold it in place upon the pillars; these latter can be unscrewed
from their places and put into the loops A3 of the lid A. The lamp Gis
provided with a stem which screws into the carriage E and also screws
into a socket O on the platform, when the apparatus is to be moved from place
to place.
Instead of employing a spring F to move the lamp-carriage E along the
guides D, a weight or other motive agent can be applied thereto for a like
purpose. Or the weight of the lamp and carriage will suffice for their own
propulsion if the guides be slightly inclined. Any releasing device or motivo
agency controllable by the variation of quantity of gas in the container could bo
employed for the purposes of this invention in place of the apparatus hereinbefore
described by way of example.
Instead of a series of retorts a single long retort divided into compartments
could be used, the heating agent being caused to travel along its length to operate
in succession on different parts of its contents.
In some cases the traverse of the heater may be effected electrically by means of
a rising and falling part of the container B, or other moving part.

page_text: Instead of the operation of the container merely acting to permit the heating
device to travel it may itself effect the movement thereof. "Or it may be employed
to cut off or vary the intensity of heat supplied to the retort.
Although I have shown fixed retorts and a travelling heating device, I may in
some cases employ a stationary heating device and travelling retorts, or each may
move relatively to the other.
Conveniently a drier is interposed between the purifier L and container B, when
it is desirable that the gas should be quite dry before being used.
Having now particularly described and ascertained the nature of the said inven-
uon, and in what manner the same is to be performed, I declare that what I
claim is:-
1. Apparatus for producing oxygen in which the application of a heating ngent
to a retort is so controlled automatically as to proportion the generation of gas to
the expenditure thereof.
2. In apparatus for producing oxygen the combination of a divided retort or
series of retorts and a heating-device movable automatically in relation to each other
according to the consumption or expenditure of the gas for the purpose
specified.
3. Apparatus for producing oxygen in which the heating device is automatically
moved from one retort to the next or along a divided retort as the gas generated in
the retort or part of the retort already heated is used up or expended.
4. In apparatus for producing oxygen the combination with a divided retort or
series of retorts and a heating-device such as tending normally to move relatively
to each other of devices operating to permit such movement only upon reduction
of the quantity of oxygen in a container for the purpose specified.
5. In apparatus for producing oxygen the combination with a divided retort or
series of retorts and a heating device such as (i, tending normally to move relatively
to each other of devices to effect such movement upon reduction of the quantity of
oxygen in a container for the purpose specified.
6. In automatically-controlled oxygen-producing apparatus of the kind described
releasing gear such as M M controlling the movement of the heating device or of
the retorts and operated by the movement of a part of the gas-container B.
7. In automatically-controlled oxygen-producing apparatus the combination with
a travelling heating device such as G of a rod M and arms M thereon with or
without bulling springs or a hinged projection E for the purpose described.
8. In apparatus for producing oxygen the combination with a divided retort or
a series of retorts and a heating-device movable relatively to each other of operating
or controlling mechanism therefor.
9. In apparatus for producing oxygen the combination with a series of flanged
retorts of a frame 1 cut away as at D for the purpose specified.
10. The combination and arrangement of parts constituting a complete apparatus
for the production of oxygen substantially as and for the purpose described and
illustrated in Figures 12 and 3 of the accompanying drawings.
1002
FREDERICK J. STEDMAN.
Boult & Wade,
Agents for the Applicant.