Improvements in Apparatus for Mixing Two or More Gases in any desired Proportions.
Year: 1898

page_text: Date of Application, 26th Mar., 1898
Complete Specification Left, 24th Dec., 1898-Accepted, 4th Feb.,
1899
TRUVIDIONAL DIUITIATIV
Improvements in Apparatus for Mixing Two or More Gases in any
desired Proportions.
We, PERCY CRUNDALL DAY, of 63, Queen Victoria Street, in the City of London,
Engineer, and THE ACETYLENE ILLUMINATING COMPANY. LIMITED, of 63, Queen
Victoria Street aforesaid, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to apparatus for mixing two or more gases in any
desired proportions and is especially adapted for mixing acetylene with oil gas, or
with air, the element of danger generally present in the latter mixture being
thereby reduced to a minimum.
A characteristic feature of the apparatus is the use of two or more concentric
gas holders or gas bells, the number depending upon the number of gases to be
mixed; the volumes of the concentric cylindrical gas bells being proportional
to the relative volumes of the various gases required in the mixture.
The gases are fed into the holders simultaneously from any convenient source
of supply, each to its proper cylinder, all the gases being under a moderate pressure
of not more than say a few inches of water pressure.
Discharge pipes from the several cylinders converge at a point near the same
to form a common supply main.
1
Since the gas holders are concentric and move all together, it is evident that
when gas is drawn from the main thereby causing the holders to descend, the
quantity of gas forced out from each concentric holder will always be proportional
to the cross-section of that holder less the cross section of the cylinder (if any)
that is enclosed within it.
The gases must therefore converge in their proper proportions into the main,
provided the holders are in the correct ratio.
It is preferable to have an equal pressure in each of the gas holders, and for this
purpose the various holders may be connected by small pipes including liquid-
sealed U tubes of the ordinary type placed in a prominent position outside. The
gases flowing into the holders can be regulated from observations of the pressure
gauges.
To facilitate the intimate admixture of the gases a suitable device may be em-
ployed such for example as a set of baffles placed in a small chamber at the junction
of the outlet pipes from the holders with the supply main.
The area of the outlet pipes should be proportional to the volumes of gas to be
passed through each so that the velocities of all the gases may be equal at the
point of convergence.
The action of the apparatus is quite automatic, and after the rates and pressures
of supply have been adjusted and equalised the gases may be run in and out again
continuously at the same rate and the combined holder be kept almost stationary.
Although we have described the holders as consisting of concentric cylinders, this
being the preferred construction, they are not necessarily concentric or even placed
one within another so long as they move together and their volumes are of the
requisite relative proportions.
If thought desirable the supply valves to the gas holders can be shut off whilst

page_text: the valve between them and the main is open, thus preventing any possibility of
direct passage of gas from the sources of supply to the outlet pipes from the holders.
By connecting together the supply valves to the holders and the valve to the main
the former can be shut off when the latter is open but this will not be necessary
so long as the pressures in the gas holders are kept equal.
It is evident that if the above described arrangement be used for mixing
inflammable gas with air, a large element of danger is obviated since there is no
mixture stored in the gas holders.
Dated this 26th day of March 1898
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
Improvements in Apparatus for Mixing Two or More Gases in any
desired Proportions.
We, PERCY CRUNDALL DAY, of 63, Queen Victoria Street, in the City of London,
Engineer, and THE ACETYLENE ILLUMINATING COMPANY LIMITED, of 63, Queen
Victoria Street aforesaid, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention has reference to apparatus for mixing two or more gases in any
desired proportions and is especially adapted for mixing acetylene with oil gas, or
with air, the element of danger generally present in the latter mixture being
thereby reduced to a minimum.
A characteristic feature of the apparatus is the use of two or more concentric
gas holders or gas bells, the number depending upon the number of gases to be
inixed; the volumes of the concentric cylindrical gas bells being proportional
to the relative volumes of the various gases required in the mixture.
The gases are fed into the holders simultaneously from any convenient source
of supply, each to its proper cylinder, all the gases being under a moderate pressure
of not more than say a few inches of water pressure.
Discharge pipes from the several cylinders converge at a point near the same
to form a common supply main.
Since the gas bells are concentric and move all together, it is evident that
when gas is drawn from the main thereby causing the holders to descend, the
quantity of gas forced out from each concentric holder will always be proportional
to the cross-section of that holder less the cross section of the cylinder (if any)
that is enclosed within it.
The gases must therefore converge in their proper proportions into the main,
provided the holders are in the correct ratio.
It is preferable to have an equal pressure in the several gas holders, and for this
purpose the various holders may be connected by small pipes including liquid-
sealed tubes of the ordinary type placed in a prominent position outside. The
gases flowing into the holders can be regulated from observations of the pressure
gauges.
To facilitate the intimate admixture of the gases a suitable device may be em-
ployed such for example as a set of baffles placed in a small chamber at the junction
of the outlet pipes from the holders with the supply main.
The area of the outlet pipes should be proportional to the volumes of gas to be
passed through each so that the velocities of all the gases may be equal at the
point of convergence.

page_text: The action of the apparatus is quite automatic, and after the rates and pressures
of supply have been adjusted and equalised the gases may be run in and out again
continuously at the same rate and the compound holder be kept almost stationary.
Although we have described the holders as consisting of concentric cylinders, this
being the preferred construction, they are not necessarily concentric or even placed
one within another so long as they move together and their volumes are of the
requisite relative proportions.
If thought desirable the supply valves to the gas holders can be shut off whilst
the valve between them and the main is open, thus preventing any possibility of
direct passage of gas from the sources of supply to the outlet pipes from the holders.
By connecting together the supply valves to the holders and the valve to the main
the two former can be shut off when the latter is open but this will not be necessary
long as the pressures in the gas holders are kept equal.
SO
It is evident that if the above described arrangement be used for mixing
inflaminable gas with air, a large element of danger is obviated since there is no
mixture stored in the gas holders.
In practice it has been found preferable to alternately charge and discharge the com-
pound holder, first drawing into each concentric holder a charge of gas and then for-
cing them all out into a mixing chamber, whence the mixed gases can flow to storage
or to be used direct. The gas holders should be provided with separate annular
seals, to minimise any error which might otherwise occur from unequal pressures
in different compartments.
The concentric bells should be guided to rise and fall very smoothly and be
counterweighted to a fairly good balance by means of counterweights.
Figure 1 of the accompanying drawings is a general plan view of an apparatus
constructed in accordance with our invention, the particular apparatus illustrated
being specially adapted for mixing acetylene and oil gas for railway carriage
lighting. Figure 2 is a vertical section on a larger scale than Figure 1 of the two
concentric gas holders. Figure 3 is a section on a still larger scale of the mixing
chamber..
c is a gas bell in
a is a reservoir of oil gas and is a reservoir of acetylene.
communication by means of the pipe with the oil gas reservoir a, and e is a stop
cock on the pipe d. f is another gas bell situated within and concentric with the
gas belle and in communication with the acetylene reservoir by means of the
pipe g. is a stop cock on the pipe g. The two gas bells cand e move up and
down together within two concentric annular cylinders which are provided with
annular seals k 1. The bells are guided by a vertical rod m which passes between
guide rollers n n and through a guide way p in the fixed beam and are counter-
weighted by means of the weights r. The weights are connected to a bracket pl
on the top of the cylinder by wire ropes 2 attached at one end to hooked bars that
carry the weights and at the other end to hooks on the bracket, the ropes pass
over guide pulleys. The guide rod m is screwed at its lower end into the
bracket ¹. s is an outlet pipe from the bell and t an outlet pipe from the bell e;
these two outlet pipes both lead to a mixing chamber (seen separately in Figure 3)
5 the discharge end of the pipe t being formed with numerous outlet holes as shown
so as to facilitate the mixing of the two gases. From the mixing chamber u a
main pipe fitted with a cock w leads the mixed gases either to a storage chamber
or direct to the place of consumption as may be desired.
C
In addition to the stop cocks & and on the pipes d and h these pipes are pro-
O vided with other cocks marked respectively y¹ and y², and on the two outlet pipes s
and are cocks marked respectively y³ and y'. The levers z of these 4 cocks are
all connected to one link A and are operated simultaneously by the piston of a
hydraulic cylinder B under the ordinary pressure of the district supply main, the
When the 4 levers are 45° to
rod C of the piston being connected to the link A.
5 the centre lines of the 4 pipes dhst (as shown in Figure 1) the two charging
pipes d h are closed and the two outlet pipes s and t are open. When the levers
are parallel with the centre lines of the pipes all 4 cocks
are closed

page_text: and when the levers
are 45° to the right of the said centre lines
the two outlet pipes and are closed and the two charging pipes d
and h are open. The hydraulic cylinder and piston are actuated
by a hydraulic valve at D worked from the rise and fall of the gas bells either
direct or through the medium of the cam and weight device shown in the drawings.
This device is arranged as follows-On a spindle E (Figure 1) to which the valve
rod is connected is keyed a cam or disc F having a projection G. On another
spindle H is keyed a weighted lever J and on this spindle is also mounted a crank K
having a pin L (Figure 2) working in a stirrup M at the lower end of a long rod N.
This rod passes freely through the weights and is fitted with upper and lower
tappets P PI As the gas bells rise from their lowest position as shown in Figure 2
the weights gradually descend and when they reach the lower tappet P" they begin
to move the rod N down with them. The crank K thus causes the spindle H to
turn so that the weighted lever J is gradually lifted. When this lever passes the
vertical position it suddenly drops into the horizontal position shown in dots in
Figure 2 and in dropping it strikes the projection G on the cam and gives the cam
together with its spindle E a partial revolution by which the hydraulic valve is
consequently operated. When on the other hand the gas bells are descending and
the weights rising, the weights when they reach the upper tappet P begin to
lift the rod N with them. The weighted lever J is therefore lifted in the reverse
direction to that above described and when it passes the vertical position it drops
into the horizontal position shown in full lines in Figure 2; in dropping it strikes
the cam projection G and causes the spindle E to turn, thereby reversing the valve.
In practice, the mixing gas holders are balanced to zero pressure by adjusting
the counterweights r. The holders a and b for the unmixed gases are kept at equal
pressures of a few inches of water, and the demand from the discharge is arranged
to maintain a suction of a few inches of water pressure. The machine will then
run continuously when started until the main discharge pipe is shut off, but as
soon as the demand on the discharge ceases the whole machine will stop owing to
there being no suction in the discharge pipe. The cocks of course, be worked
by other than hydraulic means.
can,
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what we
claim is-
1. In apparatus for mixing two or more gases, the employment of two or more
gas holders or gas bells (preferably concentric) which move together and whose
volumes are proportioned to the relative volumes of the respective gases required
in the mixture, the several holders being simultaneously supplied with the respec-
tive gases from any convenient sources, and the said gas bells having separate
discharge or outlet pipes leading to a common mixing device in which the gases
become mixed before passing on to the main or to storage, substantially as herein-
before described.
2. The apparatus constructed, arranged and working substantially as herein-
before described with reference to the accompanying drawings for mixing two or
more gases in any desired proportions.
Dated this 24th day of December 1898
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.