Improvements in Acetylene Gas Generators.
Year: 1897

page_text: Date of Application, 1st June, 1897-Accepted, 3rd July, 1897
Improvements in Acetylene Gas Generators.
I, FRANK AUSTIN MITCHELL, of Wilmington, in the County of Newcastle, and
State of Delaware, United States of America, Manufacturing Roofer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
-
My invention has relation to apparatus for the manufacture of acetylene gas, and
among the objects in view is to provide an apparatus of the character referred to
wherein danger of bursting of the apparatus or blowing out of the gasometer due
to undue pressure of the generated gas is avoided; to provide an apparatus which
shall be adapted to give an alarm when the carbide is completely or nearly
exhausted; to prevent flooding of the generator with water; to prevent freezing
of the water within the water-reservoir when the apparatus is placed in exposed
positions or when used in cold climates; to provide means whereby the escape
of gas into the room when the generator is uncovored for recharging is avoided;
to provide for the complete utilization of all carbide placed within the generator
and prevent the formation of a crust upon the surface of the carbide; and also
prevent possible bursting of the holder or blowing out of the bottom thereof; to
provide an apparatus which is entirely safe and which needs no attention from the
time the same is started until all carbide is exhausted; to provide an apparatus
which is extremely compact and requires but little space thus adapting it for
convenient packing and shipment, and with the above and other objects in view,
all of which will hereinafter appear.
The invention consists in the novel construction arrangement and combinations
of parts as hereinafter fully described, illustrated in the accompanying drawing
and pointed out in the appended claim.
In the drawings :-
Fig. 1 is an elevation of the complete apparatus constructed in accordance with
my invention.
Fig. 2 is a vertical sectional view partly in elevation, and upon an enlarged
scale.
Fig. is a horizontal sectional view partly in plan of the apparatus.
Fig. 4 is a vertical sectional view of the generator, carbide holder and pump on
an enlarged scale.
Fig. 5 is a sectional view of the cover for the generator and the means for
confining the saine in position.
Fig. 6 is an elevation of the carbide holder removed from the generator.
Fig. 7 is a sectional detail view of the automatically-operated valve in the water
pipe and the means for operating it.
Fig. 8 is a similar view of the automatically-operated valve in the gas pipe and
the means for operating it.
Apparatus of the described character as constructed in many instances heretofore
are open to many and serious objections, among which may be mentioned the great
amount of space required for setting the same up, the complex working parts which
require repeated and constant attention and which frequently get out of order and
[Price 8d.]

page_text: render the machine inoperative; dangor of bursting of parts of the apparatus or
blowing out of the gasometer or of the water seal and escape of gas into the room,
improper water feed, no provision for cutting off or regulating the supply of water
to the carbide when the quantity of gas has reached a considerable extent, no
provision for cutting off the supply of gas when the pressure of the gas already
generated has reached a comparatively high degree, improper action of the water
upon the carbide and consequent loss of carbide and frequent refilling of the
holder, danger of bursting of said holder or blowing out of its bottom, and frequent
attention of a person to keep the apparatus in proper working order. All these
and other objections combine to render the present machines or many of them
decidedly objectionable, and the apparatus which forms the subject of this applica-
tion is designed to overcome all the recited objections, and in order that my
invention may be clearly understood I will describe the same in detail, referenco
being had to the accompanying drawings.
A indicates a casing of suitable material as galvanized iron, steel and the like,
which casing may, of course, be made of various dimensions and shapes. I show
a casing which is cylindrical, and the same is closed at its bottom and open at its
top and is designed to serve as a water receptacle or reservoir. It may be provided
with any suitable and convenient means for filling it, as for instance a funnel A³
attached thereto near its upper edge. It may also be provided with a draw-off or
drain-cock A located near the bottom and to which cock a hose may be attached.
If desired, the reservoir may be charged with water through said cock. The
water-reservoir is also provided at the side with a water-gauge A³ adapted to
indicate the lovel of the water within the reservoir.
Arranged within the water reservoir and adapted to rise and fall therein is a
casing B, the open end whereof is arranged downward, and the closed end upward,
the said lower end of which casing dips within the water in reservoir A. The
casing is adapted to serve as a gasometer for the generated gas and the water
serves as a seal to prevent the escape of the gas from within the gasometer. The
gasometer may be constructed of metal similarly to the water reservoir and it may
also be varied somewhat in shape, it being shown in the present instance as
cylindrical.
In order that the gasomoter may be properly guided in its rising and falling
movements and the proper position maintained, suitable guides may be provided,
as for instance a grooved or channeled rib a, attached to the inner wall of the
reservoir and within which rib fits and slides a rib a' attached to the outer wall
of the gasometer.
The capacities of the water reservoir and gasometer may, of course, be varied.
C indicates the generator which I make of the conical or tapering shape shown,
the larger end being uppermost, and this generator may vary in size and be made
of any suitable material capable of withstanding more or less internal pressure.
D indicates a lid or cover for the generator which cover is provided with a
oircumferential groove d, within which is seated a rubber or other suitable
gasket which, when the cover is in position upon the generator seats upon the
upper edge of the latter so as to make a gas-tight joint therewith.
The under face of the cover is provided with a concavity as indicated at d³,
which may be rounded or slightly conical in shape, and the edge d³ is adapted to
lie practically in a vertical plane with the circumferential upper edge of the carbide
holder, presently described more fully, when said holder is in place, and the cover
seated upon the generator. The object of this construction and arrangement is
to cause the water of condensation which will naturally collect upon the under
face of the cover within the concavity to run down along the inclined surface and
drip into the carbide holder to thus assist in generating gas, and thus I avoid the
accumulation of such water of condensation which in generators as heretofore
constructed collects in the bottom of the generators and has to be frequently
drawn off, or else acts upon the carbide when accumulated to a great extent to
produce gas in a dangerous quantity.
4

page_text: The cover is adapted to be tightly secured in place upon the generator by means
of a screw-rod or spindle E which screws within a bail E' pivotally connected to
the sides of the generator and the lower end of said screw-rod is adapted to bear upon
the upper face of the cover so that when screwed tightly down said cover will be
firmly held in position and be capable of resisting considerable pressure from the
gas within the generator, in fact more than will in practice be brought to bear
upon it.
When it is desired to empty the exhausted carbide from the generator and
holder, and charge with a fresh supply, the screw-rod is screwed up and the bail
swung down to free the cover when the latter may be easily removed.
F indicates my improved carbide holder. The same is made tapering or conical
similar to the generator within which latter it is placed, though I prefer to taper
anid holder somewhat more than the generator so that there will be formed between
the two a gradually widening space from the top downwardly, which will thus
facilitate the easy removal of the holder then desired. I also give a rounded
shape to the holder at its bottom whereby the said holder may be more readily
cleaned of its exhausted carbide which would if the bottom were flat, collect in
the corners or angles and render the perfect cleansing of the holder difficult.
The upper circumferential edge of the holder is designed to be adjacent to the
inner wall of the generator with a slight intervening space. By reason of the
relative shapes of the holder and generator and their relative arrangement, the
holder may be readily removed from the generator when necessary, and further-
more, by reason of the holder being conical the exhausted carbide can be readily
dumped out of it, leaving no particles thereof to remain within the holder.
This would not be the case were the holder made of cylindrical shape as
heretofore practiced.
I also prefer to give a rounded shape to the bottom of the generator, and provide
n draw-off or drain cock G for drawing off any water that may collect in the bottom
of the generator.
With generators as heretofore constructed when the covers thereof are removed
for cleaning and recharging, such gas as is contained in the generators (and there
is always more or less of said gas present) will escape into the atmosphere and as
this gas possesses a very pungent noxious odor, it is desirable to avoid this con-
tingency. For this purpose I provide means for removing all gas remaining in the
generator and conveying it into the gasometer, said means consisting of a suitable
pump H, the connecting pipe h, entering the generator adjacent to its bottom, said
pump being thus adapted to force the gas through the pipe I which leads from the
generator near its upper end downwardly through the reservoir A near the lower
end of the latter, and thence upwardly within the reservoir and discharging the
gas at a point above the highest water-level therein, such level being indicated by
the line. Thus by operating the pump for a few moments the generator is
freed from gas and the cover may be removed without any gas escaping into the
atmosphere.
I locate a suitable check valve K in the pipe I which opens in a direction to
permit the gas to pass from the generator to the gasometer, but prevents any
return flow.
A suitable pressure gauge M is applied to the pipe I to indicate the gas pressure
within the apparatus. I would state that in practice this gauge does not under
normal conditions, that is to say, when the gasometer is not abnormally charged
with gas indicate any pressure beyond atmospheric pressure, and only begins to
indicate the pressure of the gas when the storage tank or holder, presently
Jescribed, is filled with gas.
The generator is held to the water reservoir by supporting straps, whereby the
entire device is capable of being transported or shipped as an integral machine.
The lower end of the pipe I just before it enters the water reservoir may have.
regulating cock I' though this is not necessary; I however prefer to use it as
he quantity of gas delivered to the gasometer may thus be regulated.

page_text: N is a water gauge applied to the water reservoir to indicate the level of the
water therein.
For the purpose of conveying water from the reservoir to the generator for the
purpose of generating gas, I provide a pipe O which leads from within the upper
portion of the reservoir at a point above the high-water level, downwardly and
through the wall of the reservoir adjacent to its bottom and thence upwardly and
into the generator near its upper end.
Said pipe O is provided at a point somewhat below the high-water level with a
branch through which water feeds into the pipe O until the level falls below said
branch pipe, in which latter event the water reservoir will need recharging to
restore the level to a point above said branch.
In apparatus of this character it is desirable to automatically cut off or regulate
the supply of water fed to the generator when the quantity of gas generated
increases to a certain extent and also to increase the supply of water fed to the
generator when the consumption of the generated gas increases, and for these
purposes I provide means operated automatically by the rising and falling move-
ments of the gasometer. These means comprise a cock or valve P in the pipe O
upon the extended plug of which valve is rigidly mounted an angular lever R, one
arm r, of which is weighted at, the arrangement being such that in the normal
position of the lever, the plug of the valve will be in a position to supply water to
the fullest extent through the passage, but that when the lever is partially turned
in either direction, the supply will be diminished or entirely cut off according to
the extent to which the lever is turued. The inner wall of the gasometer is pro-
vided with two blades or ribs S S' in practically the same vertical plane, there
being a space of greater or less extent separating said blades. These blades are
adapted to strike the arm of the lever R when the gasometer rises and falls,
and thus turn the plug of the cock from its normal or fully open position.
When the quantity of generated gas increases considerably and the gasometer
accordingly rises to a considerable extent, the blade S will strike the arm r' and
turn the lever and plug of the valve so as to gradually cut off the feed of water to
the generator until finally the feed will be entirely cut off, and as the gas is
consumed the gasometer will begin to fall and the blade S will gradually permit
the lever Runder the influence of its weighted arm r, to resume its normal
position, the feed of the water in the meantime gradually increasing until the
arm clears the blade S at which moment there will be a full flow of water to
the generator. Should the carbide become exhausted and the gasometer begin
to fall, the blade S' will strike the arm and gradually turn the plug of the valve
until the supply of water is entirely cut off from the generator. In this way,
flooding of the generator is prevented.
The pipe O is provided with a regulating valve ( which can be set to control
the quantity of water fed through said pipe.
In order to provide for admitting water to the generator in considerable volume,
as for instance when it is desired to generate gas quickly, as in the beginning of
the operation of the machine, I provide a branch pipe 0 leading from the interior
of the water reservoir and joining the pipe and being provided with a valve O*.
By turning the latter valve water will be admitted in considerable volume into the
pipe 0 and thence into the generator, and as the gasometer begins to rise due to
the generating gas the cock or valve 0 is closed and the necessary water for
further generation will be supplied automatically through the valvo P in the
manner herein before explained.
"
This valve O' which I term an emergency" valve is not intended to be used
excepting in the beginning of the operation, or where at any time it is desired to
obtain gas quickly. The regular feed of water is to take place through valve P
as above mentioned.
By the described arrangement of valves, weighted lever and operating blades,
the machine after having once been started, will be automatic in its operation

page_text: with no danger of generating too great a quantity of gas or flooding of the
generator, and will require no attention after being once started until all the
carbide is exhausted.
In order to avoid any danger of blowing out of the gasometer due to considerable
gas pressure caused by accumulation of considerable gas within said gasometer, I
provide a valve T located in the gas pipe I, the plug of which valvo carries an
arm weighted at T, T, said arm lying in the path of and adapted to be struck
by a blade or rib 1 on the inner wall of the gasometer near its lower end.
Should the gasometer rise very high, the blade will strike the arm and turn
the same and the plug of the valve to cut off the flow of gas into the gasometer,
and any further accumulation of gas will How by branch pipe T5 joining the pipe 1
adjacent to the bottom of the apparatus, and into the storage or overflow tank or
holder arranged within the gasometer, which tank thus serves as a reserve or
overflow receptacle and is capable of withstanding considerable pressure.
By reason of the tank being located within the gasometer and surrounded by
water, and gas therein will be cooled and said tank by occupying considerable space
within the gasometer reduces the quantity of water necessary for operating the
apparatus.
In order that an audible alarm or signal may be given to indicate that the carbide
is becoming exhausted, I provide a bell V adapted to be operated mechanically by
the gasometer when the latter is reaching its lowest limit of movement, or said bell
may be operated electrically by providing contact plates V', V one on the gaso-
meter and the other on the water-reservoir, and providing suitable electrical
connections between said plates and the bell.
In apparatus of this character as heretofore constructed it has been customary
to feed the water on to the carbide over its upper surface. This causes the
uppermost strata of the carbide to first become exhausted and form a thick and hard
crust which prevents almost absolutely the penetration of water to the lower strata
of the carbide. In this way, great quantities of carbide are wasted and frequent
recharging becomes necessary. In order to avoid said disadvantages I so feed
the water to the holder that the lowermost strata will be first acted upon and the
gas generated from said lower strata will rise through the remaining carbide and
tend to open up or separate the particles which thus are prevented from becoming
clogged and rendering the water more easy of access between the particles. In
order to accomplish the described feed of the water I arrange the inner discharge
end of the water-supply pipe at a point just above the upper edge of the holder so
that the water flowing through said end will flow down along the inner wall of the
holder to the bottom thereof to act upon the lower strata of carbide, and as the
different strata become exhausted, the same will not affect the strata above them.
This I consider a very important feature of my invention and the advantageous
results obtained by this method of feeding the water will be at once apparent in
the practical operation of the apparatus.
Inasmuch as the inner discharge end of the water feed pipe projects slightly
beyond the upper edge of the carbide holder, said end might obstruct the free
removal of said holder, and to avoid any obstruction I provide the upper portion
of the holder with an indentation or depressed portion so that by turning the
holder around to bring the said depressed portion directly beneath the projecting
end of the pipe, said holder may be readily lifted out of the generator.
W indicates the gas service pipe which leads from a point above the high-water
level downwardly within the gasometer and out through the reservoir casing and
thence to the point at which the gas is to be used. A suitable valve W' is provided
in the pipe W, for regulating the quantity of gas delivered by said pipe.
Inasmuch as it is desirable to avoid freezing of the water within the apparatus
which might result in bursting the water reservoir or other parts of the apparatus,
I provide any suitable means for maintaining the temperature of the water above
freezing point at all times, and these meaus may consist of a burner or burners

page_text: supplied with gas from the main service pipe or they may, as shown, consist of a
coil of pipe X arranged beneath the bottom of the apparatus and supplied with a
heating medium from any suitable source.
The operation of the apparatus may be briefly described as follows: The holder
having been charged with the carbide of calcium, the cover firmly secured, and
water having been supplied to the water reservoir until the high-water level is
reached, the valve O is opened to permit a full feed of water to flow through
pipes 03, and 0, into the generator, and down the inner wall of the holder to act
upon the carbide therein. The cock or valve O' is kept open for a few moments
only, and is then closed, and as the gas generates in the generator it flows through
pipe 1 and is discharged within the gasometer above the water level. As the
generation of gas continues, the gasometer rises and the upper blade S' gradually
frees the arm, to permit the plug of the valve P to gradually open which it
does to its greatest extent when the blade clears the arm, and as the gasometer
continues to rise the lower blade 8 will strike against the arm and gradually close
the valve, thus cutting off gradually the supply of water to the generator. As
soon as the generation of gas ceases, the gasometer will remain stationary until
the consumption of gas at the burners reduces the quantity within the gasometer
when the latter will begin to fall the blade S permitting the arm to turn to cause
a corresponding increase in the water feed until when said blade fully clears the
arm there will be a full feed of water which will act to again cause a full generation
of gas and so on during the entire time that there is unexhausted carbide in the
holder.
Thus it will be seen that there is an automatic operation of the parts, the
apparatus generating gas only when it is needed, and cutting off the generation
when the burners are not consuming gas.
As the carbide becomes exhausted, the gasometer will descend gradually lower
until the cock or valve actuated by the blade S' will have entirely cut off the feed
of water and the alarm will be actuated to give warning of the exhaustion of all
carbide, and the generator may then be emptied of its exhausted carbide and
fresh carbide placed in the holder in the manner hereinbefore described.
Should the generation of gas be such that the gasometer will rise to an extent
sufficient to cause the blade to act upon the arm T" of the valve plug to close it,
the overflow of gas will then flow into the holder U through branch pipe T. Thus
the apparatus is entirely safe inasmuch as there is no chance of the gas pressure
becoming abnormally high in the gasometer at any time, as owing to the provision
of the automatically-operating valves there can be no supply of water to the carbido
when the quantity of gas already generated exceeds a certain limit.
It will be understood that various changes may be made in the arrangement
and details of construction of the parts without departing from the principle or
scope of the invention.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In an apparatus for the manufacture of acetylene gas, the combination with
a water reservoir, and a gasometer, of a generator, a valved water supply pipe
between the reservoir and the generator, and a valved branch water pipe com-
municating with the generator whereby to provide independently controllable
water feed connections between the generator and the water reservoir.
2. In an apparatus for the manufacture of acetylene gas, the combination with
a water reservoir, of a gasometer adapted to rise and fall therein, a generator a
gus pipe leading from the generator into the gasometer, a valve in the gas pipe,
vaghted arm on the plug of the valve, and a blade or rib on the gasometer
lapted to operate the arm when the gasometer rises to a predetermined height to
cut off the flow of gus to the gasometer.
3. In an apparatus for the manufacture of acetylene gas, the combination with

page_text: a water reservoir, of a gasometer adapted to rise and fall therein, a generator a
gas connection between the generator and the gasometer, a water connection
between the reservoir and the generator, a valve in the water connection, a lever
on the plug of said valve, and blades or ribs on the gasometer adapted to strike
and operate said lever in both the upward and downward movements of the
gasometer, for the purpose specified.
4. In an apparatus for the manufacture of acetylene gas, the combination with
e water reservoir, of a gasometer, a generator, a gas connection between the
generator and the gasometer, a water connection between the reservoir and the
generator, a valve in the gas connection adapted to be operated by the gasometer
when the latter rises to a predetermined point to cut off the flow of gas to the
gasometer, a valve in the water connection adapted to be operated by the gasometer
when the latter rises to a predetermined point, the parts being so arranged that
the water valve will be operated to cut off the water supply prior to the operation
of the gas cut off valve.
5. In an apparatus for the manufacture of acetylene gas, the combination with
water reservoir, of a gasometer adapted to rise and fall therein, a generator a
gas connection between the generator and the gasometer, a water connection
between the reservoir and the generator, a valve in the water connection, a lever
ou the plug of the valve, and bludes or ribs on the gasometer adapted to strike
and operate said lever in both the upward and downward movements of the gaso-
meter, said blades or ribs being in different horizontal planes and separated by
a space whereby a full supply of water will be fed to the generator in the upward
and downward movements of the gasometer from the time that the lever is freed
from one blade until it is engaged by the other blade, as specified.
6. In an apparatus for the manufacture of acetylene gas, the combination with
a generator, of a carbide holder arranged therein, a cover removably seated on
the generator, and having a more or less conical-shaped recess on its underface,
the outer circumferential edge of the recess terminating in a vertical plano not
beyond the circumferential edge of the holder whereby moisture condensed within
the recess will flow along the walls of the recess and be discharged into the holder
along its inner circumferential wall.
Dated this 1st day of Juno 1897
BOULT & WADE,
Agents for the Applicant.