Improvements in the Production and Purification of Acetylene Gas, and in Apparatus therefor.
Year: 1896

page_text: Date of Application, 24th July, 1896
Complete Specification Left, 10th Dec., 1396-Accepted, 30th Jan., 1997
PROVISIONAL SPECIFICATION.
PROVISIONAL SPECIFICATION.
Improvements in the Production and Purification of Acetylene Gas,
and in Apparatus therefor.
We, ARMAND SCHEMIDT, of 33 Avenue de la Tour, Vitry sur Seine, Engineer,
and OTTO KAUFMAN, of 10 Rue du Quatre Septembre, Paris, Merchant, both in
France, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the production and purification of
acetylene gas, and in apparatus therefor.
According to our invention we obviate the inconveniences and danger arising
from the production of acetylene gas, as now effected, and instead of causing the
water to be fed in small quantities to the generator containing calcium carbide, we
cause the calcium carbide to be fed in small quantities to the generator. In this
way we have no loss of raw material, and no longer fear crystallization or vitri-
fication, which is sometimes produced on the surface of the accumulated carbide
owing to the quantity of water required to attack it not being supplied with
mathematical correctness. In the same way as we avoid all loss of the raw material
(carbide) by the use of our improved generating apparatus, about to be described,
so we also avoid all loss of the manufactured material (acetylene gas).
Calcium carbide, as at present made for commercial purposes, is always more or
less impure; it is never chemically pure, and the acetylene, which is evolved there-
from with great violence, carries with it a certain amount of impurities, some of
which are not injurious whilst others are very injurious, not only to the illuminating
power of the flame, but also to the primary qualities of the gas.
The impurities met with in acetylene gas are:-Hydrogen, which, not being
detrimental, we retain; nitrogen, which is present under the same conditions:
carbonic oxide, which, it is true, is poisonous, but as very small quantities are
found in acetylene, we do not deem necessary to remove ammoniacal salts,
which attack lead piping, and which give to acetylene gas a very sickening and
too characteristic odour; this impurity we therefore entirely remove; sulphuretted
hydrogen, which attacks and blackens metal and gives to the gas a very disagree-
able odour of rotten eggs; this impurity we likewise entirely remove water
vapour, which is injurious to the steadiness of the flame, and which we remove by
desiccation and, finally, the small amount of tar and essential oils, which foul
the burners and nozzles, we remove by washing, or by draining off. Acetylene thus
purified no more attacks metals than does ordinary lighting gas, and, prepared
according to our invention, becomes more readily compressible and liquefies at the
normal temperature of +15° C., at a pressure of 38 to 40 kilos., whereby we are
enabled to entirely discard the use of refrigerants to effect liquefaction. We obtain
direct liquefaction and so obviate the danger of bursting of the receiving bottles
or containers we employ, which are of the kind used for compressed gas, and
which, being inade of drawn steel, are liable to become tempered by repeated
alternate subjection to a very cold temperature (such as is necessary when
employing refrigerants) and to the normal temperature.
The apparatus for the manufacture and purification of acetylene gas, according
to our invention, comprises a generator, from which the gas, on issuing, passes into
a worn wherein it is cooled. Thence it passes into a suitable number of purifiers,

page_text: say three, and into a gas holder, from which latter it is drawn by a compression
pump and delivered into a desiccator. It then enters a first receiver. The dried
gas is withdrawn from this receiver, by a second pump, and is sent into a second
receiver. On leaving this receiver, the gas is again cooled in another worm and
is admitted to the steel bottles or containers which are in communication with the
apparatus by flexible tubes.
The said generator is provided with a hopper into which crushed calcium carbide
is placed, and brought by the working of a reciprocating slide opposite an opening at
the top of the generator. The carbide then falls upon a suitably operated rocking
grid. Water is admitted through an inlet pipe at the upper part of the generator
and falls gradually onto the carbide. On contact taking place, acetylene gas is
steadily evolved and passes out through a pipe at the upper part of the generator,
whilst the lime remaining in suspension in the water, which is continuously agitated
by stirrers, runs off through a pipe at the lower part of the generator. It is
therefore unnecessary to stop, or take to pieces our new generator for re-charging,
as this is effected automatically by the slide; and moreover the continuous flow of
water keeps the apparatus clean and carries away the milk of lime resulting from
the production of the gas.
We have found that, for purifying acetylene, good results can be obtained by
the use of the following materials:-
A 10% solution of hydrochloric acid in the first purifier, for washing the gas
on its leaving the generator, and which serves to remove the ammonia.
Water containing 5% of soda, or potash, in the second purifier, for washing the
gas to remove all other traces of acids.
A saturated solution of neutral lead sub acetate in the third purifier, through
which the gas, already freed from its acids, is passed, for removing the sulphuretted
hydrogen.
And finally, drying the gas by passing it either into concentrated sulphuric acid,
or over dried calcium chloride, or over quicklime, for removing moisture or water
vapour.
Dated this 24th day of July 1896.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5 Market Street, Nottingham,
Agent for the Applicants.
Improvements in the Production and Purification of Acetylene Gas,
and in Apparatus therefor.
We, ARMAND SCHEMIDT, of 33 Avenue de la Tour, Vitry sur Seine,
Engineer, and OTTO KAUFMAN, of 10 Rue du Quatre Septembre, Paris,
Merchant, both in France, 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, reference being had to the
accompanying drawings and to the letters aud figures marked thereon, that is
to say:
Our invention relates to improvements in the commercial production of purified
acetylene, whereby the same is rendered more easily liquefiable by compression at
the normal temperature.
In carrying out our invention, we employ a special apparatus, hereinafter
described, in which the gas is generated by the reaction between calcium carbide

page_text: and water in a continuous manner. The gas is produced by adding the carbide in
small quantities at a time to a relatively large volume of water, and owing to this
and to the construction of the apparatus, we are enabled to avoid entry of air and
any undue rise of temperature in the course of the reaction, so ensuring safety and
reducing the quantity of water vapour and impurities given off with the gas. On
leaving the generator, the acetylene is caused to pass successively through a series
of purifiers or washers, the 1st of which contains a suitable acid solution, such as
hydrochloric acid, or dilute sulphuric acid, to remove ammonia; the 2nd a neutral
lead acetate solution to remove sulphuretted hydrogen; the 3rd an acil solution
of sulphate of copper to absorb phosphoretted hydrogen; and the 4th, a solution
of caustic soda to remove all traces of acid which may have been carried over.
From these purifiers or washers, the gis may pass into a gas holder, whence it
is drawn by pumps (the various parts of which may be water-jacketted to keep
them cool) which effect the compression in stages, and the liquefaction at the
normal temperature. On its way to these pumps, the gas is caused to pass through
a drying chamber in which all traces of moisture are removed by suitable hygro-
scopic substances, such as chloride of calcium. The gas thus purified, renders the
use of refrigerants unnecessary, consequently the gas-bottles or cylinders receiving
the liquefied acetylene are not liable to be rendered brittle and dangerous by any
great variations in temperature.
Acetylene thus produced can be employed for any purpose for which ordinary
acetylene is applicable, as for instance for heating or cooking, or for use in
explosion motors.
Our improved generator is shewn in vertical section in the accompanying
drawing, aud consists of a flanged cylinder a having a cover a fixed thereon by
bolts in the usual manner. Upon this cover is arranged a reciprocating slide b,
connected with any suitable mechanism for actuating it continuously. Above the
slide, is a plate c carrying a hopper d into which the carbide is fed by any suitable
means. The slide fits gas tight between the faces of the cover a' and the
plate c.
In this slide, is an aperture which, in the reciprocating movement, is brought
alternately under the mouth of the bopper and over a splayed opening or
aperture a in the cylinder cover a'. When it is in the former position it becomes
filled with carbide, which it carries and drops through the opening a³ when it
reaches the latter position.
To enable the operation to be watched and, if necessary, to permit of obstruction
being removed, a sight hole c¹ is formed in the plate immediately over the
opening a², and is provided with a removable glass plate fitted gas-tight therein.
Should the carbide stick in the aperture of the slide, it can be freed without
allowing the gas to escape, by removing the said glass plate and substituting a
stuffing-box through which would work a suitable rod or plunger.
Immediately below the opening a', is arranged a grid e upon which the carbide
falls. This grid is just below the level of the water in the generator so that the
reaction takes place while the carbide is resting thereon. During the reaction, the
carbide is kept agitated by a suitable metal brush e so as to disengage the lime,
and cause it to fall through the grid as fast as produced.
In the body of the generator, is arranged a stirrer, comprising a central rotating
rud or spindle carrying arms which keep the liquid in the generator in constant
agitation and prevent the waste material depositing. This rod is supported in a
bearing and stuffing-box 3, and carries, at its upper end, the brush et above
referred to, while its lower end is provided with bevel or other gear for causing
the rotation.
Two pipes and 9' are arranged respectively at the top and bottom of the
generator, the former serving for the supply of the water while the latter serves
for the withdrawal of the same, together with the lime and sludge. A third pipe h,
near the top of the generator, serves for the outflow of the gas. i, i, are manholes
in the wall of the generator.

page_text: When the apparatus is at work, the level of the water in the generator is
maintained just above the grid e, and the carbide falls in successive charges upon
the said grid, so that the production of the gas is continuous.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same may be performed we declare that what we
claim is
1. The improved process for the production and purification of acetylene gas,
substantially as described.
2. In the production and purification of acetylene gas, the herein described
process which consists in adding the carbide in small quantities to a relatively large
volume of water, causing the gas produced to pass through a series of washers or
purifiers each containing a suitable solution, whereby ammonia and sulphuretted
hydrogen are removed, phosphoretted hydrogen absorbed, and all traces of acid
eliminated, and drying the gas, which may then be liquefied at the normal
temperature, without the use of refrigerants.
3. In a generator for acetylene gas, the use of a reciprocating slide to receive the
carbide and transfer it from a hopper to the generator, substantially as described.
4. In apparatus for generating acetyleue gas, the combination with the generator
proper, of a reciprocating slide provided with an opening adapted to alternately
receive a charge of carbide from a hopper arranged above the generator, and to
deliver such charge into the generator, substantially as described.
5. The improved generator for use in the production of acetylene gas, constructed,
arranged, and operating substantially as described with reference to the accom-
panying drawing.
Dated this h day of December 1o30.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 54 Market Street, Nottingham,
Agent for the Applicants.