Improvements in Apparatus for Generating Acetylene.
Year: 1898

page_text: Date of Application, 15th June, 1898-Accepted, 30th July, 1898
COMPLETE SPECIFICATION.
Improvements in Apparatus for Generating Acetylene.
1, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, Consulting Engineer and Chartered
Patent Agent, do hereby declare the nature of this invention (as communicated
to me from abroad by Paul Lipcke, of No. 7, Gothestrasse, Charlottenburg, near
Berlin, Germany,) and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention has for its object an improved construction of apparatus for
generating acetylene whereby the danger of the occurrence of explosions arising
from the admixture of air with the acetylene gas is practically obviated.
Explosions occur in acetylene generators of present construction from various
causes.
Thus on first starting, the generating chamber being filled with air, the acety-
lene first generated will produce an explosive mixture therewith; also, when the
charge in the generator is exhausted and the water and sludge are discharged,
air enters the generator and forms an explosive mixture with the residual acety-
lene gas therein.
The danger of such explosions is also greatly increased by the frequent presence
of phosphoretted hydrogen. Phosphoretted hydrogen, in liquid form ignites in
the air already at ordinary temperatures, while when in gaseous form it does not
ignite at a temperature less than 100° C. Phosphoretted hydrogen has repeatedly
been the cause of the ignition of a mixture of acetylene and air in the generator.
It has been found by experiments that the pressure in acetylene generators on
the occurrence of explosions often exceeds 11 atmospheres, with certain mixtures.
Under these circumstances it is advisable for the sake of safety to construct the
acetylene generators of such strength that they will withstand the highest pressures
that may be produced by the explosion of a mixture of acetylene and air.
In acetylene generators of present construction there is provided either only a
water seal for the charging opening for the carbide supply, or there is only a
mechanical closure of such opening. The water seal alone is objectionable because
the fine powder of the calcium carbide, or even porous pieces of the carbide float
on the surface of the water in the inlet tube or channel and consequently develop
acetylene gas therein; also it sometimes happens that with a strong development
of acetylene gas, some of this escapes up this channel and through the charging
hopper, causing both loss and danger of explosion. It may also happen that with
an insufficient water supply the water level in the generator sinks to such an
extent as to uncover the lower end of the charging channel, thus entirely destroying
the water seal, and allowing the acetylene to escape.
Also, the acetylene stored in the gas holder may pass back into the generator and
escape through the said channel. The mechanical charging devices on the other
hand, are liable to other drawbacks, such as that only carbide in small pieces or
in powder form can be used.

page_text: According to the present invention the above sources of danger and disadvan-
tages are obviated by providing the acetylene generator with both a mechanical
closure and a water seal for the supply tube or channel, whereby an escape of
acetylene gas and the danger of explosions is practically obviated.
For this purpose there is employed at the upper end of the charging channel
a slide having one or more cavities for receiving the charges of carbide, which
slide can be so moved that at one time the cavity is exposed so that it can be filled
with a charge of carbide, and at another time it is brought with its lower opening
over the charging tube or channel the lower end of which is immersed in the water
of the generator,, while its upper opening is closed by a. covering plate.
Figs. 1 and 2 of the accompanying drawing shew respectively a vertical section
and a plan of an acetylene generator constructed according to the above described
invention.
On the top of the generating chamber a'is fixed a plate b on which the slide e
is made to work air tight. In the arrangement shewn by way of example the
slide is made circular, with a rotary motion, being held firmly down upon the
plate 6 by the guide ring. d.
The slide has two charging cavities, and y, which are so arranged that in the
one position of the slide one of the cavities such as a is situated with its lower
opening over the charging tube e, the lower end of which is immersed in the water,
while the upper opening of the cavity is closed by a covering plate, f secured to
the ring d by a bridge piece f¹. The second cavity, y, on the other hand is not
covered by the plate f, and can consequently be charged with carbide, so that
when so charged and brought by the rotation of the slide over the charging tube e
the charge will fall down the latter into the water in the generator. When this
has been done, the slide is turned so as to bring the solid part between the two
cavities over the opening of tube e, thus effectually closing it, while the lower end
of the tube is immersed in the water forming a water seal. If now some of the
carbide remains floating on the water within the tube e so as to generate acetylene
gas therein, the pressure of the gas will effect the depression of the water level in
the tube until the gas contained therein escapes into the generating chamber,
and passes away with the main body of gas generated therein to the gas holder
through the discharge pipe 9.
With the very instantaneous concussive nature of explosions of mixtures of
acetylene and air the inertia of the water would prevent the escape of gas should
an explosion occur.
For expelling the air contained in the generator on first starting, the chamber a
is connected with the acetylene gas holder by a small pipe h with stop cock, which
is here shewn connected to the overflow pipe i for maintaining the water level.
Thus, on starting, acetylene gas is introduced into the chamber a through pipe h,
and a cock provided at the top of the chamber a is opened to allow of the escape
of the air driven out by the entering acetylene.
By this means the great danger of the ignition of phosphoretted hydrogen in
the generator is prevented, as phosphoretted hydrogen can only exist in gaseous
form in acetylene gas, and under these conditions will only explode at a tempera-
ture of 100° C in the presence of air.
Below the lower immersed end of the charging tube e is provided a distributing
shield by means of which the descending charge of calcium carbide is uniformly
distributed in the water.
The other parts of the generator are of known construction and need not be
farther described.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is:-
1. In apparatus for generating acetylene, the combination with a supply tube
or channel the lower end of which is immersed in the water of the generating

page_text: chamber, of a slide with one or more charging cavities, so arranged that in one
position of the slide a cavity is exposed so as to receive a charge of carbide, while
in another position the cavity is brought over the said charging tube or channel
and has its upper opening closed, substantially as herein described.
2. In apparatus for generating acetylene, the use, for preventing explosions of
mixtures of acetylene and air on first starting the apparatus, of a pipe connecting
the generating chamber with an acetylene gas holder, in order by the introduction
of acetylene gas into the chamber to effect the discharge of the air therein through
a cock provided at the top of the generating chamber, substantially as described."
Dated this 15th day of June 1898.
ABEL & IMRAY,
Agents for the Applicant.