A Process to Manufacture Mixtures of Carbide of Calcium which are Free from any Danger of Explosion in Generating Gas.
Year: 1899

page_text: Date of Application, 30th Nov., 1899
Complete Specification Left, 28th Sept., 1900-Accepted, 24th Nov., 1900
A Process to Manufacture Mixtures of Carbide of Calcium which are
Free from any Danger of Explosion in Generating Gas.
FORBES LYONNET TOBY, Chemist, of 17, Euston Square, London, N.W., OSCAR
SOPHUS BORCH, Chemist, of 8, Upper Bedford Place, W.C., do hereby declare the
nature of this invention to be as follows:-
A process to prepare carbide of calcium, and make mixtures of carbide of
calcium, which generate gas with absolute freedom from any danger of explosion,
and which by purifying the gas chemically insure a steady and even light;
To prevent the residue of carbide of calcium forming into a hard lime stone,
or limestone crust;
To bring about a constant access of water into the carbide of calcium, as and
when required for the generation of gas and, to act as a conducter of heat,
reducing the temperature by radiation."
II. By this process to make that carbide of calcium in such mixtures, produces
gas slower or quicker as may be desired.
III. To use these mixtures of carbide of calcium so obtained, in lamps or
generaters, for the purpose of producing light.
IV. To compress these mixtures into cakes of any required size, and cover the
same with a cover covered by an air-tight covering.
Carbide of calcium is reduced into fine powder in air-tight chambers, is mixed
with chloride of calcium or any other hygroscopic salt or substance in certain
proportions. Such proportions to varie according as the quicker or slower genera-
tion of gas out of the carbide of calcium mixture, are desired.
The mixtures so obtained are compressed into cakes of different sizes, as
required, which cakes are covered first, with a thin metal cover, and then dipped
into mineral oil to form a second airtight outside covering.
Dated this 29th day of November 1899.
F. LYONNET TUDY.
OSCAR BORCH.
A Process to Manufacture Mixtures of Carbide of Calcium which are
Free from any Danger of Explosion in Generating Gas.
FORBES LYONNET TOBY, Chemist, 387, Mansion House Chambers, E.C., late of
17, Euston Square, OSCAR SOPHUS BORCH, Chemist, 34, Bedford Place, late of
7, 8, 9, Upper Bedford Place, do hereby declare the nature of this invention and
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in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This is
In con-
This invention relates to a process for producing mixtures, of carbide of calcium
for the purpose of producing acetylene gas, which have not the disadvantages
attended in the employment of ordinary carbide of calcium. In the use of
ordinary carbide of calcium in lamps or small apparatus on the drop or immersion
system, the lime sludge quickly forms a hard stone like substance.
attributed to the great generation of heat with a small supply of water.
sequence of the settling of the hard lime mass, the cleaning of the lamp or
apparatus is rendered troublesome; moreover some time is occupied in relighting
the lamp, as the hard layer of lime, which covers the undissolved carbide,-only
allows the water to penetrate slowly. In the carbide of calcium prepared by
this process, the lime sludge remains in a soft condition; which allows its easy
removal and, on relighting the lamp no hard lime sludge exists to prevent the
access of water to the unused carbide. This prepared carbide of calcium has
also the advantage, that as soon as the supply of water is discontinued, the after-
generation of gas quickly ceases; a most important result, which has never been
attained yet, and which is brought about by the action of parts contained in the
carbide of calcium mixtures. Moreover the acetylene gas obtained out of this
carbide of calcium mixtures will be pure; all the impurities being destroyed
and absorbed into the lime sludge during generation. This makes the gas so
much safer, as these impurities are a source of danger. The softness of the lime
sludge and the free access of the water make that the temperature of the lamp
will never be very high. This is brought about by a thorough intermixing of
carbide of calcium with a strongly hygroscopic substance chloride of calcium
(CaCl2). The proportions are about 7 lbs. of chloride of calcium to 90 lbs. of
carbide of calcium for mixtures to be used in ordinary acetylene lamps. The
proportion of chloride of calcium can be reduced if a mixture with a slower
generation is desired, and is to be increased if mixtures generating gas more
rapidly are desired. The chloride of calcium thoroughly intermixed with the
carbide, will attract the water and conduct it to the carbide. It also prevents
the carbide of calcium sludge to become a hard lime stone, or to form a stone
like crust, which prevents the access of water to the unused carbide of calcium.
The residual being a soft sludge the particles of chloride of calcium, will attract
and conduct the water to the carbide of calcium, assuring thereby a constant
access of water and an even generation of gas. The chloride of calcium will also
purify the gas and all impurities, so often dangerous will be destroyed and
absorbed into the sludge. The after-generation is reduced to a minimum,
because as soon as the supply of water is discontinued, the water contained in
the lime-sludge is retained by the strongly -hygroscopic chloride of calcium.
Moreover the undissolved carbide of calcium is coated with moist chloride of
calcium sludge, and when water is again supplied, it is quickly conducted to the
carbide, and the lamp can be relighted quickly.
The chloride of calcium can be replaced by some other hygroscopic substance
producing the same effect as for example chloride of zinc, of magnesia or the
like. The process to produce this mixture or preparation of carbide of calcium
is : Chloride of calcium is heated and will soon assume a liquid form. It is
essential that the liquid shall be transformed into an absolutely dry mass, by
evaporating it and to heat it, until all the moisture is extracted. This stage will
be arrived at, when the noise formed by evaporating over a fire has completely
ceased. A quantity of this chloride of calcium so obtained and a quantity of
carbide of calcium in the proportions of 7 lbs. of the former to 90 lbs. of the
latter, are put together into a grinding machine having airtight receptacles, and
are ground into fine powder. It is advisable to pour say 1 lbs. of oil over the
above quantity of carbide of calcium before grinding it. This will prevent any
igniting of gas during the grinding process by friction. To the powder so
obtained is added tar, say 2 lbs. for 90 lbs. of carbide of calcium and the whole

page_text: is thoroughly mixed to render it uniform. The mixture so obtained is heated
to say 120 degrees Centigrad, and then passed trough a sieve to eliminate any
larger pieces it may contain.
The mixture is then left to cool down, and it is preferable to leave it for a few
days in closed receptacles. The mixture is then passed into a briquette machine
and compressed into cakes of any desired size. If it is desired to make mixtures
of carbide of calcium, which generate gas less quick, the proportion of chloride
of calcium is reduced to say 5 lbs. or less, and an increase in the proportion of
chloride of calcium to say 15 lbs will produce very rapid generation. This is for
90 lbs. of carbide of calcium. The proportions can be adapted to the different
purposes or apparatus.
It is advisable to pack briquettes so obtained separately into a thin cover of
lead paper, or some other covering and to cover this cover by a second airtight
skin covering, by dipping into mineral oil. The carbide is not affected by the
oil and an airtight covering obtained.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare what
we claim is:-
I. The process by which mixtures or preparations of carbide of calcium can be
produced, which contain particles, which conduct the water to the carbide, and
thereby assure a constant access of water to the carbide when desired.
II. The process by which different carbide of calcium mixtures can be produced
having different degrees of quickness in generating gas to suit the different
purposes or apparatus.
III. That these mixtures of carbide of calcium on being decomposed do not
produce after generation.
IV. That no incrustation takes place at any time during generation, and
obnoxious gases are destroyed.
V. That briquettes or cakes of these mixtures by having an inner covering
which is covered by a second airtight skin covering are kept better, and while
forming a perfect airtight covering, the carbide of calcium itself is not deterior-
ated by the oil.
Sentember 28th 1900
FORBES LYONNET TOBY.
OSCAR SOPHUS BORCH.