Process for Rendering Carbide Non-hygroscopic.
Year: 1898

page_text: Date of Application, 21st Feb., 1898-Accepted, 7th May, 1898
COMPLETE SPECIFICATION.
Process for Rendering Carbide Non-hygroscopic.
I, PETER JENSEN, of 77, Chancery Lane, London, W.C., Chartered Patent Agent,
do hereby declare the nature of this invention, a communication to me from
abroad by Julius von Orlowsky, of 34, Nevsky Prospect, St. Petersburg, Russia,
Engineer, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Carbide and for instance calcium carbide as heretofore usually made has the
property of absorbing moisture from the air, causing a partial decomposition.
In order therefore to protect the carbide against such decay or to prevent as much
as possible the needless development of acetylene gas it has till now been necessary
immediately it is made, to enclose it in an air tight package, for the purpose of
preserving and transporting it.
This mode of packing the carbide is expensive and tedious and does not more-
over effectually obviate the aforesaid defect, because the carbide during the cooling
and packing, and especially during the subsequent unpacking and the charging of
it into the generator, always absorbs moisture from the surrounding air and thus
some decomposition is produced.
The new process, a result of a long series of practical experiments by my afore-
said foreign correspondent, forms an efficient means for rendering the calcium
carbide nonhygroscopic so that it does not change its character by long exposure
to damp air.
And on the other hand the useful application of the carbide for production of
acetylene gas is by this process in no wise injured. On the contrary, the advan-
tage is gained that when the carbide prepared by this process, is put in contact
with the water the evolution of the gas is not so violent as heretofore but gradual
and slow.
The invention consists essentially in the simple application of liquid hydrocar-
bons, as for instance, crude petroleum, as a medium for soaking the carbide there-
with. This soaking, when for instance petroleum residuals are used, is by.
preference effected immediately after the production of the carbide and before it'
cools. It is therefore suitable to apply the process immediately after the usual
crushing of the material as it comes from the electric furnace, the carbide while
still having a temperature of 100 to 120° C. being conveyed by a suitable conveying
device into a bath of petroleum residuals where it remains about 5 to 10 minutes.
After this soaking of the material it is withdrawn from the liquid and after the
surplus wet has drained off the carbide is shaken out of its container and put into
wooden casks (for instance like cement).
The effect of the process described is that the liquid hydrocarbon while the
carbide is hot and before the crystals have settled penetrates deeply into the mass
and thus forms a permanently protective envelope. This envelope is so adhesive
and encloses the carbide particles so completely that it will only be slowly pene-
trated and by contact with a body of water, so that the decomposition is slow and
at first hardly noticeable and then rises gradually as the particles are laid bare.

page_text: The reason why the moisture in the air does not decompose this carbide, but
that water will do it, is that the finely subdivided mass of water in the air, and the
pressure of same are too small to penetrate the protecting envelope. But the liquid
water has the opposite property and therefore it not only penetrates the envelope
but also dissolves it by the aid of the heat of reaction.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent and in what manner
the same is to be performed I declare that what I claim is :-
1. A process for producing nonhygroscopic carbide, for instance calcium carbide,
consisting in saturating the carbide with liquid hydrocarbons as for instance
petroleum.
2. A process for producing nonhygroscopic carbide for instance calcium carbide
consisting in saturating the carbide, made in the known manner immediately
after the usual crushing operation and before it becomes cool, with liquid hydro-
carbons as for instance petroleum residuals.
D
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.