Improvements in the Manufacture of Explosives.
Year: 1890

page_text: Date of Application, 17th Feb., 1890
Complete Specification Left, 18th Sept., 1890-Accepted, 29th Nov., 1890
PROVISIONAL SPECIFICATION.
[Communicated from abroad by CARL PIEPER, of 40, Hindersinstrasse 3, Berlin,
German Empire, Engineer.]
Improvements in the Manufacture of Explosives.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention to be as follows:-
This invention relates to the manufacture of granulated gun-powder from nitro-
cellulose or compounds thereof with nitrate of potash, camphor, or other substances
capable of accelerating or retarding combustion.
The said nitrocellulose or compound is first mixed with a solvent of the former and
the mixture is kneaded or rolled until it has become plastic and the nitrocelluloso
completely dissolved, or gelatinized. To the mass thus obtained I introduce a liquid
or vapor being incapable of dissolving or otherwise acting chemically either on the
nitrocellulose or on the ingredients of the said compound thereof. Preferably I
employ water or steam, or both together. At the same time the mass is stirred. By
these means the mass is caused to split up into particles or grains, which become
smaller in the measure as the stirring is continued and the temperature is raised.
The grains are then heated together with the same or any other like liquid, vapor, or
steam unadapted to act chemically thereon, the temperature being carried to a degree
somewhat above the boiling-point of the solvents employed, which are thereby
extracted from the grains and evaporated. Thereupon the grains are separated from
the liquid, or withdrawn from the steam or vapor and dried, and finally they are
treated in the ordinary manner in view of producing finished gun- or blasting-powder.
Dated the Tenth day of February 1890
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Explosives.
A communication from abroad by Carl Pieper, of 40, Hindersinstrasse 3, Berlin,
German Empire, Engineer.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, Middlesex, Gentleman
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:-
This invention relates to the manufacture of gun-powder from nitrocellulose or from
compounds thereof with nitrate of potash camphor or other substances capable of
accelerating or retarding combustion. It is based in the first place on the discovery
that gelatinized nitrocellulose, still containing the solvent employed for its gelatiniza-
tion, on being exposed to certain liquids or vapors, undergoes a kind of coagulation
and a division into small lumps, which latter is promoted by stirring. This peculiar
behaviour of the gelatinized nitrocellulose I make use of for granulating the same, or
mixtures thereof with other substances, in view of producing gun- or blasting-powder.
In the second place I treat the grains obtained after this or any other method, with
hot liquids or vapors, for driving out from the grains the solvent used in the
gelatinizing-process.
According to the methods heretofore ordinarily employed in the manufacture of
gun-powder from nitrocellulose, the said nitrocellulose, whether pure or mixed with
other substances, is either converted in its original state into grains, which are then

page_text: gelatinized on the surface by means of solvents; or it is at the onset thoroughly
gelatinized and subsequently divided by mechanical means into small pieces or
laminae. The solvent is thereupon driven out by dry heat either under atmosphoric
pressure or in vacuo. The powder produced after the first method is, however, not
resistant to the influence of damp air, while with the second method the grains
invariably turn out different in size and form, wherefrom differences in their explosive
power result. Moreover the complete expulsion of the solvent by means of dry heat
presents great difficulties, and a,superheating is easily apt to take place, which
endangers the chemical stability of the nitrocellulose. Even if the grains are treated
in vacuo with application of a moderate dry heat, no security for the complete
expulsion of the solvent is given.
For the purpose of obviating these defects I proceed as follows.
The nitrocellulose, or compound thereof with other substances, is first mixed with a
liquid or liquids adapted to dissolve the former, such as acetic ether, ethyl-ether,
methyl-ether, a solution of camphor in ether, a mixture of ether and alcohol, &c., and
the mixture is kneaded or rolled until it has become plastic and the nitrocellulose
completely dissolved or gelatinized. To the mass thus obtained I introduce a warm
liquid or vapor being incapable of dissolving or otherwise acting chemically either on
the nitrocellulose or on the ingredients of the said compound thereof. Preferably I
employ water or steam, or both together Simultaneously the mass is stirred. By
these means the same is caused to split up into particles or grains, which become
smaller in the measure as the stirring is continued and the temperature is raised.
The following may serve as a special example for carrying out the process. 20 lbs.
of nitrocellulose, with or without admixtures, are put into a dough-kneading-machine.
20 lbs. of acetic ether, or of a mixture of alcohol and ether are added, and the machine
is put in operation. After the kneading has been continued for about an hour the
nitrocellulose is dissolved and a gelatine-like mass is obtained. If thereupon about
10 lbs. of water having a temperature of about 60° Centigrade, are poured to the mass,
or an equivalent quantity of steam (which partly condenses by its application) is
introduced through a pipe at the bottom of the machine, and if the latter is caused to
proceed working, the division of the gelatine into grains is brought about in a few
minutes.
In order to expel from these grains the solvent employed, they are exposed
(preferably in a special vessel) to a hot liquid or vapor incapable of dissolving or
acting chemically on the substance of the grains, or they are boiled therein, the
temperature being carried to a degree somewhat above the boiling-point of the
solvent, so as to insure its complete expulsion. In case the said boiling-point is not
above 100° Centigrade, and if water or steam is used for the expulsion, the process
may be carried out under atmospheric pressure. But, if the boiling-point of the
solvent is above 100° Centigrade, it is advisable to apply, with water or steam, a
higher pressure, and consequently higher temperature. Also, liquids having normally
higher boiling-point than the solvent, or the vapors of such liquids, are in this case
available. The solvents, which are evaporated by this process, may be reobtained
through condensation. By thus proceeding in the wet way, a complete extraction of
the solvents is arrived at, and a far greater stability of the nitrocellulose is attained
than is possible with the aforesaid method of expulsion in the dry way.
a
After having been separated from the liquid or withdrawn from the steam or vapor,
the grains are dried and finally treated in the ordinary manner for producing finished
gun- or blasting-powder.
The described method of extracting the solvents may also be applied to grains
composed of, or containing, gelatinized nitrocellulose, which are produced by means
different from those specified.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is.
1. The process of gelatinizing and granulating nitrocellulose, or a compound thereof

page_text: with other substances, which consists in adding to the said nitrocellulose or compound
a solvent of the former, kneading the mass until it has become plastic and the nitro-
celullose thoroughly gelatinized, introducing thereto a liquid or vapor being incapable
of dissolving or otherwise acting chemically on the constituents of the mass, and
stirring the latter until complete granulation has been produced, substantially as
described.
2. The process of treating grains composed of gelatinized nitrocellulose or of a
compound thereof with other substances and still containing the solvent employed for
the purpose of gelatinization, the said process consisting in exposing the grains to a
hot liquid or vapor being incapable of dissolving or otherwise acting chemically ou
the solid constituents of the said grains, in view of expelling the solvent, substantially
as specified.
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J. H. JOHNSON & Co.,
A gents.