Improvements relating to the Manufacture of Explosives and to Apparatus therefor.
Year: 1890

page_text: Date of Application, 30th Sept., 1890
Complete Specification Left, 30th June, 1891-Accepted, 1st Aug., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by HIRAM STEVENS MAXIM, of Crayford Works,
Crayford, in the County of Kent, and 32, Victoria Street, in the City of
Westminster, Mechanical Engineer, at present residing in New York, United
States of America.]
Improvements relating to the Manufacture of Explosives and to
Apparatus therefor.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
My invention relates to the manufacture of trinitro cellulose for use in the pro-
duction of smokeless powder and for other purposes.
As heretofore made, trinitro cellulose is very costly by reason of the great
quantity of strong acid required in the manufacture thereof."
The only nitro cellulose which is of practical use in the manufacture of smokeless
powder is the insoluble kind known as trinitro cellulose; in order to produce, this
substance none but the very strongest acids can be employed and these acids, after
being only partially spent or exhausted have to be thrown away, or redistilled and
separated at considerable expense.
The main object of my present invention is the reduction of the cost of manu-
facture of trinitro cellulose by diminishing the quantity of acid required therein
whilst ensuring a very efficient and thorough nitration.
In the nitration of cotton the hydrogen of the fibre is displaced by the oxygen
of the nitric acid, and water is thus formed which dilutes the acid and so reduces
the strength thereof that, instead of trinitro cellulose, only dinitro cellulose is
produced, a substance which is perishable and totally unfit for the manufacture of
explosives.
In carrying on my improved process I dip or immerse the cotton successively in
acid baths of different degrees of strength, the final bath, which I will hereinafter
term No. 1, consisting of highly concentrated acid, the preceding bath, which I
will hereinafter term No. 2, consisting of acid not so highly concentrated; the first
bath consisting of a comparatively weak acid solution. I thus greatly reduce the
quantity of highly concentrated acid required in the production of the trinitro
cellulose. I employ for example, four or more dipping vats-No. 1 to contain
highly concentrated acids. No. 2 to contain acids which are nearly pure. No. 3
to contain acids which are somewhat weaker and No. 4 acids which have been
considerably weakened. The process is then as follows, viz. :-The thoroughly
cleansed and dried cotton is first dipped in tank No. 4. This operation will
produce only a slight nitration. The acids are then squeezed out as far as practi-
cable and the cotton is dipped in tank No. 3 wherein the nitration is increased.
The cotton is then again squeezed and is dipped in tank No. 2, after which it is
again squeezed and is dipped in tank No. 1 which contains highly concentrated,
acids.
When, by the continuation of the process with successive quantities of cotton,
the acids in tank No. 1 have been slightly weakened, a fresh tank is added of pure
No. 3 will then
or highly concentrated acids, and No. 4 tank is removed.
become No. 4. No. 2 will become No. 3. No. 1 will become No. 2 and the
fresh tank will become No. 1 the process is then continued with further quantities
of cotton.
The acids employed may be highly concentrated nitric and sulphuric acids, in
the proportion of two or more parts of the latter to one of the former.

page_text: After the dipping of the cotton in tank No. 1 the acids which adhere to or are
absorbed in the cotton are allowed to remain in it for some hours in closed chambers,
when the nitration may be considered perfect. The acids may be then squeezed
out into the tank Nos. 2, 3 or 4.
The nitrated cotton is then thoroughly quenched in a very large quantity of
water, put into a pulping mill and reduced to pulp. The pulping mill is provided
with steam pipes arranged in such a manner that the water may be heated by steam
at any time so as to produce a thorough washing and cleansing, without having to
resort to the boiling which has been heretofore practised. An alkaline solution
may also be employed in the pulping mill at the finishing stage of the process.
The pulp thus prepared may be stored in its wet state until required for use.
Dated this 30th day of September 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Explosives and to
Apparatus therefor.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 :-
My invention relates to the manufacture of gun-cotton or trinitro-cellulose, and
is chiefly designed to provide, in a more effectual manner and at a lower cost than
heretofore, for the production of trinitro-cellulose to be used in the manufacture of
smokeless powder.
My said invention also relates to apparatus for use in the manufacture of trinitro-
cellulose.
As heretofore made, trinitro-cellulose is very costly, by reason of the great
quantity of strong acids required in the manufacture thereof by the methods
hitherto adopted. The only nitro-cellulose which is of practical use in the manu-
facture of smokeless powder is the insoluble kind known as trinitro-cellulose; in
order to produce this substance, none but the very strongest acids can be
employed, and these acids, after being only partially spent or exhausted, have
hitherto had to be thrown away, or to be redistilled and separated at considerable
expense.
The main object of my present invention is to reduce the cost of manufacture
of trinitro-cellulose by diminishing the quantity of acids required in such manu-
facture, whilst ensuring a very efficient and thorough nitration of the cellulose
material.
In the nitration of cotton, a portion of the hydrogen of the fibre is replaced
by NO2, and water is at the same time formed, which dilutes the acids, and, in the
methods hitherto adopted, the water thus formed so reduces the strength of the
acids that, instead of trinitro-cellulose, di-nitro-cellulose is frequently produced, a
substance which is perishable and totally unfit for the manufacture of explosives.
In the manufacture of gun-cotton as heretofore practised, the cellulose material
is usually immersed for a short time in a bath containing a large excess of a mixture
of highly cencentrated nitric and sulphuric acids, and is then taken out together
with a considerable proportion of the acids from the said bath, and put into earthen
pots to complete the process of nitration.
But, in carrying my present invention into practice, I dip or immerse the cotton
successively in acid baths of different degrees of strength, the final bath, which I
will hereinafter term No. 1; consisting of highly concentrated acids, the preceding
bath, which I will hereinafter term No. 2, consisting of acids not so highly

page_text: concentrated and so on; the bath in which the cellulose material is first immersed
consisting of comparatively weak acids. And, between each immersion, I remove
the excess of acids by squeezing the material in any convenient manner, such
excess of acids being allowed to return to the bath in which such immersion has
taken place, or into one of the preceding baths. The nitration of the cellulose is,
therefore, partially effected by the weaker acids during the first immersion and is
continued in the successive baths. It is evident that, in the treatment of cellulose
in this manner, a very small quantity of water will be formed in the final bath of
the series, which contains the strongest acids. I thus greatly reduce the quantity
of highly concentrated acids required in the production of the trinitro-cellulose.
I find it advantageous to employ four or more dipping vats or tanks. For con-
venience of description, I will hereinafter refer to these vats or tanks by numbers.
In No. 1 tank, I place highly concentrated acids; in No. 2 acids which, though
nearly pure, are not so highly concentrated; in No. 3 tank I place acids which are
still weaker; and in No. 4 acids which have been considerably weakened. The
process is then carried on as follows, viz. :-The thoroughly cleansed and dried
cotton is first dipped in tank No. 4. This operation will produce only a slight
nitration. The excess of the acids is then squeezed out as far as practicable, and
the cotton is dipped in tank No. 3, wherein the nitration is increased. The cotton
is then again squeezed and is dipped in tank No. 2, after which it is again squeezed
and is finally dipped in tank No. 1 which contains the strongest or most highly
concentrated acids.
When, by the continuation of the process with successive quantities of cotton,
the acids in tank No. 1 have been slightly weakened, that is to say, have become
too weak to effectually complete the nitration, No. 4 bath is removed and a fresh
bath is added of pure or highly concentrated acids; No. 3 bath will then become
No. 4, No. 2 will become No. 3, No. 1 will become No. 2, and the fresh bath will
become No. 1. The process is then continued with further quantities of cotton.
In carrying on the process continuously, it may be advantageous to employ only
four tanks, and, when the acids become too weak to complete the nitration, to
drain off the weakest acids from tank No. 4 and replace them by strong or highly
concentrated acids, and then make this tank the last of the series.
The acids employed may be highly concentrated nitric and sulphuric acids, in or
about in the proportion of two or more parts of sulphuric acid to one part of
nitric acid.
After the immersion of the cotton in bath No. 1, the acids which adhere to or are
absorbed in the cotton are allowed to remain in it for some hours in closed chambers,
when the nitration may be considered perfect. The acids may be then squeezed
out into one or other of the tanks Nos. 2, 3 and 4.
The nitrated cotton is then thoroughly quenched in a very large quantity of
water, and is put into a pulping-mill and reduced to pulp. The pulping-mill is
provided with steam-pipes or other heating-pipes or coils arranged in such a manner
that the water may be heated by steam or other suitable heating medium at any
time, so as to produce a thorough washing and cleansing without having to resort
to the boiling heretofore practised. An alkaline solution may also be employed in
the pulping-mill at the finishing stage of the process.
The pulp thus prepared may be stored in its wet state until required for use.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that what I claim is :-
First. The manufacture of trinitro-cellulose by a method or process such as I
have hereinabove described, wherein the cellulose material is successively immersed
in acid baths of different degrees of strength or concentration, for the purpose
above specified.
Second. The improved method or process of manufacturing trinitro-cellulose,
consisting in successively immersing the cellulose material in acid baths of different

page_text: degrees of strength or concentration, and removing the excess of acids from the
said material after each immersion thereof, and, when the acids in the final bath
become too weak to properly complete the nitration, removing the weakest bath,
and adding a fresh bath of highly concentrated acids, substantially as herein before
described.
Third. The employment, in the manufacture of trinitro-cellulose, of a pulping-
mill provided with one or more heating pipes or coils, for the purpose above
specified.
Dated this 30th day of June 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.