An Improved Smokeless and Waterproof Explosive Compound.
Year: 1898

page_text: An Improved Smokeless and Waterproof Explosive Compound.
I, CHARLES FREDERICK HENGST, of No. 20, Burwash Road, Plumstead, in the County
of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:-
--
.
My invention relates to, and is based upon Letters Patent granted to me,
No. 13656 dated March 18th 1888 in which a certain explosive compound is
described. My invention comprised in the following Specification is a distinct
higher
improvement upon said patent, and has for its object the attainment of a
explosive force, and of a higher degree of safety than has been heretofore
obtained.
In carrying my invention into effect I prepare in a suitable receptacle a bath
containing 2 parts sulphuric acid H₂SO specific gravity 1.85 at 18° Centigrade,
one part of nitric acid HNO, from 1.42 to 1.5 specific gravity at 18° Centigrade,
mixed together, and agitated by mechanical means, or by manual power. The
process of, mixing these acids in the manner stated causes the temperature of the
resultant liquid to rise, and a certain amount of ebullition takes place. The bath
is allowed to stand until such ebullition ceases, and the temperature has fallen to the
normal condition of the atmosphere.
I then prepare esparto fibre, by passing the grass through a disintegrator until the
mass is separated into a woolly or fluffy consistence-, not bleached, since chlorine or
the like tends to deteriorate the explosive.
The esparto fibre so prepared is then immersed in the bath hereinbefore described,
when the temperature thereof is normal, a sufficient quantity being added to make
a pulp, which is left to macerate from 5 to 24 hours according to circumstances of
usage, and the atmospheric temperature externally. When the process of macera-
tion is fully effected the material so treated is removed from the tank or receptacle,
and placed in an acid proof press so that all the acid liquor capable of being pressed
out may be so treated, the residue being washed out of the mass by continuous baths
of pure water, until litmus, or other acid tests are not affected. The pulp is then
placed in a boiler, and boiled from 6 to 10 hours. Potassium carbonate K,CO₂ is
added in the proportion of 0.5 to 50 during this part of the process. I prefer to
carry out the boiling operation by means of steam, under pressure, since the water
becomes discoloured, and a. fresh supply has to be provided to compensate loss by
evaporation. The material is then removed to another tank or steam boiler and
treated with sufficient hydrochloride of triamidoazobenzene (H₂NCHN₂CH (NH2)2)
to color it dark brown. Then the mass is removed to an hydro-extractor, or
centrifugal water separator with a copper net of fine mesh, water being added
during the process until the separated fluid is not coloured nor is affected by an
acid test, such as litmus or the like. At this point of manufacture the material has
become of an highly explosive nature and great care must be exercised in drying it.
I prefer to carry out the drying process by means of chequered steam pans
subjected to steam pressure from 30 to 40 lbs. per square inch, motion being

page_text: imparted to the mass during the operation to prevent caking. This may be
effected by mechanical or manual means. A second quantity of disintegrated pulp
may be put in the acid bath, but as the mixture has deteriorated by the first
process, the duration of the time of the macerating process has to be increased by
one half. Said bath may also be used a third time, with a slight addition of fresh
acid.
After the pulp is dried as described, I place it in an edge running grinding mill,
previously preparing amylose (CH100), mixed with water to form a paste, with no
lumps remaining, then boiling to render it of a gummy consistency, after which it is
amalgamated with the pulp in the grinding mill, about 5% of commercial charcoal
and 10% of pure potassium nitrate KNO, being added at the same time; such
quantities being varied according to the conditions of usage of the explosive com-
pound whether for small arms, ordnance, or blasting. Now, for large ordnance in
which a slow burning powder is required I prefer at this period of the process to
add 8% of one of the normal paraffins such as the Octane, CH₁s which is of a jelly
like consistency. The whole mixture is then ground in the edge running mill for
three to four hours, until it becomes an homogenous mass, after it is again dried by
the steaming apparatus until the liquid portion has evaporated. I may add at this
stage a small quantity of barium nitrate Ba(NO3). When the mass is thoroughly
dry it is passed through fine sieves or screens, to remove all lumps and reduce it
to a fine powder, which may then be pressed or moulded into any required shape.
Then, in order to render the granules, blocks or cubes water and damp proof, I utilise
some waste material, of the compositions hereinbefore described, mixing therewith 2
parts of acetone or dimethyl ketone CO
I
CH3
1 CH3
and 1 part of benzoline or phenol CH₂OH.,
mixing these with the waste material until it becomes of gummy cousistence in which
the granules or blocks are dipped or otherwise coated. This renders the explosive
compound perfectly water and damp proof.
An alternative method of waterproofing, which is in practice more expensive,
consists in placing the pulverized material (before pressing and forming) into an air
tight mixing machine, adding the acetone and phenol in quantities sufficient to dis-
solve the powder, and render it pasty, when it is cut or pressed into the desired shape.
It may subsequently be dried by steam, but preferably a vacuum process in order
to recover the residual products. The granules,, blocks or the like when cut, pressed,
'or formed, resemble glass, and are impervious to moisture, and combustion during
explosion is at a slow rate, giving a low pressure with a high velocity.
I may mention that in practice the first second and third pulps prepared in the
acid bath should be mixed together in the grinding process so as to produce a
uniform compound.
The explosive herein described is not ignited by concussion, standing the hammer
and anvil test, is practically smokeless when fired, and is free from nitrous or other
fumes, and it does not corrode or otherwise attack the metal of a gun or the like in
which it may be used.
An Improved Smokeless and Waterproof Explosive Compound.
I, CHARLES FREDERICK HENGST, of No. 20), Burwash Road, Plumstead, in the County
of Kent, Engineer, do hereby declare the nature of this invention and in what

page_text: manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My invention' relates to, and is based upon Letters Patent granted to me No. 13656
dated March 18th 1888 in which a certain explosive compound is described. My
invention comprised in the following specification is a distinct improvement upon
said patent, and has for its object the attainment of a higher explosive force, and of a
higher degree of safety than has been heretofore obtained.
In carrying my invention into effect I prepare in a suitable receptacle a bath con-
taining 2 parts sulphuric acid H₂SO, specific gravity 1-85 at 18° Centigrade, one part
of nitric acid HNO from 1.42 to 1.5 specific gravity at 18° Centigrade mixed together;
and agitated by mechanical means, or by manual power. The process of mixing these
acids in the manner stated causes the temperature of the resultant liquid to rise, and
a certain amount of ebullition takes place. The bath is allowed to stand until such
ebullition ceases, and the temperature has fallen to the normal condition of the
atmosphere.
"I then prepare esparto fibre, by passing the grass through a disintegrator until the
mass is separated into a woolly or fluffy consistence, not bleached, since chlorine or
the like tends to deteriorate the explosive.
The esparto fibre so prepared is then immersed in the bath herein before described,
when the temperature. thereof is normal, a sufficient quantity being added to make a
pulp, which is left to macerate from 5 to 24 hours according to circumstances of
usage, and the atmospheric temperature externally. When the process of maceration
is fully effected the material so treated is removed from the tank or receptacle, and
placed in an acid proof press so that all the acid liquor capable of being pressed out
may be so treated, the residue being washed out of the mass by continuous baths of
pure water, until litmus or other acid tests are not affected. Heretofore such
process has taken from two to four weeks to eliminate the acid but I prefer to turn
the pressed and partly washed pulp into a bath containing 3 ounces of potassium
bicarbonate in six gallons of water, (or in this proportion for larger quantities) and the
bath is agitated and the boiling point is maintained for 6 or 8 hours, the loss by
evaporation being made up by the addition of fresh water, or old solution.
I prefer to add to the pulp prior to boiling a liquid composed of permanganate of
potash in the proportion of about 4 ounces to ten gallons of water. The pulp or
material is then removed to another tank, cylinder or steam boiler and treated with
sufficient hydrochloride of triamidoazobenzene to color it dark brown. Then the
mass is removed to an hydro-extractor, or centrifugal water separator with a copper
net of fine mesh, water being added during the process until the separated fluid is
not colored nor is affected by an acid test, such as litmus, or the like. At this point
of manufacture the material has become of an highly explosive nature and great
care must be exercised in drying it. I prefer to carry out the drying process by
means of chequered steam pans subjected to steam pressure from 30 to 40 lbs.
per square inch, motion being imparted to the mass during the operation to prevent
caking. This may be effected by mechanical or manual means.
A second quantity
of disintegrated pulp may be put in the acid bath, but as the mixture has deteriorated
by the first process, the duration of the time of the macerating process has to be
increased by one half. Said bath may also be used a third time, with a slight addition
of fresh acid.
The pulp may then be placed in a closed receptacle or cylinder, which is fed from
the bottom and relieved from the top side through suitable orifices, said cylinder or
receptacle having perforated shelves or baffle plates suitably staggered arranged
internally, and said pulp is treated from 6 to 10 hours. Potassium carbonate K,CO
is added in the proportion of 0.5 to 5.0 during this part of the process. I prefer to
carry out this drying and heating operation by means of steam under pressure at
about 276° Fah. which renders the substance impervious to ordinary temperature
tests in storage or transport afterwards. The water becomes discolored, and a fresh
supply has to be provided to compensate loss by evaporation. I use a paper saturated

page_text: with iodide of starch, which when applied to the exhaust from the steam outlet shows
by discoloration or otherwise the condition of the pulp. After the pulp is dried and
heated as described, I place it in an edge running mill, previously preparing starch
or amylose (CHO) mixed with water to form a paste, with no lumps remaining,
then boiling to render it of a gummy consistency, after which it is amalgamated with
the pulp in the grinding mill, about 5% of commercial charcoal and 10% of pure
potassium nitrate KNO, being added at the same time, such quantities being varied
according to the conditions of usage of the explosive compound, whether for small
arms, ordnance, or blasting. Now for large ordnance in which a slow burning powder
is required I prefer at this period of the process to add 8% of one of the normal
paraffins such as the Octane, CH₁, which is of a jelly like consistency. The whole
mixture is then ground in the edge running mill for three to four hours, until it
becomes an homogenous mass, after it is again dried by the steaming apparatus until
the liquid portion has evaporated. I may add at this stage a small quantity of
barium nitrate Ba(NO3)2
When the mass is thoroughly dry it is passed through fine sieves or screens, to
remove all lumps and reduce it to a fine powder which may then be pressed or
moulded into any required shape. Then, in order to render the granules, blocks or
cubes water and damp proof, I utilise some waste material of the compositions herein-
before described, mixing therewith 2 parts of acetone or dimethyl ketone
CH3
CH3
CO
and 1 part of benzoline or phenol C,H,OH, mixing these with the
waste material until it becomes of a gummy consistence, in which the granules or
blocks are dipped or otherwise coated. This renders the explosive compound perfectly
water and damp proof.
An alternative method of waterproofing, which is in practice more expensive,
consists in placing the pulverized material (before pressing and forming) into an
airtight mixing machine, adding the acetone and phenol in quantities sufficient to
dissolve the powder, and render it pasty when it is cut or pressed into the desired
shape. It may subsequently be dried by steam, but preferably a vacuum process
in order to recover the residual products. The granules, blocks or the like, when cut,
pressed or formed, resemble glass, and are impervious to moisture, and combustion
during explosion is at a slow rate, giving a low pressure with a high velocity.
I may mention that in practice the first, second and third pulps prepared in the
acid bath should be mixed together in the grinding process so as to produce a uniform
compound.
The explosive herein described is not ignited by concussion, standing the hammer
and anvil test, is practically smokeless when fired, and is free from nitrous or other
fumes, and it does not corrode or otherwise attack the metal of a gun or the like
in which it may be used.
יד
Having now fully described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
First. The combination of ingredients and the process of forming and producing a
safe and smokeless explosive, substantially as herein described.
Second. The combination in an explosive compound of esparto fibre, treated
substantially as herein described.
Third. In the process of manufacturing an explosive compound, the operation of
boiling to remove free acids and the like, substantially. as herein described.,
Fourth. In an explosive compound as referred to in the preceding claims, the
method of and means for waterproofing by dimethyl ketone and phenol substantially
as herein described.
Fifth. In an explosive compound as referred to in the preceding claims, the
method of and means for waterproofing by saturation and drying utilising the waste
material substantially as herein described.
:

page_text: Sixth. In an explosive compound as referred to in the preceding claims the
method of and means for heating after boiling by steam pressure in a cylinder or
receptacle substantially as and for the purposes herein set forth.
Dated this 23rd day of May 1899.
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E., Agent for the Applicant.