An Improvement in the Manufacture of Charcoal for Explosives and other Purposes and Apparatus for that Purpose.
Year: 1887

page_text: Date of Application, 22nd June, 1887
Complete Left, 21st Apr., 1888
Complete Accepted, 25th May, 1888
An Improvement in the Manufacture of Charcoal for Explosives
and other Purposes and Apparatus for that Purpose.
I, HERMANN GÜTTLER of Reichenstein, Preussich Schlesien in the German Empire,
Manufacturer do hereby declare the nature of this invention to be as follows:
My invention relates to means of converting vegetable materials, such as wood,
peat, straw, pith, cotton, flax, hemp, nuts or kernels, sugar, starch, gum or the like,
into charcoal of various qualities suitable for the manufacture of explosives, by a
process and apparatus whereby the pressure and temperature under which charring is
effected can be completely regulated, and the arresting of the charring process and
cooling of the charred product can be effected suddenly without deterioration of
the charcoal produced.
In carbonizing such vegetable materials by the known methods, in particular
at low temperatures, imperfect results are obtained, as the degree of carbonisation
varies considerably in one and the same charge, and the carbonisation frequently
continues after the charges have been withdrawn, in consequence of the residual heat
contained therein. The principal reason of the imperfect or uncertain condition of
the charcoal produced lies in the fact that in carrying out the existing processes it is
not possible to exclude atmospheric air from the charcoal while still highly heated,
or while cooling down, when its porosity and capacity for absorbing air is very great.
By effecting the rapid extinguishing and cooling of the charcoal in the carbonizing
cylinder by means of a suitable neutral gas at a low temperature according to my
invention, I effectually prevent the atmospheric air from coming in contact with the
charcoal, and at the same time cause the charcoal, on account of its absorbing power,
to take up such neutral gases to a large extent within its pores, thereby becoming
uniformly saturated and forming a very homogeneous product. Such saturated and
rapidly cooled charcoal cannot take up oxygen from the air suddenly and in large
quantity, and it is therefore safe against spontaneous ignition.
My invention also affords ready means for suddenly arresting the process of
carbonisation at any desired temperature or for simultaneously cooling the charcoal
internally and externally in an energetic manner, so that all the above named
substances may be effectually carbonized so as to produce either a red, brown, or
black charcoal of a very uniform chemical composition.
By carbonizing at a low temperature the cellular structure of the material is
maintained as much as possible intact.
Thus the density and rapidity of ignition and explosion of the explosive to be
produced may be increased or decreased at will by the employment of a carbonaceous
material having a chemical composition best suited for the purpose.

page_text: This fact is of the greatest importance for the manufacture of a charcoal suitable
for the production of gunpowders such as are required at the present day.
I will describe a suitable arrangement of apparatus such as I employ, referring to
the accompanying drawings. Figs. 1 and 2 are longitudinal sections respectively
on X X and Y Y of Fig. 3 which is a transverse section, and Fig. 4 is a sectional
plan on Z Z. On a fire grate R is kindled a fire, preferably of coke, the products of
combustion from which ascend heating on their way a coiled pipe S. They then pass
over the bridge and descend past a muffle M which they heat, passing through
passages ff to a flue E whence they escape to a chimney.
Within the muffle M is an airtight casing C closed by a removeable end cover D
and within the casing C is an inner casing T containing the material. For facility of
charging and discharging the material may be first placed in a perforated cylinder,
which is then introduced into the vessel T to be charred, this vessel being open at one
end.
The casing C and the vessel T have ribs or studs projecting from them for steadying
them in position, leaving annular spaces round them. To the fixed end cover of the
casing C is connected a pipe leading from the coil S, to the other end of which leads
a pipe with a cock, and through this cover also passes another pipe t communicating
with the interior of the inner vessel T to carry off the gases produced during the
charring. The ends of the muffle M are closed by slabs through which there are
holes that can be closed by plugs, and at the under side of the muffle M there
is a passage to the flue E closed by a sliding damper H. The vessel T M is charged
with the material to be charred and the casing C is then closed, and carbonic acid gas
or other gas that does not act chemically on the material treated is sent by the pipe
through the coil S and pipe into C. The gas heated by passing through the coil S,
and the heat of the muffle M radiated inwards effect the charring of the material
in the vessel T, the temperature being regulated partly by regulating the fire on R
partly by opening some of the plugs and the damper H and partly by admitting more
or less of the heated gas by the pipe 1. Also, the pressure under which the charring
is effected may be regulated by forcing in the supply of gas by the pipe under
pressure or by exhausting the discharge of gaseous products by the pipe t, while the
supply of gas is more or less wire drawn.
go
In order that the pressure and temperature may be properly regulated a pressure
gauge and pyrometer are connected to the casing C. When the charring is complete,
the fire on R is extinguished the plugs are withdrawn and the damper valve H
is opened, and the draught of the chimney causes a current of air to pass through the
annular space in the muffle, cooling the casing C and the vessel T and its contents.
The cooling is aided by closing the cock on r and opening a cock on a pipe
that communicates with the pipe and with a reservoir containing cold gas of the
above described nature, so that such cold gas is then sent into the charring vessel,
thereby effectually arresting the carbonizing process and saturating the charcoal with
the gas as above described.
The slide H and openings may also be more or less opened during the charring
process in order to regulate the temperature, reducing the same if it should rise above
the required degree.
If desired, the carbonizing cylinder or the muffle itself may be made rotatable on
its axis in order to increase the uniformity of the heating. Several muffles and
carbonizing cylinders might be contained in the same furnaces.
If carbonic acid is employed it may be used in the gaseous form for heating and
in the liquid form for cooling.
The gas used for the purposes of my invention may if desired, be separated by any
known method from the other gases escaping with it from the cylinder and be used
over again.
n
"
ABEL & IMRAY,
Agents for the Applicant.

page_text: other Purposes and Apparatus for that Purpose.
I, HERMANN GÜTTLER of Reichenstein, Proussisch Schlesien in the German Empire,
Manufacturer, 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 means of converting vegetable materials, such as wood,
peat, straw, pith, cotton, flax, hemp, nuts or kernels, sugar, starch gum or the like, into
charcoal of various qualities suitable for the manufacture of explosives by a process
and apparatus whereby the pressure and temperature under which charring is effected
can be completely regulated, and the arresting of the charring process and cooling of
the charred product can be effected suddenly without deterioration of the charcoal
produced. In carbonizing such vegetable materials by the known methods in particular
at low temperatures imperfect results are obtained as the degree of carbonization
varies considerably in one and the same charge, and the carbonization frequently
continues after the charges have been withdrawn in consequence of the residual heat
contained therein. The principal reason of the imperfect or uncertain condition of
the charcoal produced lies in the fact that in carrying out the existing processes it is
not possible to exclude atmospheric air from the charcoal while still highly heated, or
while cooling down when its porosity and capacity for absorbing air is very great.
By effecting the rapid extinguishing and cooling of the charcoal in the carbonizing
cylinder by means of a suitable neutral gas at a low temperature according to my
invention effectually prevents the atmospheric air from coming in contact with the
charcoal, and at the same time causes the charcoal on account of its absorbing power
to take up such neutral gases to a large extent within its pores thereby becoming
uniformly saturated and forming a very homogeneous product. Such saturated and
rapidly cooled charcoal cannot take up oxygen from the air suddenly and in large
quantity, and it is therefore safe against spontaneous ignition.
My invention also affords ready means for suddenly arresting the process of carboni-
zation at any desired temperature or for simultaneously cooling the charcoal internally
and externally in an energetic manner, so that all the above named substances may be
effectually carbonized so as to produce either a red, brown or black charcoal of a very
uniform chemical composition.
By carbonizing at a low temperature the cellular structure of the material is main-
tained as much as possible intact.
Thus the density and rapidity of ignition and explosion of the explosive to be
produced may be increased or decreased at will by the employment of a carbonaceous

page_text: material having a chemical composition best suited for the purpose. This fact is of
the greatest importance for the manufacture of a charcoal suitable for the production
of gunpowders such as are required at the present day.
I will proceed to describe a suitable arrangement of apparatus such as I employ
referring to the accompanying drawings. Figs. 1 and 2 are longitudinal sections
respectively on X X and Y Y of Fig. 3 which is a transverse section, and Fig. 4 is
a sectional plan on Z Z. On a fire grate R is kindled a fire preferably of coke, the
products of combustion of which ascend heating on their way a coiled pipe S They
then pass over the bridge and descend past a muffle M which they heat passing through
passages ff to a flue E whence they escape to a chimney. Within the muffle M is an
airtight casing C closed by a removable end cover D and within the casing C is an
inner vessel T containing the material to be charred, this vessel being open at one
end. For facility of charging and discharging, the material may be first placed in a
perforated cylinder which is then introduced into the vessel T. The casing C and the
vessel T have ribs or studs projecting from them for steadying them in position leaving
annular spaces round them. To the fixed end cover of the casing C is connected a
pipe leading from the coil S to the other end of which, leads a piper with a cock
and through this cover also passes another pipe & communicating with the interior of
the inner vessel T to carry off the gases produced during the charring. The ends of
the muffle M are closed by slabs V through which there are holes that can be closed
by plugs, and at the underside of the muffle M there is a passage to the flue E closed
by a sliding damper H. The vessel T is charged with the material to be charred and
the casing is then closed, and carbonic acid gas or other gas that does not act
chemically on the material treated is sent by the piper through the coil S and pipe r
into C.
The gas heated by passing through the coil S, and the heat of the muffle M. radiated
inwards effect the charring of the material in the vessel T the temperature being
regulated partly by regulating the fire on R, partly by opening some of the plugs
and the damper H and partly by admitting more or less of the heated gas by the
pipe. Also the pressure under which the charring is effected may be regulated by
forcing in the supply of gas by the pipe under pressure or by exhausting the
discharge of gaseous products by the pipe t while the supply of heated gas is more or
less wire drawn. In order that the pressure and temperature may be properly regu-
lated, a pressure gauge and pyrometer are connected to the casing C. When the
charring is complete the fire on R is extinguished, the plugs are withdrawn and the
damper valve H is opened and the draught of the chimney causes a current of air to
pass through the annular space in the muffle cooling the casing C and the vessel T
and its contents. The cooling is aided by closing the cock on r and opening a cock
on a pipe that communicates with the pipe 1 and with a reservoir containing cold
gas of the above described nature, so that such cold gas is then sent into the charring
vessel thereby effectually arresting the carbonizing process and saturating the charcoal
with the gas as above described.
I
The slide H and openings may also be more or less opened during the charring
process in order to regulate the temperature, reducing the same if it should rise above
the required degree.
If desired, the carbonizing cylinder or the muffle itself may be made rotatable on
its axis in order to increase the uniformity of the heating. Several muffles and
carbonizing cylinders might be contained in the same furnaces. If carbonic acid is
employed it may be used in the gaseous form for heating and in the liquid form for
cooling. The gas used for the purposes of my invention may if desired be separated
by any known method from the other gases escaping with it from the cylinder and be
used over again.
It will be evident that the carbonic acid required for effecting the charging of the
carbonaceous material as described may be derived directly from a furnace, such as
from the fuel in the furnace R itself in which case the heating coil S would be
dispensed with and the gaseous products of combustion from the furnace be forced by
any suitable means such as a fan or blower directly into the charring cylinder C.

page_text: In order to effect the charring of the carbonaceous material in a very uniform
manner, more particularly when low temperatures are employed, the carbonaceous
material should be prepared in such a manner as to offer with the most uniform
shape attainable for the separate particles the greatest possible amount of surface
for contact with the said gases; thus for instance, in charring wood at low tempera-
tures it is advisable to use it in the form of rolled or perforated chips or in the
form of loose "wood wool" wood powder, shavings, wood cubes, cylinders, spun
fibres &c. for introduction into the charring cylinders, which are thus charged with
loosely heaped material.
In order to enable the charring cylinder C to be more conveniently charged and
emptied, it may be arranged so that it can be drawn out of the muffle M by providing
any convenient means for readily disconnecting it from and connecting it to the
pipes that supply the gases. In addition to the obvious advantage of increased
facility in the above respect, this arrangement also enables a greatly increased yield
to be obtained from each furnace, as the cylinder C can be removed from the muffle
as soon as the charring process has been arrested, so as to effect the cooling of the
material outside the furnace which is thus made available during that time for
effecting the charring of a fresh charge contained in another cylinder.
The above arrangement of effecting the cooling outside the furnace is also of
advantage as regards the heating of the latter and its durability, although the
variations in temperature due to the cooling within the furnace are not such as
would act injuriously upon the latter.
In order to effect a very intimate contact between the heating and cooling gases
and the materials in the cylinder to be treated, the said gases may be forced to pass
in definite directions through the cylinder, by introducing into the same partitions,
such for example as those shown at Figs. 5 to 11 inclusive of the drawings. Thus
the partitions shown at a b c and d force the gases to flow in the directions indicated
by the arrows Fig. 5-while at the same time they divide the cylinder charge into
separate thin layers, which greatly facilitate a uniform packing of the same. The
partitions shown at e and fare of tubular or cellular form, each containing a charge
of the material to be charred, and which are introduced separately into the cylinder C.
By the employment of these receptacles the variation in the density of the charge is
avoided which otherwise arises from the pressure exerted by the upper part of the
loose charge upon the lower part.
With the cylindrical receptacles as at e, the size of which is regulated according
to the nature of the material to be charred, the gas passing through can also pass
through the spaces left between the receptacles. With receptacles of hexagonal
shape such as those at f, which leave no spaces between them, either the whole of
the receptacles may be filled, or some of them may be left empty for the passage of
the gases. The receptacles e and may either be arranged parallel with the axis
of the cylinder or at an angle thereto, and the sides thereof may either be of solid
or perforated sheet metal or of wire gauze.
In addition to the above described forms of partitions any other forms may be
employed suited to the nature of the materials to be charred.
By the above described means it is also possible to effect the simultaneous charring
in one and the same furnace of different kinds of carbonaceous materials, for the
purpose of obtaining mixed charcoals producing certain desired effects.
The combination of the several ineans above described insures an increased
productive power of the furnace, and a considerably improved product.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. The process for the manufacture of charcoal wherein the charring of the
carbonaceous material, as also the arresting of such carbonization, and the cooling
of the charcoal is effected by means of gases, such for example as carbonic acid, and
combustion gases free from oxygen, that are chemically neutral as regard the material

page_text: treated, and that are consequently capable of arresting the charring with certainty
when suitably reduced in temperature.
2. Apparatus for charring vegetable substances in the manner set forth in the
preceding claim consisting of a coil or receptacle S situated in a furnace for heating
gases that are brought in contact with the material contained in a cylinder C within
a muffle M such cylinder and muffle being heated externally by the products of
combustion from the furnace during the charring process, while means are provided
for circulating cold air through the muffle and cold gas through the carbonizing
cylinder for arresting the carbonization, substantially as herein described with reference
to the accompanying drawings.