IMPROVEMENTS IN THE MANUFACTURE OF FUEL
Year: 1858

page_text: LETTERS PATENT to George Hinton Bovill, of Durnsford Lodge, Wim-
bledon, in the County of Surrey, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF FUEL."
Sealed the 2nd August 1858, and dated the 27th May 1858.
PROVISIONAL SPECIFICATION left by the said George Hinton Bovill
at the Office of the Commissioners of Patents, with his Petition, on
the 27th May 1858.
I, GEORGE HINTON BOVILL, of Durnsford Lodge, Wimbledon, in the
County of Surrey, do hereby declare the nature of the Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF FUEL," to be as follows:-
My Invention relates to the method of manufacturing breeze or small coke,
or small coke of boghead cannel mixed with tar, pitch, or any suitable bitu-
minous matter into blocks for fuel, and such method consists in mixing with
the breeze or small coke a sufficient quantity of coal tar, melted pitch, or
other suitable bituminous material to saturate the particles of breeze or small
coke. The mixed materials are pressed into moulds by a squeezing pressure
which shall be sufficient to concentrate the block of fuel to a density of 60 lbs.
per cubic foot at the least; but I prefer to press the blocks to a density of
68 lbs. per cubic foot.
1 would here remark, that I am aware it has before been proposed to
manufacture breeze or small coke into blocks for fuel, but such methods have

page_text: failed to be practically useful, and have not come into general use, which I
have found to result from the want of a sufficient squeezing power being
employed. I am aware also that it has been proposed to give the necessary
solidity to the blocks of breeze or small coke fuel by employing percussive
force, such as that of a steam hammer, to hammer the materials solidly into
moulds.
In manufacturing blocks of breeze or small coke fuel by my process, the
squeezing pressure must exceed 3,000 lbs. per square inch on the surface of
the block of fuel acted upon by the pressing stamp of the machine. The
blocks of fuel may be pressed by any suitable lever or other presses, or other
well-known mechanical means, such as are used for manufacturing fuel from
small coals; and I would remark, that I prefer to have the blocks from four
to five inches square, by about four inches thick when compressed, as the
most suitable size for conveniently manufacturing of the proper density; tho
loose materials are filled into moulds to the depth of seven inches, and are
squeezed down to about four inches, or in like proportion for larger blocks.
The blocks of fuel, as removed from the pressing machine, can be used at
once, but when made with coal tar alone, will not bear knocking about in
delivering from the manufactory. I therefore bake the blocks of fuel in
suitable chambers or ovens, (as is adopted in the manufacture of fuel from
small coal), so as to drive off the volatilo portions of the bituminous matter;
after being baked and cooled down the blocks become hard and solid. When
making fuel with pitch, or a mixture of pitch, I keep the mass of materials
heated by means of forcing superheated steam or heated air through them, or
by heating the mixing vessel containing the materials for supplying the moulds
of the pressing machine; after the hot materials have been pressed into blocks
and cooled, the fuel is hard and ready for use.
My Invention further consists in an improved mode of baking or car-
bonizing fuel so as to utilizo the products evolved in the process of baking, and
preventing the nuisance and smoke hitherto attending the process; the blocks
of fuel are placed in a tightly closed oven or chamber which is heated up to
the necessary temperature, and which I prefer to be from 500° to 700°,
according to the character of fuel required, the volatile gases given off are
passed through a series of pipes in which a portion will condense from these
condenser pipes, the uncondensed gases are passed into heated retorts charged
with coal, coke, charcoal, peat, or other carbonaceous matters, and are there
mixed with the gas from the materials in the retorts, converted into permanent
gas, and pass into the gas holders, any remaining condensible products are
caught in the hydraulic main and gas condensers. And, I further claim as a

page_text: part of my improvements in baking blocks of fuel, to heat the chambers or
ovens containing the same by passing or blowing into them superheated steam
of the required temperature, so as to accelerate the process of baking; the
steam combines with the volatile gases evolved or boiled off from the fuel, and
may be utilised, as herein-before described, when the products are passed into
retorts.
Altho I have described my method of manufacturing a mixture of small
coke or breeze with bituminous matter into blocks for fuel, I would have it
understood that I do not confine myself exclusively to those materials, as I find
it is advantageous to add small proportions of small coal when it is desirable
to make the fuel to burn more freely, but the breeze or small coke should
form at least two-thirds of the materials employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George linton Bovill in the Great Seal Patent Office on
the 27th November 1858.
st
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HINTON BOVILI, of Durnsford Lodge, Wimbledon, in the County of Surrey,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of May, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Hinton Bovill, Her special licence that I, the said George
Hinton Bovill, my executors, administrators, and assigns, or such others as I,
the said George Hinton Bovill, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
mako, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF FUEL," upon the condition (amongst
others) that I, the said George Hinton Bovill, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said George Hinton Bovill, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
My Invention relates to the method of manufacturing breeze or small coke,
or small coke of boghead cannell mixed with tar, pitch, or any suitable bitu-
minous matter into blocks for fuel; and such method consists in mixing with
the breeze, or small coke, a sufficient quantity of coal tar, melted pitch, or other
suitable bituminous material, to saturate the particles of breeze or small coke.
The mixed materials are pressed into moulds by a squeezing pressure, which
shall be sufficient to concentrate the block of fuel to a density of 60 lbs. per
cubic foot at the least; but I prefer to press the blocks to a density of 68 lbs.
per cubic foot.
I would here remark, that I am aware it has before been proposed to
manufacture breeze or small coke into blocks for fuel, but such methods have
failed to be practically useful and have not come into general use, which I
have found to result from the want of a sufficient squeezing power being
employed. I am aware also that it has been proposed to give the necessary
solidity to the blocks of breeze or small coke fuel by employing percussive
force, such as that of a steam hammer, to hammer the materials solidly into
moulds.
In manufacturing blocks of breeze or small coke fuel by my process, the
squeezing pressure must exceed 3,000 lbs. per square inch on the surface of
the block of fuel acted upon by the pressing stamp of the machine. The
blocks of fuel may be pressed by any suitable lever or other presses, or other
well-known mechanical means, such as are used for manufacturing fuel from
small coal; and I would remark that I prefer to have the blocks from 4 to 5
inches square, by about 4 inches thick, when compressed, as the most suitable
size for conveniently manufacturing of the proper density. The loose materials
are filled into moulds to the depth of 7 inches and are squeezed down to about
4 inches, or in like proportion for larger blocks.
The blocks of fuel, as removed from the pressing machine, can be used at
once, but when made with coal tar alone, will not bear knocking about in
delivering from the manufactory; 1 therefore bake the blocks of fuel in
suitable chambers or ovens (as is adopted in the manufacture of fuel from
small coal), so as to drive off the volatile portions of the bituminous matter;
after being baked and cooled down the blocks become hard and solid. When
making fuel with pitch or a mixture of pitch, I keep the mass of materials
Leated by means of forcing superheated steam or heated air through them,

page_text: or by heating the mixing vessel containing the materials for supplying the
moulds of the pressing machine; after the hot materials have been pressed
into blocks and cooled, the fuel is hard and ready for use.
My Invention further consists in an improved mode of baking or carbonizing
fuel so as to utilize the products evolved in the process of baking and pre-
venting the nuisance and smoke hitherto attending the process. The blocks
of fuel are placed in a tightly closed oven or chamber which is heated up to
the necessary temperature, and which I prefer to be from 500° to 700°,
according to the character of fuel required; the volatile gases given off are
passed through a series of pipes, in which a portion will condense; from these
condenser pipes the uncondensed gases are passed into heated retorts charged
with coal, coke, charcoal, peat, or other carbonaceous matters, and aro there
mixed with the gas from the materials in the retorts, converted into permanent
gas and pass into the gasholders, any remaining condensible products are
caught in the hydraulic main and gas condensers; and I further claim as a part
of my improvements in baking blocks of fuel to heat the chambers or ovens
containing the same, by passing or blowing into them superheated steam of
the required temperature, so as to accelerate the process of baking; the steam
combines with the volatile gases evolved or boiled off from the fuel, and may
be utilized, as herein-before described, when the products are passed into
retorts.
Although I have described my method of manufacturing a mixture of small
coke or breeze with bituminous matter into blocks for fuel, I would have it
understood that I do not confine myself exclusively to those materials, as I
find it is advantageous to add small proportions of small coal when it is
desirable to make the fuel to burn more freely; but the breeze or small coke
should form at least two-thirds of the materials employed.
In manufacturing fuel according to my Invention I ordinarily employ from
10 to 14 gallons of common gas tar to the ton of breeze, or for a fuel which is
to be used without baking, I substitute about 70 lbs. of pitch of the cheapest
description which can be obtained; or in place of pitch, other bituminous
substances capable of being rendered liquid by beat and which in cooling
set into a hard solid mass may be employed. The machinery which I
employ in the mixing and moulding processes is similar to that heretofore
employed in the manufacture of fuel. The mixing machine is an ordinary
pug mill, such as is used for grinding clay; and the breeze, and tar, or pitch,
or bituminous matter, are continuously introduced at the top in suitable pro-
portions. When pitch or bituminous matter is employed, I clothe the mixing
machine with a jacket, into which I adinit superheated steam or heated air, at

page_text: as high a temperature as can be applied without volatilizing the matters in the
machine to an injurious extent (600° Fahrenheit is a very suitable temperature).
I also heat the materials in the machine by leading a pipe into it near tho
bottom, and through this pipe I force in steam heated to the temperaturo
before mentioned, or air heated to 500°. By either of these methods the
substances are kept heated to such a degree that they pass readily from the
pug mill into the moulds; these moulds are 4 or 5 inches square and 7 deep,
and are arranged in a circle around a table which turns on a centre pin or
axis, and carries the moulds in succession under the pug mill. The moulds
employed are bottomless, but they are closed underneath by a slab, on which
the table rests, and this slab serves to prevent the materials falling from the
moulds when they are filled by passing under the pug mill, and also while the
moulds are passing on to the point where the pressure is applied. As tho
moulds move forward, step by step, after they have been filled, they come in
succession underneath a plunger which works up and down between guides
with a stroke of sufficient length to descend down three inches into the moulds
so as to compress the material to a thickness of 4 inches; this plunger I prefer
to work by a connecting rod and crank, the whole of the parts being made of
great strength, and actuated by a sufficient power to ensure the descent of the
plunger, notwithstanding the resistance offered to it by the materials. The
moulds afterwards pass on to a point where the bottom slab is cut away, so as
to leave the moulds open, and another plunger then enters the moulds and
passes down a sufficient distance to force the moulded blocks out. This
machinery being similar to that already employed in the manufacture of fuel,
and being well understood I have not considered it necessary to describe all
its details. The moulded blocks, if they require baking, are placed in waggons
which are run into an oven, or are placed on shelves in the oven, which is
furnished with a closely fitting door, which is rendered perfectly tight by luting
with clay, if necessary; the oven is heated underneath by a furnace, the flues
of which also circulate round it; and the oven is protected at the points most
exposed to the fire by fire-tiles; when charged the oven is raised to about
500° to 700° Fahrenheit, the higher heat being employed if a smokeless fuel
is required, and the fuel is retained in the oven until gas and vapor cease to
pass from it in any quantity. The gases and vapours from the oven, as
already mentioned, are passed through pipes to separate the more readily
condensible part of the vapour; these pipes may be kept cool by immersion
in water, but this is not necessary if a considerable length of pipe is employed;
afterwards, the gas and remaining vapour is caused to enter gas retorts (if
convenient, otherwise it is allowed to escape). The number of gas retorts

page_text: connected with the oven varies according to the quantity of fuel roasted; the
gas and vapour from two tons of fuel may be thrown into a single retort.
When the baking oven is heated by steam, I heat the steam to a tempera-
turo exceeding that at which I wish to maintain the oven by 50 or 100
degrees, and I admit it in sufficient quantity to obtain the temperature
required. The steam, and the gas, and vapours may in this case be passed
direct to gas retorts which need not necessarily be charged with gas-making
materials, but may be charged with coke, charcoal, or other carbonaceous
substance.
In witness whereof, I, tho said George Hinton Bovill, have hereunto
set my band and seal, this Twenty-seventh day of November, in tho
year of our Lord One thousand eight hundred and fifty-eight.
Witness,
JNO. ALCOCK.
GEORGE HINTON BOVILL. (L.S.)