In- PROVEMENTS IN KILNS FOR BURNING CEMENT, LIME, AND OTHER SUBSTANCES."
Year: 1872

page_text: LETTERS PATENT to George Burge, the younger, of Rochester, in the
County of Kent, Cement Manufacturer, for the Invention of "In-
PROVEMENTS IN KILNS FOR BURNING CEMENT, LIME, AND OTHER SUBSTANCES."
PROVISIONAL SPECIFICATION left by the said George Burge at the
Office of the Commissioners of Patents, with his Petition, on the
21st June 1872.
I, GEORGE BURGE, the younger, of Rochester, in the County of
Kent, Cement Manufacturer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN KILNS FOR BURNING CEMENT, LIME, AND
OTHER SUBSTANCES," to be as follows:-
. The object of my Invention of improvements in kilns for burning
cement, lime, and other substances, is to effect an economy in the
manufacture of or in the burning or calcining of these substances by
utilizing the waste heat evolved during the manufacture.
My Invention is more particularly applicable to the manufacture of
--hown it to necessay to

page_text: dry the ingredients or drive off superfluous moisture therefrom before
placing the raw materials in the kiln for burning or calcining. To
this end I construct the kiln or calcining chamber in a peculiar
manner, so that the heat evolved from the fuel may be made to act more
uniformly and effectually on the charge, and after passing through the
kiln may be further employed to dry or prepare the material for the
subsequent calcining operation.
My improved kilus are of rectangular form and of any convenient
dimensions, according to the nature of the substance to be operated upon
and the quantity desired to be calcined at one time, but I have found
a kiln of about 24 feet long, 10-6" wide, and 9 feet high, to give very
satisfactory results. The floor of the kiln or calcining chamber is
provided with a perforated false bottom, resting on arches or supports,
so as to form flues for conducting the heated gases from the fire to every
part of the floor. The heated gases pass up through the perforated floor
and act on the charge in the kiln, which quickly becomes raised to a
high temperature.
At the upper part of the sides and ends of the chamber or kiln, and
above the level of the charge, are a number of lateral openings commu-
nicating with horizontal flues or passages, into which the heat and gases
escape, and are conveyed by downward flues at one end to another series
of horizontal flues below the floor of a drying chamber or room, which
is level with the floor of the kiln. The kiln or calcining chamber is
open at both ends, so that the chamber may be entered from either end;
but when it is charged and ready for firing, these open ends are tem-
porarily closed by means of brickwork.
From the above explanation it will be understood that the ingredients
of which the cement is composed are dried on the drying floor at one end
of the kiln by the waste heat that escapes from the kiln.
I find by experience that this is effectually done while the previous
charge is being burned in the kiln, and that the waste heat is amply
sufficient to dry a greater quantity of the cementitious ingredients than
is required to fill the kiln for a second charge.
I would also remark that as the drying floor is contiguous to and on
a level with the floor of the kiln or calcining chamber, the labour of
charging my improved kilns is very much less than that of charging a
kiln of the old construction.

page_text: When the charge has been properly burned or calcined, the opposite
end of the kiln is opened by pulling down the wall that temporarily
closes it, and then the charge may be wheeled out on a level in barrows
and conveyed direct to the grinding mill. The charging end may then
be opened and a fresh charge barrowed in from the drying floor.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Burge in the Great Seal Patent Office on
the 20th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
BURGE, the younger, of Rochester, in the County of Kent, Cement
Manufacturer, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of Junc, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Burge, the younger, Her special licence
that I, the said George Burge, the younger, my exccutors, administrators,
and assigns, or such others as I, the said George Burge, the younger, 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 make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
KILNS FOR BURNING CEMENT, LIME, AND OTHER SUBSTANCES," upon the condition
(amongst others) that I, the said George Burge, the younger, my
exccutors 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 Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Scal Patent Office within six calendar months next and immediately.
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Burge, the younger, do hereby
declare the nature of my said Invention, and in what manner the same.
is to be performed, to be particularly described and ascertained in and

page_text: unto annexed, and to the letters and figures marked thereon (that is to
say) :—
The object of my Invention of improvements in kilns for burning
cement, lime, and other substances is to effect an economy in the
manufacture, or burning, or calcining of these substances by utilizing
the waste heat evolved during the manufacture.
My Invention is more particularly applicable to the manufacture of
Portland or other cements or other processes where it is necessary to
dry the ingredients, or to drive off the superfluous moisture therefrom
before placing the raw materials in the kiln for burning or calcining.
To this end I construct the kiln or calcining chamber in a peculiar
manner, so that the heat evolved from the fuel may be made to act more
uniformly and effectually on the charge, and after passing through the
kiln may be further employed to dry or prepare the material for the
subsequent calcining operation.
In the accompanying Drawing I have shewn views of one of my
improved kilns. Fig. 1 is a longitudinal vertical section; Fig. 2, a
transverse vertical section; and Fig. 3, a horizontal section of one of
the kilns with a drying floor attached.
It will be seen that the kiln proper A is of rectangular form, and it
may be of any convenient dimensions, according to the nature of the
substance to be operated upon, and the quantity desired to be calcined
at one time; but I have found a kiln of about twenty-four feet long by
ten feet six inches wide and nine feet high to give very satisfactory
results.
The floor of the kiln or calcining chamber is provided with a per-
forated false bottom a, a, resting on arches or supports b, b, Fig. 2, so as
to form flues c, c, c, for conducting the heated gases from the fire to every
part of the floor. The heated gases pass up through the perforated
floor, and act on the charge placed thereon in the kiln, which quickly
becomes raised to a high temperature.
At the upper part of the sides and ends of the chamber or kiln and
above the level of the top of the charge, are a number of lateral
openings d,.d, d, communicating with horizonal flues or passages d², d',
indicated by dots in Fig. 1, into which the beat and gases escape from.

page_text: the calcining chamber, and are conveyed by downward flues d, d², at one
end to another series of horizontal flues below the floor e, e, of a drying
chamber or room B, which is level with the floor of the kiln.
The kiln or calcining chamber A is open at both ends, as at A¹, A³,
so that the chamber may be entered from either end; but when it is
charged and ready for firing, these open ends are temporarily closed by
means of brickwork, as shewn in the Drawing.
From the above explanation it will be understood that the ingredients
of which the cement is composed are dried on the drying floor e of the
chamber B at one end of the kiln by the waste heat that escapes from
the kiln A, and passes under the floor e of the drying chamber on its
way to the chimney shaft
I.
I find by experience that this drying is effectually done while the
previous charge is being burned in the kiln A, and that the waste heat
therefrom is amply sufficient to dry a greater quantity of the cementitious
ingredients than is required to fill the kiln for a second charge.
I would also remark that as the drying floor e is contiguous to and
on a level with the floor a of the kiln or calcining chamber A, the labour
of charging my improved kilns is very much less than that of charging
a kiln of the old construction.
When the charge has been properly burned or calcined the opposite
end of the kiln is opened by pulling down the wall that temporarily
closes it, and then the charge may be wheeled out on a level in barrows
and conveyed direct to the grinding mill. The charging end may then
be opened and a fresh charge barrowed in from the drying floor.
I would here remark that before the dried lumps of cement will begin
to calcine in the kiln a large quantity of water that they contain must
be driven off, the first operation therefore of the heated gases which pass
up through the perforated floor a, a, and percolate among the lumps of
cement will be to drive off the water. This will rise in the kiln in the
form of steam, which will pass off through a short chimney or opening a*
in the dome or arch of the kiln. When all the water has been driven
off the chimney may be closed by means of a damper, and the heated
gases will then pass into the side flues and under the floor of the drying
chamber as already explained.

page_text: The drying chamber B may be either a close chamber, provided with
suitable outlets for the steam from the wet materials to escape by, or it
may be simply a floor covered in with a roof to keep out the rain.
In some situations it may be found.more convenient to have the
floor of the drying chamber raised above the level of the floor of the
kiln. For instance, it might be placed on a lovel with the top of the
kiln, or the roof of the kiln might even form the floor of the drying
chamber. In such cases the hot air flue would be made to descend at
the back end of the kiln, as shewn in the Drawing, but would be con-
tinued straight on under the floor of the drying chambor.
Moreover, instead of forming the horizontal flues in the side walls of
the kilns, they might be constructed in the roof itself, which if con-
structed level on its upper side would form the floor of a drying
chamber.
Having now described my Invention of "Improvements in Kilns for
Burning Cement, Lime, and other Substances," and having explained
the manner of carrying the same into effect, I claim as the Invention
secured to me by Letters Patent as aforesaid, constructing kilns for
burning cement, lime, and other substances with hollow perforated floors
in combination with lateral flues for the escape of the heated vapours or
gases, which are utilized by being conducted below the floors of drying
chambers, as and for the purposes hercin set forth.
In witness whereof, I, the said George Burgo, the younger, have liere-
unto set my hand and seal, the Eighteenth day of December, in
the year of our Lord One thousand eight hundred and seventy-
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