IMPROVEMENTS IN LIME AND Cement KILNS
Year: 1875

page_text: LETTERS PATENT to James Hall, of Wrays, Horley, in the County of
Surrey, for the Invention of "IMPROVEMENTS IN LIME AND Cement
KILNS."
:
Sealed the 4th May 1875, and dated the 29th January 1875.
PROVISIONAL SPECIFICATION left by the said James Hall at the
Office of the Commissioners of Patents, with his Petition, on the
. 29th January 1875.
I, JAMES HALL, of Wrays, Horley, in the County of Surrey, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN LIME AND
CEMENT KILNS," to be as follows:-
This Invention has for its object improvements in lime kilns.
I form the body of the kiln of a cylindro-conical form, with a wide
opening at the bottom for the discharge of the lime into trúcks standing
in an archway or tunnel over which the kiln (or series of ķilns) is built.
The body of the kiln is covered at the top with an iron dome or hood,
for the purpose of improving the draft, and thic outlet passage or chimney

page_text: is at the top of the dome. The dome is made in two parts, and one of
the parts is movable along a railway, so as to afford a ready access to
the interior, for the purpose of feeding in the limestone or materials.
The opening at the bottom of the body of the kiln is provided with
gridirons which serve to support the materials in the kiln, and at the
same time allow the air to pass up very freely amongst them. Beneath
the gridirons is a chamber of a capacity to contain the quantity of lime
which it is desired to draw at one time.
:
The chamber is provided at the bottom with trap doors; they are
closed at the commencement of the drawing operation, and the gridirons
are drawn back by suitable mechanical appliances. The lime is then
able to descend and fill the chamber, and afterwards the gridirons are
replaced, and the trap doors are opened to allow the lime to fall out of
the chamber into the trucks.
The trap doors can if desired be partially closed during working, but
it is desirable to have a very free current of air upwards through the
gridirons and through the materials in the kiln.
The kiln may be used with solid fuel supplied at the top in the, usual
way, or I sometimes employ gaseous fuel prepared in gas producers.
The gas is led into a gas flue or passage surrounding the body of the
kiln, and communicating with it by a number of openings. The gas
will be burnt by the ascending current of hot air in the body of the
kiln, or the combustion may be effected by means of heated air separately
supplied.
The air may be heated by causing it to circulate in air flues arranged
"around the body of the kiln
१
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hall in the Great Seal Patent Office on the
29th July 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES 30
HALL, of Wrays, Horley, in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of January, in

page_text: the year of our Lord One thousand eight hundred and seventy-five, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and. grant unto me, the said James Hall, Her special
license, that I, the said James Hall, my executors, administrators,
and assigns, or such others as. I, the said. James Hall, 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 LIME AND CEMENT KILNS," upon the condition (amongst others) that I,
the said James Hall, 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 Invention, 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.-
NOW KNOW YE, that I, the said James Hall, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say:―
This Invention has for its object improvements in lime kilns.
:
!
'
I form the body of the kiln of a cylindro-conical form, with a wide
opening at the bottom, for the discharge of the lime into trucks, standing
in an archway or tunnel over which the kiln (or series of kilns) is built.
The body of the kiln is covered at the top with an iron dome or hood,
for the purpose of improving the draft, and the outlet passage or chimney
is at the top of the dome. The dome is made in two parts, and one of
the parts is moveable along a railway so as to afford a ready access to
the interior, for the purpose of feeding in the limestone or materials.
The opening at the bottom of the body of the kiln is provided with
gridirons which serve to support the materials in the kiln, and at the
same time allow the air to pass up very freely amongst them. Beneath
the gridirons is a chamber of a capacity to contain the quantity of lime
which it is desired to draw at one time.
°
The chamber is provided at the bottom with trap doors; they are
coment of the drawing onemation and the gridirons

page_text: $
are drawn back. by. suitable mechanical appliances. The lime is then
able to descend and fill the chamber, and afterwards the gridirons are
replaced, and the trap doors are opened to allow the lime to fall out of
the chamber into the trucks.
The trap doors can if desired be partially closed during working, but
it is desirable to have a very free current of air upwards through the
gridirons and through the materials in the kiln.
The kiln-may be used with solid fuel supplied at the top in the usual
way, or I sometimes employ gaseous fuel prepared in gas producers.
The gas, is led into a gas flue or passage surrounding the body of the 1
kiln, and communicating with it by a number of openings. The gas
will be. burnt by the ascending current of hot air in the body of the
kiln, or the combustion may be effected by means of heated air separately
supplied.
In the Drawings hereunto annexed I have shown a kiln having my 2
various improvements embodied in it. Figure 1 is a vertical section of
the kiln, and Figure 2 a horizontal section of the same. .
A is the kiln, covered at the top with an iron dome or hood with an
outlet at the top, one half B of which is moveable, and is supported by
wheels running upon rails, as shown, so that this portion of the hood 2
'may be run back and give a ready access to the interior of the top of the
furnace, for the purpose of feeding in limestone or materials. The
lower part of the kiln is above a tunnel C, through which the trucks for
receiving the lime or cement can pass. A series of kilns may be built
above this tunnel. Across the opening at the bottom of the kiln are a
"two gridirons D which serve to support the materials in the kiln, and at
the same time allow air to pass up freely from the tunnel. Each of the
grids shown in the Drawings is composed of rods D carried at their rear
ends by a rod E, and at their front ends by the links of a chain F. The

page_text: chain Fand rod E are at their ends carried between two opposite sides
of a three-sided frame G. Upon two sides of the frame are rollers H
which run upon rails I, and which have corresponding rails above them
to keep them from rising, as is shown clearly at Figure 3, which is a
section taken through the line x, y, Figure 2. Upon the ends of the
two sides of the frame are also other rollers J to bear horizontally against
rails K, as is also shown at Figure 3, and so prevent the sides of the
frame springing inwards, and thereby keeping the chains F taut. At a
distance below the grids D are trap doors L, which as above described
are to be closed at the commencement of the drawing operation. For
this purpose chains attached to either side of the doors are led over
pulleys M, and the chains attached to one side of each of the doors aro
coupled to a chain leading to a barrel N on the axis N'. This axis has
upon ´it a toothed wheel N², into which gears a pinion, which can be
revolved by a crank handle. As the barrels N are thus turned in a
direction to close the doors L another barrel O upon the same axis winds
up a chain to which is suspended a heavy weight N³. When the doors L
have been closed they are retained by a pawl acting with a ratchet
wheel P. upon the axis of the barrels N. The weight N³ thus raised is
then transferred to a chain passed around a barrel upon another axis Q
this axis being retained by a pawl and ratchet wheel Q'. Upon the
axis Q are two drums R; these have chains $, S, wound around them.
Each chain is attached directly to the side of that grid which is nearest
to the drums, and is also carried onwards, and after being led over
pulleys T is led back and attached to the other grid, so that whenever
the chains S are wound up to the drums R both grids are simultaneously
drawn back, and the drawing back of the grids is effected quickly by the
falling of the weight N³. The descent of the weight is controlled by a
friction strap N around a pulley on the axis N'. By drawing back the
grids quickly, as above described, the whole of the material in the
furnace is allowed to descend equally as well at the sides as at the
centre. When the material in the kiln has thus been allowed to descend
the grids are again drawn together, so that they may again support the
materials in the kiln. The grids are drawn together by chain U (colored
red), which are led over pulleys U' upon the sides of one grid, and led
back and attached to the sides of the other grid. The chains U at their
opposite ends are secured to drums W on the axis Q, which has also a
toothed wheel X upon it, into which gears a pinion worked by a crank
handle.