IMPROVEMENTS IN CALCINING KILNS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We, JAMES TREVELYAN RAYNES, of 17 Rock Park, Rock Ferry, Birkenhead, in
the County of Chester, Quarry Proprietor, and BRIERLEY DENHAM HEALEY, of
55 Hope Place, Liverpool, in the County of Lancaster, Civil Engineer, do hereby
declare the nature of our invention for IMPROVEMENTS IN CALCINING KILNS to
be as follows:-
Our invention has reference to the construction of kilns in which gaseous fuel is
used for calcining lime, ores, or other analogeous substances. The operation of
calcining is carried on continuously without the employment of dampers for
changing the direction of the heated currents. The gaseous fuel enters the
combustion chamber or chambers through ports on each side and passes into the
material under treatment. Air to support combustion. enters at or near the
drawing doors and passing through the calcined material below the ports becomes
heated before meeting the gas. The upper part of the kiln contains the feeding
hopper which is provided with one or more doors and a suitable shaft for leading
off the waste gases. The lower part of the kiln has one or more combustion
chambers below which the structure narrows to the drawing door or doors. Gas.
flues are formed around the lower part of combustion chamber or chambers and the
ports are so formed in the lower parts of these flues that they are not liable to be
choked by the material. The combustion chamber or chambers is or are slightly
increased in size for a few feet above the gas ports thence the internal shape of
kiln narrows to the top. In cases where two combustion chambers are formed as
in large sized kilns a central partition is built from the bottom so that each chamber
has a separate outlet or draw door. The partition contains a gas flue or flues and
ports in the lower part as before described, air ventilating flues are also formed in
the partition over the gas flue which ensure free circulation and make the partition
more durable than hitherto. The kiln may be round, square, or rectangular, but
for the two latter forms the corners of the inner lining are well rounded off.
Valves are provided for regulating the supply of gas to each of the gas flues, the
gas being conveyed to the kiln by flues or tubes from the generators which are
built near to the kiln. Air inlet doors are fixed in the outer casing opposite each
gas port so that if the lime sticks in the kiln the gas is turned off and the air doors
Price 6d 1

page_text: are opened until it falls.
The kiln is started in the old way by using solid fuel
until the flues at level of ports shew a red heat, the gas being then ready it is
turned in and regulated so that no flame is seen above the sight holes in upper
part of chambers. We now dispense with the deflector arches above combustion
chambers shewn and described in the specification of a patent granted to us.
A.D. 1882 No. 2430. which in practice was found to be objectionable and very
troublesome. Nor do we use the side outlets in top of kiln for waste gases, or the
air inlet flues as shewn near the draw doors in said specification.
Dated this seventeenth day of January 1884.

page_text: We, JAMES TREVELYAN RAYNES, of 17 Rock Park, Rock Ferry, Birkenhead, in
the County of Chester, Quarry Proprietor, and BRIERLEY DENHAM HEALEY, of
55 Hope Place, Liverpool, in the County of Lancaster, Civil Engineer, do hereby
declare the nature of our invention for IMPROVEMENTS IN CALCINING KILNS and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Our invention has reference to the construction of Kilns in which gaseous fuel is
used for calcining lime, ores, or other analogeous substances. The operation of
calcining is carried on continuously and without the employment of dampers for
changing the direction of the heated currents. The gaseous fuel enters the
combustion chamber or chambers through ports on each side and passes into the
material under treatment. Air to support combustion enters at or near the drawing
doors and passing through the calcined material below the ports becomes heated
before meeting the gas.
The upper part of the kiln contains the feeding hopper which is provided with
one or more doors and a suitable shaft for leading off the waste gases. The lower
part of the kiln has one or more combustion chambers below which the structure
narrows to the drawing door or doors. Gas flues are formed around the lower part
of combustion chamber or chambers and the ports are so formed in the lower part
of these flues that they are not liable to be choked by the material. The combustion
chamber or chambers is or are slightly increased in size for a few feet above the
gas ports thence the internal-shape of kiln narrows to the top.
A central partition is built across the inner part of the kiln from the bottom so
that each chamber has a separate outlet or draw door. The partition contains a
gas flue or flues and ports in the lower part as before described, air ventilating flues
are also formed in the partition over the gas flue which ensure free circulation and
make the partition more durable than hitherto. The kiln may be round outside
and nearly rectangular inside with the corners of the inner lining well rounded off.
Valves are provided for regulating the supply of gas to each of the gas flues, the
gas being conveyed to the kiln by flues or tubes from the generators which are
built near to the kiln. Cleaning doors are fixed in the outer casing opposite each
gas port so that if the lime sticks in the kiln the gas is turned off and the doors are
opened until it falls.
The kiln is started in the old fashioned way by using solid fuel until the flues at
level of ports shew a red heat. The gas being then ready it is turned in and
regulated so that no flame is seen above the sight holes in upper part of chambers.
We now dispense with the deflector arches above combustion chambers shewn and
described in the specification of a patent granted to us A.D. 1882 No. 2430 which
in practice was found to be objectionable and very troublesome. Nor do we use
the side outlets in top of kiln for waste gases, or the air inlet flues as shewn
near the draw doors in said specification.
And in order that our Invention may be understood we will now describe it with
reference to the sheet of drawings accompanying this specification and the best
means we are acquainted with of carrying the same into effect, like reference
numbers being used to denote the same or similar parts where repeated in the
various diagrams.
Figure 1 is a vertical section across what we term a twin kiln, that is a kiln
with two combustion chambers. Figure 2 is a plan on line A. B. and figure 3 is a
section on line C. D. Figure 4 is a section across a twin kiln with a central wall
above partition instead of coping blocks.

page_text: The gas enters the kiln by the main flues 1 and side branches 2 leading to the
side distributing flues 3 and by uptakes 4 at each end of central flue 5. Regulating
dampers are provided for the inlets at 2 and 4 of any suitable pattern. The air
enters through the drawings doors 6 and meets the gas at the ports 7 where
_combustion takes place. The material under treatment is calcined in the chambers 8
and cooled in the cones 9 by the incoming air. Feeding doors 10 are provided on
each side of the top of kiln which may be superceded by covers or flap doors resting
ón suitable frames or lutings. The inclined part of drawing holes is formed of
screen bars for the purpose of separateing the small lime from the large. The
ports 7 are bevilled downwards. at an angle of about 60° so that the material will
not rest on the slopes and choke them. The central partition has air flues 11
running from end to end which are open at both ends to the atmosphere for the
purpose of making this part of the kiln more durable.
In the arrangement shewn by figure 4 the central partition has two gas flues
in it, so that each half of kiln may be worked separately when required by shutting
one set of gas dampers. Small; cleaning doors 12 are fixed in line with each gas
port, and large doors 13 are fixed at angles of distributing flues 3 and opposite the
uptakes 4. The small doors 14 placed about five feet above the ports are used as
sight holes through which the heat of the kiln is judged.
Having now described and ascertained, the nature of our Invention and explained
how we carry it into effect, we wish it to be understood that we do not confine
ourselves to the precise outlines of construction shewn on the drawings hereunto
annexed, but we claim as our Invention.
First. Constructing calcining kilns with a central partition having gas flues and
air ventilating flues substantially as herein shewn and described.
Second. Constructing the inclined part of the drawing holes of calcining kilns
with screen bars for the purpose herein named and described.
E'
Third. Constructing twin kilns so that either half may be worked separately
substantially as herein shewn and described.
In Witness whereof we the said James Trevelyan Raynes and Brierley
Denham Healey have hereunto set our hands and seals this sixteenth
day of October 1884.