Improvements in Kilns for Drying and Burning Bricks, or for analogous purposes.
Year: 1894

page_text: Date of Application, 19th Nov., 1894
Complete Specification Left, 10th Apr., 1895-Accepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Kilns for Drying and Burning Bricks, or for
analogous purposes.
I, JOHN CRAVEN of Westgate Common Foundry, Wakefield, in the County
of York, Engineer, do hereby declare the nature of my invention to be as
follows:-
My invention relates to kilns for drying and burning bricks or for analogous
purposes and more especially to those of the kind known as Hoffman kilns of
whatever shape, the object of my invention being to provide efficient means for
utilizing the heat from a chamber or chambers, while the bricks or the like is or
are cooling, for drying green goods in another or other of the chambers and for
effecting the proper and economical consumption and utilization of the fuel in the
heating and burning of the goods.
According to my invention I make a flue or passage for hot air from chamber to
chamber the said flue or passage being made in the wall of the kiln underneath
the smoke chamber there being passages or connecting flues from each chamber of
the kiln into the said hot air flue each such connecting flue being provided with a
chamber to open and close communication between either kiln chamber and the hot
air flue as required. From each kiln chamber there are as usual damper controlled
passages to the smoke chamber which is in communication with the chimney as
usual. The said hot air flue and smoke chamber in kilns consisting of double rows
of chambers will preferably be in the mid-wall between the chambers so that the
said hot air flue is kept hot and the passages between it and the kiln chambers are
as short as possible.
The adjacent chambers of the kiln are separated by division walls provided with
flues to conduct the heat from chamber to chamber. In front of each division
wall I build another wall extending upwards for a suitable distance and providing
a space between itself and the adjacent division wall into which space fuel is fed
from openings in the arch or roof above. In the said space I fix bricks or the
like underneath the feed openings and below these again other bricks or the like
beneath the spaces between the bricks or the like above and beneath these again
there may be other similar bricks the said bricks constituting a step-grate which
intercepts the fuel and ensures its proper combustion in the said space and the gas
which is at once generated therefrom passes out at the top of the space and into
the chamber to burn the goods therein.
When the kiln is in operation the chambers in which goods are being burnt and
those in which green goods are being dried preparatory to being burnt are put by
the dampers in communication with the smoke chamber and chimney. Those
chambers which are cooling down have the dampers to the smoke chamber and
chimney closed and the dampers of tlie passages communicating between the air
flue and those of the chambers which are cooling down and those which contain the
green goods are opened so that the hot air from the chambers which are cooling
down passes through the hot air flue into the chambers containing the green goods
and thence is drawn through the smoke chamber and to the chimney.
Dated this 19th day of November 1894.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: Improvements in Kilns for Drying and Burning Bricks, or for
analogous purposes.
I, JOHN CRAVEN, of Westgate Common Foundry, Wakefield in the County
of York, Engineer, 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 kilns for drying and burning bricks or for analogous
purposes, and more especially to those of the kind known as "Hoffmann kilns"
whatever shape they may be, the object of my invention being to provide efficient
means for utilizing the heat from a chamber or chambers while the bricks, or the
like, is or are cooling, for drying green goods in another, or other of the chambers,
and for effecting the proper and economical consumption and utilization of the fuel
in the heating and burning of the goods.
According to my invention. I make a flue or passage for conveying hot air from
chamber to chamber, the said flue or passage being made in the wall of the kiln
underneath the smoke chamber, there being passages, or connecting flues from each
chamber of the kiln into the said hot air flue each such connecting flue being
provided with a damper to open and close communication between either kiln
chamber and the hot air flue as required. From each kiln chamber there are
damper-controlled passages to the smoke chamber in communication with the
chimney as usual. The said hot air flue and smoke chamber in kilns consisting of
double rows of chambers will preferably be in the mid-wall between the chambers
so that the said hot air flue is kept hot and the passages between it and the kiln.
chambers are as short as possible. The adjacent chambers of the kiln are separated
by division walls provided with openings to conduct the heat from chamber to
chamber. In front of each division wall I build another wall extending upwards
for a suitable distance and providing a space between itself and the adjacent
division wall into which space fuel is fed from openings in the arch or roof above.
In the said space I fix fire bricks or the like underneath the feed openings and
below these again other bricks or the like beneath the spaces between the bricks or
the like above, and beneath these again there may be other similar bricks the said
bricks constituting a step-grate made of fire bricks which intercepts the fuel and
ensures its proper combustion in the said space, and the gas, which is at once
generated therefrom, and ignited passes out as flame at the top of the space and
into the chamber to burn the goods therein.
Figure 1 of the accompanying drawings represents in horizontal section (along
the line ef Figures 3 and 4) a kiln constructed according to my invention for drying
and burning bricks or other articles.
Figure 2 is a longitudinal vertical section taken along the line ab Figure 1.
Figures 3, 4 and 5 are transverse sections of the same taken respectively along
the lines c, d, g, h, and ij Figure 1.
The kiln shewn in the drawings is of oblong form with semi-circular ends (but
if desired the ends may be built of other curved form or rectangular). The kila
is shewn as containing fourteen chambers (marked respectively 1 to 14) two
situated at each end and the others arranged back to back on opposite sides of the
longitudinal central wall 15 in which is formed the smoke flue 16 communicating
with the chimney. Each chamber to 14 is in communication with the smoke
flue 16 by a short flue or passage 14* each provided with a valve 17 by means of
which the communication between either of the chambers and the smoke flue 16
can be opened and closed as required. In the wall 15 beneath the smoke flue 16 is
a flue 18 (which I term the hot air flue) with which flue the chambers 1 to 14

page_text: communicate by short flues 19 provided with dampers 20 by means of which the
communication between either chamber 1 to 14 and the said hot air flue 18 can be
opened and closed as required. In the division walls 21 which separate the
chambers one from another are openings or passages 22 through which flame can
pass from one chamber to another.
In each chamber at a short distance from one of the division walls 21 is another
wall 23 also provided with passages 24 for the gases and flame to pass through but
which are situated out of line with the openings or passages 22 in the wall 21 so
that the gases and flame are more effectually distributed in the chambers. This
wall 23 may extend to any desired height and into the space between the walls 21
and 23 fuel is supplied through openings 25 in the arch, the fuel when being
supplied falling into projections or obstructors 27 arranged in the space at different
heights, but not in the same vertical plane (forming what I term a step grate) so
that the fuel falling into this step grate is separated or distributed so that its
combustion is readily effected.
When the kiln is in operation the chambers in which goods are being burnt,
and those in which green goods are being dried preparatory to being burnt, are
put by the dampers in communication with the smoke chamber and chimney. Those
chambers which are cooling down have the dampers to the smoke chamber and
chimney closed and the dampers of the passages communicating between the air
flue and those of the chambers which are cooling down, and those which contain
the green goods, are opened so that the hot air from the chambers which are
cooling down passes through the hot air flue into the chambers containing the green
goods and thence with the vapour arising from the goods is drawn through the
smoke chamber and to the chimney.
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. In kilns for drying and burning bricks or for analogous purposes a flue or
passage arranged as herein before described for the passage of hot air from chamber
to chamber of the kiln so that the hot air from a chamber or chambers in which
burnt bricks or the like are cooling down is utilised to assist in drying bricks or
the like in another chamber or in other chambers substantially as herein before
described.
2. A kiln for drying and burning bricks or for analogous purposes consisting of
a double row of chambers having a mid-wall between the rows of chambers in
which mid wall is the smoke flue leading to the chimney and beneath the smoke
flue, a flue or passage for conducting hot air from chamber to chamber substantially
as and for the purpose herein before described.
3. In a kiln for drying and burning bricks or for analogous purposes having a
number of chambers the combination with each of the partition walls, of an
additional wall in front thereof leaving a space between itself and the partition
wall and openings in the arch for feeding in fuel and projections or obstructors in
the said space by means of which the fuel is separated and its combustion more
readily effected, substantially as herein before described.
4. The combination and arrangement of parts constituting the kiln for drying
and burning bricks or for analogous purposes substantially as hereinbefore
described and illustrated by the accompanying drawings.
Dated this 10th day of Anril 1805
JOHNSONS & WILLCOX,
Agents.