IMPROVEMENTS IN GAS KILNS HAVING A CONTINUOUS ACTION
Year: 1880

page_text: LETTERS PATENT to Hermann Wedekind, of 158, Fenchurch Street, in the
City of London, Engineer, for an Invention of "IMPROVEMENTS IN GAS KILNS
HAVING A CONTINUOUS ACTION." A communication from abroad by Herrmann
Escherich, Managing Director of the Schwandorf Pottery Works, of Schwandorf,
in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Hermann Wedekind at the
Office of the Commissioners of Patents on the 19th March 1880.
HERMANN WEDEKIND, of 158, Fenchurch Street, in the City of London, Engineer.
"IMPROVEMENTS IN GAS KILNS HAVING A CONTINUOUS ACTION." A communication
from abroad by Herrmann Escherich, Managing Director of the Schwandorf Pottery
Works, of Schwandorf, in the Empire of Germany.
This Invention relates to improvements in kilns for burning goods and substances
that can be placed or set with intervening spaces or interstices, such as bricks of
clay or cement, tiles, pottery and china ware, drain pipes and annealing pots
containing malleable cast iron, and for burning lime, roasting sundry ores, etc.
=
These improvements relate in part more particularly to the, Invention described
in the Specification, No. 4381, A.D. 1878, of the Letters Patent granted to Frank
Wirth, as a communication from Herrmann Escherich. They are also partly
applicable to already existing kilns.
These improvements consist, firstly, in effecting a more equable distribution of
the combustible gas, and a more rapid admixture thereof with the atmospheric air.
To this effect the combustible gases are supplied in fine jets issuing at right angles
to the direction of the current of the air supply in the firing chamber or chambers-
of the kiln. In carrying this out gas pipes similar to those described in the above
named Specification are employed, but these outlets are set solely at the two opposite
sides of the said gas pipes.
The direction of these openings is further set at right angles to the direction of the
current of the air for combustion, so that the gas flames issuing therefrom are also
at right angles to the air draught and to the longitudional axis of the fire chamber.
The gas is caused to issue from my particular construction of vertical gas pipes,
the number of which is suitably proportional to the width of the firing chamber.
The gas may also be made to issue through small openings in both of the side walls
Posice T

page_text: of the fire chambers, and, as before, also at right angles to the direction of the air
draught. To this effect gas pipes provided with openings at one side only can be
built into the side walls of the kiln.
With kilns having very narrow firing spaces or chambers independent gas pipes
are not required, but only pipes as described built into the side walls.
When it is intended to burn goods requiring a reducing flame then gas in excess
is supplied into the firing space in such amounts that the atmospheric air present is
insufficient in quantity to burn completely the said gas. In order that the residue
of this gas may not escape unburnt, and be thereby lost, atmospheric air is admitted
through the gas pipes by opening suitable valves communicating therewith, and
with the atmosphere, at suitable periods in the working of the kiln.
According to the Invention described in the above recited Letters Patent,
No. 4381, A.D. 1878, the atmospheric air only is heated previous to combustion.
In order to increase the pyrometric duty the combustible gas itself may be heated
before its inlet to as high a temperature as possible. For this purpose we apply the
heat that is taken up by the walls of the kiln. The combustible gases are for this
purpose led through suitable channels made in the walls of the kiln, the heat of
which the gases take up during their passage.
If it be required to place particular portions or divisions of the kiln temporarily
out of action, or to change the direction of the draught, or to effect the cooling down
of the burnt ware by means of combustible gas (or in other words by means of a
reducing atmosphere or medium), then it is preferred to construct the kiln of a
series of parallel chambers. These chambers are so arranged that a continuous and
endless passage may be constituted therefrom. Each chamber is in communication
with its two adjacent chambers by means of a pair of passages, which may be opened
or closed as required by dampers; these two passages are placed at the two opposite
ends of the chambers. According to the relative arrangement of these dampers
either the air, the combustible gases, or the products of combustion may be conducted
in any required direction through the kiln.
In order to facilitate the charging and discharging of the goods, and to allow the
use of firing chambers of little height, a moveable hearth or floor may be employed.
In this case also the kiln may be heated with gas supplied from pipes either built
into the walls of the kiln or set up on the moveable flooring itself. In the latter
case channels may be placed in communication by means of an iron tube on the one
side with the vertical gas pipes, and on the other with the gas conduits.
In the application of this gas continuous kilu to burning cement it is necessary
to employ a material that will not combine or flux with the cement itself. The
gas pipes of such cement kilns are hence made of cement itself, in the mode already
indicated in the Specification of the Letters Patent, No. 4831, A.D. 1878.
The gas pipes of such kilns for burning cement may hence be made of the shape
indicated in the Drawings of the Specification of the Letters Patent, No. 4831,
A.D. 1878.
Or the gas pipes may be built of cement bricks; said bricks are so set as to form
a hollow column closed at the top and leaving suitable openings at its sides for the
exit of the gas.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hermann Wedekind in the Great Seal Patent Office on the 18th
September 1880.
HERMANN WEDEKIND, of 158, Fenchurch Street, E.C., in the City of London,
Engineer. "IMPROVEMENTS IN GAS KILNS HAVING A CONTINUOUS ACTION." A
communication from Hermann Escherich, Managing Director of the Schwandorf
Pottery Works, of Schwandorf, in the Empire of Germany.
This Invention relates to improvements in kilns for burning goods and substances
that can be placed or set with intervening spaces or interstices, such as bricks of
clay or cement, tiles, pottery and china ware, drain pipes and annealing pots
containing malleable cast iron, and for burning lime, roasting sundry ores, &c.
These improvements relate in part more particularly to the Invention described
in the Specification, Number 4381, A.D. 1878, of the Letters Patent granted to
Frank Wirth, as a communication from Hermann Escherich.
They are also partly applicable to already existing kilns.
These improvements consist, firstly, in effecting a more equable distribution of
the combustible gases and a more rapid admixture thereof with the atmospheric
air. To this effect the combustible gases are supplied in fine jets issuing at right
angles to the direction of the current of the air supply in the firing chamber or
chambers of the kiln. In carrying this out gas pipes similar to those described in
the above named Specification are employed, but their outlets are set solely at the
two opposite sides only of the said gas pipes. The direction of these openings is
further set at right angles to the direction of the current of the air for combustion,
so that the gas flames issuing therefrom are also at right angles to the air draught
and to the longitudinal axis of the fire chamber.
The gas is caused to issue from my particular construction of vertical gas pipes,
the number of which is suitably proportioned to the width of the firing chamber.
The gas may also be made to issue through small'openings in both of the side walls
of the fire chambers, and, as before, also at right angles to the direction of the air
draught. To this effect gas pipes provided with openings at one side only can be
built into the side walls of the kiln. With kilns having very narrow firing spaces
or chambers independent gas pipes are not required, but only pipes as described
built into the side walls.
When it is intended to burn goods requiring a reducing flame, then gas in excess
is supplied into the firing space in such amounts that the atmospheric air present is
insufficient in quantity to burn completely the said gas.. In order that the residue
of this gas may not escape unburnt, and be thereby lost, atmospheric air is admitted
through the gas pipes by opening suitable valves communicating therewith and
with the atmosphere at suitable periods in the working of the kiln.
According to the Invention described in the above cited Letters Patent, No. 4381,
A.D. 1878, the atmospheric air only is heated previously to combustion. In order
to increase the pyrometric duty the combustible gas itself may be heated before its
inlet to as high 'a temperature as possible. For this purpose we apply the heat that
is taken up by the walls of the kiln. The combustible gases are for this purpose
led through suitable channels made in the walls of the kiln, the heat of which the
gases take up during their passage.
If it be required to place particular portions or divisions of the kiln temporarily
out of action, or to change the direction of the draught, or to effect the cooling down
of the burnt ware by means of combustible gas (or in other words by means of a
reducing atmosphere or medium), then it is preferred to construct the kiln of a series
of parallel chambers. These chambers are so arranged that a continuous and endless
passage may be constituted therefrom. Each chamber is in communication with its

page_text: two adjacent chambers by means of a pair of passages, which may be opened or
closed as required by dampers; these two passages are placed at the two opposite
ends of the chambers. According to the relative arrangement of the dampers either
the air, the combustible gases, or the products of combustion may be conducted in
any required direction through the kiln.
•
In order to facilitate the charging and discharging of the goods, and to allow the
use of firing chambers of little height, a moveable hearth or floor may be employed.
In this case also the kiln may be heated with gas supplied from pipes either built
into the walls of the kiln, or set up on the moveable flooring itself. In the latter
case channels may be placed in communication by means of an iron tube on the one
side with the vertical gas pipes, and on the other with the gas conduits.
In the application of this gas continuous kiln to burning cement it is necessary
to employ a material that will not combine or flux with the cement itself. The gas
pipes of such cement kilns are hence made of cement itself, in the mode already
indicated in the Specification of the Letters Patent, No. 4381, A.D. 1878. The gas
pipes of such kilns for burning cement may hence be made of the shape indicated
in the Drawings of the Specification of the Letters Patent, No. 4381, A.D. 1878.
Or the gas pipes may be built of cement bricks; said bricks are so set as to form a
hollow column, closed at the top, and leaving suitable openings at its sides for the
exit of the gas.
Having now set forth the nature of my Invention, I will proceed to more fully
describe the same, reference being made to the accompanying Sheet of Drawings.
In the said Sheet Fig. 1 A indicates the sectional elevation, Fig. 2 A the plan,
and Fig. 3 A the cross section of a kiln constructed with two parallel firing chambers,
separated by a central partition, within which the regeneration or pre-heating of
the combustible gases is effected. Within the partition dividing the two firing
spaces is set the channel for the gas. The partition is itself divided in two halves
by means of a narrow wall m. Each half is connected with the gas generator by
means of conduits, the communication being regulated by dampers d, d. At the
other end of the two channels they run into one. The object of this arrangement
is to give the gas a circuitous route, and to keep it as long as possible in contact
with the heated brickwork before its inlet into the firing chamber. As can be
observed in Fig. 3 A, the outlets in the gas channel for the left-hand compartment
open below, and for the right-hand compartment they open from above. The gas
is thus supplied into the left-hand compartment up its gas pipes from below, while
its two moveable gas pipes and the pipes fixed in the side-walls are fed from a
single channel z. These four gas pipes may be all regulated by a single valve.
The gas pipes of the right-hand firing chamber are supplied with gas from above,
and each one is fitted with a separate damper or valve. The moveable pipes are
fed through apertures left in the roof, and lined with earthenware, or preferably
with porcelain tubes. These tubes (see Fig. 4 A) are made with trumpet mouths
and turned down flanges or lips, which are let into sand joints, in order that they
may set themselves to any accidental rise or fall in the roof of the kiln.
By means of the conical valve c (see Fig. 4 A) which fits on the trumpet mouth
of the tube the opening can be regulated or completely closed, according to require-
ment. The inlets of the two pipes built into the side walls are regulated by means
of ordinary bell valves. In order to admit atmospheric air into the pipes for
burning the gaseous fuel left remaining in the advance portions of the kiln whenever
a reducing atmosphere is required, each gas channel is provided with an air-valve v,
see Fig. 4 A.
In the left-hand firing chamber the connection of the gas pipes with the outer
air is formed by means of the inlet k.
5
The channel for the outlet of the products of combustion is set underneath the
gas conduit, and the handles or rods for the smoke valves or dampers are led through
the centre wall or partition m in such wise as to protect said rods from the action 5
of the heated gases.
Within the firing chamber, to the right of Fig. 3 A, is indicated the application

page_text: of the gas jets. They form a sort of grate work over the whole section, through
which flows the atmospheric air.
I shall now proceed to set forth by means of Drawings a kiln according to this
Invention built with twelve parallel firing chambers, six of which are arranged in
combination with moveable hearths set on trucks or cars. Fig. 3 B shews a sectional
plan through a horizontal plane taken a short distance above the level of the ground;
Fig. 1 B is a transverse section through the broken line E, F, G, H; Fig. 2 B, a
section through the centre line C, D, of the kiln; and Fig. 4 B a transverse section
through the line I, K, and the broken line L, M, N, O, P, these several lines being
indicated on the plan, Fig. 3 B.
In this instance also the gas conduit is carried through the central partition
separating the two halves of the kiln. The smoke channel R is arranged under
the same.
The gas generator is set in the one side wall, and the chimney at the
opposite end of the kiln.
The heating of the gaseous fuel previous to its inlet into the firing chamber is
effected firstly in the gas channel g, next in passages z, z, which are built in the
hottest parts of the brick work of the kiln, see Fig. 1B. The said passages may
be connected alternately with the gas channel g or the outer air. Thence the gas
or the air respectively flows down from above through vertical channels left in the
brickwork of the walls of the kiln into the gas pipes. In order that it may reach
the moveable pipes the gas is conducted along the flooring of the firing chamber by
means of passages in the said flooring from below into the pipes (one of which is
indicated by p in Fig. 1 B), wherein it takes up additional heat.
For conducting the gas into pipes set upon the platform of a moveable car (see
Fig. 5 B) both the gas pipes fixed in the gas channel or conduit and that on the
platform of the car are fitted with a bent tube. These two bent tubes are united
by means of an inverted U-shaped pipe, and the temporary joints thereof are made
in the usual manner.
The smoke conduit is arranged underneath the gas channel in such wise that the
bell valves for the outlets do not get injured by the heat, being set about eighteen
inches, more or less, below the flooring of the firing chamber. To further protect
the handles of the valves from the heat, and to prevent any communication between
the channel g and the outlet for the products of combustion, they are encased by
tubes which pass through the roof of the gas channel. The bottom ends of the
tubes are protected by sand, indicated by 8 in Fig. 4 B.
The direction of the draught may be changed as required by setting the dampers
as found needful. According to the arrangement of the dampers shewn in Fig. 3 B
(the plan) the direction of the draught in the divisions I., IV., VII., and IX. is out-
wards. In the divisions II., VI., VIII., and X. it flows inwards, while Nos. III.
and V. are closed. Chamber V. has just finished firing, but is nevertheless red-hot;
it is cooled down by allowing gas to flow out of the pipe nearest the inner wall.
The gas flows through the chamber No. V. from the inside to the outside towards
the working door, where it gets consumed by its meeting with the current of hot
air coming from chamber IV. The chambers or divisions IV., II., and I. are
rapidly cooled down by the flow through them of the atmospheric air; while, on
the other hand, this cooling action takes place much more slowly in the closed off
chamber III.
By the application of dampers which are so adapted_as_to_only_partly close-the--
passages either air, flame, or smoke may be led into each separate division, and in
greater or less quantities, above or below, as may be required. If, for instance, it
be wished to moderate in the divisions being cooled down a too rapid cooling action
towards the flooring, then the bottom part of the said passages are closed by means
of small dampers, so that the air flows only through the upper spaces of the divisions.
If, on the other hand, it be required to send the flames towards the flooring, then
only the upper part of the said passages are closed by the dampers.
The working of my kiln with a moveable flooring or hearth on adjustable cars or
trucks, as shewn in the separate chambers VII. to XII., mainly differs from other

page_text: °
known kilns of this class in so far as each separate car may be shoved in or pulled
out at intervals suited to the requirements of the class of goods to bo burnt. This
is effected by making the length of each car equal to that of a firing chamber. In
working a kiln with a moveable hearth sand is heaped up inside, and a wall is built
on the outside of the platform of the car.
Having now set forth the nature of this Invention, and more fully described the
same by means of Drawings, I declare that I claim,―
Firstly. Arranging the outlets of the vertical gas pipes for the issue of the
combustible gas in such wise that the jets thereof are directed at right angles to the
longitudinal axis of the kiln, substantially as described and illustrated.
Secondly. The arrangement of the gas pipes set in the side wall of the kiln, as
described and illustrated, in combination with moveable gas pipes, substantially as
described and illustrated.
Thirdly. The mode and method by which the heat that collects within the inside
walls of the kiln is applied to warming the gas previous to combustion, substantially
as described and illustrated.
Fourthly. The arrangement, as described and illustrated, whereby particular
portions or divisions of my kilns, built with six, eight, ten, twelve, or more parallel
chambers, can be temporarily disconnected, or whereby the direction of the currents
of air, gas, or smoke can be changed as required.
Fifthly. The mode and method by which the gas for combustion is conveyed to
vertical gas pipes set upon trucks, substantially as described and illustrated.
In witness whereof, I, the said Hermann Wedekind, have hereunto set my
hand and seal, this Fourteenth day of September, in the year of our Lord
One thousand eight hundred and eighty.