IMPROVEMENTS IN REGENERATIVE GAS FURNACES OR KILNS AND GAS PRODUCERS
Year: 1878

page_text: LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gate,
Westminster, in the County of Middlesex, for the Invention of "IMPROVEMENTS
IN REGENERATIVE GAS FURNACES OR KILNS AND GAS PRODUCERS."
Sealed the 6th August 1878, and dated the 20th February 1878.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens at
the Office of the Commissioners of Patents on the 20th February 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN REGENERATIVE GAS FURNACES OR
KILNS AND GAS PRODUCERS."
My Invention relates to the construction of regenerative gas furnaces or kilns
applicable for burning or baking ceramic ware, annealing glass, and such like
operations, and also to the construction of gas producers for supplying such furnaces
and regenerative gas furnaces generally.
For the purpose of burning or baking bricks, tiles, earthenware, porcelain, and
other ceramic materials, or for annealing glass, I employ a regenerative gas furnace
or kiln of the following description:-I provide an annular chamber having a floor
of refractory material, such as fire-tiles, mounted on wheels which run on circular
lines of rail, so that the whole floor can be caused to revolve within the chamber.
I protect the wheels, axles, and rails below the floor from the influence of heat
applied above the floor by means of a sand joint formed by making lips or flanges
project from the edges of the floor down into annular sand troughs, one on each
side. Over the floor I provide an arch roof.
Over one portion, which I may term the baking zone, of the annular structure,
this roof is some height above the floor; but on each side of this zone, over portions
of the circular ring, which may be termed respectively the heating and the cooling
or annealing zones, the roof is lower, the decrease of height being made either
gradually by a slope of the roof or by successive steps.
A portion of the circle opposite to the baking zone is open, leaving the floor
exposed, so that articles to be baked can be placed on it, and those that have been
гD..

page_text: baked can be removed from it. At each side of the baking zone, or preferably on
the outer side at each end of it, I construct a pair of regenerators with their flues;
and I provide a duplicate set of valves for altering the flow of the gas, air, and
products of combustion, these valves being preferably arranged between those two
sets of regenerators. For a time these valves are set so that the gas and air heated
in the one set of regenerators are brought together for combustion in the baking
zone, and the flame sweeping through it passes through the other set of regenerators
to the shaft or chimney. When the one set of regenerators are thus sufficiently
cooled and the other set heated, the valves are shifted so as to make the flame
sweep in the opposite direction through the baking zone.
The annular floor, charged at its exposed part with the articles to be baked, is
moved slowly round either by a continuous motion or intermittently step by step.
The articles on it are thus passed slowly through the heating zone, in which they
are dried and heated, then through the baking zone, in which they are baked, and
finally through the cooling or annealing zone, thus returning in a cooled condition
to the exposed portion of the circle, whence they are removed.
The amount of heat in the heating and cooling zones may be regulated by
arranging at several places along them chimnies or flues which may be connected
with the main chimney, these flues being provided with dampers, so that more or
less of the flame from the baking zone may be caused to enter and pass through
When a kiln of this kind is used for
portions of the zones on either side of it.
annealing glass or like wear, the preliminary heating zone may be dispensed with,
the kiln chamber then consisting of only two zones, the hot zone and a long zone
for gradually cooling.
In order to obtain a pure and regular supply of combustible gas for such ovens
as are above described, I arrange gas producers in an improved manner; and the
improvements in these which I am about to describe are applicable to gas producers
for regenerative furnaces generally.
Producers are generally constructed in pairs or in groups of four; that is to say,
two or four adjacent chambers having fire-grates at the bottom supporting a mass
of fuel, and pipes at the top by which the gas produced from the partial combustion
of the fuel is conducted away to be used in the furnace.
For the supply of fuel to such producers I adopt the following arrangement :-I
provide an opening in the middle of the arch close to the back wall of the producer,
and under this opening I fix a plate of conical or inclined form; or I construct a
sloping surface in brickwork, so that coals supplied through the opening fall upon
this conical or inclined surface, and are thereby scattered evenly over the fuel in
the chamber below. When a plate is used for this purpose it is attached to hooks
built in the brickwork, so that it can be readily removed or replaced.
The coal may be fed by a charging box of any known construction, but I prefer
a charging apparatus constructed and arranged in the following manner:- -Above
the fuel hole is a hopper which is from time to time charged with fuel. The bottom
of the hopper is a cylindrical cavity, within which a hollow cylinder is caused to
revolve either continuously or intermittently, or to make a partial revolution
forwards and backwards alternately. This cylinder has a side opening, which in
one position of the cylinder is presented upwards towards the mouth of the hopper,
so that fuel falls from the hopper into the cylinder. The cylinder then being
turned partly round, so that its opening is presented downwards, the fuel falls from
it into the chamber of the producer.
The cylinder may be divided into two or more compartments by radial partitions,
each having its opening to receive and discharge the supply of fuel.
When two, four, or other even number of producer chambers are arranged in a
group, each pair back to back, the feed cylinders above described being arranged in
one axial line, can all be fixed on one shaft, so as to be moved simultaneously from
any convenient motor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the 19th
August 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN REGENERATIVE GAS FURNACES OR
KILNS AND GAS PRODUCERS."
My Invention relates to the construction of regenerative gas furnaces or kilns
applicable for burning or baking ceramic ware, annealing glass, and such like
operations, and also to the construction of gas producers for supplying such furnaces
and regenerative gas furnaces generally.
For the purpose of burning or baking bricks, tiles, earthenware, porcelain, and
other ceramic materials, or for annealing glass, I employ a regenerative gas furnace
or kiln of the following description :-I provide an annular chamber having a floor
or table of refractory material, such as fire tiles, mounted on wheels which run on
circular lines of railway, so that the whole floor can be caused to revolve within
the chamber. I protect the wheels, axles, and rails below the floor from the
influence of heat applied above the floor by means of a sand joint formed by
making lips or flanges project from the edges of the floor down into annular sand
troughs, one on each side. Over the floor I provide an arch roof.
Over one portion, which I may term the baking zone, of the annular structure,
this roof is some height above the floor; but on each side of this zone, over portions
of the circular ring, which may be termed respectively the heating and the cooling
or annealing zones, the roof is lower, the decrease of height being made either
gradually by a slope of the roof or by successive steps.
A portion of the circle opposite to the baking zone is open, leaving the floor
exposed, so that articles to be baked can be placed on it, and those that have been
baked can be removed from it. At each side of the baking zone, or preferably on
the outer side at each end of it, I construct a pair of regenerators with their flues;
and I provide a duplicate set of valves for altering the flow of the gas, air, and
products of combustion, these valves being preferably arranged between the two
sets of regenerators. For a time these valves are set so that the gas and air heated
in the one set of regenerators are brought together for combustion in the baking
zone, and the flame sweeping through it passes through the other set of regenerators
to the shaft or chimney. When the one set of regenerators are thus sufficiently
cooled and the other set heated, the valves are shifted so as to make the flame
sweep in the opposite direction through the baking zone.
The annular floor, charged at its exposed part with the articles to be baked, is
moved slowly round either by a continuous motion or intermittently step by step.
The articles on it are thus passed slowly through the heating zone, in which they
are dried and heated, then through the baking zone, in which they are baked, and
finally through the cooling or annealing zone, thus returning in a cooled condition
to the exposed portion of the circle, whence they are removed.
The amount of heat in the heating and cooling zones may be regulated by
arranging at several places along them chimnies or flues which may be connected
with the main chimney, these flues being provided with dampers, so that more or
less of the flame from the baking zone may be made to enter and pass through
portions of the zones on either side of it. When a kiln of this kind is used for
annealing glass or like ware, the preliminary heating zone may be dispensed with,
the kiln chamber then consisting of only two zones, the hot zone and a long zone
for gradually cooling.
In order to obtain a pure and regular supply of combustible gas for such ovens
as are above described, I arrange gas producers in an improved manner; and the
improvements in those which I am about to describe are applicable to gas producers
for regenerative furnaces generally.
Producers are generally constructed in pairs or in groups of four; that is to say,

page_text: Fig. 1 is a sectional plan on the line A, A, (Fig. 2) of a regenerative gas furnace
or kiln according to my Invention; Fig. 2 is a section on the line B, B (Fig. 1);
and Fig. 3 is a section on the line C, C (Fig. 1).
T is the annular floor or table having refractory facing and mounted on wheels t, t,
which run on circular rails. On the under side of the table T is a rack gearing
with a wheel on a shaft W, by turning which the table is caused to revolve in the
direction of the arrow within the annular chamber of the kiln. To protect from
heat the wheels and axles of the table, it is provided at its inner and outer edges
with lips or flanges projecting down into sand troughs 8, 8.
Two sets of regenerators R, R, with suitable valves V arranged between them
have their apertures 2, p', opening into one are or portion X of the annular kiln
chamber, which portion may be termed the baking zone. On the one side of it is
the heating zone Y, and on the other side is the cooling zone Z. These two zones
have roofs lower than that of the baking zone X, and have chimnies y and z
provided with dampers, by more or less opening which a greater or less quantity of
the hot products of combustion from the baking zone is drawn through the heating
and cooling zones, so as to regulate their temperature as desired. Between the
heating and cooling zones Y and Z is a zone O, being an open part of the annular
chamber where the table T is exposed to receive on it the articles to be baked, and
to have removed from it those which have been operated on. The mouths of the
zones Y and Z are provided with shutter valves M.
The operation is as follows:-Gas and air, entering the baking zone X by the
apertures p, p, from the one set of regenerators R, are ignited, and the flame
sweeping through the zone X issues from it by the other set of apertures p¹, p¹,
heating up the other set of regenerators. A portion of the heat of the zone X is
conveyed to the adjacent zones Y and Z, as determined by the dampers in the
chimnies y and z. The articles to be treated being placed on the table T exposed
at the open zone O, the abutter valves M are raised and the table T is turned partly

page_text: round by working the shaft W until the articles that have been placed on the table
are brought into the heating zone Y, and those that were previously in the cooling
zone Z are brought for removal into the exposed zone O. The shutters M are then
closed. By this movement of the table the articles previously within the heating
zone Y, where they had been gradually heated up, are moved into the baking zone X,
and those that were formerly in the baking zone are brought into the cooling zone Z,
where they become gradually cooled before their removal.
When the one set of regenerators has become sufficiently cooled and the other set
has become sufficiently heated, the valves V are altered so as to reverse the direction
of the flame according to the well-known system of working regenerative furnaces.
The regenerators may be arranged in the ordinary manner, each having duplicate
chambers, one for heating the gas, and the other for heating the air with valves
arranged as shewn in Figs. 1 and 2; or they may have single chambers for heating
the air only, as shewn in Figs. 4, 5, and 6, Fig. 4 being a part sectional plan, the
upper half on the line D, D (Fig. 5), and the lower half on the line E, E (Fig. 5),
Fig. 5 being a section on the line F, F (Fig. 4), and Fig. 6, a section on the line
G, G (Fig. 4). In this arrangement the gas is admitted by a flue K into either of
the two flues L, L, as determined by opening one or other of the dampers k, k, and
the gas rises thence through vertical flues l, l, meeting the heated air issuing from
the regenerator R. Also both sets of the dampers k, k, may be partially opened,
the one supplying gas to mix with the heated air issuing from the one regenerator
into the kiln, and the other supplying gas to the current entering the other
regenerator, so that the latter can be rapidly and highly heated. This mode of
working is particularly applicable when a highly oxidising flame or a current of
highly heated air is required in the kiln.
For producing the gas I employ producers arranged in pairs, as shewn by the
vertical section, Fig. 7, or in sets of four, a pair of these being shown in vertical
section at Fig. 8; and the arrangements shewn in these Figures are to be understood
as applicable to producers for regenerative gas furnaces generally. According to
these arrangements the fuel is fed into hoppers H, whence it is passed in successive
portions by a feeding cylinder h. These portions fall on to a conical, pyramidal, or
inclined plate J, by which they are scattered over the mass of fuel already in the
producer.
The feeding cylinders h may be worked continuously by worm gearing, as shewn
in the Figures, the cylinders of a number of producers or groups of producers when
arranged in line being worked from one worm shaft.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,-
First. The use, for baking ceramic ware, annealing glass, and such like operations,
of a regenerative gas furnace or kiln in which an annular floor or table charged
with the articles to be treated is caused to revolve so as to move the articles through
successive zones of temperature, substantially as herein described.
Second. The use, for feeding fuel to producers of gas for regenerative gas furnaces,
of apparatus consisting of a hopper and feed cylinder arranged in combination with
a conical, pyramidal, or inclined plate on which the fuel is dropped in successive
portions, and by which it is scattered over the mass in the producer, substantially
as herein described.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Nineteenth day of August, in the year of our Lord
One thousand eight hundred and seventy-eight
C. WILLIAM SIEMENS. (L.S.)