IMPROVEMENTS IN THE CONSTRUCTION AND WORKING OF KILNS FOR BURNING BRICKS AND OTHER GOODS
Year: 1877

page_text: LETTERS PATENT to Hermann Wedekind, of No. 158, Fenchurch Street, in the
City of London, Civil Engineer, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION AND WORKING OF KILNS FOR BURNING BRICKS AND OTHER
GOODS." A communication from abroad by Helmuth Dueberg, of the City of
Berlin, Germany, Civil Engineer.
PROVISIONAL SPECIFICATION left by the said Hermann Wedekind at the
Office of the Commissioners of Patents on the 9th October 1877.
HERMANN WEDEKIND, of No. 158, Fenchurch Street, in the City of London,
Civil Engineer. "IMPROVEMENTS IN THE CONSTRUCTION AND WORKING OF KILNS
FOR BURNING BRICKS AND OTHER GOODS." A communication from abroad by
Helmuth Dueberg, of the City of Berlin, Germany, Civil Engineer.
These improvements relate to kilns for burning bricks, tiles, and other similar
earthenware goods. They consist in constructing such kilns in the form of a long
chamber or gallery with a moveable floor, constituted of a series of coupled trucks
set on rails. On these the green bricks are supplied from the outside and then
drawn into the kiln, the whole remaining stationary during the process of
burning.
The goods are fired from a
under the name of Hoffmann.
from the kiln by drawing out
bricks.
series of top holes in the plan now generally known
The said goods when sufficiently burnt are removed
the moveable floor or train of trucks containing the
A single chamber or gallery on this plan forms an intermittent kiln.
By connecting two or more such galleries by means of channels, regulated by
shutters or dampers in the well-known manner, a kiln able to work continuously
may be formed.

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 9th April
1878.
HERMANN WEDEKIND, of 158, Fenchurch Street, in the City of London, Civil
Engineer. " IMPROVEMENTS IN THE CONSTRUCTION OF AND WORKING OF KILNS
FOR BURNING BRICKS AND OTHER GOODS. A communication from abroad by
Helmuth Dueberg, of the City of Berlin, Germany.
These improvements relate to kilns for burning bricks, tiles, and other earthen-
ware goods. They consist in constructing such kilns in the form of a long chamber
or gallery with a moveable floor, constituted of a series of coupled trucks set on
rails. On these the green bricks are supplied from the outside and then drawn into
the kiln, the whole remaining stationary during the process of burning.
The goods are fired from a series of top holes on the plan now generally known
under the plan of Hoffmann. The said goods when sufficiently burnt are removed
from the kiln by drawing out the moveable floor or train of trucks containing the
bricks.
A single chamber or gallery on this plan forms an intermittent kiln.
By connecting two or more such galleries by means of chambers, regulated by
shutters or dampers in the well-known manner, a kiln able to work continuously
may be formed.
By means of these improvements the labour of loading and unloading the green
and burnt goods respectively is much diminished, while the progressive motion of
the Hoffmann system of firing is adapted in such wise that the train of loaded
trucks constituting the bottom of the kiln can remain at rest during the actual
firing. By this plan the many objections are avoided which are found in practice
to exist with a platform requiring to be moved during the process of burning, while
the attendant advantages are gained.
I shall now proceed to fully set forth the nature and mode of carrying out my
Invention by means of the accompanying Drawings.
On Sheet I. Figs. 1, 2, and 3 respectively show a longitudinal section, cross
section, and plan of an intermittent kiln on this system with a single gallery or
burning chamber, and Figs. 8 and 9, on the same Sheet, a section and plan of a kiln,
which can be worked continuously.
On Sheet II. are shewn a single pair of these kilns built alongside of each other,
and so arranged as to be also able to be worked continuously.
On all the Figures the same letters are used to designate the same parts, but
reference may now be had more particularly to Figs. 1, 2, and 3 of Sheet I.
In these A indicates the burning chamber or gallery. It is arched over at top
or otherwise suitably closed up. The floor of each chamber being formed of a train
of trucks F, F, fitted with flanged wheels running on two or more rails, the green
bricks or other goods to be burnt can be stacked on the same, outside the kiln, and
thereupon the whole run in.
When burning chambers or galleries of more than seven feet width, or there-
abouts, are to be set up, I prefer to employ the arrangement shewn in Fig. 7,
Sheet II., in which the trucks are seen to run on three rails, the centre wheels being
double flanged, while the outer ones have plain rims. The fuel is dropped down
a series of firing holes indicated by b, b, b, which are now generally known in the
brick and earthenware trades under the name of Hoffmann. By this method,
which is now generally understood, the fire progresses through the stacked bricks
left at rest on the platform constituted by the tops of the trucks. When said bricks

page_text: have been sufficiently burnt, the whole train can be drawn back again and the
burnt goods removed. The line of rails on which the train of trucks runs preferably
extends the whole length of the burning chamber, being continued outside of the
same up to the drying floor or sheds.
In measure as the goods to be burnt are stacked on the trucks, said trucks are,
one after the other, run into the burning chamber, one end of which is left open
for the purpose.
On the kiln being filled this opening is closed by means of a
temporary wall B.
The opposite end of the burning chamber is closed by a perforated wall, which
communicates through the perforations with the flue C and smoke stack G. The
goods are stacked in such wise on the platform trucks F, F, that they nearly fill up
the transverse section of the burning chamber, leaving clearance sufficient to avoid
touching the inside walls. On the trucks being pushed into the burning chamber
the joints between the sides of the platforms are made tight by means of lutings of
sand or other similar means.
The joints or openings between the fronts and backs of the trucks may also be
suitably filled up by plastering clay on the back end of the platform of each truck,
the joint being made on pushing the truck in together. The burning chamber
being thus charged and its bottom closed up, a grate E (see Figs. 1 and 8, Sheet I.)
is fitted behind the last truck, and the whole chamber closed up by the aforesaid
temporary wall B. Or the grates E and E', as shewn in Figs. 4 and 6, Sheet II.,
may be set on a level or thereabouts with the line of rails. In this case it is
necessary to remove said grates whenever the kiln is to be unloaded. A fire is
then lighted on the grate, and the goods on the first two or three platform trucks
being brought to a red heat the fuel is dropped through the holes b, b, in the top
of the burning chamber. The distance between these holes in the direction of the
length of the burning chamber is preferably made equal to the length of the
platform F, F, and between the goods stacked upon two adjacent platforms a space
of from four to eight inches in width is left, on which the fuel dropped through the
holes b, b, is consumed. As the fuel must be supplied only through those holes b, b,
where the goods below have already attained a red heat, this firing necessarily
begins down the holes next to the grate E, and this so-called top firing advances
towards the smoke stack. When the goods next the grate E have been com-
pletely burned the fire on the grate is let out, and as the fire advances towards the
stack it is stopped from behind as soon as the goods have been thoroughly burnt.
The introduction of fuel from above is preferably carried on simultaneously between
two or more of the platforms. On the end of the burning chamber being reached
the removal of the burnt goods can be begun with; for this purpose the temporary
wall B is removed, as also the grate E (if it be above the level of the rails), and the
platform trucks F, F, are successively drawn out of the kiln as soon as they have
cooled down sufficiently for this purpose.
The platform of the truck next to the grate E may be provided with an apron
(see Fig. 5, Sheet II. of iron plate, protected by fire-bricks or tiles.
d
In place of the temporary wall B a simple shutter or slide may also be employed;
S is a shutter or damper by which the communication between the flue C and
chimney stack G is regulated.
The kiln, shewn in Figs. 1, 2, and 3 of Sheet I., can necessarily only be worked
intermittently; that drawn to a somewhat larger scale on Sheet II. can be worked
continuously.
Fig. 4 is a sectional elevation through the line x, x, of the plan, Fig. 6; and
Fig. 5, a section through the line y, y, z, z, on the same plan.
In this instance two burning chambers or galleries (A, A¹,) are built side by side,
communicating at their ends by two passages P, P₁, in such a manner as to form a
continuous circuit.
Each gallery is provided with a line of rails running along its entire length,

page_text: and out at the open ends B, B', to the drying floors or sheds or other required
dirctions.
The green bricks are stacked on the railway trucks, twenty of which are in
this case held by each gallery. After one of the galleries, for instance, that
indicated by A, has been filled with loaded trucks, a temporary wall is built
at B, the passage P is stopped by a shutter S, and all the Blues C, C, are opened. A
fire is then lighted on the grate E, the smoke therefrom and moisture from the
bricks escaping into the chambers D, D, and thence into the chimney G. The fire
is gradually increased and the flues C, C, are closed by suitable valves, such, for
instance, as are used in the Hoffmann kiln, the last one only, which runs from the
passage P, being left open in order to keep up the draught. As soon as the bricks
on the first two or three trucks next to the grate E have become red hot fuel is
dropped down the holes b, b, in the arch of the gallery, the successive apertures
being the same as with the single or intermittent kiln. Before the fire reaches the
end of the gallery A, the second gallery A¹ is filled with loaded trucks, a temporary
wall is built at B¹, the shutter S is withdrawn from the passage P and dropped into
the passage P¹. At the same time the last flue of the gallery A is closed, and all
the flues of the gallery A¹ are opened. The waste heat, which passes off from A,
before escaping into the chimney has to flow the bricks in A', preparing them
for being fired. By the time the fire has arrived at the end of the gallery A the
bricks at the beginning of the gallery A' will be red hot, and fuel is now fed
through the holes b, b, of this gallery. As soon as the bricks in A are sufficiently
cool the temporary wall B is removed, the trucks taken out one by one, and the
gallery again charged with green bricks, and so on.
Sundry other arrangements may be made by which several single intermittent
kilns of this kind can be combined to work simultaneously.
Figs. 8 and 9, on Sheet I., show another combination for a continuously working
kiln, forming a square in plan, in which four such burning chambers or galleries
with their several lines of railway are united together around a central chimney
stack G and smoke chamber D, D.
The mode of working this kiln will be readily understood from the foregoing
description of the single intermittent and double continuous kiln; A indicates the
gallery being actually fired, with the arrows shewing the course of the draught;
B, the temporary wall of this gallery; C, C, the Blues leading into the smoke
chamber; E, the grate; b, b, the Hoffmann firing holes; F, F, the trucks; and S,
the adjustable shutter for directing the fire gases into the stack at the spot required
by the actual course of working of the kiln.
Now I am
aware that kilns have been previously constructed with a floor
constituted of trucks coupled together and running on a line of rails. Such series
of trucks and the firing apparatus of the kiln have been combined in such wise that
it was necessary to move during the actual firing the line of loaded trucks against
a stationary fire, such firing being from the top or otherwise. This plan is obviously
attended with many difficulties in practice. But I am not aware that any other
kiln has heretofore been constructed in which the goods to be burnt are, as
described above, set on trucks, which remain at rest during the burning process
while the fire progresses through the bricks.
I therefore declare that I claim as novel,-
1. A kiln, in which bricks, tiles, and other similar goods are burnt by a fire pro-
gressing through the goods supplied on a moveable floor left stationary during the
process of firing, substantially as described.
2. The mode of supplying the green goods on and removing the burnt goods from
a kiln floor made moveable for these purposes and left stationary during the process
of firing, substantially as described.
3. The construction and working of an intermittent kiln, substantially as
described, with one such gallery or chamber.

page_text: 4. The construction and working of a continuous kiln, substantially as described
by the combination of one or more pairs of such galleries or chambers.
In witness whereof, I, the said Hermann Wedekind, have hereunto set my
hand and seal,. this Eighth day of April, in the year of our Lord One
thousand eight hundred and seventy-eight.
HERMANN WEDEKIND. (L.B.)