IMPROVE- MENTS IN KILNS OR 'OVENS FOR BURNING BRICKS AND OTHER LIKE SUBSTANCES
Year: 1874

page_text: LETTERS PATENT to Hermann Wedekind, of Great Tower Street, in
the City of London, Engineer, Humphrey Chamberlain, of Barnsley,
in the County of York, Engineer, and John Craven, of Wakefield,
in the County of York, Engineer, for the Invention of "IMPROVE-
MENTS IN KILNS OR 'OVENS FOR BURNING BRICKS AND OTHER LIKE SUBSTANCES."
-A communication from abroad by Friedrich Hoffman, of Berlin,
in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Hermann Wedekind,
Humphrey Chamberlain, and John Craven at the Office of the
Commissioners of Patents, with their Petition, on the 2nd December
1874.
We, HERMANN WEDEKIND, of Great Tower Street, in the Oity of
London, Engineer, HUMPHREY CHAMBERLAIN, of Barnsley, in the
County of York, Engineer, and JOHN CRAVEN, of Wakefield, in the
County of York, Engineer, do hereby declare the nature of our said
Invention for "IMPROVEMENTS IN KILNS OR OVENS FOR BURNING BRICKS AND.

page_text: OTHER LIKE SUBSTANCES," a communication to us from abroad by Friedrich
Hoffmann, of Berlin, in the Empire of Germany, to be as follows:-
This Invention relates more particularly to kilns or ovens for burning
bricks and other like substances constructed on what is known as
Hoffman's system, and it has for its object the utilization of a larger
portion of the heat evolved from the bricks in the process of cooling for
the purpose of heating and drying those which are in a green or soft
state, whereby the labor and expense entailed by the use of fires in the
doorways for drying the lower courses of the bricks under treatment may
bo obviated, whilst at the same time the operation is performed in an
efficient and uniform manner.
In order to effect these objects it is proposed to construct an annular
or continuous hot air flue by preference beneath the level of the ground
instead of the upper hot air flue ordinarily employed. This additional
flue, which is constructed and connected with the different chambers or
compartments, may, in the case of existing kilns, be arranged outside of
the foundations or outer wall, but in constructing new kilns it is
preferred to place it between the outer wall and the wall of the burning
chambers or compartments, although it may, if found desirable, be
arranged underneath the floor of the burning chamber or compartment
or within the inner wall of the same.
Beneath the floor at each doorway there is formed an opening com-
municating with the lower flue either directly or (when the flue is
constructed otherwise than between- the foundations of the outer wall)
through a branch flue leading thereto, which opening is closed by a short
tube of cast iron and a lid fitted with a sand joint, and is covered over
for facilitating the insertion and removal of the bricks.
A door composed of sheet iron or other suitable material is also
provided to cover the opening in the outer wall forming each doorway in
order to exclude the external air at such times as it is desired to close
the respective doorways.*
a
The lower flue operates in the following manner :-The lids are
removed from the flue openings in two or more doorways and
circulation of air is established through the flue between any desired
chambers or compartments.
The brick wall forming the inner doorway of the chamber or com-
partment from which the heat is to be drawn is opened at the top by

page_text: removing a few layers of the bricks, while the brick wall of the chamber
or compartment to be dried has an opening made near the floor.
Selecting 7 chambers or compartments numbered respectively 1, 2, 3,
4, 5, 6, and 7, as an example of the operation. of the flue, let it be
assumed that the bricks in compartment No. 2 are to be dried, that
compartment No. 3 is being charged with green bricks, that No. 4
compartment is empty, whilst compartments Nos. 5, 6, and 7 are cooling.
It is therefore necessary to conduct the heat accumulating in compart-
ments Nos. 4 and 5 to compartment No. 2. This is effected in the
following manner, viz. :-Compartment No. 2 is divided from the rest by
means of two intercepting dampers, the brick wall inside the doorway is
erected leaving a large opening above the floor. The lid having been
removed from the flue and the outer door placed against the wall and
made air-tight a large opening is made in the top part of the inner brick
wall of doorway No. 6, and the lid is removed from the corresponding
flue opening, and the outer door placed air-tight against the external
wall. All the remaining openings in the hot-air flue are closed as well
as all smoke flues, except that one belonging to compartment No. 1,
which is the last of the compartments in connection with the fire, and
causes the draft in the burning section; and the whole of the doorways
are also closed, except those of compartments Nos. 3 and 4. The valve
of the smoke flue leading to compartment No. 2, which has been
separated from the rest, is now opened, and the chimney draws the air
from this compartment, which air is replaced through the hot-air flue
from the cooling compartments Nos. 5 and 4 through the opening in the
brick wall of doorway No. 6. The air having entered the kiln through
the doorways 3 and 4, has thus in its courso absorbed the heat of the
burnt bricks, and a continuous influx of warm air from the compartment.
No. 5 to compartment No. 2 takes place.
This circulation of the air may be facilitated by providing in the hot
air flue a number of throttle valves or dampers, the whole of such valves
or dampers in the shorter route between doorways Nos. 6 and 2 being
kept open whilst the others are maintained closed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Hermann Wedekind, Humphrey Chamberlain, and
John Craven in the Great Seal Patent Office on the 2nd June
1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HERMANN
WEDEKIND, of Great Tower Street, in the City of London, Engineer,
HUMPHREY CHAMBERLAIN, of Barnsley, in the County of York, Engineer,
and JOHN CRAVEN, of Wakefield, in the County of York, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of December, in the year of
our Lord One thousand eight hundred and seventy-four, in the 38th year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said Hermann Wedekind, Humphrey Chamberlain, and
John Craven, Her special license that we, the said Hermann Wedekind,
Humphrey Chamberlain, and John Craven, our executors, administrators,
and assigns, or such others as we, the said Hermann Wedekind,
Humphrey Chamberlain, and John Craven, our executors, administrators,
or assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN KILNS OR. OVENSF OR BURNING BRICKS
AND OTHER LIKE SUBSTANCES," a communication to us from abroad by
Friedrich Hoffmann, of Berlin, in the Empire of Germany, upon the
condition (amongst others) that we, tho said Hermann Wedekind,
Humphrey Chamberlain, and John Craven, our executors or admini-
strators, by an instrument in writing under our hands and seals or under
the hand and seal of one of us, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said Hermann Wedekind, Humphrey
Chamberlain, and John Craven, do hereby declare the nature of our said
Invention, and in what manner the same is to be performed, to be

page_text: particularly described and ascertained in and by the following state-
ment, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
-
The said Invention relates more particularly to kilns or ovens for
burning bricks and other like substances constructed on what is known
as Hoffmann's system, and it has for its object the utilization of a larger
portion of the heat evolved from the bricks in the process of cooling for
the purpose of heating and drying those which are in a green or soft
state, whereby the labor and expence entailed by the use of fires in the
doorways for drying the lower courses of the bricks under treatment may
be obviated, whilst at the same time the operation is performed in an
efficient and uniform manner.
In order to effect these objects there is substituted for the upper hot
air flue ordinarily employed an annular or continuous hot air flue
constructed beneath the level of the ground. This additional flue,
which is connected with the different chambers or compartments, may,
in the case of existing kilns, be arranged outside of the foundations or
outer wall, but in constructing new kilns it is preferred to place it
between the outer wall and the wall of the burning chambers or com-
partments, although it may, if found desirable, be arranged underneath
the floor of the burning chamber or compartment or within the inner
wall of the same.
Beneath the floor at each doorway there is formed an opening
communicating with the lower flue either directly or, when the flue is
constructed otherwise than between the foundations of the outer wall,
through a branch flue leading thereto, which opening is closed by a short
tube of cast iron and a lid fitted with a sand joint, and is covered over
for facilitating the insertion and removal of the bricks.
A door composed of sheet iron or other suitable material is also
provided to cover the opening in the outer wall forming each doorway in
order to exclude the external air at such times as it is desired to close
tho respective doorways.
And in order that the said Invention may be fully understood we shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the
corresponding Figures.

page_text: b
section of a kiln in which the hot-air flue is constructed between the
foundations of the outer wall and the wall of the burning chamber or
compartment.
Figure 2 is a similar view of a kiln in which the hot-air flue is
arranged at the exterior of the foundation of the outer wall.
Figure 3 is a horizontal section, the left-hand half of which corresponds
with the vertical section Figure 1, whilst the right-hand half corresponds
to Figure 2.
Figures 4 and 5 are details which will be herein-after referred to.
And Figure 6 is a diagram of a circular kiln, illustrating the operation
of the hot-air flue.
Referring to Figures 1 to 5, A is the hot-air flue which is connected
with the burning chambers or compartments B, B, either directly
through the doorways C, C, as in the arrangement, Figure 1, or through
branch passages D, D, as in the modification Figure 2. For this purpose
there is formed in the floor of each doorway C an opening a, which is
closed by a short metal tube 6 and a lid c, a tight joint being obtained
by means of sand packed around the same. The upper part of the
openings a may also be covered with a plank or otherwise so as to
facilitate the insertion and removal of the bricks. Doors d, d, composed
by preference of sheet iron are employed for the purpose of covering the
usual openings d', d', at the doorway C, C, in the outer wall E in order
to exclude the external air when required.
The lower flue operates in the following manner :-The lids c and the
planking when employed are removed from the fluc openings a, a, at
two or more doorways, and a circulation of air is established through the
flue A between any desired chambers or compartments B, B.
The brick wall e forming the inner doorway of the compartment from
which the heat is to bo drawn is opened at the top as shewn at f, Figuro
1; by removing a few layers of the bricks, whereas the brick wall of the
compartment to be dried has an opening g made near the floor, as shewn
in Figure 2.
In describing the operation of the kiln we shall refer more particularly
to the diagram, Figure.6, which shows a kiln constructed of circular

page_text: .
Selecting seven chambers or compartments, numbered respectively 1,2,
.3, 4, 5, 6, and 7, as an example of the operation of the flue, let it be
assumed that the bricks in compartment No. 2 are to be dried, that
compartment No. 3 is being charged with green bricks, that No. 4
compartment is empty, whilst compartments Numbers 5, 6, and 7 are
cooling, it is therefore necessary to conduct the heat accumulating in com-
partments Nos. 5 and 6 to compartment No. 2. This is effected in the
following manner, videlicet:-Compartment No. 2 is divided from the
rest by. means of two intercepting dampers h, h, the brick wall inside the
doorway is erected, leaving a large opening above the floor, as shewn at
g, Figure 2. The lid 6 (closing the opening a, Figure 4, of the hot air
flue) of No. 2 compartment having been removed from the flue, and
the outer door & placed against the wall E and made air-tight, a large
opening f, Figure 1, is made in the top part of the inner brick wall e of
doorway No. 6, the lid 6 is removed from the corresponding flue opening
and the outer door d placed air-tight against the external wall E. All
the remaining openings in the hot air flue are closed as well as all the
smoke flues F and the smoke flue F leading to the central smoke
chamber G, which communicates with the chimney, the whole of the
smoke flues being provided with valves i, Figures 1 and 2. The smoke
flue F³ belonging to compartment No. 1, which is the last of the com-
partments in connection with the fire, and causes the draft in the
burning section, is alone open, and the openings d², d, of the whole of
the doorways C, C, are also closed bymeans of doors d, d, except those of
compartments Numbers 3 and 4. The valve i of the smoke flue F' leading.
to compartment No. 2 which has been separated from the rest is now
opened, and the chimney draws the air from this compartment, which
air is replaced through the hot air flue A from the cooling compartments
Numbers 5 and 6 through the opening f, Figure 1, in the brick wall e of
doorway No. 6. The air having entered the kiln through the doorways
3 and 4 has thus in its course absorbed the heat of the burnt bricks, and
a continuous influx of warm air from the compartment No. 5 and No. 6
to compartment No. 2 takes place.
This circulation of the air may be facilitated by providing in the hot
air flue a number of throttle valves or dampers H, Figure ŏ, the whole of
such valves or dampers in the shorter route between doorways Numbers 6
and 2 being kept open whilst the others are maintained closed. The hot
air flue A may, if desired, be arranged beneath the floors I of the
burning compartments B, B, or within the inner wall K of the same.

page_text: Having now described and particularly ascertained the nature of the
said Invention and the manner in which the same is or may be used or
carried into effect, we would observe in conclusion that what we consider to
be novel and original, and therefore claim as the Invention secured to us
by the herein-before in part recited Letters Patent is, the application and
use to and with kilns for burning bricks and other like substances of a
hot-air flue arranged below the level of the ground and operating,
substantially as and for the purpose herein-before described and as
illustrated by the accompanying Drawings.
In witness whereof, I, the said Hermann Wedekind, on behalf of
myself and the said Humphrey Chamberlain and John Craven,
have to this our Specification set my hand and seal, the First
day of June One thousand eight hundred and seventy-five.