Improvements in Calcining Furnaces.
Year: 1892

page_text: Date of Application, 5th Sept., 1892
Complete Specification Left, 1st June, 1893-Accepted, 26th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Calcining Furnaces.
I, AUGUST DAUBER of Bochum Alleestrasse 169 Westfalia, Germany, Merchant
do hereby declare the nature of this invention to be as follows :-
The calciuing furnaces in use for calcining and roasting limestone, cement,
gypsum, dolomite and the like are not able to turn out an uniform and equal
product. This causes a double loss: fuel is wasted and the product is partly of
inferior quality, and this is caused by the insufficient and irregular admission of air
and in a cold state of the same into the material to be treated.
The calcining of the said, materials in circular furnaces of Hoffmanns system is
too expensive without garanteeing a better result.
The furnace invented by me for continuous calcining, roasting and burning of
lime, cement, gypsum, dolomite and other suitable materials answers all the
purposes, without having the draw backs of the ordinary furnaces. Its peculiar
construction guaranties a practical working, a faultless product, and requires very
little fuel.
On the accompanying drawing:
Figure 1 is a vertical section of the furnace ;
Figure 2 is a horizontal section in the level of the outlet doors;
Figure 3 is a similar section of the lower part of the furnace;
Figure 4 is a vertical section of a part of the furnace in an enlarged scale;
Figure 5 is a sectional plan of Fig. 4;
Figure 6 shows the supporting girders of the delivery cone and the air inlet and
regulating valves;
Figure 7 is a cross section of an air valve;
Figure 8 is a section through an auxiliary fire place of the furnace.
The furnace consists of a conical shaft or pit A built upon a cylindrical or poly-
gonal lower part or socle and pillars B. This socle carries on girders D the
delivery cone E and above it the conical furnace A. is .built, having six outlet
doors F and being surmounted by a chimney G.
The girders D support a ring girder H, which carries the table I with the air
valves K. The delivery cone E is cut off at its upper part, forming an open
truncated cone, and upon this part are fixed the lanterns or caps L L and the
closing cap M, allowing air passages between them. The delivery cone is
immovable, the caps L L and M are fixed by arms N to a vertical shaft O, so that
by means of gearing P at the bottom they may be turned round, if found desirable;
the lower cap is therefore provided with rollers Q, which stand upon the cone E.
Trapdoors R serve for closing the outlet openings F. When opened these doors
serve at the same time as shoots for guiding the material into the waggons below
them, and also as grates for separating ashes and small material from the big pieces.
They are therefore provided with slots. Counter doors S are linked to them,
which are also made like a grate, but so, that the solid bars cover the openings of
the doors R, when these are closed, as shown in Fig. 4.
In order to prevent the outfall of more finished material, than is desired, when
the doors R are opened, there are bars T so connected to their lower part, that the
spikes U linked to their inner ends are raised into the furnace through holes
provided for that purpose in the cone plate E, as shown in Fig. 1. on the right side,
and which thus prevent the sliding down of the material above them.
The spaces right and left of the outlet doors are made roof shaped, as shown at V
in Fig. 5.
The raw material and the fuel are fed into the furnace at the top of the pit at W.
In ander to be abl
1 1

page_text: and into the hollow space so formed, the gas is introduced, coming from a generator,
by means of a pipe Z; tuyere like openings b admitting the gas into the furnace a.
A bell door may be fitted to the top of the furnace and then the furnace gases
may be let away by openings c into a collecting channel d.
In those cases, when the furnace gases go direct into the chimney, they may be
used for producing steam in a pipe..e which is connected to a water tank y mounted
round the chimney and serving for increasing the draught of the chimney.
Into the solid spaces between the outlet doors F special fire places I are arranged
(Figs. 5 & 8) by means of which the furnace can be heated separately; the heating
gases produced in these auxiliary fire places entering through channels m into the
gas jackets a, whence they are let into the calcining furnace through the openings b.
These auxiliary fires are also valuable in such cases where it is not desirable to
mix the fuel with the material to be treated in the calcining furnace and where no
special gas generator is at hand.
Dated this 30th day of August 189
AUG. DAUBER.
Karl J. Mayer,
Agent.
COMPLETE SPECIFICATION.
Improvements in Calcining Furnaces.
1, AUGUST DAUBER of Bochum Westfalia, Germany, Merchant Neu
Strasse No. 16 late of Bahnhofstrasse 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:-
The calcining furnaces in use for caleining and roasting limestone, cement,
gypsum, dolomite and the like are not able to turn out a uniform and equal product.
This causes a double loss: fuel is wasted and the product is partly of inferior
quality and this is caused by the insufficient and irregular admission of air and in
a cold state of the same into the material to be treated.
The calcining of the said materials in circular furnaces of Hoffmanns system is
too expensive without guaranteing a better result.
The furnace invented by me for continuous calčining roasting and burning of
lime, cement, gypsum, dolomite and other suitable materials answers all the
purposes without having the draw backs of the ordinary furnaces. Its peculiar
construction guaranties a practical working a faultless product and requires very
little fuel.
On the accompanying drawing:
Fig. 1 is a vertical section of the furnace;
Fig. 2 is a horizontal section in the level of the outlet doors;
Fig. 3 is a similar section of the lower part of the furnace;
Fig. 4 is a vertical section of a part of the furnace in an enlarged scale;
Fig. 5 is a sectional plan of Fig. 4.
Fig. 6 shows the supporting girders of the delivery cone and the air inlet and
regulating valves:
Fig. 7 is a cross section of an air valve;
Fig. 8 is a section through an auxiliary fire place of the furnace.
The furnace consists of a conical shaft or pit A built upon a cylindrical or
polygonal lower part or socle and pillars B. This socle carries on girders D the
delivery cone E and above it the conical furnace A is built, having 6 outlet
doors and being surmounted by a chimney G.
The girders D support a ring girder which carries the table I with the air
valves K. The delivery cone E is cut off at its upper part, forming an open
truncated cone and upon this part are fixed the lanterns or caps L L and the
closing cap M allowing air passages between them. The delivery cone is

page_text: immovable the caps L L and M are fixed by arms N to a vertical shaft O, so that
by means of gearing P at the bottom they may be turned round if found desirable;
the lower cap is therefore provided with rollers Q which stand upon the cone E.
Trapdoors R serve for closing the outlet openings F. When opened, these doors
serve at the same time as shoots for guiding the material into the waggons below
them and also as grates for separating ashes and small material from the big pieces.
They are therefore provided with slots.. Counterdoors S are linked to thein which
are also made like a grate, but so, that the solid bars cover the openings of the
doors K when these are closed as shown in Figure 4. In order to prevent the
outfall of more finished material than is desired, when the doors R are opened,
there are bars T so connected to their lower part, that the spikes U linked to their
inner ends are raised into the furnace through holes provided for that purpose in
the cone plate E, as shown in Fig. 1 on the right side, and which thus prevent the
sliding down of the material above them.
The spaces right and left of the outlet doors are made roof shaped as shown
at V in Fig. 5.
The raw material and the fuel are fed into the furnace at the top of the
pit at W.
a
In order to be able to heat the furnace by gas it is surrounded by a jacket
and into the hollow space so formed, the gas is introduced, coming from a
generator, by means of a pipe Z; tuyere like openings admitting the gas into the
furnace a.
A bell door may be fitted to the top of the furnace and then the furnace gases
may be let away by openings c into a collecting channel d.
In those cases when the furnace gases go direct into the chimney they may be
used for producing steam in a pipe which is connected to a water tank
y mounted
round the chimney and serving for increasing the draught of the chimney.
Into the solid spaces between the outlet doors F special fire places are arranged
(Figs. 5 & 8) by means of which the furnace can be heated separately; the heating
gases produced in these auxiliary fire places entering through channels m into
the gas jackets a, whence they are let into the calcining furnace through the
openings b. These auxiliary fires are also valuable in such cases where it is not
desirable to mix the fuel with the material to be treated in the calcining furnace
and where no special gas generator is at hand.
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. A furnace for continuously calcining and roasting therein limestone, cement,
gypsum, dolomite and the like materials having central annular entrance openings
for the air above the delivery cone E and between the caps L L, M and the
regulating valves K as described and for the purpose specified.
2. In a furnace for calcining and roasting limestone, cement gypsum, dolomite
and the like materials as just specified the combination of outlet doors R, arms T
and spikes U with counterdoors S for preventing the outfall of the upper material
from the furnace and also for separating ashes from the roasted goods below the
spikes U.
3. The arrangement of the jacket a forming a gas chamber round the stack of
the furnace and the gas outlets c and gas channels d for leading away the furnace
gases and using them for heating purposes.
4. Arranging the spiral piper and its connection with a water tank y in order
to generate steam in the pipe and increasing the draught of the chimney."
Dated this 30th day of May 1893
AUGUST DAUBER,
Per Karl J. Mayer,
Agent.