Improvements in Furnaces and Kilns.
Year: 1890

page_text: Date of Application, 11th Sept., 1890-Accepted, 21st Mar., 1891
COMPLETE SPECIFICATION.
Improvements in Furnaces and Kilns.
I, AUGUST DANNENBERG, of Görlitz, in the Empire of Germany, Manufacturer,
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 :-
This invention relates to periodically and continuously worked chamber and annular
furnaces and has for its purpose to effect economy in the working of such furnaces
beside obviating other inconveniences hereafter referred to.
For working furnaces of this order with direct or gas firing, various grate and
channel constructions were heretofore required owing to the absence of a rationally
constructed universal firing arrangement, for instance with the gas chamber furnace
necessitating the application of expensive gas generators and long gas conduits
with costly valves and closings, which are moreover difficult to superintend.
With direct firing separate grate firings are required for each single chamber
which firings not only render the erection of the furnace unproportionally expensive,
but also necessitate a very complicated construction thereof owing to the circum-
stance that the grate firings can only be arranged at right angles to the escape of
the gaseous products of combustion (instead of opposite the same).
In the working of annular furnaces either grit firing had hitherto to be resorted
to-which however has met with very limited application for baking ceramic material
of a better class-or the gas pipe firing, which on account of its expensiveness,
obstructive handling within the furnace space proper and difficulty of regulating
the condition of flame, has likewise found but few adherents.
To remove these and similar drawbacks, I have invented a new and peculiar
process for baking bricks in the shape of a transportable firing contrivance & shown
in Figs. XIII, XIV and XV of the accompanying drawing illustrating my inven-
tion, Fig. XV being shewn as turned through a right angle. Said contrivance
which is provided with furnace grate plane grate or step grate is so constructed as
to be adapted for use as an independent grate for producing direct flame and also
for supplying fire gases from above to baking furnaces of various construction.
By the improved arrangement all complicated gas conduits with their closings are
dispensed with in gas chamber furnaces.
The improved heating contrivance is placed direct above the chamber to be
heated, whereby the watching of the fire is facilitated and rendered more reliable.
Moreover tar condensations, non-acting of the gas valves and explosions are
excluded.
In continuous, directly fired chamber furnaces the great number of expensive
plane grate arrangements and the strong support walls required therefor, as also the
periodical heating and cooling of the grate firings become superfluous, consequently
economy is attained in building and working expenses.
The improved transportable grate devices k are adapted, when once put to work,
to be rapidly conveyed without cooling down from the finished chamber to the next
chamber to be heated and placed into use afresh.
Annular furnaces, that is to say, such with open firing duct returning into itself,
are at the present time mostly worked by means of grit firing; in these furnaces
the combustion material falls between the material to be baked. Thereby, when
producing very high temperature and when baking glazing, the ashes burn fast in
the shape of slag on the goods to be baked which are consequently deteriorated.
Also here my transportable grate firing can be advantageously employed. by
providing below the heating holes h¹ (in lieu of heating shafts m shewn in Fig. IV

page_text: which are built up step grate fashion) high heating shafts n having interstices at
their sides as shewn by Figs. X and XI whereby a better distribution of the flames
is attained.
Fig. 1 shows the top view and plan of a chamber furnace and
Fig. 2 is à longitudinal vertical section to Fig. 1.
Fig. 1 shows the improved heating device (k and k¹) as working the chambers II
and III.
The device works with gas fire, the cooling heat escaping from chamber i being
conducted through the ducts ae and e up the rear side of the fire stands f, where it
mixes at with the generator gases and is burned.
Above chamber III, k works with direct fire; the admission of the hot air from
chamber 2 being prevented, a ready flame must have already been produced on the
grate and conducted into the oven.
(In this manner also the periodical baking furnaces are worked with my improved
firing.)
With continuous firing, the fire gases or smoke gases flow also through
chambers IV, to V and so forth, until they are sufficiently cooled, and finally pass
through ducts a and c and the "closeable" smoke collector 9, to the flue and into
the atmosphere.
Figs. III and IV are top view, plan and vertical longitudinal section of an annular
furnace (likewise with firings k and hollow shafts n) as it is put to work.
Fig. V is a cross section of an annular furnace and Fig. XII of a chamber
furnace with the improved firing device k applied thereto.
Fig. XIII is a horizontal section XIV a longitudinal section, and Fig. XV a
cross section of a transportable universal firing device k with plane grate.
The improved contrivance can be made in various modifications and conformed to
local requirements; also single or several coupled firings may be employed for
narrow or broader cross sections of furnace.
The same applies to the transport and selection of the materials for making the
firing devices proper k which, in order to obviate radiation of heat are provided
outside with any material or materials having a low rate of thermal conductivity or
with isolating layers.
Under certain conditions it may also be required to place stationary instead of
transportable firings k on the furnace top in order to finish the baking in the
chambers from above, which will be particularly recommendable for some periodical
furnaces.
It is to be observed that for "choking" (i.e. drying) bricks or ceramics newly
introduced into the furnace, so called smoking-fires or smokies and smoke
furnaces have already been employed on the top of furnaces for producing low
Jemperatures.
This method however has nothing in common with the improved method of finishing
the baking of the material from above in the described manner.
The following is a further novelty and improvement in the mode of firing annular
furnaces. In the latter the combustion material as is known, is strewed through the
top plate of the furnace on so-called heating shafts, which are in most cases formed
by the objects to be baked. The stoker however rarely succeeds in uniformly
distributing the firing material in all layers, owing to the difficulty in handling the
stoke bar within the glowing oven or in the heating shafts while the filling out of
the shafts with stones, which is sometimes applied is rarely done to satisfaction.
My process is accordingly as follows:-
When filling_out_the_chambers, small_plates_(preferably of fire-proof material).
are at the same time put in as shown by 02, 03 and o* Figs. VI VIII and IX.
The firing of the furnace is then so effected in stories, that when the lowermost
storey situated below o² is finished baking, the plates o² are tilted over by means of
a fire hook as shown by o¹ Figs. VI and VIII and in plan and side view. The
finishing baking then takes place below o³ and after this is done, also the plates o³
and subsequently the plates of are tilted over.

page_text: Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The process of finishing from the top of the furnace the baking of the material
in baking furnaces for brick,--clay goods,-stoneware, china, lime, and cement
-industry by means of transportable or stationary firing devices, substantially as
set forth.
2. The process, in filling up annular baking furnaces with the material to be treated,
of so placing small plates, or stones into the heating shafts as to allow the same to
be tilted over through the heating hole from the top during baking, by means of a
fire hook, and thereby the goods to be baked storey-fashion, substantially as set
forth.
Dated this 11th day of September 1890.
AUGUST DANNENBERG.
By Huelser & Co.,
Temple Chambers, London, his Attorneys.