Improvements in Ovens for Baking Earthenware and the like.
Year: 1892

page_text: Date of Application, 21st Sept., 1892-Accepted, 14th Jan., 1893
COMPLETE SPECIFICATION.
Improvements in Ovens for Baking Earthenware and the like.
I, CARL MOELLENHOFF of Hamm, Westphalia, in the Kingdom of Prussia,
Engineer, 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 :-
My invention relates to the arrangement of baking ovens for potteries in such a
manner that quite uniform baking of the earthenware with respect to colour and
hardness is obtained and so that the heat in excess after the burning down of the
kiln or a part of same may be used for heating preparatorily one or several other
parts of the kiln.
The improved baking oven shown in the Figures 1-3 of the accompanying
drawings and annularly arranged for the intended purpose consists of several
chambers or compartments A B C etc. serving to receive the earthenware to be
baked. These chambers are taper and each is provided with two fire-places a and b
from which the hot gases pass first into a channel extending in front of the chambers
round the kiln and divided by dampers n and m in such a manner that the gases
cannot flow from the fire-places of the chamber A say into B or K, but must enter
through p directly their respective chamber.
There are at the bottom of the several chambers openings e¹ and d' orifices of
channels e and d which separated from each other, lead to a smoke chamber G
arranged round the chimney H in the central part of the kiln and susceptible of
being opened or closed by means of plugs dampers or valves g and h.
In addition to this a third channel f leads through the back wall of each chamber
directly into the smoke chamber G; the channel can be shut off by a damper f¹.
The smoke-chamber G is through the flues J in direct communication with the
chimney H. By arranging the flues in the described manner, it will be possible to
distribute the heat quite at will in the different chambers. If, for instance, the
dampers and h are closed, but g opened, the highest temperature will be produced
in the front part of the chamber; if, on the contrary, h is opened and g closed the
highest heat is concentrated in the rear part of the chamber. The opening of
channel and the closing of d and e produce an energetic draught of the fire-gases
through the central part of the chambers, while by closing and opening d and e
the gases are forced towards the bottom and flow through the chamber downwards.
For this reason it is very easy to obtain by means of a suitable position of the
dampers and valves f¹g and h in combination with the conical or taper construction
of the chambers such a distribution of the fire-gases that there is in all the different
parts of the chamber the same temperature.
By this the principal requirement for rational baking is fulfilled, as the various
earthenware articles to be burnt, without regard to where they may be placed in
the chamber, are all subjected to a heat of the same high degree so that a quite
uniform baking with respect to colour and hardness will take place.
Moreover the working of the kiln is very economical as owing to the improved
construction of the kiln, the high temperature which after the baking is still in the
chambers is utilized in a very simple way.
When for instance, the baking process has terminated in the chamber A, the
fire-places a and b of the same are shut off by means of a shell, by filling with sand,
by separating by masonry, or in other suitable way, the channels de and fare
closed and the dampers and valves g h and f' of the flues in B or K are opened so
that the direct draught to the chimney is shut off in the chamber A but is
established in the chamber B or K whereupon the dampers n and m are opened
and the hot gases contained in chamber A pass to the chamber B or K.

page_text: Into the chamber, after the baking operation is completed, fresh air must of
course be admitted in substitution of the discharged hot air and for this purpose the
chamber is to be put in communication with the open air.
To attain this an iron conduit z is provided in front of the corresponding channel f
after the burning down of the chamber in the smoke collector G through a suitable
aperture in the roof of the collector through which conduit the required fresh air
penetrates into the chamber.
The chambers to be heated preparatorily are of course previously charged with
fresh earthenware to be burnt and heated in this way, nearly without any expense,
to a somewhat high temperature, which is increased then by the fire-places a and b
to the required highest degree.
In lieu of, from the chamber A to the chamber B, the heat in excess may be
transmitted to any other chamber; for this purpose it is only necessary to shut off
the flues in the intermediate chambers and to open in the channel c the slides m
and n up to the chamber in question. The preparatory heating of several chambers
may of course also take place from one chamber. This construction affording by
the utilization of the hot gases in excess a large saving in fuel and permitting a
continuous working, offers furthermore an essential advantage as it assists to a very
high degree in the rapid manufacture of the earthenware because it renders it
unnecessary to wait for the complete drying of the wares
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An arrangement of ovens for baking earthenware or the like consisting of
several cone-shaped or taper.chamber or compartments such as A B K and in
which the flues are arranged in such manner that the fire gases pass from the fire-
places a and b through a channel c extending in front of the chambers round the
oven and divided by dampers m n into separate sections corresponding to the
number of chambers into the latter whence they are led through passages e and d
arranged in the bottom of the chambers or through the channels in the back wall
of the chambers first into a smoke chamber G surrounding the chimney arranged
in the central part of the kiln and then into the chimney H substantially as
described and illustrated in the accompanying drawings.
2. The combination and arrangement of parts constituting a circular bench of
ovens for baking earthenware and the like substantially as described and illustrated
in the accompanying drawings.
Dated this 21st day of September 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicant.