Improvements in Drying Stoves for Bricks, Ceramic Materials, and such like.
Year: 1890

page_text: Date of Application, 23rd July, 1890-Accented, 30th Aug., 1890
COMPLETE SPECIFICATION.
Improvements in Drying Stoves for Bricks, Ceramic Materials, and
such like.
1, ALBERT SCHAAF of Halle /Saale, in the Empire of Germany, Brick Manu-
facturer 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 drying stoves or furnaces more particularly for bricks,
artificial stones and ceramic products and has for its purpose to provide the means for
attaining a more effectual drying process and more perfect utilization of the heat
employed.
The drying in the open air of various products, especially of pottery articles being
to a most inconvenient extent dependent on climatic influences, this great drawback
is generally sought to be obviated by drying such materials in closed spaces, in which
temperature and supply of air can be artificially regulated. This mode of drying
however involves relatively great expense and is by no means void of inconveniences.
It has proved absolutely necessary, that, in order to conquer the difficulties connected
with a systematic application of the counter current, the articles to be dried should
be guided towards the air current and the latter compelled to play about every single
piece from all sides. The results attained in this direction are of a very unsatisfactory
character, as in the respective arrangements hitherto known, the warmer and dryer-
therefore lighter-strata of air accumulate at the top regions of the drying apparatus
and consequently fail to produce the desired effect on the material placed below.
Moreover the moving of the material in the horizontal plane necessitates considerable
waste of motive force.
The drawbacks above referred to are intended to be removed by the arrangement
hereafter described which has for its purpose not only to conduct the material to be
dried towards the warm air without expenditure of motive force, but also to divide the
warm air into currents of small cross section, especially of inferior height, and to
allow such division to be with facility regulated during work so as to preclude a
separation of the warm and dry air-strata within the single air channels and every
article to be exposed on all sides to the action of an air current, the properties of
which are in a proper ratio to those of the piece to be dried.
Reference being had to the drawings sheets I to III hereunto annexed,
Fig. 1 is a longitudinal section,
Fig. 2 a section along line M N Fig. 1,
Fig. 3 a top view,
Figs. 4 and 5 represent details,
Fig. 6 shows a modification,
Figs. 7 and 8 are details of the improved drying apparatus. It is obvious, that
with the movement of hot air in a large undivided space; heat continually radiates
from the sides of such space, and the movement of the air causes the sides to come
incessantly into contact with new strata of the enclosed air. When however super-
posed passages or channels are arranged in juxtaposition, such radiation takes place
from the top side only of the drying furnace and can moreover be partially neutralized
11
Figs. and represent decans,
Fig. 6 shows a modification,
Figs. 7 and 8 are details of the improved drying apparatus. It is obvious, that
with the movement of hot air in a large undivided space; heat continually radiates
from the sides of such space, and the movement of the air causes the sides to come
When however super-
incessantly into contact with new strata of the enclosed air.
posed passages or channels are arranged in juxtaposition, such radiation takes place
from the top side only of the drying furnace and can moreover be partially neutralized
section imparte
as shewn in Fig. 1. The air thus divided into currents of small
its heat very completely to the material to be dried ; loss of heat is almost absolutely
excluded and the smallest quantities of heat can be utilized. The superfluous
quantities of heat are thus sufficient also in unfavourable and cold weather and no
addition of any special heating appliances is required.
The movement, without expenditure of motive force, of the materials to be dried is
produced by causing the same to slide by their own weight down an inclined plane

page_text: and retarding such movement by providing a horizontal plane as a continuation of
the inclined plane. Furthermore a contrivance is provided for conducting the warm
and dry air in divided currents along every piece to be treated and for so regulating
said currents as to cause the same to act not only on that side of the object, which
faces the current, but to come into uniform contact with the whole free surface of
every object to be dried.
The drying chamber proper A Fig. 1, is protected from the effects of the external
air by means of any suitable material of low thermal conductivity: B is the passage for
introducing the material to be dried, into the chamber A, while channel C serves
for the removal of the dried articles and for the admission of fresh air. D is a flue
for the escape of the utilized air; this flue may also be replaced if required, by
an aspirator or other suitable device. The chamber A communicates with B through
the upper side a band with C through the lower side c d of chamber A. The
dimensions a cor bd are suited in every particular case to the properties of the
material to be dried and to the quantity of heat at disposal, while the extension of
the apparatus in the direction of a a' and bb' (Fig. 2. section along line M. N. Fig. 1,
and Fig. 3. top view) is not subject to limitation. It may be rectilinear and of any
desired length or arranged in curves around an annular kiln. The inclined portion of
the base a c of chamber A terminates with a slight curve into a horizontal plane.
The whole chamber A is divided by means of boards e f into single passages, which
run parallel or approximately parallel with, that is to say, correspond in inclination
and transition into the horizontal to, the base a c and are supported and stiffened
by vertical sides g h. The cross section of the numerous drying channels thus formed
is adapted as closely as possible to the size of the articles to be dried.
Fig. 4 is a longitudinal section and Fig. 5 a cross section along line M N Fig. 4,
illustrating the connection of the boards ef with the sides gh by means of bars i
secured to the latter. The sides g h are also provided with an additional number of
such bars m n. On these bars, which form guides for the material, are placed the
plates or boards for receiving the articles to be dried.
In the lower portion of chamber A, the transition of base a c and boards e f into
the horizontal is so made as to leave space for placing sources of heat. The latter
preferably consist of pipes, as shewn in Fig. 4, in which moves or circulates live or
waste steam, hot vapour, hot water or other heating agent. When the heating is
effected by means of a liquid, the latter can be differently distributed in the different
pipes.
If another source of heat, more difficult of distribution, is to be employed, for
instance, the air heated at the sides of a kiln or furnace, the contrivance illustrated
by Fig. 6 is used, R representing an annular furnace with smoke collector and a
series of chambers K. In this figure, A likewise is the drying chest, B the space
from which the material is supplied, C the channel for removing the dried material
at c d. The air heated at the sides of the annular furnace flows in the spaces CC in
the direction indicated by arrows, but it does not pass to C but flows through the
perforated horizontal portion of base a c into the space A. For the purpose of
admitting of a proper distribution of the drying air, the boards e f are also perforated
in their lower portions or made from laths or bars, the cross section or capacity of
direct passage thereby produced being lessened for each next higher channel as
shewn in Fig. 6. All spaces through which the current of drying air is not to pass,
and from which cold air could enter, must of course be properly isolated from space A.
Also the discharge opening c d is to be covered by flaps, doors or slides which are
opened only as far as necessary.
The flue or other draft producer is likewise provided above B as in Fig. 1.
To allow the drying-air current to be regulated in the manner mentioned above,
strips of any suitable material, preferably textile fabric, are suspended curtain-fashion
in the manner of the so-called soffits in theatres from the lower side of the single
plates or boards as illustrated in Fig. 7. vis the cross section of such a curtain,
which is moreover adapted to be pulled up or let down entirely by means of a small
cord (twine) s as it may be required by the height of the articles placed on the next

page_text: lower board or plate. The curtain is adjusted prior to bringing the plate p into the
space A similar curtains are attached to the stationary boards e f; these curtains w
are adjustable by means of stronger cords t extending from bottom to top along the
underside of board e f into the receiving space B, whence they are worked i.e. pulled
or slackened. These cords are connected with the curtains w through cords s'.
The position of these curtains relatively to the articles to be dried may be seen
from figs. 4 and 5 also the manner in which the current of air is pressed by the same
against the single pieces of drying material.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. A drying apparatus for ceramic or other material consisting of a series of ducts
or channels arranged above and beside each other and separated by boards and sides,
said channels occupying an inclined position which is changed near the lower end into
a horizontal position for the purpose of allowing the material, to be dried, to slide
downward, while the drying air flows upwards, substantially as set forth.
2. In the drying apparatus forming the subject of claim 1, the application of guide
bars m n secured to the sides of each channel and so placed as to allow the boards or
plates on which the objects, to be dried, are placed, to slide uniformly downward,
substantially as and for the purpose set forth.
3. In the drying apparatus forming the subject of claim 1, the application of sources
of heat which are placed into into interstices produced by deviation of curvature in
the lower limits a cand e f of the drying channels and of slide bars m n substantially
as and for the purpose set forth.
4. In the drying apparatus forming the subject of claim 1, the application of
perforations in the superposed boards or intermediate plates for the purpose of
allowing the drying air, rising from a source of heat placed below, to be distributed to
the single channels substantially as set forth.
5. In the drying apparatus forming the subject of claim 1, the application of
movable curtains suspended within drying channels and serving to regulate the
drying-air current, substantially as illustrated and described.
Dated this 23rd of July 1890.
ALBERT SCHAAF.
By Huelser & Co.,
142, Fleet Street, London, Attorneys.