Improvements in Roasting or Calcining Drums.
Year: 1899

page_text: Date of Application, 16th June, 1899-Accepted, 19th Aug., 1899
COMPLETE SPECIFICATION.
Improvements in Roasting or Calcining Drums.
I, JOHANN LUDWIG HERMAN HINZ, of Liebigstrasse, 3, Giessen, Germany,
Director of Manufactory, do hereby declare the nature of this invention, and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
In roasting or calcining drums according to this invention the material to be
dried is moved onward with varying velocity either in consequence of the chang-
ing inclination of a rib or rake arrangement or in consequence of variation of
the configuration of the external wall of the drum.
Figs. 1 to 4 inclusive of the accompanying drawings represent two examples
of the first-named kind and Figs. 5 to 8 inclusive two examples of the last-named
kind.
For roasting or calcining drums with internal rib or rake arrangements, either
conical or cylindrical tubes a may be employed. The conical drum (Fig. 1)
may be supported in a horizontal position, whilst the cylindrical one (Fig. 2)
requires to be supported in an oblique position in order to attain a like effect.
To the internal surface of the wall of the drum, there are fixed, over the entire
length, longitudinal ribs r, which are equidistant from one another and in any
desired number, and which are variously directed with respect to the longitudinal
axis of the drum.
These longitudinal ribs may be specially fastened to the internal surface of the
wall of the drum or they may be formed by suitably shaped pressed-in portions
of the wall of the drum (Fig. 9) or by a special lining of refractory material
(Figs. 10 and 11). Such pressed-in portions or such lining may advantageously
have, as shown, a cross-sectional internal shape made up of arcs of circles, a
shape which has proved itself in practice to be very good.
For such a lining fire-bricks f and y (Figs. 10 and 11) of two different
shapes but exactly equal in length are used, each of those f of one shape having
an exactly median depression and each of those g of the other shape having an
exactly corresponding projection. The abutting edges, which lie in a line in
the case of the 1st, 3rd, 5th, etc. rows of fire-bricks, and in the case of the 2nd,
4th, 6th, etc. rows of fire-bricks, are provided with grooves and tongues, so that
the fire-bricks, when joined together, are held absolutely fixed on the internal
surface of the wall of the drum.
The material to be treated is introduced into one end of the drum a through a
shoot s.
Here the course of the ribs corresponds to the direction of revolution
of the drum in order to convey the material towards the interior as fast as
possible. Then in order to effect a slower advance of the material under treat-
ment the ribs r are either disposed exactly in the direction of the length of the
conical casing or parallel to the longitudinal axis of the cylindrical drum.
this they run in the opposite. direction to the direction of revolution of the drum,
in order again to produce a slower advance, or a damming or heaping up of the
material under treatment. Finally, a quicker motion of the material is again
יו -
After

page_text: necessary for the purpose of discharging, wherefore the ribs run again exactly
in the longitudinal direction of the drum from here to the end.
The roasting or calcining drum under discussion is thus in a sense divided
into as many zones as desired, each of which is provided with a definitely directed
longitudinal rib or rake arrangement. The object thereof is first of all to give
the material that is introduced into the drum, a preliminary warming, to intro-
duce it then quite gradually to the roasting or calcining zone proper, to keep it
there a rather long time, and then, after the completion of the roasting or
calcining process, to convey it away quickly..
In a similar manner various
other combinations of speed variations may be produced to correspond to the
kind of roasting or calcining effect desired.
The two examples represented in Figs. 5 to 8 inclusive are drums having
external walls with varied configurations. These are likewise divided into
zones, which are joined directly to one another and are either cylindrical or more
or less conical. The drum represented in Figs. 5 and 6 is mounted in a hori-
zontal position and that represented in Figs. 7 and 8 in an oblique position.
In the first case, the third, or true roasting or calcining, zone is cylindrical, and
in the latter it is conical.
The length of each individual zone, the number of such zones, and their order
in succession may, of course, vary according to the nature of the roasting or
calcining process in question; likewise, the rib or rake arrangements, or the
several truncated cones, can be sloped to any required extent.
Having now particulary described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A revolving roasting or calcining drum in which the advance of the material
to be roasted or calcined along the longitudinal axis of the drum, which is
supported as required horizontally or obliquely, ensues with varying velocity
and independently of the speed of rotation either by reason of the changing
direction of a longitudinal rib or rake arrangement or by reason of cylindrical
and conical sequentially arranged drum portions.
2. A roasting or calcining drum according to Claim 1, comprising a hori
zontally supported conical, or an obliquely supported cylindrical, tube, the
internal surface of whose wall is divided into several zones and is provided with
a longitudinal rib or rake arrangement with varying inclination.
3. A roasting or calcining drum according to Claim 1, consisting of cylindrical
and more or less conical tube-lengths joined directly to one another in a variable
sequence.
4. A roasting or calcining drum according to Claim 2 in which the rib or rake
device has a cross-sectional internal shape made up of arcs of circles, substantially
as described.
5. A roasting or calcining drum according to Claim 2 or 3, in which the rib or
rake device is formed by fire-bricks provided with tongues and grooves for the
purpose of securing firm joints notwithstanding the movement of the drum.
6. A roasting or calcining drum constructed, arranged, and operating as here-
inbefore described with reference to and shown respectively in Figs. 1 and 2 and
in Figs. 3 and 4 (and the same as modified according to Fig. 9, or Figs. 10
and 11), in Figs. 5 and 6, and in Figs. 7 and 8 of the accompanying drawings.
Dated this 16th dor of Tune 1800
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.