siccaas
Year: 1889

page_text: declare the nature of my said invention, and in what manner the same is to be
erformed, to be particularly described and ascertained in and by the following
statement :-
My invention relates to an apparatus for uniformly drying, desiccating and roasting
various products.
Figure 1 is a longitudinal section of my improved apparatus.
Figure 2 is an end view, and
Figure 3 a section on the line a-y in Figure 1.
The material to be roasted, dried or desiccated is fed into the rotary drum, which
is tapered towards both ends, through the one hollow shaft, whilst the other serves
to lead in the gaseous or other matter for effecting the drying, desiccating or roasting
process.
The interior of the drum is provided with helical or screw like surfaces, the object
of the same being on the one hand to intimately mix the product or material to he
treated and hold the same in suspension, on the other hand, to allow the apparatus to
act as ventilator and exhauster for driving the gaseous products of combustion
through the apparatus so as to enable the same to exercise their action on the material
to he treated.
The helically formed guide surfaces in the one half of the drum arranged in
opposite direction to those in the other half of the drum and besides this the pitch
of the said surfaces is not the same but symmetrical to the central axis of the
drum.
The two halves of the drum a which taper towards the ends do not, at their larger
ends, come in contact with each other but are connected by thin staves a¹, which
have little effect in reducing the free cross section of the apparatus. The central
portion of the drum is closed by a circular slide b, which is operated from the
exterior of the apparatus by means of the handle c, so that when the slide is opened
the treated material will suddenly fall into the annular receptacle ¿, which runs
around the drum. The drum is held in the frame by means of guide rollers e,,

page_text: Figs. 1 and 2, and is rotated from the driving shaft' by means of one or more gear
wlieels, as represented in Figure 2.
The charging tube with lateral hopper enters the axis of the drum at the one end,
whereas the tube g provided with the socket g' enters axially at the other side of the
said drum a and serves to lead in the products of combustion and eventually also air,
said tube g and socket ' being provided with appropriate throttle valves h, h¹ for
regulating the supply.
The operation of my improved drying, desiccating and roasting apparatus is as
follows: The material or product to be treated is charged into the drum a, through
the hopper and tube f, is impelled by centrifugal force against the walls of
the apparatus, is then distributed by the helical guide surfaces & and held in suspension
in the said drum a. The products of combustion entering through the tube at the
opposite side of the drum a, are distributed uniformly by the spiral or screw and
are fed to the material to be treated by the helical guide surfaces, said products of
combustion escaping through the tube f after having operated on the material or
products in the drum a. The temperature may be observed by using an appropriate
pyrometer and the progress of the operation be ascertained by taking samples from
time to time through the opening m, which is usually kept tight by means of a suitable
lid or cover.
As soon as the product or material under treatment is properly dried, desiccated
or roasted, the handle e of the slide is drawn outwards, so that the contents of the
drum pass into the receptacle i, whereupon the slide is again closed. All burning of
the material under treatment, can be readily avoided.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, what I claim is :-
1. A drying, desiccating and roasting apparatus, consisting of the rotary divided
drum a, the parts of which are connected by bolts a' so as to form a space enclosed
by the annular slide 6, said drum a being charged with the material to be treated
through the charging opening or hopper and tube f, the tube g at the opposite end
of the said drum serving to lead in the gaseous or other matter for the drying,
desiccating or roasting process, which is led by the helical wings or surfaces in the
one half of the drum to the right and in the other half to the left, so that the action
of the drying medium, energetically sucked through the said drum, on the material to
be treated, which is held in suspense in the central space, is produced and the treated
material can pass into the receptacle when the annular slide 6 is operated, substan-
tially as and for the purpose set forth.
2. The general construction, arrangement and combination of the parts in my
improved drying, desiccating and roasting apparatus, substantially as and for the
purpose set forth in the foregoing specification, and shown in the accompanying
drawings.
Dated this 29th day of April 1889