Improved Apparatus for the Desiccation of Solid Matters.
Year: 1891

page_text: Date of Application, 23rd July, 1891-Accepted, 19th Sept., 1891
COMPLETE SPECIFICATION.
Improved Apparatus for the Desiccation of Solid Matters.
We, EUGENE DONARD, Chemist, of 24 Rue Thiers, and GASTON BOULET
the Younger, Distiller, of 12 Quai Montriboubet, both in Rouen, in the Republic
of France, 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 :-
There are many solid organic matters, animal or vegetable, for instance the mash
or grains from distilleries and breweries, the residue from beetroot and other
industrial residues, the immediate use of which is impossible, which are lost because
in their state of humidity they cannot be kept.
Moreover, there are some matters which cannot be submitted to some special
process, without having been dessicated first; for example certain residues before
the extraction of the oils by displacement.
For a long time a practical process has been sought for dessicating matters,
either in the open air, with the aid of steam, hot water, or hot air, or by vacuum,
so as to reduce as much as possible the weight and bulk of these products and to
allow of their preservation and storage, or to prepare them for some further
operations.
After numerous experiments, we have found that it was only under vacuum that
moist solid matters could be rapidly and economically dessicated; retaining, in so
doing, their nutritive qualities, preventing the alteration of the oils and nitrogenous
matter for example.
To realise this principle, we have invented an apparatus in which the matter to
be dessicated, first brought to a suitable state, is submitted to vacuum and to a
more or less high temperature. The matter, moreover, is kept in a state of con-
tinuous agitation, so as to successively bring each of its particles in contact with
the heating surface.
•
The amount of the heating surface must naturally depend on the quantity of
heat to be furnished and on the degree of conductibility of the material to be
dried.
The annexed drawing, Figure 1, gives an exact idea of one of the combinations
of our dryer or evaporator, which is composed of the following pieces :
A. Metallic shell revolving on its shaft.
ur, n. Pedestals and bearings.
H, J, H. Entry and outlet chambers for the steam or other fluid.
L. Outlet pipe leading the vapours produced by the dessication to the
condenser.
M. Stuffing box for vacuum.
N. Conical screen preventing the aspiration of matter through pipe L.
The steam or fluid heating the drying apparatus (or evaporator) enters through
the hollow shaft and through the distributing box D. This hollow shaft is divided
for a portion of its length into two divisions: one V serving for the entering steam
or fluid, and the other V₁ acting as an outlet for the condensed steam. The
distributing box D is fixed, but the hollow shaft turus with the evaporator. The

page_text: two divisions V and V' are always and at every point of the revolution, in com-
munication, one with the branch pipe a and the other with the branch pipe a' by
the openings c and c' and annular passages 6 and 6'. The two stuffing boxes d
and d prevent any communication between the heating steam or fluid and the
outer air.
The steam chamber on the left is divided into two equal divisions H and H¹ ;
H being in communication with V and H' with V.
The steam, entering by a and passing through V fills the chamber H and through
the corresponding half of the heating tubes into the chamber J, and then back
through the other half of the heating tubes into the chamber H'. The condensed
steam collecting in the chamber H³ runs out through the passage V₁ c¹ and a' at
each revolution, when the chamber H' rises above centre of shaft. This water
passing through a' is collected, by preference, into a self acting drain.
pump
The matter to be treated, properly prepared, is introduced into the bod
evaporator, through which the heating tubes pass, by a suitable opening
opening being hermetically closed, a vacuum is formed by means of an ai
and condenser. Steam is admitted through V and the apparatus is set turning.
Through the influence of the heat and vacuum, evaporation begins at once and the
vapor so produced passes through the hollow shaft L into an ordinary condenser in
communication with the air pump.
The products being submitted to a low temperature, in proportion to the degree
of vacuum, retain all their nutritive qualities, especially if care has been taken,
when necessary, to line the inside of the apparatus with a metal which is not
attacked by the matter submitted to dessication.
It goes without saying that the form of the apparatus may be modified as long
as the general disposition is conserved. The heating tubes can be also replaced by
coils suitably disposed, or by double shells through which steam, hot water or hot
air will circulate. It is also possible to combine together and in different ways
these several modes of heating.
For example, Figure 2 represents an apparatus in which the two last described
modes of heating have been united. S is a coil in which the fluid destined for
heating the material to be treated, circulates. ' and jare the steam chambers
and is a steam heating space formed around the apparatus in which the heating
fluid also circulates. The steam circulation is arranged similarly to that before
lescribed in the tube heating apparatus Figure 1.
From an examination of Figure 2 it will be seen that one or the other of the
neating systems shown can be used separately if desired. Each will have its
special advantages depending on the material to be treated and the form of the
apparatus.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, and reserving to ourselves
the right of varying at will the materials, proportions, dimensions and forms, as
well as the accessory dispositions, we declare that what we claim is :-
The above described apparatus for the dessication of solid matters in vacuum,
revolving round an axle, or as otherwise described, heated by steam, hot water or
hot air circulating through tubes, coils or double shells, and which can be modified
in form.
CARPMAEL & Co.,
Agents for the Applicants.