An Improved Mode of and Apparatus for Desiccating various Substances.
Year: 1897

page_text: Date of Application in the United Kingdom, 25th June, 1897
Complete Left, 22nd Feb., 1898-Accepted, 26th Mar., 1898
PROVISIONAL SPECIFICATION.
An Improved Mode of and Apparatus for Desiccating various
Substances.
I, ALPHONSE HUILLARD, of 95, Boulevard Beaumarchais, Paris, in the Republic
of France, Engineer, do hereby declare the nature of this invention to be as
follows:
When it is desired to desiccate commercially a pasty product, an extract, a
syrup, an organic or other liquid, it is usual to proceed in the following manner:
In certain cases, the material is introduced into a closed apparatus, heated by
steam, as in the vacuum pans used in sugar making and in extract manufactories.
In other cases, the product to be desiccated is put on shelves or plates, which are
introduced either into a stove or a vacuum apparatus.
In the case of certain materials, which heat more or less affects, the desiccation
on shelves may be effected in the open air at ordinary temperatures.
When heat is not employed to evaporate the liquid contained in the product to
be desiccated, the operation is extremely long, and necessitates, in consequence,
considerable plant. But in nearly every case heat is employed, and it is caused
to act on the whole mass during the whole time that is necessary to produce the
evaporation of the small quantity of liquid that it is desired to eliminate.
This prolonged action of the heat has its inconveniences, and may affect the
quality of the product under treatment.
It may be remarked, that even when effected in a vacuum, and the product is in.
direct contact with the heating or heated surface, the real temperature of the mass
to be desiccated is intermediate between that corresponding to the vacuum and
that of the heating medium.
In all the circumstances just mentioned, this principle is involved:-Prolonged
heating of the wliole mass, in order to eliminate a very small quantity of liquid.
Now the object of the present invention is to so produce the desiccation, that
this prolonged heating is entirely overcome, and the invention consists in placing
the material under conditions suitable for desiccation, without contact with the
heating surface, that is to say, the pasty product is arranged in one or more very
thin layers, and the dried or desiccated part of the mass is removed as soon as
produced.
To this end, then, the invention has reference to a process of desiccating, and to
apparatus to he used therefor.
To obtain the desiccation under the conditions above described, the material to
be desiccated is placed in a suitable receiver, and into it projects a continuously
moving endless apron of wire gauze or other woven fabric, which becomes impreg-
דגם...מ

page_text: nated with, or takes up, the material during its passage through the mass.. The
endless apron then passes through a heating chamber, where the drops or particles
retained in the meshes of the fabric are dried, and become pellicules, which are
detached by any suitable means, and drop into a separate receiver.
Instead of employing an apron of woven material, it may be a band of metal,
which, in its passage through the material to be dried, becomes coated on both'
sides with a thin layer thereof.
The apron passes up and down round guiding drums or rollers, and the upper
drums or rollers receive rotary motion through mitre gearing on a shaft, and from
the belt pulley.
One or more partitions may be employed to divide up the drying chamber into
several compartments, and to produce a sepentine path, so as to obtain the greatest
possible circulation of air.
The apron passes out of the chamber and round a roller, after which the apron
is submitted to the action of a series of rotary brushes.
The heating apparatus may consist of pipes, plain, or provided with rings.
A driven pulley transmits motion by bands or otherwise to the brushes.
The working of the apparatus will be readily understood.
The particles retained in the meshes of the apron are dried in their passage
through the drying chamber, and are afterwards detached by the action of the
brushes. The material thus dried or desiccated, drops into a receiver, whilst
the apron, thus freed from the solid particles, passes onwards, to be recharged in the
tank.
ין
From what is described above, it will be seen that in the new process of desicca
tion, only a very small quantity of material is acted upon at one time, and the
evaporation can take place froin both faces, the conditions of the temperature,
and the duration, being the most favourable, and, what is more, the desiccated
material is immediately put on one side, and all without bringing the material into
contact with any heated or heating surface.
For certain products,, the apparatus may be used without heat.
It will be evident that, according to the material to be treated, so the path of
the apron may be increased or diminished, and its speed may be regulated.-
As is well known, there exists certain bodies, and, in particular, certain tanning
extracts, which it has never been possible to dry by the old processes, because the
heating, more or less prolonged, to which they are subjected, somewhat changes.
their nature.
By the application of the new process, the desiccation or drying of these sub-
stances can easily be effected, a result of considerable commercial importance.
In fact, tanning extracts can be obtained in an entirely new form, which is of
advantage, not only from the point of view of their employment, but also of thein 4
transport, because they are in a completely dry state.
Dated thin 05th day of Tue 1007´
An Improved mode of and Apparatus for Desiccating various
Substances.
I, ALPHONSE HUILLARD, of 95, Boulevard Beaumarchais, Paris, in the Republic
of France, 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 50
and by the following statement:
'
When it is desired to desiccate commercially a pasty product, an extract; a
syrup, an organic or other liquid, it is usual to proceed in the following manner":
87

page_text: In certain cases, the material is introduced into a closed apparatus heated by
steam, as in the vacuum pans used in sugar making and in extract manufactories.
•
In other cases, the product to be desiccated is put on shelves or plates; which" are
introduced either into a stove or a vacuum apparatus.
In the case of certain materials, which leat more or less affects, the desiccation
on shelves may be effected in the open air, at ordinary temperatures.
When heat is not employed to evaporate the liquid contained in the product to
be desiccated, the operation is extremely long, and necessitates, in consequence,
considerable plant. But in nearly every case heat is employed, and it is caused
to act on the whole mass during the whole time that is necessary to produce the
evaporation of the small quantity of liquid that it is desired to eliminate.
This prolonged action of the heat has its inconveniences, and may affect the
quality of the product under treatment.
i
It may be remarked, that even when effected in a vacuum and the product is in
direct contact with the 'heating or heated surface, the real temperature of the mass
to be desiccated is intermediate between that corresponding to the vacuum and
that of the heating medium.
In all the circumstances just mentioned, this principle is involved, Prolonged
beating of the whole mass, in order to eliminate a very small quantity of liquid.
Now the object of the present invention is to so produce the desiccation, that
this prolonged heating is entirely overcome, and the invention consists in placing
the material under conditions suitable for desiccation without contact with the
heating surface, that is to say, the pasty product is arranged in one or more very
thin layers, and the dried or desiccated part of the mass is removed as soon as
produced.
To this end, then, the invention has reference to a process of desiccating, and to
apparatus to be used therefor.
:
For the purposes of description, and by way of example only, let it be supposed
that a tanning extract is under treatment.
In the accompanying drawings,
Figs. 1, 2 and 3 represent diagrammatically a theoretical apparatus which is
given for the purpose of clearly explaining the nature of the process, while :
Fig. 4 shows a practical apparatus for carrying out the process above referred to..
To obtain the desiccation under the conditions above described, the material to,
be desiccated is placed in a suitable receiver A, and into it projects a continuouslý
moving endless apron B of wire gauze or other, woven fabric, which becomes
impregnated with, or takes up, the material during its passage through the mass.
The endless apron then passes through a heating chamber C, where the dropsior
particles retained in the meshes of the fabric are dried, and become pellicules,
which are detached, at D, by any suitable means..
Instead of employing an apron of woven material, it may be a band of metal,,
which, in its passage through the material to be dried, becomes coated.
sides with a thin layer thereof.
d. on both
As has been said above, the apparatus which it is preferred to use for the purpose
of this invention, is that shown at Fig. 4.
'
The material to be desiccated is placed in the tank A, situated in the lower part.
of the apparatus. Into this tank enters, the endless apron B, which, on leaving the
tank, passes upwards into the drying chamber or stove C, placed above the
receiver A.
The apron moves in the direction indicated by the arrows T, and passes up and
down, round guiding drums or rollers F. The upper drums or rollers receive;
rotary motion through mitre gearing on the shaft G and the belt pulley G.
One or more partitions K may be employed to divide up the drying chamber into
several compartments, and to produce a serpentine path, so as to obtain the greatest
possible circulation of air.
L
The apron passes out of the chamber C at I, and round the roller I', after which

page_text: the apron is submitted to the action of a series of rotary brushes L, before it passes
round the roller I2 back to the tank A.
The heating apparatus may consist of pipes M, plain, or provided with rings,
as shown.
Cold air enters the apparatus at N and, becoming heated, eventually passes round
the bottom of the partition K to the chimney K.
A driven pulley N transmits motion by bands or otherwise to the brushes L.
The working of the apparatus will be readily understood.
The particles retained in the meshes of the apron are dried in their passage
through the chamber C.and are afterwards detached by the action of the brushes L.
The material thus dried or desiccated, drops into the receiver 1, whilst the apron,
thus freed from the solid particles, passes onwards, to be recharged in the tank A.
From what is described above, it will be seen that, in the new process of desicca-
tion, only a very small quantity of material is acted upon at one time, and the
evaporation can take place from both faces of the apron or band, the conditions of
the temperature and the duration being the most favorable, and, what is more,.
the desiccated material is immediately put on one side, and all without bringing the
material into contact with any heated or heating surface.
For certain products, the apparatus may be used without artificial heat, thei
heating chamber being suppressed, and the ordinary atmosphere being relied upon.
It will be evident that according to the material to be treated, so the path of
the apron may be increased or diminished, and its speed may be regulated.
As is well known, there exists certain bodies, and in particular certain tanning'
extracts, which it has never been possible to dry by the old processes, because the
heating more or less prolonged to which they are subjected, somewhat changes
their nature.
By the application of the new process, the desiccation or drying of these sub-
stances can easily be effected, a result of considerable commercial importance.
In fact, tanning extracts, can be obtained in an entirely new form, which is of
advantage not only from the point of view of their employment, but also of their
transport, because they are in a completely dry state..
'
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. The new process of desiccation above described, and which consists in this,
that the material to be desiccated, instead of being heated in bulk for a prolonged.
period, is presented without contact with a heated or heating surface, and in very
small quantities, to the action of the drying medium for a very short period, the
material in a perfectly dry state being separated as soon as dried from the undried
portions of the mass to be desiccated, as set forth.
'
2. For the purpose of carrying out the process described in Claim 1, an apparatus
consisting of an endless apron, to which continuous movement is given, and which
passes into a tauk containing the material to be dried, taking up, on both sides, the
material, and afterwards passing into a drying chamber, or the open air, the
desiccated product thus obtained being subsequently brushed off from the apron 4
or band, or otherwise removed into a suitable receiver, as set forth.
3. The new products obtained by the above described process, that is to say,
those it has not hitherto been possible to completely dry, without their sustaining
an appreciable change of nature, such, for example; as certain tauning extracts,.
pharmaceutical products, and chemical products.
noted this 22nd day of February 1908.