Improvements in and relating to Apparatus for Drying or Desiccating Granular, Pulverulent, and other Materials.
Year: 1893

page_text: Date of Application, 17th Oct., 1893
Complete Specification Left, 17th July, 1894-Accepted, 18th Aug.. 1894
Improvements in and relating to Apparatus for Drying or Desiccating
Granular, Pulverulent, and other Materials.
I, PIETER ANNE VAN DER MADE, of Amsterdam, in the Kingdom of Holland,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to apparatus for drying or desiccating granular, pulverulent,
and other materials.
The improved apparatus constructed according to my said invention differs from
the installations heretofore employed for similar purposes especially in respect of
the principle underlying its construction, which enables the maximum quantity of
material which it is capable of holding in a given space to be subjected either
continuously or intermittently to the action of a minimum volume of hot gases,
thus effecting the drying or desiccation of the greatest quantity of material in the
shortest time and with the least amount of heat in an installation which is not
expensive and requires but little space.
The principle which serves as a basis for carrying out the mode of drying or
desiccation thus characterized consists in causing the material to pass through a
space of any suitable section in one direction, the said material being at its greatest
density, that is to say filling up the entire space into which it is introduced,
and in causing hot gases to pass through the aforesaid space in the opposite
direction to evaporate the moisture for the purpose of withdrawing the same from
the material. By this means the whole surface of each of the particles of the
material will be touched by the gaseous medium which traverses the space and
which cannot in the latter follow the easiest ways, of escape as takes place in
spaces not completely filled so that portions of the material are withdrawn from
its action.
The most elementary constructional form of this apparatus would be a simple
tube or cylinder by preference arranged vertically and into which the material to
be dried or desiccated is introduced from the top, while the hot current is admitted
at the bottom where also the discharge of the dried material takes place, which is
controlled in such a manner that the forward movement of the material can be
regulated at will in the tube or cylinder, the lower orifice of which must therefore
be provided with a special device for permitting at the same time the discharge of
the material and the admission of the hot gas.
Accordingly my improved drying or desiccating apparatus possesses the
characteristic feature that it constitutes part of a pipe for hot gases, filled
entirely with material to be dried which is automatically caused to advance and
upon which the whole volume of gas passing through the said pipe exerts its
integral effect.
With equal surfaces it is preferable to employ the annular section in lieu of the
cylindrical section, I will therefore proceed to describe my improved drying or
desiccating apparatus more particularly with regard to this constructional form.
In all the examples hereinafter set forth the body or cylinder of the drying or
desiccating apparatus is rendered annular by the insertion of a cylinder of smaller
diameter.
For the purpose of enabling the discharge of the material and the admission of

page_text: the hot current to take place at the same time at the bottom of the cylinder the
latter must be permeable to the gases and also be of a nature to retain the solid
material which however it allows to pass out through suitable orifices. The means
to be most advantageously interposed between the gas and the solid material are
wire gauze, perforated sheet metal or the like which may constitute the entire
bottom of the cylinder if it is flat, and even the side up to a certain height, but
this arrangement of the bottom would not be practical for several reasons and
it is preferable in every respect to construct it in the form of an inverted
truncated cone the top of which, terminating in a pipe, constitutes the orifice for
the discharge of the material, the outlet and consequently the velocity of descent
of which
may be regulated at will either in a continuous manner or intermittently
by the aid of valves which are kept open more or less or are opened and closed for a
longer or shorter time. In one arrangement the bottom is made annular, forming
in section a truncated cone the point of which is provided with a certain number
of discharge pipes.
The conical and perforated bottom of the cylinders traverses vertically a second
cylinder closed on all sides, into which hot air is forced at a pressure which can be
produced by.a blower in communication with the device for heating the air, and
while the hot air rises in the material so as to evaporate progressively the moisture
of its successive layers the dried or desiccated material descends and is received
below the cylinder for the hot air in suitable receptacles or by a conveyor or other
transporting device.
In the arrangements described the interior cylinders terminate in a cone at the
top, these cones having for their object to effect the uniform distribution of the
material in the annular space when it is introduced by a bucket chain which feeds
the material continuously upon a plate terminating at the top of the distributing
cone. Above this plate the cylinder is contracted and terminates in a chimney for
allowing the escape of the vapours and the gases which have produced them.
The aforesaid blower and bucket chain are both actuated by the same motive-
power engine.
Instead of a blower I may also employ a suction fan. In this case the material
is introduced into a hopper which constitutes the top of the cylinder the orifice of
the hopper terminating immediately above the point of the cone of the interior
cylinder so that an empty space is formed between the sides of the hopper and the
upper surface of the material, which is almost hermetically closed by the material
in the hopper. Around this empty space I may provide exteriorly a tubular
gallery to which is adapted the suction pipe of the fan, which thus forms the
pipe for the discharge of the air after it has produced its effect and of the
vapours generated. In this arrangement the air is heated as it passes through
a device for heating by steam or the like, suitably arranged near, below or even
in the cylinder particularly adapted for this purpose.
In case the material to be dried or desiccated is much divided and at a certain
height causes on this account too great a density for the proper operation of the
drying or desiccating apparatus I may divide the latter, that is to say pass the
charge into it in fractions of less height the density of which is not opposed to
the passage of the hot current nor to the production of vapours. In this arrange-
ment the cylinder is provided with perforated hoppers also containing distributing
cones, the first hopper receiving the material from the bucket chain in order to pass
the same, after it has been subjected to a certain drying or desiccating action, into
the following lower hoppers where the drying or desiccation to the desired degree
is continued in the described manner.
My improved drying or desiccating apparatus may be either erected in the open
air or be surrounded by a wall of masonry or have double walls heated by air or
steam according to requirements.
It is evident that this improved apparatus may be used for desiccating any
quantity of materials as long as they are not too much divided, for drying malt and
the like. A purpose for which it is particularly suitable is the drying of green

page_text: coffee beans, which has to be effected in a very short time. Large quantities can
be dried at a time by this apparatus the operation of which takes place rapidly and
continuously.
Dated this 17th day of October 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in and relating to Apparatus for Drying or Desiccating
Granular, Pulverulent, and other Materials.
I, PIETER ANNE VAN DER MADE, of Amsterdam, in the Kingdom of Holland,
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
and by the following statement:-
My invention relates to apparatus for drying or desiccating granular, pulverulent
and other materials.
The improved apparatus constructed according to my said invention differs from
the installations heretofore employed for similar purposes especially in respect
of the principle underlying its construction, which enables the maximum quantity
of material which it is capable of holding in a given space to be subjected either
continuously or intermittently to the action of a minimum volume of hot gases,
thus effecting the drying or desiccation of the greatest quantity of material in the
shortest time and with the least amount of heat in an installation which is not
expensive and requires but little space.
The principle which serves as a basis for carrying out the mode of drying or
desiccation thus characterized consists in causing the material to pass through a
space of any suitable section in one direction, the said material being at its greatest
density, that is to say filling up the entire space into which it is introduced, and in
causing hot gases to pass through the aforesaid space in the opposite direction to
evaporate the moisture for the purpose of withdrawing the same from the material.
By this means the whole surface of each of the particles of the material will be
touched by the gaseous medium which traverses the space and which cannot in the
latter follow the easiest ways of escape as takes place in spaces not completely
filled so that portions of the material are withdrawn from its action.
The most elementary constructional form of this apparatus would be a simple
tube or cylinder by preference arranged vertically and into which the material to
be dried or desiccated is introduced from the top, while the hot current is admitted
at the bottom where also the discharge of the dried material takes place, which is
controlled in such a manner that the forward movement of the material can be
regulated at will in the tube or cylinder, the lower orifice of which must therefore
be provided with a special device for permitting at the same time the discharge of
the material and the admission of the hot gas.
Accordingly my improved drying or desiccating apparatus possesses the
characteristic feature that it constitutes part of a pipe for hot gases, filled
entirely with material to be dried which is automatically caused to advance and
upon which the whole volume of gas passing through the said pipe exerts its
integral effect.
With equal surfaces it is preferable to employ the annular section in lieu of
the cylindrical section, I will therefore proceed to describe my improved drying
or desiccating apparatus more particularly with regard to this constructional form.
In the accompanying drawing
Figure 1 represents in diagram a side elevation partly in section of the drying
apparatus, with the device for forcing the hot current.

page_text: igure is a piau of the same.
Figure 3 shows the same drying apparatus with an annular discharge orifice.
Figure 4 is a modification of the drying apparatus relative to the division of the
charge, and
Figure 5 is the same drying apparatus with the device for drawing the hot
current.
In all the examples hereinafter set forth the body or cylinder T of the drying
or desiccating apparatus is rendered annular by the insertion of a cylinder C of
smaller diameter.
For the purpose of enabling the discharge of the material and the admission of
the hot current to take place at the same time at the bottom of the cylinder the
latter must be permeable to the gases and also be of a nature to retain the solid
material which however it allows to pass out through suitable orifices. The means
to be most advantageously interposed between the gas and the solid material are
wire gauze, perforated sheet metal or the like which may constitute the entire
bottom of the cylinder if it is flat, and even the side up to a certain height, but this
arrangement of the bottom would not be practical for several reasons and it is
preferable in every respect to construct it in the form of an inverted truncated cone
Figure 1 the bottom of which, terminating in a pipe t constitutes the orifice for the
discharge of the material the outlet and consequently, the velocity of descent of
which may be regulated at will either in a continuous manner or intermittently by
the aid of valves which are kept open more or less or are opened and closed for a
longer or shorter time. In the arrangement shown in Figure 3 the bottom is made
annular, forming in section a truncated cone the point of which is provided with a
certain number of discharge pipes.
The conical and perforated bottom of the cylinders T traverses vertically a
second cylinder T¹ closed on all sides, into which hot air is forced at a pressure
which can be produced by the blower V in communication with the device for
heating the air, and while the hot air rises in the material so as to evaporate pro-
gressively the moisture of its successive layers the dried or desiccated material
descends and is received below the cylinder T' for the hot air in suitable receptacles
or by a conveyor or other transporting device.
In the arrangements described the interior cylinders C terminate in a cone at
the top, these cones having for their object to effect the uniform distribution of
the material in the annular space when it is introduced by a bucket chain G
which feeds the material continuously upon a plate R terminating at the top of
the distributing cone. Above this plate the cylinder T is contracted and
terminates in a chimney for allowing the escape of the vapours and the gases
which have produced them.
The aforesaid blower and bucket chain G are both actuated by the same motive
power engine M.
Instead of a blower I may employ a suction fan; and in this case the drying
apparatus is arranged as shown in Figure 5. The material is introduced into a
hopper constituting the top of the cylinder T, the orifice of the hopper terminating
immediately above the point of the cone C of the interior cylinder so that an
empty space is formed between the sides of the hopper and the upper surface
of the material, which is almost hermetically closed by the material in the hopper.
Around this empty space I may provide exteriorly a tubular gallery E to which
is connected the suction pipe of the fan, which thus forms the pipe for the
discharge of the air after it has produced its effect and of the vapours generated.
In this arrangement the air is heated as it passes through a device for heating
by steam or the like, suitably arranged near, below or even in the cylinder T¹
particularly adapted for this purpose.
In case the material to be dried or desiccated is much divided and at a certain
height causes, on this account, too great a density for the proper operation of the
drying or desiccating apparatus I may divide the latter that is to say pass the
charge into it in fractions of less height the density of which is not opposed to

page_text: the passage of the hot current nor to the production of vapours. In this arrange-
ment shown in Figure 4 the cylinder C is provided with perforated hoppers P also
containing distributing cones; the first hopper receiving the material from the
bucket chain in order to pass the same, after it has been subjected to a certain
drying or desiccating action, into the next lower hoppers where the drying or
desiccation to the desired degree is continued in the described manner.
My improved drying or desiccating apparatus may be either erected in the open
air or be surrounded by a wall of masonry or as shown in Figure 3, have double
walls heated by air or steam according to requirements.
It is evident that this improved apparatus may be used for desiccating any
quantity of materials as long as they are not too much divided, for drying malt and
the like. A purpose for which it is particularly suitable is the drying of green
coffee beans which has to be effected in a very short time. Large quantities can be
dried at a time by this apparatus the operation of which takes place rapidly and
continuously.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First. A drying or desiccating apparatus characterized by the feature that it
constitutes part of a conduit for hot gases, filled entirely with the material to be
dried or desiccated which advances automatically in one direction in the body of
the apparatus which is traversed in the other direction by the hot gases, substantially
as described.
Second. In the drying or desiccating apparatus described in the first claim the
arrangement of bottoms for retaining the material undergoing desiccation but
permeable to the hot gases and as such by preference the truncated form, and the
insertion of these permeable bottoms into the drum for the hot gases arranged in
such a manner that the adjutage for discharging the material will be outside the
drum, substantially as described and represented in the drawing.
Third. In the drying or desiccating apparatus described in the first claim, the
annular form of the body of the apparatus and the arrangement at the axis of a
dividing cone immediately below the feed channel or funnel for the uniform
distribution of the material into the annular surface, substantially as described and
represented in the drawing.
Fourth. The dividing up of the drying or desiccating apparatus by inserting
one or more superposed funnels with sides permeable to the gases while permitting
of the automatic descent of the material in order to obviate the inconvenience
arising from too great a density of the material, and the employment of a dividing
cone above each of the fractioning funnels, substantially as herein before described
and represented in the drawing.
Fifth. The combination of the drying or desiccating apparatus before characterized
with a compression or suction fan for establishing the hot current and with a bucket
chain for the feed, substantially as described and shown in the drawing.
ECU WILA GUA UT
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.