Improvements in Apparatus for Drying Granular and other Materials.
Year: 1896

page_text: Date of Application, 9th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Drying Granular and other
Materials.
I, DR. CARL GUSTAV JOBST MÖLLER, of No. 19, Friedrich-Wilhelmstrasse,
Berlin, in the Empire of Germany, Manufacturer, do hereby declare the nature of
this invention to be as follows:-
This invention consists of apparatus for drying materials in granular condition,
in lumps, or in a semiliquid condition; for which purpose the material to be dried
is brought into the path of a violently agitated current of heated air, whereby it
is carried along and forced, either through a pipe, or direct, into a drying chamber.
The dry material then drops to the bottom of the chamber, while the air separates
therefrom.
This method of desiccation enables the water, contained in the materials to be
dried, to evaporate very rapidly, while the material itself, at the same time, 30
far cools down-owing to this evaporation of moisture-that the temperature of
the heated "drying" air may not in any way affect the nature of such material.
By the arrangement herein described, therefore, materials very sensitive to heat
may, without any risk of being impaired be rapidly dried, by means of highly
heated dry air.
A fan generates a very powerful current of air in the blast-pipe, while the
furnace and flues serve to heat such current of air. The material to be dried, on
being charged through the hopper, descends into the blast or air-pipe where it
is taken up by the current of air and carried along by the same-slowly at first,
and then with gradually increasing speed-through the pipe, and on to the dry-
ing chamber. The material here drops to the bottom of the chamber; the dry
air escapes through a dust-intercepting partition into the chimney, whereas the
dried material is, either continuously or at intervals, removed through an orifice.
Owing to the fact that the dry air is compelled to drive along each individual
particle of the material under treatment, such air and material are violently
forced into contact with each other, the consequence being a rapid evaporation of
any water the material may carry upon or within it. Again, as the material
descends to the bottom of the drying chamber, there takes place a further close
contact of the individual particles of such material with the dry air. The blast-
pipe may, if preferred, be erected so as to convey the blast either upwards or
downwards; or it may be curved in case of need. Besides, a number of such pipes
may, if desired, be arranged in juxtaposition or in superposition.
In one form or arrangement the drying material drops, through the hopper,
in front of the orifice or mouth of a blast pipe or wind channel and is, by the highly
heated current of air, blown into the drying chamber direct. The drying medium
here employed consists of a mixture of the combustion gases supplied by the
furnace and of air admitted through a pipe; the mixing process-and also, con-

page_text: sequently, the temperature of the resulting "drying gas -being controllable
by means of two dampers.
Where it is desired very considerably to raise the temperature of the drying gas
or air, however, the result is, that the fan is greatly affected by the heat. It is in
view of this fact that, in another arrangement, the products of combustion are
forced into the drying apparatus without passing through the fan or blast mechan-
ism. In this case the blast pipe of such mechanism has its reduced or tapering
end extended unto a suction jet or nozzle. Under the action of the current of air
rushing through the blast-pipe, a vacuum will be obtained in the suction chamber,
which will draw in the products of combustion from the combustion chamber and
conduct it to the said nozzle or jet, wherein this combustion air" will mix with
the air from the blast, and (jointly therewith) impinge upon the material being
dried.
By forcing, in addition to this, air that has been heated beforehand, through
the blast pipe, an ejector-blast will be obtained, enabling a current of dry air,-
heated to a temperature no matter how high, and rendered no matter how power-
ful, to be produced without conducting the combustion gases through a fan.
The above described arrangement may, moreover, be carried out with a
generator, located at or near the combustion chamber instead of the open furnace;
the ejector drawing in the combustible gases through the orifice therein. In this
case, as such combustible gases mix with the current of air issuing from the blast
pipe, there forms a thin (blow-pipe) flame, at the nozzle, which strikes the
material to be treated, as it drops through the funnel, and brings about, in
consequence, a very rapid desiccation.
According to another modification I combine the arrangement just described
with a return-channel. The fan, which produces the current of air in the blast-
pipe, exhausts the air wholly or partly from the drying chamber, so that the
larger quantity of air circulates within the drying apparatus, while there only
escapes, through the chimney, just as much dry air as is drawn in underneath
the fire-grate in the furnace. From the blast-pipe there branches off a junction
pipe leading under the grate of the furnace and conducting a small portion of the
air, circulating in the drying apparatus, through the fuel.
In a further modified form of drying apparatus such apparatus is provided with
an ejector-blast and combined with a rotary drum or barrel. An arrangement
such as this is required for drying materials in somewhat large lumps, as such
materials do not yield up their moisture as readily as they should do, to be capable
of satisfactory desiccation in any of the arrangements described above; which,
in addition to this, the heavier pieces of such materials are not readily enough
moved along by the air-blast. The incline of the hopper, along which the
material slides down into the blast-pipe, is here extended, such extension consist-
ing of a grate, along which the material travels down into the barrel, it being at
the same time impinged upon with considerable violence by the heated dry air.
Owing to the provision of the barrel, or of other means for imparting motion,
contact between the material being dried and the drying medium, or air, may be
ensured for a somewhat long space of time. In order to bring about a thorough
mixture of the air-blast and the combustion gases in the suction-pipe, the blast
pipe, at its orifice, is divided into a series of smaller suction pipes or tuyeres.
Between the several jets issuing from such tuyeres, the combustion gas is
exhausted from the furnace and reaches the material, being dried, in the con-
dition of a thorough mixture. The preparatory heating of the air-blast is provided
for by the arrangement of a surface-heater. The suction pipe of the fan or blast
is connected with the heating chamber, which is heated by a furnace, the combus-
tion gases from which are drawn up or exhausted by an ejector.
DL: Oh
November 180
HASELTINE, LAKE & Co.,
45 :Southampton Buildings, Landon, W.C., Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Drying Granular and other
Materials.
I, DR. CARL GUSTAV JOBST MOLLER, of No. 19, Friedrich-Wilhelmstrasse,
Berlin, in the Empire of Germany, Manufacturer, 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:-
This invention consists of apparatus for drying materials in granular condition,
in lumps, or in a semiliquid condition; for which purpose the material to be dried
is brought into the path of a violently agitated current of heated air, whereby it
is carried along and forced, either through a pipe, or direct, into a drying chamber.
The dry material then drops to the bottom of the chamber, while the air separates
therefrom.
This method of desiccation enables the water, contained in the materials to be
dried, to evaporate very rapidly, while the material itself, at the same time, so
far cools down-owing to this evaporation of moisture-that the temperature of
the heated "drying" air may not in any way affect the nature of such material.
By the arrangement herein described, therefore, materials very sensitive to heat
may, without any risk of being impaired be rapidly dried, by means of highly
heated dry air.
In the accompanying drawing
Figure 1 is a longitudinal section of drying plant constructed acording to this
invention.
Figure 2 is a section of an apparatus in which the drying medium and the air
passes through a fan.
Figure 3 shows an arrangement in which the products of combustion are
forced into the apparatus without passing through the fan.
Figure 4 is a modification of the same and
Figures 5 and 6 show an arrangement with an ejectar blast and a rotary drum.
A fan e generates a very powerful current air in the blast-pipe b, Figure 1,
while the furnace f and flues g serve to heat such current of air. The material
to be dried, on being charged through the hopper a, descends into the blast or air-
pipe b, where it is taken up by the current of air and carried along by the same→
slowly at first, and then with gradually increasing speed through the pipe b
and on to the drying chamber c. The material here drops to the bottom of the
chamber; the dry air escapes through a dust-intercepting partition into the
chimney, whereas the dried material is, either continuously or at intervals,
removed through an orifice i. Owing to the fact that the dry air is compelled to
drive along each individual particle of the materal under treatment, such air and
material are violently forced into contact with each other, the consequence being
a rapid evaporation of any water the material may carry upon or within it. Again,
as the material descends to the bottom of the drying chamber.c, there takes place
a further close contact of the individual particles of such material with the dry
air. The blast-pipe 6 may, if preferred, be erected so as to convey the blast,either
upwards or downwards; or it may be curved in case of need. Besides, a number
of such pipes 6 may, if desired, be arranged in juxtaposition or in superposition.
In Figure 2 is shown an arrangement wherein the drying materials drops,
through the hopper a, in front of the orifice or mouth of a blast-pipe or wind
channel b, and is, by the highly heated current. of air, blown into the drying
chamber c direct. The drying medium here employed consists of a mixture of
the combustion gases supplied by the furnace f and of air admitted through a
ipe k; the mixing process and also, consequently, the temperature of the

page_text: i
resulting drying gas"-being controllable by means of two dampers and h¹.
Where it is desired very considerably to raise the temperature of the drying gas
or air, however, the result is, that the fan e is greatly affected by the heat. "It
is in view of this fact that, in the arrangement represented in Figure 3, the pro-
ducts of combustion are forced into the drying apparatus without passing through
the fan or blast mechanism. In this case the blast pipe of such mechanism has
its reduced or tapering end extended into a suction jet or nozzle m. Under the
action of the current of air rushing through the blast-pipe 1, a vacuum will be
óbtained in the suction chamber n, which will draw in the products of com-
bustion from the combustion chamber f and conduct it to the said nozzle or jet m
wherein this "combustion air" will mix with the air from the blast, and (jointly
therewith) impinge upon the material being dried.
By forcing, in addition to this, air that has been heated beforehand, through
the blast pipe 4, an ejector-blast will be obtained, enabling a current of dry air,-
heated to a temperature no matter how high, and rendered no matter how power-
ful, to be produced without conducting the combustion gases through a fan.
The arrangement illustrated in Figure 3 may, moreover, be carried out with: a
generator, located at f instead of the open furnace, the ejector drawing in the
combustible gases through n. In this case, as such combustible gases mix with
the current of air issuing from the blast pipe I, there forms a thin (blow-pipe)
flame, at the nozzle m which strikes the material to be treated, as it drops through
the funnel a and brings about, in consequence, a very rapid desiccation.
1
Figure 4 shows a combination of the arrangement just described with a return-
channel o. The fan e, which produces the current of air in the blast pipe 1,
exhausts the air wholly or partly from the drying chamber e, so that the larger
quantity of air circulates within the drying apparatus, while there only escapes,
through the chimney d, just as much dry air as is drawn in at p underneath the
fire-grate in the furnace f. From the blast-pipe there branches off a junction
pipe q leading under the grate of the furnace f and conducting a small portion of
the air, circulating in the drying apparatus, through the fuel.
l
The drying apparatus shown in Figures 5 and 6 is provided with an ejector-
blast and combined with a rotary drum or barrel. An arrangement such as this
is required for drying materials in somewhat large lumps, as such materials do not
yield up their moisture as readily as they should do, to be capable of satisfactory
desiccation in any of the arrangements described above; while, in addition to this,
the heavier pieces of such materials are not readily enough moved along by the
air-blast. The incline of the hopper a, along which the material slides down into
the blast-pipe, is here extended, such extension consisting of a grate r, along which
the material travels down into the barrel, it being at the same time impinged upon
with considerable violence by the heated dry air. Owing to the provision of the
barrel, or of other means for imparting motion, contact between the material
iing dried and the drying medium, or air, may be ensured for a somewhat long
space of time. In order to bring about a thorough inixture of the air-blast arl
the combustion gases in the suction pipe m, the blast pipe 7, at its orifice, is divided
into a series of small suction pipes or tuyeres u. Between the several jets issuing
from such tuyeres, the combustion gas is exhausted from the furnace, and reaches
the material being dried, in the condition of a thorough mixture. The preparatory
heating of the air-blast is provided for by the arrangement of a surface-heater.
The suction pipe of the fan or blast e is connected with the heating chamber v
which is heated by a furnace f, the combustion gases from which are drawn up or
exhausted by the ejector e.
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 w od
claim is:-
1. Drying apparatus for materials in a granular condition, in lumps or
semi-liquid condition, wherein a heated current of air is produced and
through one or more pipes of any suitable shape, arranged either horizonta.or

page_text: vertically and (in the latter case) so as to conduct the air either upwards or down-
wards; the said current of air being so powerful that the material to be dried,
as it is charged or fed at one end of the pipes, is carried along by (and with) the
current of air and by it discharged into a collecting chamber or receiver, where
it descends to the bottom, whereas the dry air escapes into the chimney.
2. Drying apparatus of the class referred to in the first claim, wherein the
aterial to be dried is by a heated current of air driven direct into a large drying
chamber or tower and reduced to dust, or pulverised; the drying process taking
place during this descent, while the dry air escapes through the chimney.
3. Drying apparatus such as referred to in the first claim, wherein the fan or
blast arrangement operates an ejector by which combustion gases are drawn
in and caused to mix with the air-blast, the resulting mixture driving the
material to be treated further along on its course
4. Drying apparatus of the type characterized in the 3rd claim, wherein the
ejector draws in combustible gases, which mix with the air-blast from the fan and
form a thin hot-flame (a "blow-pipe" flame) which impinges upon the material
under treatment.
5. Drying apparatus of the type referred to in the first and third claims, in
combination with a back-flow channel, such as o, whereby the drying gases,
already conducted through the drying chamber, are led back to the fan or blast,-
so that they may again be forced through the nozzle of the blast and partly-by
means of a branch pipe-through the furnace and he once more brought into
contact with the material being dried (Figure 4).
Doted this 14th dor of Anos 1907
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.