Improvements in Process and Apparatus for Drying Brewers' Grains and like material.
Year: 1892

page_text: Date of Application, 22nd Nov., 1892-Accepted, 14th Jan., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by BIRNEY CLARK BATCHELLER, Drexel
Building, City and County of Philadelphia, State of Pennsylvania, Engineer,
SPENCER D. SCHUYLER, 71, Broadway, New York City, New York,
Gentleman, and WILLIAM M. CRAMP, Drexel Building, Philadelphia,
Pennsylvania, Gentleman, all in the United States of America.]
Improvements in Process and Apparatus for Drying Brewers' Grains
and like material.
I, HENRY HARINGTON LEIGH, Assoc. Mem. Inst. C.E., Fel. Ch. Inst. P.A.,
Fel. I. Inst. practising as Phillips & Leigh, of No. 22, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer and Chartered Patent
Agent, 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 relates generally to a method and an apparatus for drying wet
material, such as brewer's grains and similar substances.
The improved method consists in dropping the wet material in a thin stream
across a longitudinally open space through which a current of very highly heated
air is passing in the same direction the material is to pass, whereby immediately the
wet material meets the current of hot air each individual grain is caked upon its
exterior so that its nutrious watery substances are confined within the husk and the
grains are thereby prevented from sticking together and to the surrounding surface
of the drier. For this purpose it is necessary that the air should be heated to a
high temperature, say approximately 700 degrees F., and that the material be
allowed to pass onward in the direction of the air current, thereby presenting the
incoming wet material at first to the hottest current which as it carries the material
onward more or less dried, has lost and looses its heat and consequently does not
scorch said material. The feeding of the material directly into a longitudinally
open space permits the highly heated air current to carry it onward without danger
of carrying it against a heated surface of the drier which under the force of the air
current would cause it to stick to such surface and tend to clog up the drier and at
the same time break up the partially dried exterior of the material so that the
nutrious substances would become separated from the husks and lodge in the drier
to further clog it up.
The apparatus adapted for the carrying out of this method consists substantially
of a longitudinally open cylinder or drum into one end of which the wet material
is fed, so that where it meets the hot air current there is a free open space for the
air current to carry it onward without danger of meeting a heated surface in its
course. This cylinder or drum is provided internally with a number of longi-
tudinally extending and radially projecting curved blades or buckets, which catch
the material after it has first met the hot air current and been caked upon its
exterior, and has fallen to the bottom of the cylinder, and in the rotations of the
latter carry the material upward and drop it in streams constantly across the centre
or unoccupied space of the cylinder and through what is naturally the hottest
portion thereof. At one end of this cylinder there may be provided a feeding
hopper for receiving the material to be dried and feeding it in
any desired
quantities into the open space across the hot air current passing directly and
unobstructedly through the cylinder; or the cylinder may have the hopper placed
immediately over it so that it may be fed through a proper opening in larger
quantities directly into the cylinder.
At the same end the cylinder is connected with a hot air supply conduit which
leads the hot air into the cylinder so that the current is directed lengthwise in the

page_text: !
same direction as the course of the material through the cylinder to become
intimately mingled with the material that is constantly falling or dropping in the
cylinder and carry the material as it becomes more or less dried progressively
forward to the opposite end thereof where the material is discharged and the spent
air and moisture conducted onward or escaping.
There is also provided with the drying cylinder a mechanical conveyor for
conveying the more or less partially dried grains from the discharge end of the
cylinder back to the entrance end whereby the grains may be circulated through
the cylinder two or more times according as the amount of moisture they carry
will require.
Furthermore, there is provided automatic dampers by which the cold air is kept
from being drawn into the cylinder by the feeding in of the grains or other material,
and by the discharge of the grains or other material; and there is also provided
means by which the grains after they have become thoroughly dried may be
discharged from the apparatus.
With this general description of the apparatus, a detailed description thereof
will now be given, reference being had to the accompanying drawings, in which:
Figure 1, is a sectional elevation partly in section of the improved drier and
conveyor..
Fig. 2, is an end view of the same.
Fig. 3, is a longitudinal sectional elevation of the drier.
Fig. 4, is a cross section of the drying cylinder on the line 4, 4 of Fig. 3.
Fig. 5, is a cross sectional elevation of the drier taken on the line 5, 5 of Fig. 1,
looking in the direction of the arrow.
Fig. 6, is a sectional elevation on the line 6, 6, of Fig. 1, looking in the direction
of the arrow.
Fig. 7, is an enlarged detail longitudinal section showing the connection between
the rotating drum and the stationary hot air conduit.
Fig. 8, is a diagram of a modified apparatus; and
Fig. 9, a partial elevation of the same.
Referring to Figs. 1, 2 and 3, it is to be understood that the drier consists of a
cylinder or drum G of suitable diameter and length supported horizontally to
rotate on roller bearings a, driven in any suitable manner as by a sprocket chain
or belt b, engaging with a toothed ring c, on the cylinder, and a sprocket pinion on
a counter shaft d, driven by a belt passing around a pulley secured to said shaft
from a pulley on a driving shaft.
The cylinder is substantially an open-ended cylinder but is preferably provided
at each end with a continuous ledge f, of substantially the width of the buckets or
blades with which the cylinder is provided, as hereinafter described, so that the
openings at each end of the cylinder are restricted in size and the material is
prevented from premature discharge.
The cylinder, see Fig. 4, is provided internally with a number of longitudinally
extending curved blades or buckets g, projecting inwardly toward the center of the
cylinder, are preferably curved in cross section so as to form a number of pockets
which catch the material and elevate it and constantly discharge it through the
center or unoccupied space of the cylinder.
At the entrance end of the cylinder it is provided with a conical extension G¹
the wider end of which extension coincides with the restricted opening of the
cylinder formed by the ledge f, and the smaller and outer end of said extension
coincides with the hot air conduit B. At the opposite or discharge end of the
cylinder G the flange f, terminates in a horizontal circular lip f¹, that enters a
short distance into the discharge chamber H.
At or near the entrance end of the cylinder there is provided a means for feeding
the material into the cylinder consisting of a hopper E to receive the material, and
which hopper terminates in a spout extending into the conical extension of the
cylinder. At the bottom of the hopper there is provided a weighted damper or
valve F by which the material is allowed to fall through the leg of the hopper in

page_text: suitable quantities into the cylinder, the purpose of which damper will be merem
after set forth.
Instead of supplying the material in comparatively small quantities by means of
the hopper E, the cylinder may be provided with an opening closed by a door E¹
through which a large quantity or mass of material may be fed into the cylinder G,
as from a bin E indicated by dotted lines, Fig. 3.
At the opposite end of the drying cylinder there is provided the discharge
chamber H, stationary with respect to the rotations of the drying cylinder, and
registering with the opening at the end of the cylinder as before described. This
discharge chamber is provided with an outlet D for the dried material and a
conical extension I for leading off the hot or spent air from the apparatus as by
an exhaust fan L; the chamber being separated from said conical extension by a
screen C of suitable material, such as fine wire cloth, to stop the further movement
of the dried material as it is carried from the drying chamber by the current of
air. At one or more places intermediate of the ends of the cylinder there may be
arranged an impeding or delay screen J, of wire cloth, indicated by dotted lines
in Fig. 3, so that the forward movement of the material in the current of hot air
is temporarily stopped and thrown down so as to pass said screen between its outer
edges and walls of the cylinder.
In the operation of the apparatus as thus constructed the material, such as
brewer's grains, is fed from the feed hopper in suitable quantities, by the dumping
movement of the damper F, into the entrance end of the cylinder so that it falls,
after first meeting the hot air current, onto or into the blades or buckets 9. A
current of highly heated air at approximately a temperature of 700° F.-and under
more or less pressure is allowed to pass or is forced or drawn into the entrance end
of the cylinder and thence longitudinally through it and out by the extension I.
The cylinder is constantly rotated by the connections heretofore described so that
the grains caught by the buckets are carried partially around with the cylinder
and kept constantly dropping or falling in streams through the central unoccupied
portion of the cylinder, across the hottest portion of the current of highly heated
air. In this way the wettest material is dropped in the presence of the hottest.
air and in the hottest part of the drying cylinder, and the drier grains or dried
grains are successively dropped in a gradually decreasing temperature so that
the liability of scorching or over-heating is prevented. As the grains are being
constantly dropped and fall across the current of heated air those grains that are
driest and hence lighter than those that carry more moisture will be carried'
forward and onward by the current of heated air toward the discharging end of
the cylinder and into the discharge chamber H. The direct discharge of these
drier or dried grains may be impeded or delayed one or more times by the
impeding screens J which allow the air current to pass onward but compels the
material to pass to one side to be dropped possibly again so that they may
ultimately pass the outer edge of the screen or screens to be again dropped in
the presence of the current of air and being sufficiently dried will be carried by
the current of air out of the drying cylinder into the discharge chamber H,
where meeting the stopping screen C will fall into the outlet D to be removed from
the cylinder.
From the foregoing it will be understood that the improved method of drying
herein employed consists in presenting the wettest material in an open and free
space to the hottest air, whereby such heat is expended in absorbing the moisture
on the exterior of the grains and caking the glutinous film enveloping them so that
the watery substances are immediately confined within the grains and saved and
the air being thereby gradually cooled, and such cooler air meeting the drier
material is prevented from scorching or overdrying it.
By the use of this improved method 'the nutritious substances are saved and
discharged with the husks, instead of being wasted or reduced to a mass by leaving
the husks and coating the interior of the drying cylinder.
In the use of a single drying cylinder, or where it is desirable to economize

page_text: space, or where it is thought necessary to lead the grains a second time through
the same cylinder, whether one or more cylinders are used, there is provided a
mechanical conveyor M, for receiving the grains from one end of the cylinder or
of another cylinder and conveying them to the other end of the same or another
cylinder for passage through the cylinder again.
In the present instance this conveyor consists of an endless band, belt or chain
carrying suitable flights, and supported at either end upon suitable sprocket or
other wheels m, n, within a closed conduit N, that is arranged in an inclined
position as shown in Fig. 1, inclining upwardly from the discharge opening D, to
the feeding end of the cylinder. It is essential that this conduit N, and its con-
nections with both ends of the drying cylinder be entirely closed to the atmo-
sphere to prevent the conveyor from drawing in cold air and thereby materially
reducing the heat in the cylinder and destroying the efficiency of the hot air
current. In order to convey the discharged grains either partially or wholly
dried from the discharge opening D, there is preferably provided in said opening
a feed screw or screw conveyor o, mounted in suitable bearings in said opening and
having a sprocket wheel p, that receives motion from the sprocket on the end of
the shaft of the endless conveyor sprocket m, or in any other suitable manner, see
detail Fig. 14.
The discharge opening D, as shown in Fig. 5, leads into the lower end of
the closed conduit N, so that the screw conveyor will deposit the dried or
partially dried grains in the path of the flights of the endless conveyor. At the
upper end of the closed conduit, there is arranged another screw conveyor P, within
a horizontal conduit q, that extends from the closed conduit N or from a hopper
therefrom, to the leg of the feeding-in hopper E. The screw conveyor P is
mounted in suitable bearings so as to rotate in said conduit q, through a suitable
wheel r, on the end of the shaft of the conveyor which receives motion by a belt
from a pulley on the main driving shaft, as shown in Figs. 1 and 6. The grains
elevated by the flights of the endless conveyor M fall into the horizontal con-
duit q, and are conveyed by the screw conveyor into the leg of the feeding-in
hopper below its damper or valve F, and thence pass into and through the cylinder
as before.
Suitable motion is imparted to the endless conveyor M, through a pulley S, fast
to the shaft of the sprocket wheel n, at the upper end of the closed conduit, said
pulley being driven by a belt extending from a pulley on the main driving shaft.
It is obvious that the grains may be wholly discharged at any point immediately
connected with or adjacent to the discharge opening D or at any point along the
closed conduit N ; but as shown, and in the preferred construction, the discharge
conduit Qis arranged in connection with the upper end of the closed conduit
or immediately connected with the conduit g, as shown in Figs. 1, 2 and 6 so that
the grains to be discharged are taken by the flights of the endless conveyor
upward to the upper end of the closed conduit and by the screw conveyor P fed
into said discharge conduit Q; a damper or valve t, being arranged at the mouth
of said conduit to open and close the opening into said discharge conduit. This
discharge conduit is also provided with another damper or valve u, a short distance
below the entrance of the conduit which damper or valve is weighted so that when
a sufficient quantity of grain accumulates over said damper said damper will yield
to allow the grain to pass and again close until another lot of grain of sufficient
weight accumulates over the damper to cause it to again open automatically. The
damper Facts in a similar manner to the damper u, just described, their function
being to allow the passage of grain and yet to close the passages so as to prevent
the escape of hot air and also to reduce to the minimum the quantity of outside air
that can be drawn in by the exhaust fan I, so that the air passage through the
drying cylinder will not be diluted and lowered in temperature by the undue
mixture of the outside cold or cooler air.
In the modification Fig. 8, the partially dried grains from one cylinder G
are allowed to pass to a second cylinder G2 and after passing therethrough with the

page_text: same hot air or with another supply of hot or hotter air is discharged into a vertical
conveyor M' of proper form to receive and carry the discharge material from the
discharge end of the second drying cylinder G2 up into the entrance end of the first
cylinder G to pass through it again; and becoming thoroughly dried may be
finally discharged from the apparatus at any suitable point in its course therethrough
as for instance at the point a or at the point y.
The connection of the rotating cylinder with the stationary parts of the
apparatus may obviously be of any suitable construction that will guard the
entrance of the outside air, or, in other words, properly pack the joints and yet
permit the drying cylinder to freely rotate. One such construction is shown in
Fig. 7, wherein the end of the upper supply conduit B is provided with a circular
track 20, of L-shape in cross section with which engages an annular packing
wheel 21, that is supported or connected to the end of the drying cylinder or the end
of its conical extension C¹, by a flanged U-shaped rim 22; the said annular packing
wheel 21 being seated in the recess between the parts of the U, permitting said
cylinder to have a slight motion circumferentially with respect to the annular
wheel and the stationary conduit B, and also permitting the cylinder and annular
wheel to have a slight longitudinal motion with respect to the stationary conduit B.
A similar means of packing the opposite end of the cylinder may be employed.
Thus, the annular packing wheel, instead of being carried by a flange of the
rotating cylinder is carried by a flange on the end of the stationary discharge
chamber H, which packing wheel rests upon the horizontal lip f¹, projecting from the
end of the rotating cylinder.
While there is shown a single and double arrangement of drying cylinders, it is to
be understood that the invention is not necessarily limited thereto, as any desired
number of cylinders may be used; and that any proper form of conveyor may be
employed that will carry back the more or less partially dried material to one or
the other of the drying cylinders through which it has passed before.
While it is preferred to employ a screw conveyor or similar mechanical
device to carry the grains positively laterally into the closed conduit N or in
the feeding-in leg of the feed hopper, yet in handling some material or in handling
nearly dried grains, a simple inclined chute may be used for the lateral transfer of
the material, in which case such chute will be the equivalent for the screw conveyor
particularly described.
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
1. The hereindescribed method of drying brewers' grains, which consists in
dropping the wet grains directly into a longitudinally open space and through
a current of air heated to the temperature approximately of 700° F.; so that the
exterior of the grains are immediately caked and allowing the air current and
grains to pass onward together in the same direction without deviation or
obstruction.
2. The hereindescribed horizontal and rotating drying cylinder having longi-
tudinally arranged buckets, and an exit opening at one end concentric with the
circumference of the cylinder and of less diameter than the cylinder whereby
a continuous end ledge is provided to prevent the premature discharge of the
partially dried material, and a hot air supply leading to the opposite end of the
cylinder whereby the hot air current passing through the cylinder carries the dried
material out through said restricted exit opening.
3. The combination with the rotating drying cylinder adapted to permit the
drying material to pass longitudinally through it, of a conduit leading from one
end of the cylinder to the other closed with respect to the atmosphere and a
mechanical conveyor therein for receiving the partially dried or drier material and
conveying it back to said drying cylinder, substantially as described.
4. The combination with the stationary air conduit, of a rotating drying cylinder

page_text: forming a continuation of the air conduit, and an annular packing wheel closing the
joint between the rotating and stationary parts, substantially as described.
Dated this 22nd day of November 1892.
HENRY H. LEIGH,
Chartered Patent Agent.