Improvements in Drying Apparatus, chiefly designed for Drying Granular or like Substances.
Year: 1896

page_text: Date of Application, 2nd June, 1896-Accepted, 4th July, 1896
COMPLETE SPECIFICATION.
Improvements in Drying Apparatus, chiefly designed for Drying
Granular or like Substances.
I, THOMAS TELFER OLIVER, of 2306 Indiana Avenue, Chicago, in the
County of Cook and State of Illinois, United States of America, Physician,
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 inveution relates to rotary drying apparatus, but more particularly to that
class of driers used for drying granular or semi-granular substances, and in
which steam, hot air or other heated fluid is employed for raising the temperature
of the heating surfaces with which the substance to be dried comes in contact.
The primary object of my invention is to greatly increase the superficial area
of the drying surfaces without thereby increasing the bulk or exterior dimensions
of the apparatus.
Another object of my invention is to greatly prolong the passage of the
steam or other heating medium through the drier without thereby increasing its
dimensions.
And a still further object is to provide improved means for automatically
discharging the waters of condensation and conducting the same away from the
machine.
And my invention has for its object finally to improve and simplify the general
construction and arrangement of the parts of rotary driers.
With these ends in view my invention consists in certain features of novelty in
the construction, combination and arrangement of parts by which the said objects,
and certain other objects hereinafter described, are accomplished, as fully explained
with reference to the accompanying drawings and more particularly pointed out in
the claims.
In the said drawings,
Figure 1 is a vertical longitudinal section of my improved drier, the driving
gear being shown in elevation.
Figure 1A is a detail view of the driving gears.
Figure 2 is a transverse section of the rotary cylinders, taken on the line 2-2
Figure 1.
Figure 3 is a similar section taken on the line 3-3 Figure 1.
Figure 4 is an enlarged detail view of the valve and operating mechanism, and
Figure 5 is a detail view hereinafter described.
In these drawings, wherein like signs of reference indicate like parts throughout
the several views, A is a post or standard, or other suitable frame, in which is
journalled in suitable bearings, B a horizontal shaft C, provided at one end with a
suitable pulley D, by means of which power may be transmitted to such shaft for
rotating the drier, as will be hereinafter explained. Mounted upon and secured to
the shalt C, is a worm or screw E with which engages a worn wheel F, secured to
a shaft G, which forms one end of the axis of the rotary drier. The shaft G is
journaled or m unted in a suitable sleeve or journal bearing H, which is provided
on its under side with an inverted U-shaped yoke h, through whose depending ends
or cars the shaft C passes, and between which ends or ears the worm E is mounted.
The journal bearing H if desired, may be in two parts, like an ordinary journal

page_text: box, as shown in Figure 1, and immediately above the worm E it is cut away to
receive the worm wheel F. The shaft G passes through a suitable sleeve, formed
on or secured to the bearing H at its outer end, while at its inner end it is secured
to a hub J, upon which the outer cylinder or jacket K is mounted at one end,
while the other end is mounted on a similar hub J', from which latter projects a
shaft G which is coincident with the shaft G, and constitutes the outer end of the
axis of the drier.
The shaft G is mounted on an adjustable bearing or collar H¹, provided with
any suitable means for restricting it to a vertical movement and changing its
altitude. I have shown in the drawing, and I prefer to use, a slotted standard or
post A, in which the bearing or collar H' fits with capability of sliding up and
down throughout the length of the slot in such standard; and the said standard
at a suitable point below the bearing or collar H¹ is provided with a cross-bar a,
in which is threaded an upwardly projecting screw L, whose upper end supports
the bearing H, and whose lower end is provided with a suitable knob or hand
wheel, by means of which the screw may be turned and the bearing or collar H'
adjusted to the proper elevation.
Thus it will be seen that by the manipulation of the adjusting screw L, the
inclination of the drier may be quickly and conveniently varied without
interrupting the operation of the apparatus, inasmuch as the journal bearing H
is pivoted with capability of rotating concentrically about the axis of the
worm E, and consequently holds the wheel F in engagement with the worm E
at all times, however high or low the rising and falling end of the apparatus
might be.
The head M2 at the upper end of the apparatus is provided with an opening in
which is fitted a hood & having flanges embracing the edge of the opening in
the head M2, and thus forming a tight joint while permitting the rotation of the
head. This hood k may be provided in one side with an opening i for the
admission of the air blast and in the other side with an opening S through which
the material to be dried is fed to the machine. The sleeve I passes through a
suitable opening in the hood k and is provided with number of supporting
arms I secured thereto and also to the inner side of the hood whereby the latter
is firmly supported independently of the head M².
Arranged within the cylinder or jacket K is a second cylinder or lining M, which
is arranged preferably concentrically therein and secured thereto at its ends so as
to form between the two cylinders a closed space or annular chamber m, for steam
or other heating medium. As a convenient manner of securing the two cylinders
together, I arrange between the two cylinders at each eud, a ring m³ to which the
cylinders are suitably secured.
Both of the hubs J J' are hollow, and each is provided with radial spokes or
arms N, which are also hollow, and which support the cylinders K, M on the hubs,
and at the same time serve to place the annular space or chamber m and the hollow
hubs J J', in communication. The hubs J J' may be provided at suitable intervals
on their peripheries with hollow interiorly threaded bosses j, into which the
threaded inner ends of the spokes N are screwed, while the outer ends of such
spokes may be threaded and passed through openings in the lining or cylinder M,
and held therein by jamb nuts n threaded upon the spokes N and bearing upon the
inner periphery of the lining M, while the extreme ends of such spokes are threaded
in bands or rings n which encircle the said lining, thereby firmly clamping the
parts together and constituting a steam tight joint.
The shaft is hollow, and constitutes the inlet pipe for steam or other suitable
heating medium, and to which source of heating medium it may be connected in
any convenient manner, and the shaft or journal G¹ is also hollow, and constitutes
the outlet or exit for the heating medium, after it has passed through its various
channels and passages in the drier.
The hubs JJ are connected together by a pipe or tube O, which is preferably
in axial alignment with the shaft G', and constitutes a continuation of the latter,

page_text: and has its one en 1 secured in the inner end of the hub J, by meaus of a suitable
ring or nut o, or equivalent device, while its other end is secured in a nut o' which
also constitutes a coupling for the shaft G'. The pipe or tube O is preferably
round or cylindrical, and arranged around and preferably in contact with this
cylindrical pipe O, with their ends screwed or otherwise secured into the inner ends
of the hubs J J', are a number of tubes or pipes P, which however, are flat in
cross section throughout their length between the hubs, and are so arranged as
to form flat radial wings or drying blades, as more clearly shown in Figure 3. For
the sake of convenience in securing these flat tubes P in the hubs J, J', the en 1s
of such tubes may be left cylindrical, and expanded or otherwise secured in the
complementary holes in the hubs.
The outer ends of the hubs J, J', if desired, may be provided with removable
heads ', held in place in any convenient manner.
The purpose of flattening the pipes P is to increase their superficial areas, so as
to present a larger heating surface for contact with the material agitated within
the rotating cylinder M, and also to form fat wings or blades which will be capable
of catching the material as it falls upon them, and conveying it upward, causing it
in its ascent to first come in contact with the central pipe O, and then to shift onto
the next lowest pipe or blade P, from which it will slide back into the cylinder.
In ordinary rotary driers, it is common to employ on the interior of the cylinder
a number of wings or agitators which catch the material as the cylinder rotates and
carry it upward it being cast in its course from one of such agitators to another,
and thus a more thorough agitation of the material is effected than could possibly
be accomplished by means of the cylinder alone. Such wings or agitators as these
might be used in conjunction with my improved hollow blades P and pipa O, which
also constitute agitators, but in order that the superficial heating surfaces of the
drier may be still further increased, I use, instead of such plain wings or agitators,
a series of hollow wings or agitators which have communication with the annular
chamber m, whereby the steam or other heating medium circulating in such
chamber will also enter and heat the hollow wings, and thus greatly expedite the
drying of the material as it is agitated and carried around by them. These wings
may be constructed in any of many ways which will readily suggest themselves to
the ordinary mechanic; a convenient and simple construction consists of two
longitudinal plates q, secured together at their inner edges at an angle, and fastened
at their outer edges to the lining M, the lining M being provided with perforations
or openings gl, through which the steam or heating medium enters the wings or
agitators The ends of the hollow wings are of course closed by suitable sheets
or plates q, so as to prevent the escape of the stem or heating medium into the
interior of the apparatus where the substance undergoing the drying process, is
situated. If desired, one of the plates g of each wing may be arranged on the
diameter of the cylinder so as to be radial to its axis, whereby the wings will hold
the material throughout a greater range of their travel.
In order that the steam or other heating medium as it enters the apparatus
through the pipe G may not rush directly through the tubes O, P, but may be
compelled to pervade the chamber m, and the hollow agitators as well as the
tubes O, P, I arrange over the upper ends of the tubes O, P, a shield or deflector T
which closes direct communication between the shaft G and such tubes without
cutting off communication between the tubes themselves, the deflector being
concaved or cup shape as shown in Figure 1, thus constituting a direct passage
through the machine. This deflector may be conveniently held in place by resting
its edge against the inner side of the hollow hub J around the outer edges of the
tubes P, and providing the end of the hollow shaft G, or the opening in the hub J
through which such shaft enters, with a spider or cross-bar N between which and
the shield T bears a set-screw which may be threaded in the spider as shown in
Figure 1, thus forcing the spider and shield in opposite directions and holding the
two in place.

page_text: It will now be understood that when the steam or other heating medium is turned
on through the hollow shaft G it will enter the hub J and striking the shield T
will be deflected into the chamber m via the hollow spokes N leading to the hub J
From the hub J', its only course of escape is through the tubes or drying blades P
back again towards the hub J because the shaft GI does not communicate with the
hub Jbut is connected directly with the tube O. After entering the drying
blades P it passes between the shield T and the ends of the tubes into the tube
and finally passes off via the exit or shaft G', having in its course pervaded the
various pipes and passages of the drier and heated the drying surfaces to a high
degree. In order however that the temperature of the drier may be regulated, I
provide the exit G with a regulating valve R, by means of which the steam or
heating medium may be compelled to discharge less freely, and hence caused to
more thoroughly pervade the apparatus, and in so doing raise the temperature to a
greater degree than would be attained, were the heating modium allowed to
escape as freely as it entered. When it is desired to reduce the temperature, it
is only necessary to open the valve R, and permit the free escape of the steam.
The material to be dried, as it is fed into the machine through the food chute
or pipe S, drops into the apparatus, and during the revolution of the latter, caused
by the rotation of the worm E as explained, such material is caught by the agitators Q
and carried aloft and scattered upon and between the pipe O and blades P, when:e
it spills back into the cylinder, and throughout its course it is subjected to the
combined drying influence of the heated surfaces and the air from the blast pipe i,
which may be hot or cold, and which serves to carry off the moisture as it evaporates
from th material. The air and material of course, discharge from the lower end
of apparatus, which is open as usual.
Inasmuch as the cylinders K, M, are constructed preferably, of thin material
and are of great length it is desirable to re-enforce or stiffen them in order that they
may not sag or bend. To accomplish this and at the same time still further
prolong the course of the steam or heating medium through the chamber m,
and also to compel it to enter the hollow agitators Q, I arrange between
the two cylinders an angle iron or rib V which takes a spiral course around the
inner cylinder and is of sufficient width to fill the cross section of the chamber m;
thus constituting a spiral passage for the steam within the chamber m and
preventing it from passing directly from the upper to the lower spokes, and
also compelling it to enter the hollow agitators in order to pass the angle iron
or rib.
In order to permit the passage of the waters of condensation from the chamber m
without at the same time permitting the steam to e-cape, I provide the outer
cylinder Kat its lower end with an opening which is guanled by a valve W held
normally closed by a spring X sleeved on the valve stem an1 bearing between a
shoulder thereon and the spider Y. The said opening to the cylin ler K is in
communication via the valve with a chamber Z which may be conveniently formed
in one piece with the valve seat z as shown in Figure 4. The valve stem projects
through a suitable stuffing box Z' un the chamber Z and is engaged by a lever Z,
one end of which is pivoted in any suitable manner as shown in Figure 4, ta
support on the chamber Z while its other end is provided with an anti-friction
ruller Z, whereby when the lever Z is forced upward the valve W will be opened,
and any water contained in the chamber m permitted to escape into the chamber Z.
In order that this opening of the valve may be effected automatically when the
valve comes to a low position as shown in Figure 1, I provide a shoe w which is
arranged under the drier in a position to be struck by the anti-friction roller 23,
and thus force the valve W open.
In order that the water may be carried off from the chamber Z, I connect the
latter by means of a tube Z' with the pipe G as shown in Figure 1, so that when
the chamber Z reaches an upward position the water will gravitate through such
tube into the pipe G1, the tube or duet Z being connected to the chamber Z at a

page_text: point between the valve W and the exit pipe G¹ and the latter pipe being inclined
and the discharge end of the pipe Z being attached to the pipe G¹ at a paint
beyond the hub and heating chamber so that the point of communication between
the tube Z and the pipe G is lower than the point of communication between the
said pipe G and the hollow spokes, the water will not run back into the latter or
the hollow spokes.
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. A rotary drier having the flat hollow drying blades arranged together at the
centre of the drier and adapted to catch and hold the substance operated upon in
combination with the agitators arranged upon the inner side of the drier, all
constructed, arranged and combined substantially as described and shown.
2. A rotary drier having the hollow agitators arranged around its inner side;
the centrally arranged drying blades and means for conducting a heating melium to
Faid blades and agitators, all constructed combined and arranged substantially as
shown and described.
3. A rotary drier having the hollow hubs and flat hollow blades in combination
with means for admitting a heating medium to said hubs, all constructed, combined
and arranged substantially as herein shown and described.
4. The berein described rotary drier having the tube or pipe extending between
the hollow hubs in combination with the flat hollow blades arranged in juxtaposition
to said pipe and the steam inlet for one and the outlet for the other of said
hubs, all constructed, combined and arranged substantially as herein shown and
described.
5. The herein described rotary drier having the flat hollow blades provided with
rounded ends secured in the hollow hubs, all constructed, combined and arranged
substantially as herein shown and described.
6. The herein described rotary drier having the two casings arranged one within
the other so as to form a closed heating chamber and an open drying chamber
disconnected with said heating chamber; the continuous pipe or passage extending
through said casings and having connection at one end with a source of heated
fluid; a valve at the other end of said pipe or passage for regulating the exit
therefrom, and the pipes connecting said passage with said heating chamber;
whereby the exit from said passage and heating chamber may be controlled by
one valve, all constructed, combined and arranged substantially as shown and
described.
7. The herein described drying machine provided with means for checking the
exit of the heating medium from the heating chamber and from the continuous
passage extending through the drying chamber whereby the heating medium may
be caused to accumulate in said heating chamber and passage, all constructed,
combined and arranged substantially as shown and described.
8. The herein described rotary drier provided with a common exit for the heating
medium from the drying and heating chambers and the hollow drying blades and
means for checking the escape of the heating medium from said blades and thereby
forcing the same into the heating chamber, all constructed, combined and arranged
substantially as shown and described.
9. The herein described drier having the shield interposed between the inlet for
the heating medium and the ends of the interior drying tubes whereby the heating
medium will be deflected into the surrounding heating chamber and prevented from
directly entering said tubes, in combination with the hollow hubs and spokes all
constructed and arranged substantially as shown and described.
10. The herein described rotary drier having a drain aperture closed by a valve;
means for opening the valve as the drier rotates, the chamber communicating with
said drain aperture, the tube connecting said chamber with the exit, and the point
of communication between the discharge end of said tube and said exit being

page_text: below the point of communication between the exit and the heating chamber of
the drier, all constructed, combined and arranged substantially as shown and
described.
Dated this 2nd day of June 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.