Granular, Pulverulent, and similar Substances.
Year: 1886

page_text: Granular, Pulverulent, and similar Substances.
I, LYDIA JANE CADWELL of the City of Chicago County of Cook, State of
Illinois, United States of America, Manufacturer, do hereby declare the nature of
my invention for "IMPROVEMENTS IN DRYING APPARATUS CHIEFLY DESIGNED FOR
DRYING GRANULAR, PULVERULENT AND SIMILAR SUBSTANCES" 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 principally to rotary driers more especially adapted to the
treatment of ground fertilizers, brewers grains and similar substances. It has for
its object to provide an apparatus of superior efficiency and economy in operation,
and it consists in the several matters hereinafter set forth and pointed out in the
appended claims.
In the accompanying drawings which illustrate one form in which my improved
apparatus may be embodied;
Figure 1 is a plan of the apparatus, including a cooling reel.
Figure 2 is a longitudinal vertical section in the parallel planes indicated by
lines y-y Figures 4 and 5.
Figure 3 is a repetition of part of Figure 2, but shows in addition, and in side
elevation an air heating furnace by which dry air is supplied to the rotating
driving chamber.
Figure 4 is an end elevation of the entire apparatus as shown in Figure 1,
excepting the air heating furnace, from the position of which the view is taken.
Figure 5 is a transverse vertical section taken in the parallel planes indicated by
the indirect line xx of Figure 2, and looking in the direction of the arrow on
that line.
Figures 6, 7 and 8 illustrate modifications which are embraced within my
invention as equivalents of other devices shown and described.
A (Figures 2 and 5) represents a hollow metal cylinder which will be commonly,
say 20 to 40 feet long and say five to six feet in diameter. A' A¹ are a series of
stationary rollers arranged in position to sustain the cylinder A and to allow the
latter to be rotated on its axis. The cylinder has annular circumferential tracks a

page_text: which ride on the rollers A¹ and one of which is desirably provided with flanges a¹
to retain the cylinder longitudinally in place. B B is a structure (in this instance
of masonry) which rises about the sides of the cylinder A and is supplemented by
a semi-cylindric cap plate B₁ to form an inclosure which laterally surrounds the
cylinder A at a distance of a few inches therefrom. The structure B in this case,
supports the rollers A¹ and is provided with a horizontal flue or passage B' beneath
the cylinder which communicates at one or more points (as b) with passages 6ª
leading into the chimney D.
In the case of a cylinder of the length suggested, the passage B is preferably
divided centrally by a transverse partition 62 (Figures 2 and 5) each part of the
passage connecting with a furnace fire. C is a furnace which delivers its products
of combustion into the passage B². This furnace is preferably located opposite
the partition of the flue B³ and desirably has two fire boxes C¹ and C³, one
connecting with one and the other with the other compartment of the said flue B²
by passages b³ indicated partially by dotted lines in Figures 2 and 5.
At the head or receiving end of the cylinder A (as seen at the left in Figures 1
and 2) a driving gear and feed mechanism are shown. E is an annular rack fixed
to the outer circumference of the cylinder A. F is a drive shaft mounted on a
suitable support F1 and provided with a pinion f which meshes with the rack E ag
shown in Figure 1 and in dotted lines of Figures 2 and 5. F' is a pulley on the
shaft F to receive a driving belt from any suitable motor or counter-shaft.
G is a stationary non-rotating plate constructed to practically close the adjacent
end of the cylinder A and supported in any suitable manner preferably indepen-
dently of said cylinder. H is a shell or drum attached to the plate G by the
flange g and communicating with the interior of the cylinder A through openings g¹.
I is a hopper or the terminal of a feed pipe intended to deliver the material to be
treated to the cylinder A. I¹ is a horizontal tube leading from the hopper I
through the shell H and plate G, and 12 is a spiral conveyor extending across the
bottom of the hopper I and through the tube I¹. The inner end of the shaft i of
said conveyor is supported in a bearing upheld by arms i¹ attached to the plate G
and the outer end of said shaft rotates in a suitable bearing i². The shaft is
rotated by a belt trained over the pulley or otherwise in any suitable manner.
The opposite end or tail of the cylinder A is closed by a stationary sheet metal
hood J provided at the bottom with a hopper J into which the contents of the
cylinder are discharged in the operation of the machine. This hood is represented
as being upheld in place by attachment with the structure B B¹. K is a pipe
leading from the air heating chamber of a suitable furnace or other air heating
device L through the hood J, so as to deliver hot or dry air into the tail of the
cylinder A. Preferably said air pipe is broadened put horizontally at its con
nection with the hood plate as represented at j, figures 1 and 4, so that the air
enters the cylinder in a correspondingly broad sheet, or current.
The cylinder A is provided on its inner surface with a series of longitudinal
flanges or wings A² (Figures 2 and 5) preferably pitched or inclined forwardly or
in the direction of their motion, towards their free edges, whereby in the rotation
of the cylinder, they act as buckets and lift the material towards or to the top of
the cylinder and thence discharge or drop it. Any desired form besides that of
the inclined flat blades shown may be given to those wings or buckets, that will
best serve the purpose of thus raising and then dropping the material across the
interior of the cylinder.
The wings A are also shown as being inclined longitudinally so as to operate in
a familiar manner to carry the material slowly lengthwise of the cylinder, from
the head to the tail thereof when the latter is rotated. The equivalent and
familiar expedient of setting the reel with its tail end lower than the head, may
of course be employed for this purpose though I prefer to set the cylinder, in a
horizontal position and to rely on the direction of the said wings A³ to effect the
desired progress of the material through the cylinder in the operation of drying.

page_text: M is an air flue connected with the shell H. and leading into the ash pit or space
beneath the grate of the furnace C. N is a branch or by-pass connected with the
pipe M and provided with a suction fan or air-mover N. Valves m and n located
in the flues M and N respectively enable the fan and by-pass to be used or excluded
from use at pleasure.
O is a grate located at the foot of the chimney D above the point at which the
products of combustion enter the same.
The operation of the mechanisms so far described is as follows;—
The cylinder A has a rather slow rotative movement in which the material fed
into it by the spiral conveyor I is gradually carried from the head towards the
tail thereof. The cylinder itself is directly heated by the products of combustion
from the furnace C, and correspondingly heats the materials contained therein and
brought into contact with it with the effect of vaporizing the moisture contained
in such material. During the progress of the material through the cylinder, said
material is also disintegrated or opened out as a mass, by the blades A' which lift
it in parts and pour it in particles across the interior of the cylinder so that all parts
of the mass are subjected to the heat of the cylinder, and are also so exposed as to
permit the vapor to pass freely away. While the material is falling the heated
and dry air which is admitted at the tail of the cylinder and has its exit through
the openings g¹ at the head of the cylinder, encounters the thus separated particles
of the mass and takes up the moisture evaporated therefrom.
The direction of the hot air current relative to that of the material through the
cylinder is significant in this respect, to wit, that the moisture taken up by the
air at any given point in the cylinder is carried towards a point therein where
the material has greater moisture, and not towards a point where it has less, as
would be the case if the direction of the material and air were the same. The
advantage gained at any point in the cylinder is therefore retained and the air is
continually effective in taking up moisture during its entire progress through the
cylinder.
Another advantage of giving the hot air a direction opposite that of the material
being treated relates to the obvious fact that the finer particles of the material
become dry first. In this relative movement of the hot air current, these dry or
dryer particles are borne into contact with the more moist and larger particles
near the bead of the cylinder and adhere to them so that the former are arrested
and also re-absorb moisture from the particles to which they adhere. They are
thus made to aid in equalizing the hydrous condition of the mass besides being
prevented from escape and loss by the action of the air current.
Still another advantage of this relative direction of movement on the part of
the heated air, accompanies the expansion of the vapors which are more highly
heated thereby and by such expansion, impel themselves forward toward the outlet
at the head of the cylinder where alone they find free escape.
The pipe M is intended to conduct the vapors and gases from the drying cylinder
to the fire of furnace C, where they are consumed. Advantages of this disposition
of them are a lessening of the quantity of other fuel required to maintain the fire
and a prevention of the escape of unpleasant or noxious odors into the outer air
through the chimney. In the case of fertilizers made from the residua of rendering
tanks the latter consideration is of great importance, and, to fully insure the
desired result, the grate O is located in the chimney D above the entrance of the
passage b so that, when necessary, a secondary fire may be there built through
which the products of combustion from the furnace C may pass with the effect
of consuming such of the gases as shall have escaped consumption in said furnace C.
Of course it is not necessary that these identical fires shall be relied on for the
whole or any part of this work, as the same result will be attained by conducting
the vapors and gases to another fire or succession of fires, maintained in available
distance from the drier.

page_text: 4
When the destruction of odors is a desideratum or it is only desired to utilize
the gases as fuel, it will commonly be practicable to increase the efficiency both of
the drying air current and of the fire by putting the fan N¹ into operation, and
thus applying a suction to the drying cylinder and a blast to the fire. For this
purpose when two pipes, as M and N are present the valve m will be closed and
the valve n opened. If it be found at times desirable to maintain a given draft or
force of air current through the cylinder A, and to supply less than the entire
volumn of moisture laden air to the fire, a part of the latter may be given escape
elsewhere than beneath the furnace grate, as provided for in an ordinary escape
flue, as M¹ Figure 4.
In treating some materials it is desirable to cool them after drying, and for this
purpose the cylinder F is shown. This cylinder is represented as being provided
with an axial shaft (seen at p in Figure 4 and in dotted lines in Figure 1) and
radial arms supporting the cylinder from said shaft. When of considerable length
it is further supported, like the drying cylinder, by stationary rollers p². The
cylinder P is provided with interior longitudinal wings P¹ doubly inclined for the
purpose of simultaneously advancing and agitating the material therein, also as in
the drying cylinder. The colling cylinder, if on the same floor with the dryer, will
commonly be arranged parallel with the drying cylinder, and with its head
adjacent to the tail of said drying cylinder. As shown in the drawings Q is a belt
conveyor and its box which, with a suitable hopper q, is arranged to receive the
material discharged from the drying cylinder, and to carry it to the feed hopper Pa
of the cooler, whence it is taken into the cylinder P by a spiral conveyor on the
shaft p. The cooling cylinder is constructed at its delivery end with a non-rotating
hood R, having a discharge hopper or spout R' and through this hood a pipe Š
supplies a blast of air to the interior of the cylinder. The opposite end of the
cylinder is closed by a non-rotating head T corresponding with the head G of the
drier, and which therefore need not be described in detail. V is a section of a flue,
or an open shell through which the air escapes. A gentle current of cool or cold
air may be impelled through the cooling cylinder by a fan S¹ attached to the
pipe S, as seen in Figures 1 and 4. Appropriate motion may be imparted to the
cylinder P through the pulley P³ on the shaft p.
The cool air admitted through the pipe S may advantageously be first dried and
then cooled by any of the familiar devices known for such purposes in order to
further dry as well as cool the material, if desired, or to prevent moistening it
again to any degree by contact with air not thoroughly dry.
It will obviously be practicable to dispense with a conveyor and to employ only
a spout or box when the cooler is located on the floor below or elsewhere beneath
the drier.
In Figures 6 and 7 are shown in transverse vertical section modifications of the
drying or cooling chamber above described, and intended to be embraced in my
invention as herein claimed.
The cylinder A in Figure 6 does not necessarily rotate, but within said cylinder
is mounted a rotating skeleton reel W having appropriately inclined longitudinal
blades or buckets W₁ supported from a central shaft w.
These buckets W¹ sweep
near or in contact with the cylinder, and lift and drop the material therein, and
also advance it through the cylinder in precisely the same way as it is carried. in
the drier as first described.
In: Figure 7 is shown a cylinder A which may be substituted for either the.
drying or cooling cylinder of Figures 1 to 5 inclusive, and which may either
rotate or not, as preferred. It has no interior buckets or wings, and to give the
desired disintegrations of the material, a flyer X having wings x-x is placed
above the bottom running through the entire length. of the cylinder, said flyer
being rapidly rotated on its axis. The material being treated will be thrown up
and dissipated as shown with the same result in kind as produced by pouring the
same off the buckets of the cylinder of the dryer or cooler as at length shown and

page_text: described. If the flyer has its wings arranged spirally about its shaft as suggested
in Figure 8, the desired advance of of the material through the cylinder will be
thereby effected.
By the employment of a jacketed drying cylinder in the combination with an
internal drying current and an external heater, instead of a single shell cylinder
heretofore known I am enabled to distribute the heat uniformly over all parts of
the drier proper and avoid burning the material under treatment, while in con-
nection with the drying current I get a uniform result.
Distillers slops may be dried for feed economically by the above described
apparatus in a manner next to be stated. As is well known such slops, even after
settling and draining off the free water, are too wet for the manipulation described
while brewers grains are so far less wet as to be easily disintegrated as a mass by
the means set forth. The drying of the slops is therefore effected by mixing them
after draining with about an equal quantity, more or less, of previously dried or
partially dried brewer's grain which gives a mass that may be disintegrated in the
drier suitably for the operation thereon of the drying air current which passes
through the cylinder. The mixing may be effected by any well known machine
for similar purposes from which it is sent to the drying chamber.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is;-
1. In a drying apparatus the organism described embracing a drying chamber
constructed to simultaneously dissipate the mass being treated and carry it from
one end to the other of the drying chamber, a jacket affording a heating space
exterior to the drying chamber, means for producing a current of air through the
drying chamber in a direction opposite to that in which the material advances, and
any suitable means for supplying heat between the jacket and the drier.
2. The combination, with a rotary drying cylinder, a furnace for supplying the
same with dry or heated air internally and a furnace for heating the drying
cylinder externally, of a sheath or shell constituting a chamber about the drying
cylinder for the purpose of retaining and evenly distributing all the heat evolved
from the external furnace, and thus preventing loss of heat from the motion of the
drying cylinder or otherwise.
3. In combination with a drier for pulverulent fertilizers and similar substances
provided with means for dissipating the mass within the drier, means for pro-
ducing a current of air through the drier, a furnace separate from the means for
producing the current of air and a flue arranged to conduct vapor and gases from
the drier to this furnace.
4. In combination with a drier constructed to dissipate within its drying
chamber the mass being treated, a furnace constructed to supply heated air to the
drying chamber, a separate furnace arranged to heat the wall of the drying chamber
and a flue arranged to conduct the vaprous air and gases from the drying chamber
to one of the furnace fires.
5. In combination with a drier constructed to dissipate within the drying
chamber the material being dried, a furnace constructed to supply heated air to
tbe drying chamber, a furnace arranged to heat the wall of the drying chamber, a
flue arranged to conduct the vapor and gases from the drying chamber to the fire
of one of said furnaces, and a fire box for a secondary fire, located in position to
receive the products of combustion from the furnace to which said vapor and gases
are first conducted.
6. The combination, with a metal drying cylinder A, and a housing therefor,
of a transversely divided passage B2 in the housing, a furnace, a chimney, passages
leading from the furnace to the several compartments of the passage B² and
passages leading from the said several compartments to the chimney, substantially
as described.

page_text: 7. The combination, with a metal walled drying chamber, a furnace arranged to
heat the drying chamber by contact of its products of combustion with the chamber
wall, a flue leading from the drying chamber to the furnace, a chimney having a
receiving flue 62 leading from the furnace, and a fire grate O located in the
chimney above the grate, substantially as and for the purpose set forth.
8. The combination, of a drying chamber, means for supplying said chamber
with air, a furnace and a flue leading from the drying chamber to the fire box of
the furnace, and provided with a branch passage whereby a part only or the whole
of the vapor laden air from the dryer may be delivered to the fire.
Dated this 28th day of November A.D. 1885.
LYDIA JANE CADWELL.