Improvements in Apparatus for Drying, Cooking, Processing, and Treating Organic and other Substances.
Year: 1898

page_text: Date of Application, 5th Apr., 1898-Accepted, 11th June, 1898
COMPLETE SPECIFICATION.
Improvements in Apparatus for Drying, Cooking, Processing, and
Treating Organic and other Substances.
I, ABRAHAM THOMAS WELCH, of 351, Equitable Building, in the City of Balti-
more, State of Maryland, and United States of America, Inventor, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to improvements in drying apparatus. The objects of
the invention are to dry, cook, process and treat organic and other substances
rapidly, thoroughly and evenly, by unconfined heat and to subject the substance
to the highest heat on entering the drier, and to a progressively-decreasing degree
of heat as it passes to the discharge end of the drier.
In the accompanying drawing, forming a part of this specification, I have illus-
trated one form of embodiment of my invention, although it is to be understood
that other forms of embodiment thereof may be employed without departing from
the spirit of the same, in these drawings:
Figure 1 is a view, in sectional elevation, of a drier.
Figure 2 is a transverse, sectional view, taken on the line 2-2, Figure 1.
Figure 3 is a similar view, taken on the line 3-3, Figure 1, showing the arrange-
ment of the shelves on the inside of the drum.
Figure 4 is a view of one of the shelves.
Figure 5 is a side view of a modified form of drum.
Figure 6 is a vertical longitudinal section of the gas apparatus.
Figure 7 shows a top plan and an end view of the float.
Figure 8 is a diagram or section showing the position of the float in the
carburetor when the oil has been lowered.
The apparatus to produce gas for heating, is shown in Figures 6, 7 and 8 and
will first be described.
Referring to the drawings, A, designates the carburetor chamber, or box, prefer-
ably made of metal, which chamber is to contain suitable hydro-carbon oil, A¹;.
an oil-supply pipe, a, enters the box and its open end is near the bottom to insure
being sealed by the oil, and the outer end of the pipe is closed by a cap; an air
inlet-pipe a', has a check-valve, a², and enters up through the bottom of the box;
a gas delivery pipe, a³, leads from the top of the box. Within this box is a float, B,
having tight top and sides, downward-projecting ends, and an open bottom; one
downward-projecting end being vertically longer than the other and attached
below to the box by a hinge, b; this short and free end of the float has perfora-
tions, 61, and this end is maintained with its upper part just above the surface of
the oil by one or more air-tight cylinders or buoys, b².
An air-chamber, 63, is thus left in the float above the oil into which the said air-
inlet pipe, a', opens. As the oil is evaporated and produces gas which is carried
off by the pipe, a³, the buoys at the free end of the float are more and more sub-
merged, the float tilts on its hinge, and said free end with its perforations gradually

page_text: sinks deeper into the oil. The float is preferably made narrow at the hinged end
and horizontally broad at the perforated end.
Air in regular quantity and at a uniform pressure passes through pipe, a¹, into
air-chamber, 63; this air is moderately heated by the action of the steam jacket, J,
surrounding a part of the pipe, à¹. The warm air in chamber, 63, discharges over
the buoys, ba, through the perforations, 61, and forces through the oil outside the
float and will create a light foam, spume, or spray, thus forming gas which seeks
the space, a. As the discharge of air through the perforations is mainly hori-
zontal, the oil will be driven before it and this causes a circulation of the oil and
prevents stratification and ensures a continual homogeneousness of the liquid, the
circulation of the liquid causes it to come in contact with the sides of the box,
taking its temperature, and thus keeping the whole at a substantially uniform
temperaturė and preventing refrigeration, and results in a gas-product of
uniform quality. By the delivery pipe, a³, the carbureted air or gas passes off
for use.
This carburetor may be supplied with air by any suitable device that will main-
tain a uniform pressure.
One form of air-supply device is shown in Figure 6; it comprises a weighted
air-holder, C, submerged in liquid, having an air-intake pipe, c, supplying air
under pressure to the holder, this pipe may be connected with an air-blower or
air-compressor, not shown. Attached to the pipe, c, is a blow-off pipe, c¹, having
a valve, ², which is operated by lever, c³, connected with the air-holder, C; this
valve opens when the air-holder is at a certain height, and closes as it sinks. When
the valve, 2, is open the excess of air above what is required to maintain the holder
at its limit of elevation, blows off through the pipe, c¹, thus a uniform pressure
in the air-holder is maintained. The air-discharge pipe, a³, connects with the
air-inlet pipe, a¹, of the carburetor.
A rotary metallic drum or cylinder, D, has secured to its interior circular wall
a plurality of shelves, d, having knife-edges, the shelves increasing in number
from the entrance end to the discharge end thereof,-that is to say, there may
be at the entrance end, say, eight of these shelves, further on sixteen, and at the
discharge end thirty two or any other number. The shelves with knife edges
will carry the material to be dried on the up moving side of the revolving drum,
until it is lifted to an elevation above the horizontal and then the material
will drop through the stream of flame and heat that passes through the cylinder;
at the entrance end where the shelves with sharp edges are fewest in number the
moist material will be carried or lifted up in large masses and upon falling be
subjected to the greatest heat. At each revolution of the cylinder the lifting and
then falling of the material will be repeated; falling on the sharp edges of the
shelves serves to break up the material and divide it; as the material moves for-
ward in the cylinder the increased number of shelves operate to still further divide
the material, and the close assemblage of the shelves near the discharge end
effectually prevents the nearly-dry material from balling or massing. By this
construction and operation the moist material to be dried is subjected to an inter-
mittent heat, that is, the material is in the heat only when falling; it will be
subjected to the highest heat on entering the drier, and then as it moves toward
the discharge end to a progressively-decreasing degree of heat. The exterior of the
cylinder has surrounding bands, e, which rest on rollers, e¹, e, mounted on a bed-
piece, f, below; one or both of the rollers may have flanges, as the one, e¹. The
bed-piece, f, at the entrance end of the cylinder is supported by an upright, f,
and at the discharge end by screw-jacks, f. By altering the screw-jacks the
cylinder may be placed in an inclined position, that is lowest at the discharge end,
and this inclination may be varied to cause a slower or faster movement of the
material through the revolving cylinder.
The entrance end of the cylinder is closed by a stationary head-plate, g, and
the inclined cylinder is kept against this plate by a band gear, g¹, secured to the
exterior of the cylinder and on each side by a roller, ga, pressing against the band;

page_text: the roller is journalled in an adjustable box, g³, on a standard, g, and a screw, g,
bears against the box and presses the roller to the band. The teeth of the band-
gear, gl, are engaged by a bevel-gear, h, driven from a suitable source of power.
The head plate, g, is provided with a hopper, E, and an opening in the head allows
the material to pass from this hopper into the cylinder, the opening being covered
by a hinged door, i, which opens inwardly, but closes by gravity, to prevent escape
of heat and odours. Any suitable means may be employed for feeding the moist
material to the drum, such as a toothed feed or disintegrating roller, ³, arranged
in the hopper, E.
The heat is supplied to the interior of the cylinder by a combustion-chamber, F,
which opens through the head-plate, g. Mounted upon the outer.open end of the
combustion chamber is a movable collar, ¹, the function of which is to increase
or diminish the draught or pull on the flame issuing from the gas burner, G, the
latter being designed to keep the flame circular around the air-pipe, aº, which is
central in the burner and projects beyond and into the combustion chamber. The
circular flame issuing from the burner is kept distinct in its form by the central
forced air from pipe, a, and the surrounding induced air entering the open end
of the combustion chamber; this arrangement prevents the too sudden cooling
of the gas by the admixture therewith of atmospheric air inside and out, and
serves to heat the air gradually after its inlet to the combustion-chamber and before
its outlet from the end that connects with the cylinder. Perfect combustion will
be produced at the end of the chamber, F, which opens into the cylinder. If the
collar, ¹, is moved close to the burner, G, there will be a strong pull on the flame
from the burner, and if the collar is moved back, so as to increase the space the
pull will be diminished, thus the projection of the flame into the cylinder may
be varied. The heating medium or fuel, in this instance, is gas, the same being
supplied from the carburetor, A, through a pipe, a³, to the burner; and tapped
into this pipe, a³, is a by-pass pipe, j, terminating adjacent to the open end of the
gas-burner, and constituting a pilot burner therefor; and on both these pipes, a³,
and, j, there is a flame-arrestor, j, to prevent the flame from going back into the
pipe; a valve, 2, is on the air pipe, a, and a similar valve on the gas-pipe for
the purpose of regulating the supply of air and gas to produce the flame. In
Figure 1 the air is supplied from an ordinary airometer, C, into which steam is
supplied through a pipe, k, leading from a suitable source of supply, this is a
modification of the device shown in Figure 6. On this steam pipe is an injector, k¹, .
which operates to force air and steam with great force into the airometer, C¹, and
on the pipe, k, within the latter is arranged an inverted dish-shaped plate, k³, as
a deflector; this has peripheral openings; the steam and air escape into the water
contained in the airometer, from a chamber, ³, provided with openings; the
steam condenses and the air passes through the peripheral openings into the top
of the airometer. In order to drain partial condensation in the pipe, k, the latter
is provided with a trap, k. To regulate the supply of steam to the airometer in
proper quantities the pipe, k, is provided with a valve, 5, which has a lever, l, and
to this lever is connected a vertical rod, /, which passes loosely through an arm, 12,
5 secured to the top of the airometer. Upon the rod, l, are two stops, m, which
are separated by a distance equal to the height the drum of the airometer may lift
and drop. When the airometer has lifted to its limit the arm, 12, by contacting
with the upper stop, m, will litt the valve-lever, 1, and thereby close the valve, k,
and, when the airometer sinks to its limit, the arm, 12, will contact with the lower
stop, m, and open the valve. By this arrangement, the supply of steam and air
to the airometer in proper quantities is automatically governed. Within the
airometer is an outlet pipe, a³, with its upper end above the water-level, the other
end, a', of this pipe is open under the float, B, of the carburetor. This air-pipe
has a four-way union, n, and attached to this union are two pipes, one of which, a,
passes through the burner, G, and into the combustion-chamber, F, and the other
pipe, a, enters a conveyor-pipe, H, presently to be described.
At the discharge end of the cylinder is arranged a chute, I, which delivers into

page_text: a cylindrical screen, o, inclosing a rotary shaft, p, carrying brushes, p¹, and a
pulley, p², which may be driven from any suitable source of power. Below the
screen is an opening, q, into the conveyor-pipe, H, which latter may lead to any
suitable point of deposit, as into a room, and the discharge end of the pipe is flared
at, r, in order to reduce the speed of the discharging material and thereby obviate
producing dust. The object of the cylindrical screen is to pulverize the dried
substance, so that any remaining moisture will be driven off by the air-blast from
pipe, a. The discharge end of the drum is incased by a hood or dust arrestor, L,
immediately above the chute, I; this hood at top and sides constitutes about three-
quarters of a circle, and opens at its bottom into the chute. The top, sides and
end of the hood are perforated and the perforations are kept free from accumulation
of lust by means of an L-shaped brush, s, carried by the discharge end of the
drum. Thus, as the drum revolves, this brush will scour the perforated top, sides
and end of the hood. The dust which escapes to the outside of this hood, passes
into a dust room, N, provided with a flue or stack, P, which is larger than necessary
to carry off merely the vapors from the drier. The upper part of walls of this
room is provided with openings, t, by which atmospheric air can pass to the interior
of the room, and chill and settle the dust, afterwards to be collected.
In Figure 5 is shown a form of drum in which the fine particles of material may
be separated from the coarser particles and be removed from the drum when
quickly drying is required so as to obviate waste of heat and also injury to the
material. This drum has a series of holes or screens, u, located, preferably, about
the middle of the length of the drum, and another series, ¹, at the discharge end.
By this means the fine, dry, material of some substances can be separated from
the coarser, damp material."
Arranged at any point above the cylinder is a tank, Q, for containing sulphuric
acid, and leading therefrom is a pipe, v, which enters through head-plate, g, into
the cylinder, in this instance, just below the hopper opening and terminates within
at a suitable point. This pipe, v, carries a chamber w, which will contain one
charge of acid, and above and below this chamber the pipe has a valve, r, ¹, the
first operating to cut-off the supply of acid from the tank, Q, to the chamber, w,
and the latter to permit flow of acid from the chamber into the cylinder; a
vent pipe, y, projects up and permits free escape of acid from the chamber.
stated the chamber, w, will contain a quantity of acid sufficient to process a pre-
determined amount of material, so that undue waste of the acid will be avoided,
as only a quantity sufficient for accomplishing the objects aimed at will be admitted
to the cylinder at one time.
As
The apparatus herein described may be employed for drying many different
materials, but is particularly adapted for processing fish, which is accomplished
by subjecting the fish, when wettest, alternately to high and low degrees of heat,
the heat progressively-decreasing as the material nears the discharge end of the
cylinder. It will thus be seen that by this arrangement there will be no danger
of scorching or burning the fish, as the heat decreases in direct proportion as the
moisture evaporates. By the employment of the shelves, the material will be
picked up and repeatedly dropped through the flame or heat to the bottom side
of the cylinder; thus the material is subjected to intense heat only for brief
periods; it is out of direct contact with the heat for a greater period than it is in
direct contact with it, this longer interval of time, in which the material is out of
direct contact with the flame, being sufficient to permit it to thoroughly absorb
the heat, which will thus pass through the entire mass. After the fish has moved
a distance equal to, say, one-sixth of the length of the cylinder, or at a point where
the fish is cooked, the sulphuric acid is let into the cylinder, and, by reason of the
moist condition of the fish, will be readily mixed and soaked into the fish and
bones. The superheated steam quickly expands the bones and prevents too sudden
drying and allows dissolving of the bones by the moist acid. The dry material
on discharging passes to the screen, and is there finely broken
up, and.
ing moisture will be thoroughly eliminated by the blast from the pipe, a'.
any remain-

page_text: When the material to be dried enters the cylinder and is subjected momentarily
to the intense heat, any light particles of material that may separate from the mass
will at once be blown by the air which is forced from pipe, as, through the cylinder;
at all stages the draught through the cylinder is sufficient to carry the light
particles forward. In the operation of this apparatus the wall of the cylinder is
heated but comparatively little and the exterior surface of the cylinder will
promptly radiate any heat it receives, whereby in practice the cylinder does not
become heated; the material that is being tumbled within the cylinder is hot,
but as the latter is not, the material will not stick or adhere thereto.
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. The combination in a carburetor of a vessel to contain oil; a float in said
vessel having outlets for air into the oil of the full width of the vessel, said outlets
opening in one direction only, below the plane of the liquid surface and dis-
charging air into the liquid only in one direction to create a constant circulation,
substantially as described.
2. The combination of a closed vessel to contain hydro-carbon liquid and pro-
vided with a delivery pipe; an open bottom float having top, sides and one end
closed; hinged at the closed end and perforated at the other end, and an air-inlet
pipe opening in the vessel beneath the float, substantially as described.
3. The method of preventing refrigeration and stratification of carbureting
liquid, effecting equilization of temperature of the surface of the liquid with its
body, which consists in causing motion of the liquid onward and return, by intro-
ducing the aeriform fluid into the liquid in one direction only and on a line the
entire width of the vessel containing the liquid, substantially as described.
4. The method of drying material consisting in subjecting the material to a
tumbling or vertically-rotary movement and while in its most moist condition apply
the highest degree of heat and then as it gradually dries continuing said move-
ment and subjecting it to a constantly decreasing degree of heat.
5. The method of drying material consisting in subjecting the material to a
tumbling or vertically rotary movement and to heat for brief periods only, and
alternating each period of heat with a period of withdrawal from the heat, so that
the material is repeatedly in and out of the heat.
6. The herein described method of drying material consisting in subjecting
the same, in a revolving drum or cylinder alternately to high and low degrees of
direct heat for brief periods only, the heat progressively decreasing as the material
nears the point of discharge, substantially as described.
7. A drier comprising a revoluble drum having its interior circular wall pro-
vided with shelves or knives, the same increasing in number from the inlet to the
exit end of the drum, substantially as described.
8. The combination of a revoluble drum; an upright stationary head-plate at
the entrance end of the drum; a burner and combustion-chamber opening through
said head-plate, and a pipe also at the entrance end for supplying hot air under
pressure.
9. The combination of a horizontal or inclined revoluble drum; means to change
the inclination of the drum; shelves or knives within the said drum; a burner to
project flame into one end of the drum; and an inlet to admit the material to be
dried at the same end as the burner.
10. An apparatus for drying material, consisting of a revoluble cylinder; means
for supplying heat into one end; an acid supply in connection with the cylinder;
and means for gauging the supply of acid thereto.
11. The combination with the drier cylinder, of a gas-burner and an air-pipe
to deliver air under pressure somewhat ahead of the gas or oil-flame to prevent
chilling the flame and imperfect combustion, substantially as described.

page_text: 12. The combination of a drier cylinder; a combustion chamber opening into
one end of said cylinder; a gas-burner to deliver its flame into said chamber;
and an air pipe central through the gas-burner and projecting beyond the burner
into the said chamber.
13. The herein-described method of treating bones, processing fish, or other
natter, which consists in utilizing superheated steam under atmospheric pressure
in the presence of flame, in connection with sulphuric acid.
Dated this 29th day of December 1897.
ABRAHAM THOMAS WELCH.