Note: Descriptions are shown in the official language in which they were submitted.
104'~ S
This invention is directed to apparatus for disposing
of combustible and waste material.
The disposal of hydroscopic combustible material,
such as scrap wood and bark, needs to be carried on at a
temperature of about 6~0F. or somewhat lower to prevent flash-
ing off certain volatiles which at or above that te~perature
level cause the formation of a noxious blue smoke.
The object of this invention is to provide for the
efficient disposal of combustible material without generating
and releasing to the atmosphere noxious fumes or polluting the
atmosphere with particulate material.
The present invention provides apparatus for disposing
of combustible material comprising a first circulating system
having a blower to propel air as a carrier medium in said first
system, a material reducing mill in said first system, means to
feed material into said first system adjacent said ~ill for
reduction in said mill and flow with the air in said first
system, a cyclone separator in said first system having an outlet
connected into the suction side of said blower and an inlet con-
nected to receive reduced material from said mill along with finesand dust in said first system, and said cyclone separator having
a discharge for reduced material that is substantially free of
fines and dust; and a second circulating system having an inlet
connection ad~acent the delivery side of said blower, separator
means for fines and dust connected to said second syste~ inlet,
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second blower having a suction connection at said separator
means and an outlet to atmosphere,a furnace connected into said
second system beyond said separator means in the flow direction
to receive the fines and dust drawn into said second s~stem by
said second blower and dispose of them by combustion, conduit
means connected to said furnace and to said first system adjac-
ent said mill to deliver furnace heat into said first system ~or
material drying purposes, and means connected into said furnace
to admit ambient air to regulate the temperature of the heat of
said furnace.
In operation a large volume of air moves through the
furnaca to provide the needed heat for drying the material to a
state where it can be consumed by serving as a fuelO The air vol-
ume so moved is dust laden, and the apparatus concentrates -the
dust and particulate material for burning, and effec~ively mixes
the combustible products with cleansed air to produce a source of
heat at a controlled temperature level.
The invention will now be described with reference
to the accompanying drawings, in which:
Fig. 1 is a schematic view of one embodiment of appar-
a~us and system for disposing of combustible and waste material
such as wood, barka coal, and the like;
Fig. 1~ is a fragmentary sectional view taken at line
lP~ o:~ FigO l;
FigO 2 is a fragmentary sectional view of a ro~ary
valve providing means for leaking ambient air into the primary
separator to increase the amount of fines passing over with air;
FigO 3 is a schematic view of only a portion of a com
plete system, as depicted in Figure 1, for the purpose of dis-
closing a modified arrangement of apparatusO and
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Fig. 4 is a schema-tic view of a system of apparatus
similar to Fig. 1, but differing in the character of reducing
mill for the material.
Reference will now be directed to Fig. 1 o~ the ac-
companying drawing where there is schematically shown apparatus
for practicing the invention heretofore briefly summarized.
The primary arrangement of apparatus includes a suitable conveyor
10 for bringing the wood chips, bark, coal, and other material to
be reduced to a hopper 11 which directs the material into a feed
unit 12 of conventional feed screw construction having a driving
motor 12A. Any feed means can be used, but it is preferred in
this instance to use a screw feed mechanism and to operate the
unit 12 with the hopper 11 continually filled so as to exclude as
much as possible the inflow of ambient air. The screw feed until
12 delivers the material into an upwardly directed passage 13
which opens at the upper end into an expansion chamber 14. The
passage 13 includes a portion having a venturi throat 15 which
is both an outlet and an inlet for a suitable mill M having a
rotor 17 which is operable to run in either direction.
The expansion chamber 14 above the passage 13 opens
into a conduit 18 which delivers material tangentially into a
conventional cyclone separator 19 where the material flowi~ in
the airstxeam is separated out through a rotary valve 20 and is
collected in a suitable bin B, while the air carrying dust and
fines is delivered through conduit 21 to the suction side of a
blower 22. The conduit 23 from the outlet of the blower 22. The
conduit 23 from the outlet of the blower 22 returns the air to
the mill M at passage 13 below the venturi 15.
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The ap~ratus of Fig. 1 is designed to reduce friable
material such as wood chips and bark to a uniform product which
is delivered into the bin s. The wood chips and bark, delivered
to the hopper 11, are conveyed by the screw feed unit 12 into
the passage 13. The blower 22 is, of course, operated to create
a circulation or flow of air upward through the venturi 15 and
around the circuit including the expansion chamber 14, the
cyclone separator 19 and the return conduit 21 to the blower 22.
A damper 24 is operably mounted in the conduit 21 near the suc-
tion inlet of the blower 22 so that the velocity of the circu~
lating air through the venturi 15 can be regulated as desired.
The material delivered to the passage 13 contains a certain per- :
centage of dust and fines along with the larger chips, chunks
and pieces. The flow through the venturi 15 is, therefore,
regulated by the damper 24 so that the fines are caused to float
upwardly into the expansion chamber 14 while gravity causes the
larger and heavier particles and pieces to fall through the
venturi 15 where it is ground and reduced by the hammer rotor 17
and flung backwardly t.hrough the venturi 15, and exhausted by the
flow being delivered through the conduit 23 below the venturi 150
The flow through the passage 13 and expansion chamber 14 will con-
tain a fluid medium composed of dust and fines suspended in air
and this medium will traverse the conduit 18 to the c~clone
separator 19 where a desired separation occurs and airborne dust
and fines are delivered through the top outlet conduit 21 while
the material separated out is collected in the bin B.
Control over the amount of dust and fines carried out of
c~clone separator 19 through the air exhaust box 25 is provided by
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means of a hinyed skimmer ~ 26 (E'ig. lA) which may be a~-
justably positioned more or less into the vortex flow entering
the cyclone 19 from the inl:et conduit 18. The vane 26 is po-
sitionable to skim out the finer or smaller portions of the
material entering the cyclone 19 for flow through the exhaust
box 25 and into the exit conduit 21 and delivery to the blower
22. The delivery side of blower 22 is subject to suction at the
connection of conduit 27 which is connected to a bag separator
28, and the separator 28 is under suction from blower 29 through
conduit 30. The portion of the material skimmed out by the vane
26 for delivery to the separator 28 and eventual delivery through
a rotary valve 31 to a screw conveyor device 32 driven by motor
33 to conduit 34 is conducted to the burner 35 of a furnac~ 36.
Thus the fines extracted by the skimming vane 26 will be consumed
in the furnace 36 to act as fuel and furnish heat for drying
purposes. At the same time selective portions of the material
delivered to the cyclone separator 19 will be collected in the
closed bin B.
Fig. 1~ illustrates one means for selective extraction
of the dust and fines from the chamber of the cyclone separator
19. :~f the skimming vane 26 is not desired, the same effect can
be obtained by creating the unusual leakage of ambient air into
the cyclone charr~ber through the rotary valve 20. For this pur-
pose, the valve 20 (Fig. 2~, driven by suitable motor means A,
has its multi-bladed rotor 20A enclosed between opposed side walls
20B adjustably mounted by bolts 20C to the side plates 20D (one
being seen) of the valve housing mounted at the apex of the
cyclone chamber l9P.. The side walls 2013 can be adjusted toward or
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away from the path of motion o~ the valve blades 20~ to vary the
ambient air leakage into the cyclone chamber apex. The air
leaking into the cyclone is greatest, and the result is that
dust and fines reaching the apex zone are whisked upwardly to the
outlet conduit 1~ while the desired larger particles are exhausted
through the rotary valve to the bin B.
Returning to Fig. 1, the apparatus is arranged with a
furnace 36 which is provided with a standard wood fuel burner 35
to ~hich an outside source of oil or ~as fuel is connected at
pipe 37. Combustion air is supplied into conduit 34 by conduit
; 38 from the blower 39. The furnace 36 has a cyclone chamber 40
lined with a suitable refractory. The cyclone chamber has an in-
let at conduit 41 to deliver the hot gases through conduit 43
into conduit 23 at a junction adjacent the mill M. me furnace
inlet 41 receives a supply of combustible material from conduit
44 which is connected to conduit 27 in by-pass of the bag sepa-
rator 28, and a suitable valve 45 is placed in the by-pass con-
duit 44. A supply of combustion air for the furnace is obtained
through conduit 46 controlled.by valve 47. The amount of air
admitted at conduit 46 is regulated to replace moisture laden air
exhausted from the system at the outlet conduit 48 of blower 29
under the control valve 49.
In employing the furnace 36 with a cyclone chamber 40,
the non-burnables, such as sand, rock and the like, work their
way along the bottom wall and can be exhausted through a dump
chute 50 having a rotary valve 51. The material so dumped can be
collected by a suitable belt conveyor 52 for movement to a dis-
posal station.
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The op~ration of the system of Fig. 1 is to produce
drying heat for the incoming material, and to use portions of
that material as a fuel to produce the heat for drying the pro-
duct portions not used in this system as a fuel. Thus, the in-
coming material at passage 13 undergoes a first sorting step
where the fines capable of floating in a controlled air stream
are moved along to a cyclone separator 19. The larger portions
of the incoming material pass by gravity to the mill M for re-
duction before being returned to passage 13. The second sorting
step takes place in the cyclone separator 19 where the dust and
fines are intentionally passed into the cyclone outlet conduit 21,
thereby keeping this portion of the material out of the product
portion that is discharged to the bin B. The second sorting step
is accomplished either by using the adjustable skimmer vane 26
(Fig. lA) to direct the dust and fines into conduit 21 through
the exhaust bo~ 25, or by closing the vane 26 and adjusting one
or both of the rotary valve side walls 20B (Fig. 2) to allow
leakage of ambient air through the product outlet to sweep the
dust and fines upwardly in the cyclone 19 to the exhaust box 25.
The product collected in bin 20 may be further treated to convert
it to a gaseous fuel.
The flow of dust and fines in the carrier air stream
in conduit 21 and blower 22 is subjected to the suction effect
at the connection of conduit 27 to the outlet conduit 23 of blow-
er 22. The dust a~d fines are drawn off in conduit 27 to the bag
separator 28 by reason of the operation of blower 29 connected to
the bag separator. The air and moisture therein is discharged to
atmosphere at conduit 48, and the fines and dust are discharged
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by the bottom rotary valve 31 into a screw conveyor 32 which
delivers the material into conduit 34. The material flow in
conduit 34, along with amb}ent air from blower 39 is fed to the
burner 35 of the furnace 36. The burner 36 is of the type that
does not allow the passage of a large quantity of air, so the
fuel is, there~ore, burned in a controlled air volume, normally
in the range of about fourteen (14%) percent excess oxygen.
Because of this feature of the burner 36, and the permissible
reduction in size of the bag separator 28, about seventy (70%)
percent of the air, fines, and dust is by-passed at conduit 44
directly to the furnace inlet 41. The entrance of air, fines,
and dust is directed tangentially of the furnace wall, and re-
fractory lining is used to reduce abrasion and heat effect on the
furnace shell. The furnace 36 acts like a cyclone and the dust
and fines are concentrated toward the flame issuing from the
burner 35 where they are consumed to produce the heat that is
conveyed by the air out to conduit 43. The exit heat level is
maintained at about 600F. by adjusting the air admitted at con-
duit 46 past valve a~7,
It has been noted that the material carried into the
furnace 36 contains non-combustible material. This material is
moved by the cyclone action to exhaust chute 50 where it is dis-
charged :lay the rotary valve 51 onto the carry-over conveyor 52.
Also, any oversize particles of material received therein remain
for the time required to effect complete conibustion, as such
material is effectively trapped by the cyclone action and moved
into the flame area under violent mixing conditions. When the
burner flame has been established in the furnace 36, the outside
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fuel source is cut off, and the dust and fines needed to con-
tinue combustion can be supplied in sufficient amounts by ad-
justing the skimmer vane, or by adjusting the rotary valve side
walls 20B to the desired leakage condition.
A modification of the apparatus of Fig. 1 is seen in
Fig. 3 where similar parts and components are similarly enumer-
ated so that only the additional parts and components will be
described. As shown the heat outlet from the cyclone furnace 36
is conduit 43A which is connected directly to a cyclone chamber
53 where the heat level can be more closely controlled and any
particulate material carried out of the furnace 36 will have a
chance to separate out and be discharged through rotary valve 54.
~he control of the temperature level is partly obtained by lead-
ing a portion of the exhaust flow of blower 29 through conduit
controlled by valve 56 to the cyclone 53. The hot gas ~,air)
issuing from the chamber 53 is led by conduit 57 into a junction
(not seen but similar to Fig. 1) with conduit 23 of blower 22
adjacent the mill M.
In the operation of the system of apparatus seen in
Fig. 1, the temperature of the hot gases (air) at the furnace
outlet conduit 43 is desired to be of the order of 600F. so as
to be below the flash temperature of the volatiles in the wood
waste. The temperature is regulated by the quantit~ of air
brought in at conduit 46. In Fig. 2, the cyclone furnace 36 can
operate at a higher temperature for better consumption of the
burnable material. ~hile the temperature of the gases issuing
from furnace 36 at conduit 43A can be considerably higher than
600F., such gases are led into the chamber 53 and mixed with
clean air from conduit 55 so the final gas temperature at cc,nduit
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57 is at the desired level. Further, the cyclone action in
chamber 53 throws out of the gases substantially all of the
parti~ulate material that might be carried out of the furnace.
Turning to Fig. 4, the system of apparatus is similar
to that shown and described in Eig. l, except that the hammer
mill M has now been replaced with a rotary mill RM. This modi-
fied system is suitable for handling such material as coal.
The difference is in the way the hot gases (air) are fed to the
mill RM. A rotary or roller mill RM has the grinding rolls 58
connected to a vertical shaft 59 driven through a reduction gear
train 60 and a belt drive 61 from the motor 62. The motor 62
and drive is disposed in a suitable foundation 63 which supports
the scroll casing 64 surrounding the grinding chamber of the mill
RM. The ca~ing 64 has a plurality of inlets 65 opening to the
grinding chamber, while the casing 64 is connected to the end
of conduit 23. The hot gas supply conduit 43 is joined into con-
duit 23 adjacent the inlet 65. The forced flow of hot gases in
the scroll casing 64 flows into the grinding chamber and carries
the material upwardly past the drive shaft 59 and into the
venturi throat 15 of passage 13 in opposition to the fall of the
heavy material through the venturi throat.
The mill RM is provided with a dump chute 66 opening
from the bottom o:E the grinding chamber to the outside of the
foundation 63 where the material incapable of being easily reduced
is collected on a suitable conveyor 67. A valve 68 normally
closes the chute outlet to avoid impairing the function of the
flow of air to the venturi throat 15.
From the foregoing description it should be apparent
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that the apparatus, in any of its embodiments, is adapted for
the efficient disposal of combustible material without generating
and releasing to the atmosphere noxious Eumes, or polluting the
atmosphere with particulate material.
