FEEDER/DISTRIBUTOR APPARATUS FOR GRANULAR COAL

DISPOSITIF D'APPORT-ETALEMENT DE HOUILLE GRANULEE

English Abstract

A FEEDER/DISTRIBUTOR APPARATUS
FOR GRANULAR COAL
ABSTRACT OF THE DISCLOSURE
A feeder/distributor apparatus for granular coal includes
a frame that defines an enclosure having two inlets and one
outlet with one of the inlets receiving granular coal from an
external source for delivery through the outlet to a fluidized
bed combustion reactor. A conveyor is disposed within the
enclosure for receiving the granular coal and conveying the coal
to the vicinity of the outlet. A discharge hopper assembly is
disposed in the outlet for receiving the coal from the conveyor.
The hopper assembly includes a plurality of spaced discharge
outlets and a mechanism for dividing the coal into a plurality
of streams for introduction into the outlets with each so-formed
stream being provided to an inlet of the fluidized bed reactor.
A source of pressurized fluid introduced through the other
inlet provides a pneumatic assist to the flow of coal through
the outlets and to assist in the supression of coal dust.

Claims

The embodiments of the invention in which an
exclusive property or privilege is claimed are defined
as follows:
1. A feeder/distributor apparatus for feeding
granular coal or a mixture of granular coal and limestone
into the inlets of a fluidized bed reactor, said apparatus
comprising a frame defining an enclosure having two inlets
and one outlet, an inlet duct connected relative to said
frame and registering with one of said inlets for supplying
granular coal to said enclosure in a substantially vertical
direction, conveying means within said enclosure for
receiving the coal from said one inlet and conveying
the coal in a substantially horizontal direction to the
vicinity of said outlet, a discharge hopper assembly
extending through said outlet for receiving the coal from
said conveying means, said hopper assembly defining a
plurality of spaced, vertically extending, discharge outlets
for discharging said coal in a vertical direction, means
associated with said discharge hopper for dividing said
material into a plurality of streams for introduction into
said outlets, said other inlet located directly above
said discharge hopper, and an air duct associated with
said other inlet for introducing a pressurized fluid flow
in a vertical direction downwardly into the coal as it
flows through said discharge hopper assembly to assist the
flow of coal through said outlets.

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2. The apparatus of Claim 1 wherein said inlet duct is
adapted to be vibrated to facilitate the distribution and flow
of coal through said first-mentioned inlet and to said conveying
means.
3. The apparatus of Claim 1, wherein said dividing
means comprises a plurality of divider bars disposed within
said discharge hopper assembly and defining a plurality of flow
passages communicating with said outlets.
4. The apparatus of Claim 1, wherein the cross-sectional
area of said discharge hopper assembly tapers from a relatively
large area at its inlet end to a relatively small area at said
outlets.

5. The apparatus of Claim 2, wherein the cross-sectional
area of said discharge hopper assembly tapers from a relatively
large area at its inlet end to a relatively small area at said
outlets.

6. The apparatus of Claim 3, wherein the cross-sectional
area of said discharge hopper assembly tapers from a relatively
large area at its inlet end to a relatively small area at said
outlets.
7. The apparatus of Claim 1, Claim 2 or Claim 3, wherein
said granular coal flows by gravity from said inlet duct, through
said first-mentioned inlet and onto said conveying means.
8. The apparatus of Claim 4, Claim 5 or Claim 6, wherein
said granular coal flows by gravity from said inlet duct, through
said first-mentioned inlet and onto said conveying means.
9. The apparatus of Claim 1, Claim 2 or Claim 3, wherein
said granular coal flows by gravity from said conveying means to
said discharge hopper assembly.

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10. The apparatus of Claim 4, Claim 5 or Claim 6,
wherein said granular coal flows by gravity from said conveying
means to said discharge hopper assembly.
11. The apparatus of Claim 1, Claim 2 or Claim 3,
wherein said granular coal has a varying particle size range.

12. The apparatus of Claim 4, Claim 5 or Claim 6,
wherein said granular coal has a varying particle size range.

13. The apparatus of Claim 1, Claim 2, or Claim 3,
wherein said conveyor means comprises an endless belt, and
pulley means for driving said belt.

14. The apparatus of Claim 4, Claim 5, or Claim 6,
wherein said conveyor means comprises an endless belt, and
pulley means for driving said belt.

15. A feeder/distributor system for dividing a single
flow of granulated coal or a mixture of granulated coal and
limestone into a plurality of streams and feeding the so-formed
streams into the fuel inlets of a fluidized bed reactor, said
system comprising:
an enclosure having first and second inlets and an
outlet, said first inlet for connection to a first inlet duct
for receiving a flow of granulated coal or a mixture of
granulated coal and limestone, conveying means within said
enclosure positioned therein to receive the granulated coal or
mixture from said first inlet and for conveying same towards
and into said outlet, a discharge hopper assembly
extending through said outlet for receiving the so-conveyed
granulated coal or mixture from the conveying means, said dis-
charge hopper assembly including means for dividing the coal
or mixture received from the conveying means into a plurality
of streams and a plurality of discharge outlets for receiving
the so-divided streams for discharging same therefrom into

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conduits, said second inlet located directly above said discharge
hopper, said second inlet for connection to a second inlet duct
to a source of pressurized fluid so as to introduce a flow of
pressurized fluid into the granulated coal or mixture as it flows
through said discharge hopper to assist the flow thereof, the
direction of flow of the pressurized fluid flow substantially the
same as the direction of flow of the granulated coal or mixture,
said conduits connected to the inlets of a fluidized bed reactor
to introduce the streams of granulated coal or mixture thereto.

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Description

11'7~0~

~ FEEDE~/DXSrrE~IBUTOR ~PPA:E~TUS
FOR GRANULAR COAL

B~CKGROUND OF THE INVENTION
-
The presen-t invention relateS -to a feeder/distributor
apparatus and, more particuIarly, to such an apparatus Eor
distributing granular coal and/or limestone from a single s-tream
source to a plurality of muItiple outlet streams, which, in turn,
feed a fluidized bed combustion reactor.
Many applications exist for a feeder/distributor apparatus
which receives a single relatively large stream of granular coal
and diviaes the stream into a plurality of muItiple streams for
introduction into external equipment such as a fluidized bed
reactor. For example, many weigh-belt feeders are on the market
for feeding a granular material having a relatively wide particle
size range, such as coal and/or limestone, into a fluidized bed
boiler or combustor, or the like. However, the great ma]ority
of these devices, although providing proper metering and con-
trolling of the flow rate of the materials, only discharge the
stream of material from a single outlet. Since fluidized bed
reactors have nllmerous fuel inlets, for example, 30 to 60 inlets,
the single outlet feeders are not suitable for the con-tinuous
introduction of metered fuel into a fluidized bed reactor.


SUMMARY OF THE INVENTION
It is therefore an object of the present invention to
provide a feeder/distributor apparatus of the above type in
which granular coal covering a relatively wide range of particle
sizes is received from a single stream source and discharged
through a plurality of muItiple outlets for subsequent intro-
duction into the plural inlets of a fluidized bed reactor.

It is a further object of the present invention to pro-
vide an apparatus of the above type in which a pneumatic assist

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is provided in c~nnection with -the muItiple outlets of the
apparatus to assist the flow of coal through the outle-ts and to
assist in the supression of coal dust.
Toward the fulfillment of these and other ob~ects, the
present invention contemplates a feeder/distributor apparatus
for feeding granuIar coal or a mixture of granular coal and
limestone into the inlets of a fluidized bed reactor~ The
apparatus comprises a frame defining an enclosure having two
inlets and one outlet, with an inlet duct connected relative
to the frame and registering with one o~ the inlets for supplying
granular coal to the enclosure in a substantially vertical dir-
ection. A conveying means within the enclosure receives the
coal from the one inlet and conveys the coal in a substantially
horizontal direction to the vicinity of the outlet. A discharge
hopper assembly extends through the outlet for receiving the coal
from the conveying means and defines a plurality of spaced,
vertically extending, discharge outlets for discharging the coal
in a vertical direction. A means associated with the discharge
hopper divides the material into a plurality of streams for
introduction into the outlets, with the other inlet located dir-
ectly above the discharge hopper. An air duct associated with
the other inlet introduces a pressurized fluid flow in a vertical
direction downwardly into the coal as it flows through the dis-
charge hopper assembly to assist the flow of coal through the
outlets.
A source of pressurized fluid is associated with the other
inlet for introducing a pressurized fluid into the coal as it
flows through the discharge hopper assembly to assist the flow
of coal through the outlets and to suppress coal dust. The so-

formed plural streams of coal are then conducted to the pluralinlets of a fluidized bed reactor to thereby provide metered and




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controlled in-troduc-tion oE coal into -the reactor.


BRIEF DESCRIPTION OF THE DRAWINGS
-
The above brief description, as well as further ob~ects,
features, and ad~antages, of the present invention wl~l be more
fuIly appreciated by reference to the following detailed
description of a presently preferred but nonetheless illustrative
embodiment in accordance with the present invention, when taken
in conjunction with the accompanying drawings wherein:
FIG. 1 is a vertical sectional view showing the apparatus
of the present invention;
FIGS. 2 and 3 are sectional views taken along the lines
2-2 and 3-3, respectively, of FIG. l; and
FIG. 4 is a horizontal sectional view taken along the line
4-4 of FIG. 1.

DESCRIPTION OF THE PREFERR~D EMBODIMENT
As shown in FIGS. 1 and 2 of the drawing, the reference
numeral 10 refers in general to.a frame which defines an enclosure
having two inlets 12 and 14 at the upper portion thereof and an
outlet 16 at the lower portion thereof. An inlet duct 18 communi-

cates with the inlet 12 and is connected to the frame 10. Theduct 18 is adapted to receive granular or particulate coal and/or
limestone which may be of varying sizes such as crushed coal of
a relatively wide particulate size range or a mixture of crushed
coal.and limestone. The duct 18 may be vibrated by an external
power source (not shown) in a conventional manner to insure a
more even distribution of the granular caal as it flows
through the duct and the inlet 12 into the interior of the
enclosure defined by the irame 10.

An endless conveyor belt 20 is disposed within the enclo-

suredefined by the frame lO.and is entrained about two pulleys22 and 24. The pulley 22 is located below the inlet 12 so that


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the left end of the upper surface of the belt 20, as viewed in
FIG. 1, receives the granular coal from the inlet and the pulley
24 is located over the outlet 16 so that the material is dis-
charged from the right end of the upper surface of the belt
into the outlet. The pulley 24 is connected to a drive mechanism,
such as an electrical motor 26, by a drive belt 28 so that the
upper portion of the belt 20 moves in a direction from left to
right and therefore transports ~he granular coal from the inlet
12 to the outlet 16.
A discharge hopper assembly, shown in general by the
reference numeral 30, is disposed within the outlet 16 and is
better shown in connection with FIGS. 3 and 4. In particular,
the hopper assembly 30 includes.an inlet mouth portion 30a
which is disposed immediately below the discharge end of the
conveyor belt 20 for receiving the granuIar coal and a plurality
of spaced outlets 30b at the lower portion thereof. A plurality
of spaced, parallel flow divider bars 32 are disposed w~thin the
discharge hopper.assembly 30 and define a plurality of flow
passages communicating with the inlet 30a and the outlets 30b.
As noted from FIG. 1, the cross section of the assembly 30 is
tapered from the relatively large inlet 30a to the relatively
small outlets 30b, with the f.low divider bars being shaped
accordingly. As shown schematically in FIG. 3, the outlets 30b
are each connected by.a coal carrying conduit 100 (only four of
which.:are shown in broken-line illustration) to a corresponding
one of a plurality of coal inlets 102 of a coal-fired fluidized
bed reactor 104.
A fluid inlet duct 36 communicates with the inlet 14 of
the enclosure defined by the frame 10 and is in vertical alignment
with.the discharge hopper assembly 30. The duct 36 is connected
to a source (not shown) of pressurized fluid such as air or flue

gas and directs the fluid into and through the granular coal
flowing through the hopper assembly 30 to provide a pneumatic


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assist for the materlal as 1~ passcs thro~c3h the hopp~r assembly
30 and the outlets 30b and to suppress -the form~-tion of coal dus-t
consequent to the falling motion of the coal particles.
In operation, the granular coal or a mixture of granular
coal and limestone is fed from an external source (not shown) into
and through the duct 18 where it enters the inlet 12 of the
enclosure defined by the frame 10. The duct 18 may be vibrated
to insure a uniform distribution onto the upper surface of the
conveyor belt 12 which moves continuously within the enclosure
defined by the frame 10 to transport the coal from the area
adjacent the inlet 12 to the discharge hopper assembly 30. The
pressurized fluid is injected through the inlet 14 from the inlet
duct 36 to aid in conveying the coal through the discharge hopper
assembly 30. The coal is divided into plural streams or portions
by the flow divider bars 32 as it passes downwardly through the
assembly 30 and through the outlets 30b for providing several
discharge streams into respective conduits 100 and into respective
inlets 102 of the fluidized bed reactor 104.
It is thus seen that the device of the present invention
enables a uniform discharge of a single source granuIar coal
into a plurality of muItiple outlets while insuring a uniform
distribution of the material through the entire system.
A latitude of modification, change and substitution
is intended in the foregoing disclosure and in some instances
some features of the invention will be employed without a
corresponding use of other features. Accordingly, it is
appropriate that the appended claims be construed broadly and
in a manner consistent with the spirit and scope of the invention
herein.




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