Title of Invention

A RIFFLE DISTRIBUTOR ASSEMBLY FOR DELIVERING PULVERIZED SOLID FUEL FROM AN EXHAUSTER

Abstract A riffle distributor assembly for influencing the travel properties of a material feed stream 42 moving between a pulverizer 14 and a furnace 12 is part of a feed path 36 having one duct 44A having a branch entry 66A and another branch duct 44C having a branch entry 66C both downstream of upstream passage peripheries UPZ defined between adjacent intake vanes 114 through which the feed stream of the material 42 travels in two segregated portions. A motor drive assembly 58 moves the intake vanes 114 relative to the incoming flow reference axis IFA, whereupon intake areas defined between adjacent intake vanes 114 moves relative to the incoming flow reference axis IFA such that the travel properties of the one portion of material in the one branch duct 44A are different than its travel properties before the movement of intake areas defined between adjacent intake vanes 114.
Full Text RIFFLE DISTRIBUTOR ASSEMBLY FOR A FOSSIL FUEL FIRED
COMBUSTION ARRANGEMENT
BACKGROUND OF THE INVENTION
The present invention relates to a riffle distributor assembly for a fossil
fuel fired combustion arrangement and, more particularly, to a riffle distributor
assembly for a fossil fuel fired combustion arrangement of the type having fossil
fuel delivery systems that deliver pulverized coal to coal fired steam generators.
Coal fired furnaces are typically provided with a plurality of ducts or pipes
through which pulverized coal and air is directed to a plurality of fuel-air
admission assembhes arrayed in respective vertically extending windboxes. The
windboxes are disposed in one or more walls of the furnace and each introduces
coal and air into the furnace.
Pulverized coal firing is favored over other methods of burning coal
because pulverized coal bums like gas and, therefore, fires are easily lighted and
controlled. Such systems may include one or more pulverizers, also referred to as
mills, that sire used to grind or comminute the fuel or, alternatively, may not
include any pulverizer because a supply of pulverized coal available.
The pipes directing the coal to the respective windboxes are large and
cumbersome. Typically the pipes are provided with large couplings or bolted
flanges to couple the end abutting axially adjacent portions together. The normal
nozzle assembly requires regular maintenance because the pulverized coal has a
severe erosive effect. A typical pulverizer will move between 7 and 50 tons of
coal every hour. The coal typically moves at a velocity of 75-90 feet per second
within the fuel transport pipe.
A typical coal distribution system includes a number of distributors
intended to split the flow of air and pulverized coal into two discrete pipes. It is
desired that the distributors take the homogeneous mixture of pulverized coal and
deliver identical quantities of that homogeneous flow to each of the two discrete
pipes. Each of these distributors is a Y-shaped duct. Each of these Y-shaped ducts
has an inlet and two outlets. US Patent No. 5,934,205 to Gordon et al discloses a
Y-shaped distributor body and a splitter disposed in the distributor body for
dividing a flow of pulverized coal between first and second outlets.
In connection with the feed of pulverized coal to the feed burner nozzles of
a combustion chamber, US Patent No. 6,055,914 to Wark notes that an exhauster
fan first throws the coal radially into a primary discharge chute and that the flow
of coal/air leaving the exhauster fan is uneven, whereby the coal/air flow to the
burners tends to be light on one side or wall of the chute and heavy on the other
side or wall of the chute in terms of both particle size and distribution.
US Patent No. 6,055,914 to Wark describes a prior art solution which
involves providing "riffle boxes" in the chute between the fan and the burners. A
riffle box is a series of vertical, spaced plates separated by angled separator bars
with alternating orientation from plate to plate and US Patent No. 6,055,914 to
Wark notes that, in accordance with one theory, it is believed that the separator
bars on one plate will deflect the coal in one direction, while the separator bars on
adjacent plates will deflect the coal in the opposite direction, thereby splitting and
redistributing the flow for a more homogeneous mixture. It is further noted in this
reference that the typical arrangement is to provide a series of riffle boxes, with a
first riffle box splitting the flow like a "Y" into two chute branches, and a
subsequent riffle box on each of the first two branches splitting the flow again into
a total of four chutes. Each chute typically fuels one of four comer-mounted
burners in a tangentially-fired combustion chamber.
US Patent No. 6,055,914 to Wark notes that the riffle boxes have proven
ineffective in providing a more homogeneous mixture to the burners, and the
coal/air flow reaching the four combustion chamber burners differs significantly
from burner to burner. The reference cites several problems which result from a
riffle box anangement: too lean a mixture at a burner can create NOX; oversized
particles and inefficient burning create LOI (loss on ignition) contamination of the
ash byproduct and reduced combustion efficiency; and, perhaps most importantly,
the out-of-balance burner flow distorts the combustion chamber fireball from the
ideal spherical shape to an undesirable elliptical shape, creating hot and cold spots
in the boiler tubes and causing gas control problems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a riffle distributor
assembly for a fossil fuel fired combustion arrangement that will advantageously
substantially uniformly distribute a single stream of fossil fuel into a pair of fossil
fuel branch feed paths.
Another object of the invention is to provide a riffle distributor assembly
for a fossil fuel fired combustion arrangement that permits more precise and
reliable control of the distribution of the material between two or more branch
feed paths.
A further object of the present invention is to provide a riffle distributor
assembly for a fossil fuel fired combustion arrangement that distributes material
between two or more branch feed paths in a manner which minimizes any loss of
pressure.
An additional object of the present invention is to provide a riffle
distributor assembly for a fossil fuel fired combustion arrangement of the type
having fossil fuel delivery systems that deliver pulverized coal to coal fired steam
generators such that the riffle elements will advantageously substantially
uniformly distribute a single stream of pulverized coal into a pair of pulverized
coal branch feed paths.
In accordance with one aspect of the present invention, it has now been
found that these and other objects of the invention may be attained in an apparatus
for influencing the travel properties of a material moving between a material
supply source and a delivery location which includes means forming a feed path
along which material travels as the material is enroute from the material supply
jource to the delivery location and a riffle distributor assembly. In accordance
vith further details of the one aspect of the present invention, the feed path passes
through an upstream passage and the feed path includes one branch having a
branch entry downstream of the upstream passage and another branch having a
branch entry downstream of the upstream passage. The stream of material travels
through the upstream passage thereafter separating into at least two portions with
one portion of the material entering the one branch through its branch entry and
thereafter traveling along the one branch and another portion of the material
entering the another branch through its branch entry and thereafter traveling along
the another branch in a manner in which the another portion of the material and
the one portion of the material are segregated from one another during their
respective travel along the one branch and the another branch. Also, the riffle
distributor assembly is movable along a lateral axis perpendicular to the reference
axis such that the one portion of the material and the another portion of the
material, prior to their respective segregated travel along the one branch and the
another branch, are comprised in unseparated manner in the stream of material as
it travels through the upstream passage and the portions of the material thereafter
travel in segregated manner in their respective branches with the travel properties
of the one portion of the material in the one branch being different than its travel
properties before the movement of the one branch entry relative to the reference
axis.
According to another aspect of the present invention, the material feed
apparatus is configured for cooperation with an associated furnace having the
capability of burning coal which is delivered thereto as a mixture of pulverized
coal and air.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a front plan view, in partial section, of a fossil fuel combustion
unit having a solid fuel pulverizer and exhauster system and a furnace for
combusting a pulverized solid fuel and showing the one embodiment of the
material feed apparatus of the present invention in its installed position in line
between the solid fuel pulverizer and exhauster system and the furnace;
Figure 2 is an enlarged perspective view, in partial section, of one
embodiment of the material feed apparatus of the present invention shown in its
installed position in line between the solid fuel pulverizer and exhauster system
and the furnace of the fossil fuel combustioin unit shown in Figure 1 with the
upstream passage periphery thereof in an initial upstream position during an initial
material feed period;
Figure 3a is an enlarged perspective view, in partial section, of one
embodiment of the material feed apparatus of the present invention shown in its
installed position in line in Figure 1 and showing with the upstream passage
assembly thereof in an non-offset upstream position during an initial material feed
period;
Figure 3b is a side elevational schematic view of the riffle elements of the
upstream passage assembly in the non-offset upstream position of the upstream
passage assembly shown in Figure 3a;
Figure 4a is an enlarged perspective view, in partial section, of one
embodiment of the material feed apparatus of the present invention shown in its
installed position in line in Figure 1 and showing with the upstream passage
assembly thereof in a right-hand offset upstream position during a subsequent
material feed period;
Figure 4b is a side elevational schematic view of the riffle elements of the
upstream passage assembly in the right-hand offset upstream position of the
upstream passage assembly shown in Figure 4a;
Figure 5a is an enlarged perspective view, in partial section, of one
embodiment of the material feed apparatus of the present invention shown in its
installed position in line in Figure 1 and showing with the upstream passage
assembly thereof in a right-hand offset upstream position during yet another
subsequent material feed period;
Figure 5b is a side elevational schematic view of the riffle elements of the
upstream passage assembly in the right-hand offset upstream position of the
upstream passage assembly shown in Figure 5a;
Figure 6 is an enlarged perspective view of the riffle element plates of the
one embodiment of the material feed apparatus of the present invention shown in
its installed position in line in Figure 1 and showing as well the drive motor
assembly for adjustably positioning the intake vanes of the riffle element plates;
Figure 7 is an enlarged perspective exploded view, in partial section, of
another embodiment of the material feed apparatus of the present invention shown
in its installed position in line between the solid fuel pulverizer and exhauster
system and the furnace of the fossil fuel combustion unit shown in Figure 1;
Figure 8a is a side elevational sectional view of one modification of the
one embodiment of the material feed apparatus of the present invention showing
dual deflector plates mounted between each adjacent pair of the riffle element
plates; and
Figure 8b is a perspective view of the one modification of the material
feed apparatus of the present invention shown in Figure 8a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The material feed apparatus of the present invention will be described in
detail in connection with the operation of the two embodiments of the material
feed apparatus of the present invention to deliver a pulverized solid fuel and air
mixture to a combustion vessel for combustion of the pulverized solid fuel in a
combustion process. However, before the embodiments of the material feed
apparatus of the present invention are described in detail, reference is had to
Figure 1 for a brief description of the components of the combustion process
arrangement with which the two embodiments of the material feed apparatus of
the present invention are specifically configured to operate.
the solid fuel that is pulverized within the pulverizer 14 is entrained therewithin in
an airstream and while so entrained therein is conveyed from the pulverizer 14
through the exhauster inlet duct 24 to the exhauster 16. The airstream with the
pulverized solid fuel entrained therewith is made to pass through the exhauster 16
by virtue of the movement of a conventional exhauster fan assembly (not shown)
rotatably mounted within the exhauster 16. The pulverized solid fuel while still
entrained in the airstream is discharged from the exhauster 16 through an outlet
28. From the exhauster 16, the pulverized solid fuel entrained in the airstream is
conveyed to the furnace 12 through an exhauster outlet duct 30 to the one
embodiment of the material feed apparatus, hereinafter designated as the riffle
distributor assembly 34. The riffle distributor assembly 34 optimally distributes
the single stream of pulverized solid fuel delivered thereto by the exhauster outlet
duct 30 into tv/o respective branch feed paths, each of which delivers the
pulverized solid fuel to a respective one of the two clusters of the burners 18,
whereupon the pulverized solid fuel is injected into the furnace 12 by the burners
18 and combusted within the furnace 12.
Reference is now had to Figures 2, 3a, 3b, 4a, 4b, 5a, and 5b, which
illustrate one embodiment of the riffle distributor assembly 34, and to Figure 7,
which illustrates another embodiment of the riffle distributor assembly 34, for a
more detailed description of the manner in which the riffle distributor assembly 34
is configured to feed a material from a material supply source to a delivery
location and, more specifically, is configured to feed a material in the form of a
comminuted solid fossil fuel - namely, pulverized coal - from a material supply
source (the pulverizer 14) to a delivery location (the furnace 12).
As seen in particular in Figure 2, the riffle distributor assembly 34
comprises part of a means forming a feed path 36 along which material in the
form of pulverized coal particles 38 and air 40, hereinafter collectively designated
as the material feed stream 42, is fed from a material supply source (the
pulverizer 14) to a delivery location (the famace 12). The feed path 36 comprises
the various conventional components such as the exhauster 16, the exhauster inlet
In the combustion process arrangement, a solid fuel pulverizer and
exhauster system 10 furnishes pulverized solid fuel to a furnace 12. The solid fuel
pulverizer and exhauster system 10 comprises a pulverizer 14, and an exhauster
16 for effecting delivery of a mixture of hot gases and entrained fine solid fuel
parl;icles from the pulverizer 14 to the furnace 12. The furnace 12 operates in
conventional manner to combust the pulverized solid fuel and air fed thereinto
and, to this end, the pulverized solid fuel and air is injected into the furnace 12
through a plurality of burners 18. Additionally, the secondary air which is
required to effectuate the combustion within the furnace 12 of the pulverized solid
fuel that is injected thereinto through the burners 18. For illustration purposes
herein, the burners 18 are arranged in two discrete clusters of burners with one
burner cluster 18A having several burners commonly mounted along one comer
of the furnace 12 and the other burner cluster 18B having several burners
commonly mounted along another comer of the furnace 12.
The hot gases that are produced from combustion of the pulverized solid
fuel and air rise upwardly in the fumiace 12. During upward movement thereof in
the furnace 12, the hot gases in a manner v^ell-known to those skilled in this art
give up heat to the fluid passing through the tubes 20 that in conventional fashion
line all four of the walls of the fumace 12. Then, the hot gases exit the fumace 12
through a horizontal pass which in tum leads to a rear gas pass, both gas passes
commonly comprising other heat exchanger surface (not shown) for generating
and super heating steam, in a manner well-known to those skilled in this art.
Thereafter, the steam commonly is made to flow to a turbine 22 which is in turn
connected to a variable load, such as an electric generator (not shown), which in
known fashion is cooperatively associated with the turbine 22, such that electricity
is thus produced from the generator (not shown).
In a solid fuel feed operation, raw untrammeled solid fuel, which may be
in the form of coal, is fed from a conventional coal storage silo 26 to the
pulverizer 14 and is pulverized within the pulverizer 14. In tum, the pulverizer 14
is connected by means of an exhauster inlet duct 24 to the exhauster 16 whereby
duct 24, the outlet 28, and the exhauster outlet duct 30 which convey the
pulverized coal particles 38 and air 40 from the pulverizer 14 to the furnace 12 as
well as additional components, to be described in more detail hereinafter, which
convey the material feed stream 42 in a desired distributed load arrangement from
the exhauster outlet duct 30 to the burners 18 of the furnace 12.
The material feed stream 42 fed along the exhauster outlet duct 30 must be
distributed or allocated to the plurality of burners 18 in a manner which optimally
supports the combustion process in the furnace 12. For example, the combustion
process in the furnace 12 may be most optimally supported by an equal allocation
or loading of the burners 18 with the material feed stream 42 - in other words, a
loading in which the same, or substantially the same, load of the material feed
stream 42, as measured, for example, by mass flow rate, is fed to each burner 18
for injection thereby into the combustion chamber encompassed by the furnace 12.
Alternatively, the combustion process in the furnace 12 may be most optimally
supported, at a given operational time period, by an unequal allocation or loading
of the burners 18 with a relatively higher load or allocation of the material feed
stream 42 being fed to a selected one or ones of the burner 18 than is fed to others
of the burners 18. The riffle distributor assembly 34 is configurable to support the
desired burner loading arrangement such that the material feed stream 42
conveyed in the exhauster outlet duct 30 is distributed or allocated to the burners
18 in a manner which achieves the desired burner loading. It is to be noted that, in
this regard, the riffle distributor assembly 34 can be alternatively configured as a
fixed, non-adjustable device operable to distribute the material feed stream 42 m
accordance with a single, predetermined distribution plan or as an adjustable
device which can be adjusted to distribute the material feed stream 42 in
accordance with one distribution plan during one operational period and to
distribute the material feed stream 42 in accordance with another distribution plan
different from the one distribution plan during another operational period. The
configuration of the riffle distributor assembly as a fixed, non-adjustable device
operable to distribute the material feed stream 42 in accordance with a single.
predetermined distribution plan is shown in Figure 7. The configuration of the
riffle distributoir assembly 34 as an adjustable device which can be adjusted to
distribute the material feed stream 42 in accordance with one distribution plan
during one operational period and to distribute the material feed stream 42 in
accordance with another distribution plan different from the one distribution plan
during another operational period is shown in Figures 2, 3a, 3b, 4a, 4b, 5a, and 5b,
which illustrate the one embodiment of the riffle distributor assembly 34.
For the sake of illustrating several exemplary configurations of the riffle
distributor assembly 34, the distribution of the material feed stream 42 by the
riffle distributor assembly 34 to the burners 18 will be described with respect to a
distribution plan in which the material feed stream 42 is distributed by the riffle
distributor assembly 34 to a total of the two discrete burner clusters 18A, 18B, it
being understood that the riffle distributor assembly 34 can, as desired, be
configured to distribute a feed stream of material to, alternatively, more than two
clusters of the burners 18. Additionally, the distribution of the material feed
stream 42 can be effected, as the situation warrants, by any suitable arrangement
of multiple units of the riffle distributor assembly 34 operating in parallel or in
series.
Referring to Figure 1, it can be seen that the riffle distributor assembly 34
distributes the material feed stream 42 to the pair of the burner clusters 18A, 18B
by effecting a distribution or allocation of the material feed stream 42 being
conveyed in the exhauster outlet duct 30 to two branch ducts 44A, 44B each
separately communicated with a respective one of the burner clusters 18A, 18B
for conveying the respective allocated portion of the material feed stream 42
thereto.
Refemmg now to Figures 2, 3a, 3b, 4a, 4b, 5a, 5b, and 6, which illustrate
the one embodiment of the riffle distributor assembly 34, the riffle distributor
assembly 34 comprises a transition zone 46 to which one respective end of each of
the branch ducts 44A, 44B is communicated and which is axially spaced from a
downstream end 50 of the exhauster outlet duct 30 with respect to an incoming
flow reference axis IFA. The riffle distributor assembly 34 includes a plenum 48
that forms the downstream end 50 of the exhauster outlet duct 30 and forms, as
well, the transition zone 46 such that the plenum 48, in its entirety, forms an
enclosed space sealed against the outside extending from the downstream open
end 50 of the exhauster outlet duct 30, through the transition zone 46,
communicated with the branch ducts 44A, 44B.
The riffle distributor assembly 34 also includes a plurality of riffle element
plates 52. The riffle element plates 52 are supported within the transition zone 46
and are adjustably positionably movable relative to the exhauster outlet duct 30 by
an intake vane adjustment device 54 (shown in particular in Figure 6 and to be
described shortly hereafter) in a manner such that the intake vane adjustment
device 54 for the riffle element plates 52 is operable to change the offset, or lateral
position, of the intake openings of the riffle element plates 52 relative to a drive
movement axis DMA perpendicular to the incoming flow reference axis IFA.
In the one embodiment of the present invention, and as best seen in Figure
6, the intake openings of the riffle element plates 52 are formed by an adjusting
vane sub-assembly 110 comprising a parallelepiped frame 112 and a plurality of
intake vanes 114 each pivotally connected to a respective one of the riffle element
plates 52 by a pivot connection 116. Reference is also had to Figure 6 in
conjunction with Figure 8a, which is a side elevational sectional view, and Figure
8b, which is a perspective view of one modification of the material feed apparatus
of the present invention showing dual deflector plates mounted between each
adjacent pair of the riffle element plates 52, wherein it can be seen that the
parallelepiped frame 112 has a pair of opposed end panels III, a right hand side
panel 113, and a left hand side panel 115. The left hand side panel 115 of the
parallelepiped frame 112 (which is shown in broken lines in Figure 6 for the sake
of clarity) has, along its inner longitudinal extent, a track 117 on which a slide
drive 119 is slidably supported for sliding movement of the slide drive 119 along
the track 117 in the direction of the DMA axis. Thus, the slide drive 119 extends
parallel to the left hand side panel 115 of the parallelepiped frame 112 and is
slidably supported thereon via the track 117 such that the sHde drive 119 moves in
the direction of the DMA axis relative to the parallelepiped frame 112.
The slide drive 119 includes a plurality of cut-outs 120 punched or cut out
of the slide drive. The left hand side of each intake vane 114 is pivotally mounted
at a respective pivot location 118 to the slide drive 119 such that one portion of
the intake vane 114 extends into the respective generally triangularly shaped cut-
out 120. The pivot location 118 at which each intake vane 114 is pivotally
mounted to the frame 112 is spaced in the vertical direction along the EFA axis
from the respective pivot connection 116 at which the intake vane 114 is pivotally
connected to the respective one of the riffle element plates 52. The right hand side
of each intake vane 114 is pivotally mounted to a respective pivot bore 121
formed in the right hand side panel 113 of the parallelepiped frame 112.
The intake vane adjustment device 54 of the riffle distributor assembly 34,
as seen in Figure 6, is comprised of a motor drive assembly 58 in the form of a
step motor and a rod 60, the motor drive assembly 58 having a selectively
reversibly rotatable shaft whose end is connected via an eccentric pusher to the
rod 60. One end of the rod 60 is pivotally connected to an end of the slide drive
119. The step motor can be selectively actuated to effect extension and retraction
movement of the rod 60 along the DMA axis such that the extension and
retraction movement of the rod 60 along the DMA axis effects sliding movement
of the sHde drive 119 along the track 117 of the left hand side panel 115 relative
the parallelepiped frame 112.
As seen in Figure 6, the upstream edges of the intake vanes 114 form a
plurality of intake spaces defined between adjacent intake vanes 114 which
together define an upstream passage through which the feed path 36 passes. The
material feed stream 42 exiting the downstream open end 50 of the exhauster
outlet duct 30 is distributed or allocated by the riffle distributor assembly 34 such
that the material comprising the material feed stream 42 - namely, the pulverized
coal 38 and air 36 - which has traveled in a non-distributed or non-allocated
manner through the upstream passage bounded by the intake spaces between
adjacent intake vanes 114, is now distributed or allocated by the riffle distributor
assembly 34 according to a predetermined distribution plan into respective
portions segregated from one another during their travel along the respective
branch ducts 44A, 44B to the burner clusters 18A, 18B.
The riffle distributor assembly 34 is thus configured as an apparatus for
influencing the travel properties of a material (in the afore-described exemplary
material feed scenario, the material is the material feed stream 42) moving
between a material supply source (e.g., the pulverizer 14) and a delivery location
(e.g., the furnace 12). The riffle distributor assembly 34 comprises a means
foiTning a feed path 36 along which the material feed stream 42 travels as the
material is enroute from the material supply source in the form of the pulverizer
14 to the delivery location in the form of the furnace 12. The feed path 36 passes
through the intake areas defined between adjacent intake vanes 114 which are
each at a predetermined lateral spacings from the incoming flow reference axis
EFA (i.e., laterally along the DMA axis).
The feed path 36 includes one branch such as, for example, the branch
duct 44A, having a branch entry downstream of intake areas defined between
adjacent intake vanes 114, and another branch such as, for example, the branch
duct 44B, having a branch entry downstream of the intake areas defined between
adjacent intake vanes 114. The feed stream of the material 42 traveling through
the intake ai-eas defined between adjacent intake vanes 114 thereafter separates
into two portions with one portion ol' the material feed stream 42 entering the one
branch duct 44A through its branch entry and thereafter traveling along the one
branch duct 44A and another portion of the material feed stream 42 entering the
other branch duct 44B through its branch entry and thereafter traveling along this
other branch in a manner in which the one portion of the material feed stream 42
and the other portion of the material feed stream 42 are segregated from one
another during their respective travel along the one branch duct 44A and the other
branch duct 44B.
As seen in Figure 6, the riffle element plates 52 each have the same overall
triangular shape and extend upwardly from their bases 154 parallel to one another
along the II'A axis. The bases 154 are each fixedly mounted to the parallelipiped
frame 112 and extend upwardly therefrom parallel to the IFA axis. Accordingly.
Since each of the bases 154 of the riffle element plates 52 is fixedly mounted to
the frame 112 and is, additionally, pivotally connected via a respective one of the
pivot connections 116 to a respective one of the intake vanes 114, the sliding
movement of the slide drive 119 relative to the frame 112 effects pivoting
movement of the intake vanes 114 about their own pivot connections 118 in a
manner in v/hich the riffle element plates 52 remain in their fixed mounted
positions parallel to one another while the intake vanes 114 pivot about their
respective pivot connections 116 in a laterally left pivot movement or a laterally
right pivot movement.
A deflector element 158 is mounted between each adjacent pair of the
riffle element plates 52 and the deflector element 158 is a solid surface extending
from the bases 154 of the adjacent pair of the riffle element plates 52 along the
entirety of a respective side of the riffle element plates 52 to their topmost angle at
which another respective side of the riffle element plates 52 begins. Accordingly,
the respective adjacent sides of each adjacent pair of the riffle element plates 52
which are not covered by a deflector element 158 operate as open passages past
which the material feed stream 42 can flov/ to thereby exit the transition zone 46
and enter a respective one of the branch ducts 44A, 44B. It can thus be
appreciated that an alternating arrangement of the deflector elements 158 in which
the deflector element 158 of every other adjacent pair of the riffle element plates
52 extends along the respective adjacent sides of each adjacent pair of the riffle
element plates 52 which is opposite to the pair of adjacent sides of the next-
following adjacent pair of the riffle element plates 52 on which its own deflector
element 158 is mounted. This alternating jirrangement is the arrangement of the
deflector elements 158 of the one embodiment shown in Figure 6 and, since this
one embodiment comprises an equal number of alternately "right hand" and "left
hand" deflected passages between the riffle element plates 52, the riffle element
plates 52 are operable to deflect the mix of coal particles 38 and air 40 traveling
between each adjacent pair of the riffle element plates 52 into a respective one of
the branch ducts 44A, 44B, depending upon the placement of the respective
deflector element 158, with one-half of the material feed stream 42 being
deflected into the branch duct 44A, as is schematically shown by the dotted line
anow LH in Figure 6, and the other one-half of the material feed stream being
deflected into the branch duct 44B, as is schematically shown by the dash-square
line RH.
The intake vane adjustment device 54 is operable to move the intake areas
defined between adjacent intake vanes 114 in an offset or lateral direction relative
to the incoming flow reference axis IFA (specifically, along the DMA axis) such
that the one portion of the material feed stream 42 and the other portion of the
material feed stream 42, prior to their respective segregated travel along the one
branch duct 44A and other branch duct 44B, are comprised in unseparated manner
in the stream of the material feed stream 42 as it travels through intake areas
defined between adjacent intake vanes 114 and thereafter travel in segregated
manner in their respective branch ducts 44A, 44B with the travel properties of the
one portion of the material feed stream 42 in the one branch duct 44A being
different than its travel properties before the offset or lateral movement of intake
areas defined between adjacent intake vanes 114 relative to the incoming flow
reference axis IFA.
An understanding of how the travel properties of the one portion of the
material feed stream 42 in the one branch duct 44A are different than its travel
properties before the lateral or offset movement of intake areas defined between
adjacent intake vanes 114 can be gained from a more detailed description of the
manner in which the intake vanes 114 influence the distribution of the material
feed stream 42 into the branch ducts 44A, 44B. The offset or lateral positions of
the intake vanes 114 influence the distribution of the material feed stream 42 into
the branch ducts 44A, 44B for the reason that the intake vanes 114 influence the
overall path of movement of the feed stream of material as it exits the downstream
open end 50 of the exhauster outlet duct 30.
The influence of the lateral or offset positions of the intake vanes 114 on
the distribution of the material feed stream. 42 into the branch ducts 44A, 44B is
hereinafter explained with reference to Figures 2, 3a, 3b, 4a, 4b, 5a, and 5b. As
seen in Figure 3b, which is a schematic side elevational view of the positions of
the riffle element plates shown in Figure 3 during an initial material feed period,
the material feed stream 42 may have, for example, an instantaneous cross-
sectional distribution of the coal particles 38 across a lateral cross-section of the
downstream end 50 of the feed path 36 characterized by the property that
substantially the same proportion of the coal particles 38 in the lateral cross-
section enters into each respective intake area defined between an adjacent pair of
intake vanes 114. In other words, for illustration purposes herein, it is assumed
that the instantaneous cross-sectional distribution of the coal particles 38 across a
lateral cross-section of the downstream end 50 of the feed path 36 is such that an
approximately equal amount of coal particles 38 enter between each adjacent pair
of the intake vanes 114, whereupon the alternating right- and left-handedness
an-angement of the riffle element plates 52 ensures that approximately the same
amount of the coal particles 38 in the instantaneous lateral cross-section of the
downstream end 50 of the feed path 36 enter each of the branch ducts 44A, 44B.
The instantaneous cross-sectional distribution of the coal particles 38 across the
lateral cross-section of the downstream end 50 of the feed path 36 is designated as
the upstream feed distribution FPS and the cross-sectional distribution of the coal
particles 38 during their passage through the branch ducts 44A, 44B is designated
as the downstream feed distribution BDL. It can be seen in Figure 3b that the
intake vanes 114 are, during the initial feed period, in alignment with the axis
IFA; this position of the intake vanes 114 is deemed to be a no or zero offset
position.
The downstream feed distribution BDL changes in correspondence with
the change in the lateral or offset positions of intake areas defined between
adjacent intake vanes 114 from the initial upstream position during an initial
material feed period shown in Figures 3 and 3b to a subsequent upstream position
during a subsequent material feed period following the initial material feed period.
With particulai: reference to Figures 4 and 4b, it can be seen that a lateral or offset
movement of the intake vanes 114 effects a change in the downstream feed
distribution BDL. The motor drive assembly 58 changes the lateral position of
intake areas defined between adjacent intake vanes 114 to effect a change in the
downstream feed distribution BDL. With reference to Figures 4 and 4a, it can be
seen that the downstream feed distribution BDL has been offset during the
subsequent material feed period in that the downstream feed distribution BDL
schematically shown in Figure 4a has now shifted the cross-sectional distribution
of the coal particles 38 to the right-hand side, as viewed in Figure 4a, such that
proportionally more of the coal particles 38 in the upstream feed distribution FPS
enter into the respective passages between the riffle element plates 52 toward the
right hand side than those passages between the riffle element plates toward the
left hand side. As is schematically shown in Figure 4a, by reason of the lateral or
offset movement of the stream feed distribution BDL during the subsequent
material feed period, those passages between adjacent pairs of the riffle element
plates 52 communicated with the branch duct 44B toward the right hand side now
collectively define a relatively greater passage volume than those passages
between adjacent pairs of the riffle element plates 52 communicated with the
branch duct 44A toward the left hand side, whereupon proportionately more of the
coal particles 38 in the cross-sectional distribution flow from the transition zone
46 into the branch duct 44B than flow into the branch duct 44A, and,
consequently, the burner cluster 18B communicated with the branch duct 44B
receives a larger pulse of coal particles 38 than the burner cluster 18A.
Figures 5 and 5b illustrate a different subsequent material feed period in
which the dov/nstream feed distribution BDL has been offset during this
subsequent material feed period in that the downstream feed distribution BDL
schematically shown in Figure 5a has now shifted the cross-sectional distribution
of the coal particles 38 to the left-hand side, as viewed in Figure 5a, such that
proportionally more of the coal particles in the upstream feed distribution FPS
enter into the respective passages between the riffle element plates 52 toward the
left hand side than those passages between the riffle element plates toward the
right hand side.
Figure 7 is an enlarged perspective exploded view, in partial section, of
another embodiment of the material feed apparatus of the present invention shown
in its installed position in line between the solid fuel pulverizer and exhauster
system 10 and the furnace 12 of the fossil fuel combustion unit shown in Figure 1.
In this embodiment, the riffle distributor assembly, which is herein designated as
the riffle distributor assembly 234, is configured as a fixed, non-adjustable device
operable to distribute the material feed stream 42 in accordance with a single,
predetermined distribution plan. The riffle distribution assembly 234 includes two
sets of riffle element plates 252A, 25 2B which are mounted one behind the other
along the DMA axis in the transition zone 46. The riffle element plate 252A
comprises a plurality of deflector elements 258 which each mounted between a
respective adjacent pair of the riffle element plates 252A on the same respective
side of the riffle element plates 252A - namely, the left hand side of the riffle
element plates 252A as viewed in Figure 7. Thus, the riffle element plates 252A
operate to guide the material feed stream 42 in the transition zone 46 into the
branch duct 44A. The riffle element plate 252B comprises a plurality of deflector
elements 258 which each mounted between a respective adjacent pair of the riffle
element plates 252A on the same respective side of the riffle element plates 252B
- namely, the right hand side of the riffle element plates 252B as viewed in Figure
7. Thus, the riffle element plates 252B operate to guide the material feed stream
42 in the transition zone 46 into the branch duct 44B.
Figure 8a is a side elevational sectional view and Figure 8 b is a
perspective view of one modification of the material feed apparatus of the present
invention showing dual deflector plates mounted between each adjacent pair of
the riffle element plates 52. Thus, in addition to the deflector plate 58 mounted
between each adjacent pair of the riffle element plates 52, in this modification of
the one embodiment of the present invention, there is also a mid-position deflector
plate 59 mounted between each adjacent pair of the riffle element plates 52 and
extending parallel to the respective deflector plate 58. Also, each respective
intake vane 114 associated with a respective riffle element plate 52 is configured
as two independently pivotally vane portions 114A, 1144B, wherein each vane
portion 114A influences the travel of the material feed stream 42 into those
respective volumes defined between adjacent pairs of the riffle element plates 52
on the same respective one side of the mid-position deflector plates 59 and each
vane portion 114B influences the travel of the material feed stream 42 into those
respective volumes defined between adjacent pairs of the riffle element plates 52
on the same respective other side of the mid-position deflector plates 59.
The present invention thus provides an apparatus for feeding material
between a material supply location and a delivery location which permits more
precise and reliable control of the distribution of the material between two or more
branch feed paths. Also, the inventive apparatus for feeding material between a
material supply location and a delivery location distributes material between two
or more branch feed paths in a manner which minimizes any loss of pressure.
Moreover, the inventive apparatus for feeding material between a material supply
location and a delivery location can distribute a mixture comprised of a fluid
transport material and a solid material between two or more branch feed paths in a
manner in which the distribution of the fluid transport material between the branch
feed paths remains substantially the same following a re-distribution of the
entrained solid material between the branch paths.
While an embodiment and variations of the present invention have been
shown, it v/ill be appreciated that modifications thereof, some of which have been
alluded to hereinabove, may still be readily made thereto by those skilled in the
art. It is, therefore, intended that the appended claims shall cover the
modifications alluded to herein as well as all the other modifications which fall
within the true spirit and scope of the present invention.
WHAT IS CLAIMED IS;
1. An apparatus for influencing the travel properties of a material moving
between a material supply source and a delivery location, the apparatus
comprising:
means forming a feed path along which material travels as the
material is enroute from the material supply source to the delivery
location, the feed path passing through an upstream passage and the feed
path including one branch having a branch entry downstream of the
upstream passage and another branch having a branch entry downstream of
the upstream passage, the stream of material traveling through the
upstream passage thereafter separating into at least two portions with one
portion of the material entering the one branch through its branch entry
and thereafter traveling along the one branch and another portion of the
material entering the another branch through its branch entry and thereafter
traveling along the another branch in a manner in which the another
portion of the material and the one portion of the material are segregated
from one another during their respective travel along the one branch and
the another branch; and
a riffle distributor assembly movable along a lateral axis
perpendicular to the reference axis such that the one portion of the material
and the another portion of the material, prior to their respective segregated
travel along the one branch and the another branch, are comprised in
unseparated manner in the stream of material as it travels through the
upstream passage and the portions of the material thereafter travel in
segregated manner in their respective branches with the travel properties of
the one portion of the material in the one branch being different than its
travel properties before the movement of the one branch entry relative to
the reference axis.
2. An apparatus according to claim 1 wherein the means for relatively
moving includes means for axially moving the one branch entry relative to the
upstream passage.
3. An apparatus according to claim 1 wherein the means for relatively moving
includes means for moving the one branch entry relative to the upstream passage
along an adjustment axis extending perpendicularly to the reference axis.
4. An assembly for delivering pulverized solid fuel to a combustion vessel
for combustion of the pulverized solid fuel thereat in a combustion process;
comprising:
at least a pair of burners for injecting pulverized solid fuel into the
combustion vessel;
an exhauster for effecting delivery of a single stream of pulverized
solid fuel from a pulverizer to the pair of burners such that the pulverized
solid fuel supplied from the pulverizer is apportioned between the pair of
burners whereupon a respective portion of the pulverized solid fuel is
injected through one of the burners at the same time that another respective
portion of the pulverized solid fuel is injected through the other one of the
pair of burners; and
a riffle distributor assembly movable lateral for influencing a travel
property of the pulverized solid fuel moving between the one pulverizer
and the pair of burners so as to thereby change the apportionment of the
pulverized solid fuel injected through the pair of burners.


A riffle distributor assembly for influencing the travel properties of a
material feed stream 42 moving between a pulverizer 14 and a furnace 12 is part
of a feed path 36 having one duct 44A having a branch entry 66A and another
branch duct 44C having a branch entry 66C both downstream of upstream passage
peripheries UPZ defined between adjacent intake vanes 114 through which the
feed stream of the material 42 travels in two segregated portions. A motor drive
assembly 58 moves the intake vanes 114 relative to the incoming flow reference
axis IFA, whereupon intake areas defined between adjacent intake vanes 114
moves relative to the incoming flow reference axis IFA such that the travel
properties of the one portion of material in the one branch duct 44A are different
than its travel properties before the movement of intake areas defined between
adjacent intake vanes 114.

Documents:

00024-kol-2005 abstract.pdf

00024-kol-2005 claims.pdf

00024-kol-2005 correspondence.pdf

00024-kol-2005 description(complete).pdf

00024-kol-2005 drawings.pdf

00024-kol-2005 form-1.pdf

00024-kol-2005 form-2.pdf

00024-kol-2005 form-3.pdf

00024-kol-2005 form-5.pdf

00024-kol-2005 priority document.pdf

24-KOL-2005-(09-05-2014)-ABSTRACT.pdf

24-KOL-2005-(09-05-2014)-CLAIMS.pdf

24-KOL-2005-(09-05-2014)-CORRESPONDENCE.pdf

24-KOL-2005-(09-05-2014)-DESCRIPTION (COMPLETE).pdf

24-KOL-2005-(09-05-2014)-DRAWINGS.pdf

24-KOL-2005-(09-05-2014)-FORM-1.pdf

24-KOL-2005-(09-05-2014)-FORM-13.pdf

24-KOL-2005-(09-05-2014)-FORM-2.pdf

24-KOL-2005-(09-05-2014)-OTHERS.pdf

24-KOL-2005-(18-10-2013)-CORRESPONDENCE-1.1.pdf

24-KOL-2005-(18-10-2013)-FORM-13.pdf

24-KOL-2005-(18-10-2013)-PA-1.1.pdf

24-KOL-2005-(20-09-2013)-ABSTRACT.pdf

24-KOL-2005-(20-09-2013)-CLAIMS.pdf

24-KOL-2005-(20-09-2013)-CORRESPONDENCE.pdf

24-KOL-2005-(20-09-2013)-DESCRIPTION (COMPLETE).pdf

24-KOL-2005-(20-09-2013)-DRAWINGS.pdf

24-KOL-2005-(20-09-2013)-FORM-1.pdf

24-KOL-2005-(20-09-2013)-FORM-2.pdf

24-KOL-2005-(20-09-2013)-FORM-3.pdf

24-KOL-2005-(20-09-2013)-OTHERS.pdf

24-KOL-2005-(20-09-2013)-PETITION UNDER RULE 137-1.1.pdf

24-KOL-2005-(20-09-2013)-PETITION UNDER RULE 137.pdf

24-KOL-2005-(21-05-2013)-CORRESPONDENCE.pdf

24-kol-2005-abstract.pdf

24-KOL-2005-ASSIGNMENT.pdf

24-kol-2005-claims.pdf

24-KOL-2005-CORRESPONDENCE 1.1.pdf

24-kol-2005-correspondence.pdf

24-kol-2005-description (complete).pdf

24-kol-2005-drawings.pdf

24-kol-2005-form 1.pdf

24-kol-2005-form 18.pdf

24-kol-2005-form 2.pdf

24-kol-2005-form 3.pdf

24-kol-2005-form 5.pdf

24-KOL-2005-PA.pdf

24-kol-2005-specification.pdf


Patent Number 263675
Indian Patent Application Number 24/KOL/2005
PG Journal Number 46/2014
Publication Date 14-Nov-2014
Grant Date 13-Nov-2014
Date of Filing 20-Jan-2005
Name of Patentee ALSTOM TECHNOLOGY LTD.
Applicant Address BROWN BOVERI STRASSE 7, 5400 BADEN
Inventors:
# Inventor's Name Inventor's Address
1 JEFFREY S. MANN 86, CLUB HOUSE ROAD, APT. 3, WINDSOR, CONNECTICUT 06095
PCT International Classification Number F23K 3/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/762,624 2004-01-22 U.S.A.