BRULEUR, ET EQUIPEMENT DE COMBUSTION ET CHAUDIERE COMPRENANT UN BRULEUR

BURNER, AND COMBUSTION EQUIPMENT AND BOILER COMPRISING BURNER

Abrégé français

Cette invention concerne un brûleur de combustible solide, qui, tout en rendant la capacité supérieure à celle de l'état antérieur de la technique, peut supprimer un accroissement de région non enflammée et peut ainsi réaliser la prévention d'une augmentation de la concentration en NOx dans un gaz de combustion et la prévention d'une diminution du rendement de combustion, et un équipement de combustion et une chaudière comprenant le brûleur. Le brûleur comprend une buse (12) d'alimentation en fluide contenant du combustible alimentant un fluide contenant du combustible, à partir d'une partie de connexion dans un passage (10) d'écoulement de transfert de fluide pour transférer un fluide contenant du combustible comprenant un combustible et un milieu pour le transfert du combustible, vers une partie de sortie disposée sur la paroi d'un four (4). La buse (12) d'alimentation en fluide contenant du combustible, dans sa section transversale perpendiculaire à la direction de l'écoulement du fluide, est de forme rectangulaire, elliptique ou approximativement elliptique ayant des parties d'axe majeure et mineure à partir d'une partie de connexion (10a) dans le passage (10) d'écoulement de transfert de fluide vers la partie de sortie disposée sur la surface de paroi du four (4). En outre, l'aire d'une section transversale perpendiculaire à la direction de l'écoulement du fluide est progressivement augmentée à partir de la partie de connexion dans le passage (10) d'écoulement de transfert de fluide vers la partie de sortie. Plusieurs buses (15) d'alimentation en air pour fournir de l'air de combustion sont disposées sur la partie périphérique de la buse (12).

Abrégé anglais

The present invention provides a solid fuel burner, which,
while rendering the capacity larger than that in the
conventional art, can suppress an increase in an unignited
region and thus can realize the prevention of an increase in
NOx concentration in a combustion gas and the prevention of
a lowering in combustion efficiency, and a combustion equipment
and boiler including the burner. The burner includes a
fuel-containing fluid supply nozzle (12) which supplies a
fuel-containing fluid, from a connecting part in a fluid
transfer flow passage (10) for transferring a fuel-containing
fluid including a fuel and a medium for transfer of the fuel,
toward an outlet part provided on the wall of a furnace (4) .
The fuel-containing fluid supply nozzle (12) in its cross
section perpendicular to the direction of flow of the fluid
is in a rectangular, elliptical, or substantially elliptical
form having major and minor axis parts from a connecting part
(10a) in the fluid transfer flow passage (10) toward the outlet
part provided on the wall surface of the furnace (4) . Further,
the area of a cross section perpendicular to the direction of
flow of the fluid is gradually increased from the connecting
part in the fluid transfer flow passage (10) toward the outlet

part. One or more air supply nozzles (15) for supplying
combustion air are provided on the outer peripheral part of
the nozzle (12).

Revendications

CLAIMS:
1. A burner including: a fuel-containing fluid supply nozzle supplying a
fuel-containing fluid, containing a solid fuel and a medium for transfer of
the solid fuel,
to an outlet part disposed on a wall surface of a furnace from a connecting
part of a
fuel-containing fluid transfer flow passage that transfers the fluid; and one
or more
air supply nozzles supplying combustion air and disposed at an outer
peripheral part
of the fuel-containing fluid supply nozzle; wherein
from the connecting part of the fluid transfer flow passage toward the
outlet part disposed on the wall surface of the furnace, a cross section of
the
fuel-containing fluid supply nozzle perpendicular to a flow of the fluid has a
rectangular, elliptical, or substantially elliptical shape with major and
minor axis parts
and, from the connecting part of the fluid transfer flow passage toward the
outlet part,
a size of the major axis part of the cross section perpendicular to the flow
of the
fluid increases gradually along a direction of the flow of the fluid and a
size of the
minor axis part is unchanged.
2. The burner according to Claim 1, wherein
the fuel-containing fluid supply nozzle has, in an interior thereof,
fuel-containing fluid guide plates plurally partitioning the flow of the fuel-
containing
fluid.
3. The burner according to Claim 2, wherein
the fuel-containing fluid guide plates are disposed at a plurality of
different inclination angles with respect to planes parallel to a plane
passing
along a line extending a central axis in the direction of the flow of the
fluid in the
fuel-containing fluid supply nozzle toward the furnace and passing through a
shortest axis of the minor axis part of the nozzle.
49

4. The burner according to any one of Claims 1 to 3, wherein
the fuel-containing fluid supply nozzle has, in an interior of the
outlet thereof, fuel-containing fluid direction changing guide plates forcibly
changing a
direction of ejection flow of the fuel-containing fluid.
5. The burner according to Claim 4, wherein
the fuel-containing fluid direction changing guide plates are disposed
in a plurality of mutually different directions with respect to planes
parallel to a
plane passing along a line extending the central axis of the fuel-containing
fluid supply nozzle toward the furnace and passing through a longest axis of
the
major axis part of the nozzle.
6. The burner according to Claim 4, wherein
the fuel-containing fluid direction changing guide plates for a portion
of the fuel-containing fluid are disposed parallel to planes parallel to a
plane passing
along a line extending the central axis of the fuel-containing fluid supply
nozzle
toward the furnace and passing through a longest axis of the major axis part
of the
nozzle, and the fuel-containing fluid direction changing guide plates for
another
portion of the fuel containing fluid are disposed at an inclination angle with
respect to
planes parallel to the plane passing along the line extending the central axis
of the
fuel-containing fluid supply nozzle toward the furnace and passing through the
longest axis of the major axis part of the nozzle.
7. The burner according to Claim 2, wherein
the fuel-containing fluid supply nozzle is partitioned into a plurality of
flow passages by the fuel-containing fluid guide plates, and central axes of
the
respective flow passages are disposed at the wall surface of the furnace at a
50

plurality of mutually different inclination angles with respect to planes
parallel to a
plane passing along a line extending the central axis of the fuel-containing
fluid supply nozzle toward the furnace and passing through a longest axis of
the
major axis part of the nozzle outlet.
8. The burner according to any one of Claims 1 to 7, wherein
fuel-containing fluid partitioning plates, capable of plurally partitioning
the outlet part of the fuel-containing fluid supply nozzle, are disposed at
the
outlet part.
9. The burner according to any one of Claims 1 to 8, wherein
a flame stabilizer with an L-shaped cross section is disposed at the
outlet part of the fuel-containing fluid supply nozzle.
10. The burner according to Claim 9, wherein
a guide plate outwardly changing an ejection direction of the
combustion air in a periphery of the flame stabilizer is disposed at a front
end of the
L-shaped flame stabilizer.
11. The burner according to any one of Claims 1 to 10, wherein
a combustion air guide plate, outwardly spreading an ejection direction
of the combustion air at an outer side of the one or more combustion air
supply
nozzles disposed at the outer peripheral part of the nozzle with respect to a
fuel ejection direction, is disposed at a front end of the combustion air
supply nozzles.
12. The burner according to any one of Claims 1 to 11, wherein
a condenser, narrowing the flow passage of the fuel-containing
fluid once and then expanding the flow passage again, is disposed in an
interior of
the fuel-containing fluid supply nozzle.
51

a condenser, narrowing the flow passage of the fuel-containing
fluid once and then expanding the flow passage again, is disposed in an
interior of
the fuel-containing fluid supply nozzle.
13. The burner according to any one of Claims 1 to 12, wherein
a fluid distribution plate, distributing the fuel uniformly inside the
fuel-containing fluid supply nozzle, is disposed at an inlet part of the fuel-
containing
fluid supply nozzle.
14. The burner according to any one of Claims 1 to 13, wherein
a nozzle, ejecting a liquid fuel or a gas fuel that is an auxiliary fuel to a
vicinity of the fluid ejected from the fuel-containing fluid supply nozzle, is
disposed
at a vicinity of the fuel-containing fluid supply nozzle.
15. A combustion equipment wherein
the burners according to any one of Claims 1 to 14 are disposed in a
plurality of stages in an up/down direction at each of two opposing furnace
walls, and
a plurality of burners disposed at each stage are disposed respectively
symmetrically
in wall surface regions divided in two at a central part of width in a
horizontal direction
of the same furnace wall.
16. A combustion equipment wherein
the burners according to any one of Claims 1 to 14 are disposed in a
plurality of stages in an up/down direction at each of two opposing furnace
walls,
and burners, which, among the plurality of burners disposed in each stage of
the
same furnace wall, are adjacent each other in a horizontal direction, are
burners of
the same structure.
52

17. A boiler including: a furnace wall formed by spirally winding a set of
water wall tubes inclined with respect to a horizontal direction; wherein
openings of rectangular, elliptical, or substantially elliptical shape are
disposed in the furnace wall along a longitudinal direction of the water wall
tubes and
the burner according to any one of Claims 1 to 14 is mounted in each opening.
18. A boiler including: a furnace wail formed by a set of water wall tubes
extending in a vertical direction; wherein
openings of rectangular, elliptical, or substantially elliptical shape are
disposed in the furnace wall along a longitudinal direction of the water wall
tubes and
the burner according to any one of Claims 1 to 14 is mounted in each opening.
53

Description

75870-16 CA 02664769 2009-03-26
BURNER, AND COMBUSTION EQUIPMENT AND BOILER COMPRISING BURNER
FIELD OF THE ART
The present invention relates to a burner and a combustion
equipment and a boiler including the burner, and particularly
relates to a burner capable of performing low nitrogen oxide
(N0x) combustion at high efficiency.
BACKGROUND ART
FIG. 28 shows an example of a solid fuel (pulverized coal,
biomass fuel, etc.) burner according to a conventional art.
FIG. 28A is a side sectional view of the burner, and FIG. 28B
is a front view of the burner as viewed from a furnace (4) side.
The solid fuel burner includes a fuel-containing fluid supply
nozzle (12) , defining a fuel-containing fluid flow passage
through which a fuel-containing fluid (11) , containing a solid
fuel and a conveying primary air, flows toward the furnace (4) ,
and a combustion air sleeve (15) disposed at an outer periphery
of the fuel-containing fluid supply nozzle (12) , and air inside
a windbox (3) is supplied as a secondary air (13) and a tertiary
air (14) through a combustion air flow passage defined by the
sleeve (15) . A flame stabilizer (17) is disposed at a front
end of the fuel-containing fluid supply nozzle (12) , and
1

75870-16 CA 02664769 2009-03-26
ignition of the fuel from a vicinity of the burner is enabled
by an effect of a circular vortex formed at a wake of the flame
stabilizer (17).
A front end of the combustion air sleeve (15) is disposed
at a position facing a burner throat (16), a combustion air
guide plate (15a), spreading outside the burner, is disposed
at the front end of the sleeve (15), the tertiary air (14) is
spread outward by the combustion air guide plate (15a) to delay
mixing of air into a central part of a flame, and by promotion
of combustion under a reducing atmosphere condition of
insufficient air, generation of nitrogen oxides (N0x) in a
combustion gas is suppressed.
FIG. 10 is a sectional view taken in a direction along
an ejection flow of the fuel-containing fluid (11) at the
fuel-containing fluid supply nozzle (12) in the burner of the
conventional art, and as shown in FIG. 1D, which is a front
view of an outlet part of the fuel-containing fluid supply
nozzle (12) of the burner in FIG. 10 as viewed from the furnace
(4) side, with the burner of the conventional art, a cross
section of the outlet part of the fuel-containing fluid supply
nozzle (12) has a shape close to a circular shape. When the
fuel-containing fluid (11) is loaded into the furnace (4), the
fuel is ignited near the outlet of the fuel-containing fluid
2

75870-16 CA 02664769 2009-03-26
supply nozzle (12) by heating due to radiation inside the
furnace (4) and actions of the circular vortex at the wake of
the flame stabilizer (17).
FIG. 29A is a sectional view taken in a direction along
the ejection flow of the fuel-containing fluid (11) at the
fuel-containing fluid supply nozzle (12) in the burner of the
conventional art, and an ignition position (33) of the fuel
in the fuel-containing fluid ejected from the fuel-containing
fluid supply nozzle (12) into the furnace (4) is formed as shown
in FIG. 29B, which is a front view of the outlet part of the
fuel-containing fluid supply nozzle (12) as viewed from the
furnace (4) side. After the fuel is ignited at a surface of
the ejection flow of the fuel containing fluid (11), a flame
that is formed gradually propagates toward a central part of
the ejection flow of the fuel-containing fluid (11). FIG. 30
schematically shows a propagation behavior of the flame inside
the furnace (4) in a cross-sectional direction along the
ejection flow of the fuel-containing fluid (11) at the
fuel-containing fluid supply nozzle (12) in the burner of the
conventional art. An ignited region (32) is formed around an
unignited region (31) of conical shape.
The burner of circular cross section, shown in FIGS. 28
to 30, is frequently used in a so-called opposed firing
3

= CA 02664769 2009-03-26
75870-16
configuration in which the burners is disposed at each of a
pair of opposing furnace walls. Meanwhile, in so-called
tangential firing in which the fuel is combusted while the
fuel-containing fluid is ejected into the furnace (4) in
directions of applying a rotation along a furnace wall surface
from outlets of a plurality of fuel-containing fluid supply
nozzles (12), an outlet shape of a transverse section (section
orthogonal to the flow of the fuel-containing fluid) of each
fuel-containing fluid supply nozzle (12) is made a square shape
or a rectangular shape close to a square shape in many cases.
Burners, with which the outlet shape of the transverse
section (section orthogonal to the flow of the fuel-containing
fluid) of the fuel-containing fluid supply nozzle (12) is made
a rectangular shape, an elliptical shape, or a substantially
elliptical shape with maj or and minor axis parts, are disclosed
in the following Patent Documents 1 to 3.
Patent Document 1: Japanese Translation of International
Application (Kohyo) No. Sho 59-500981
Patent Document 2: Japanese Published Patent Application No.
Hei 8-226615
Patent Document 3: Japanese Published Patent Application No.
Hei 11-281009
4

, .75870-16 CA 02664769 2009-03-26
DISCLOSURE OF THE INVENTION
OBJECT(S) OF THE INVENTION
In general, a cross section of an outlet part of a
fuel-containing fluid supply nozzle (12) of a burner has a shape
close to a circular shape or a square shape, and there are cases
where, as shown in FIG. 30, a flame ignited at an outer side
of a fuel-containing fluid ejection flow in a furnace (4) must
propagate a considerable distance to reach a central part of
the fuel-containing fluid ejection flow. A distance in a
fuel-containing fluid (11) ejection flow direction from the
fuel-containing fluid supply nozzle (12) that is required for
the ignited flame to propagate to the central part of the fuel
ejection flow, in other words, an unignited distance Li' shown
in FIG. 30 is longer and an unignited region (31) is more
expanded the larger a diameter or a peripheral part of the
fuel-containing fluid supply nozzle (12) . Although promotion
of combustion in a reducing region in a vicinity of the burner
is important for suppressing NOx generation in a combustion
gas, expansion of the unignited region (31) inhibits the NOx
concentration suppression characteristic. Expansion of the
unignited region (31) also means that a combustion time after
ignition is short and causes lowering of combustion efficiency.
5

CA 02664769 2009-03-26
75870-16
Although increasing a burner capacity (decreasing a
number of burners) is an effective method for reducing cost
and improving operability, with the conventional art, when the
burner capacity is increased, a diameter or a length of an outer
diameter part of the fuel-containing fluid supply nozzle (12)
becomes long and the unignited region (31) expands, causing
increase of NOx and lowering of the combustion efficiency.
This problem was due to the distance from an ignited region
(32) at a fuel-containing fluid ejection flow surface to the
central part of the fuel-containing fluid ejection flow being
large. Also, with the inventions described in Patent
Documents 1 to 3 where the outlet shape of the transverse
section (section orthogonal to the flow of the fuel-containing
fluid) of the fuel-containing fluid supply nozzle (12) is made
a rectangular shape, etc. that combines major and minor axis
parts, nothing is mentioned in regard to a countermeasure for
the expansion of the unignited region (31) due to increase of
the burner capacity and the resulting increase of NOx and
lowering of the combustion efficiency.
An object of the present invention is to provide a solid
fuel burner that is increased in capacity over the conventional
art and yet is suppressed in expansion of an unignited region
to prevent increase of NOx concentration in a combustion gas
6

. .75870-16 CA 02664769 2009-03-26
and prevent lowering of combustion efficiency, a combustion
equipment and a boiler including the burner.
SUMMARY OF THE INVENTION
The above object of the present invention is
achieved by the following solutions.
A first aspect of the present invention provides a
burner including: a fuel-containing fluid supply nozzle (12)
supplying a fuel-containing fluid (11), containing a solid
fuel and a medium for transfer of the solid fuel, to an
outlet part disposed on a wall surface of a furnace (4) from
a connecting part (10a) of a fuel-containing fluid transfer
flow passage (10) that transfers the fluid (11); and one or
more air supply nozzles (15) supplying combustion air and
disposed at an outer peripheral part of the fuel-containing
fluid supply nozzle (12); and where, from the connecting
part (10a) of the fluid transfer flow passage (10) toward
the outlet part disposed on the wall surface of the furnace
(4), a cross section of the fuel-containing fluid supply
nozzle (12) perpendicular to a flow of the fluid (11) has a
rectangular, elliptical, or substantially elliptical shape
with major and minor axis parts and, from the connecting
part (10a) of the fluid transfer flow passage (10) toward
the outlet part, a size of the major axis part of the cross
section perpendicular to the flow of the fluid (11)
increases gradually along a direction of the flow of the
fluid (11) and a size of the minor axis part is unchanged.
A fourth aspect of the present invention provides
the burner according to the first aspect where the fuel-
containing fluid supply nozzle (12) has, in an interior
thereof, fuel-containing fluid guide plates (19) plurally
partitioning the flow of the fuel-containing fluid (11).
7

' 75870-16
CA 02664769 2009-
03-26
the burner according to the fourth aspect where the fuel- A fifth aspect of
the present invention provides
containing fluid guide plates (19) are disposed at a
plurality of different inclination angles with respect to
planes parallel to a plane passing along a line extending a
central axis in the direction of the flow of the fluid (11)
in the fuel-containing fluid supply nozzle (12) toward the
furnace (4) and passing through a shortest axis of the minor
axis part of the nozzle (12).
A sixth aspect of the present invention provides
the burner according to any of the first, fourth, and fifth
aspects where the fuel-containing fluid supply nozzle (12)
has, in an interior of the outlet thereof, fuel-containing
fluid direction changing guide plates (21) forcibly changing
a direction of ejection flow of the fuel-containing fluid
(11).
A seventh aspect of the present invention provides
the burner according to the sixth aspect where the fuel-
containing fluid direction changing guide plates (21) are
disposed in a plurality of mutually different directions
with respect to planes parallel to a plane passing along the
line extending the central axis of the fuel-containing fluid
supply nozzle (12) toward the furnace (4) and passing
through a longest axis of the major axis part of the nozzle
(12).
An eighth aspect of the present invention provides
the burner according to the sixth aspect where the fuel-
containing fluid direction changing guide plates (21) for a
portion of the fuel-containing fluid (11) are disposed
parallel to planes parallel to a plane passing along the
line extending the central axis of the fuel-containing fluid
supply nozzle (12) toward the furnace (4) and passing
8

. .75870-16 CA 02664769 2009-03-26
through a longest axis of the major axis part of the nozzle
(12)1 and the fuel-containing fluid direction changing guide
plates (21) for another portion of the fuel containing fluid
(11) are disposed at an inclination angle with respect to
planes parallel to the plane passing along the line
extending the central axis of the fuel-containing fluid
supply nozzle (12) toward the furnace (4) and passing
through the longest axis of the major axis part of the
nozzle (12).
A ninth aspect of the present invention provides
the burner according to the fourth aspect where the fuel-
containing fluid supply nozzle (12) is partitioned into a
plurality of flow passages by the fuel-containing fluid
guide plates (19), and central axes of the respective flow
passages are disposed at the wall surface of the furnace (4)
at a plurality of mutually different inclination angles with
respect to planes parallel to a plane passing along a line
extending a central axis of the fuel-containing fluid supply
nozzle (12) toward the furnace (4) and passing through a
longest axis of the major axis part of the nozzle (12)
outlet.
A tenth aspect of the present invention provides
the burner according to any of the first and fourth to ninth
aspects where fuel-containing fluid partitioning plates
(22), capable of plurally partitioning the outlet part of
the fuel-containing fluid supply nozzle (12), are disposed
at the outlet part.
An eleventh aspect of the present invention
provides the burner according to any of the first and fourth
to tenth aspects where a flame stabilizer (17) with an L-
shaped cross section is disposed at the outlet part of the
fuel-containing fluid supply nozzle (12).
9

. ,75870-16 CA 02664769 2009-03-26
A twelfth aspect of the present invention provides
the burner according to the eleventh aspect where a guide
plate (17a) outwardly changing an ejection direction of the
combustion air in a periphery of the flame stabilizer (17)
is disposed at a front end of the L-shaped flame stabilizer
(17).
A thirteenth aspect of the present invention
provides the burner according to any of the first and fourth
to twelfth aspects where a combustion air guide plate (15a),
outwardly spreading an ejection direction of the combustion
air at an outer side of the one or more combustion air
supply nozzles (15) disposed at the outer peripheral part of
the nozzle (12) with respect to a fuel ejection direction,
is disposed at a front end of the fuel-containing fluid
supply nozzle (12).
A fourteenth aspect of the present invention
provides the burner according to any of the first and fourth
to thirteenth aspects where a condenser (23), narrowing the
flow passage of the fuel-containing fluid (11) once and then
expanding the flow passage again, is disposed in an interior
of the fuel-containing fluid supply nozzle (12).
A fifteenth aspect of the present invention
provides the burner according to any of the first and fourth
to fourteenth aspects where a fluid distribution plate (24)
distributing the fuel uniformly inside the fuel-containing
fluid supply nozzle (12) is disposed at an inlet part of the
fuel-containing fluid supply nozzle (12).
A sixteenth aspect of the present invention
provides the burner according to any of the first and fourth
to fifteenth aspects where a nozzle (41, 44), ejecting a
liquid fuel or a gas fuel that is an auxiliary fuel to a
vicinity of the fluid (11) ejected from the fuel-containing
10

75870-16 CA 02664769 2009-03-26
fluid supply nozzle (12), is disposed at a vicinity of the
fuel-containing fluid supply nozzle (12).
A seventeenth aspect of the present invention
provides a combustion equipment where the burners according
to any of the first and fourth to sixteenth aspects are
disposed in a plurality of stages in an up/down direction at
each of two opposing furnace walls, and a plurality of
burners disposed at each stage are respectively disposed
symmetrically in wall surface regions divided in two at a
central part of width in a horizontal direction of the same
furnace wall.
An eighteenth aspect of the present invention
provides a combustion equipment where the burners according
to any of the first and fourth to sixteenth aspects are
disposed in the plurality of stages in the up/down direction
at each of the two opposing furnace walls, and burners,
which, among the plurality of burners disposed in each stage
of the same furnace wall, are adjacent each other in the
horizontal direction, are burners of the same structure.
A nineteenth aspect of the present invention
provides a boiler including: a furnace wall formed by
spirally winding a set of water wall tubes (25) inclined
with respect to a horizontal direction; and where openings
(26) of rectangular, elliptical, or substantially elliptical
shape are disposed in the furnace wall along a longitudinal
direction of the water wall tubes (25) and the burner
according to any of the first and fourth to sixteenth
aspects is mounted in each opening (26).
A twentieth aspect of the present invention
provides a boiler including: a furnace wall formed by a set
of water wall tubes (25) extending in a vertical direction;
and where openings (26) of rectangular, elliptical, or
11

75870-16 CA 02664769 2009-03-26
substantially elliptical shape are disposed in the furnace
wall along a longitudinal direction of the water wall tubes
(25) and the burner according to any of the first and fourth
to sixteenth aspects is mounted in each opening (26).
EFFECT(S) OF THE INVENTION
According to the first aspect of the present
invention, expansion of an unignited region can be
suppressed even if a burner capacity is increased, an
unignited distance can be reduced effectively in comparison
to the conventional art because the fuel-containing fluid
(11) spreads in the width direction even after the fuel-
containing fluid (11) is loaded into the furnace (4) so that
a cross-sectional area of the ejection flow of the fuel-
containing fluid (11) increases and a flow velocity
decreases, and also because the fuel-containing fluid (11)
spreads inside the furnace (4), a combustion space can be
utilized effectively and a practical furnace retention time
is made long, thereby providing effects of reducing NOx
concentration in a combustion gas and improving combustion
efficiency. Also, the size of the minor axis part of the
fuel-containing fluid supply nozzle (12) is unchanged, and
this is effective for simplification of structure. Also, a
flow velocity at an upstream side of the fuel-containing
fluid supply nozzle (12) can be made high, and this is
effective for preventing backfiring in a case of a readily
ignitable fuel, etc.
According to the fourth and fifth aspects of the
present invention, because the flow of the fuel-containing
fluid (11) is partitioned plurally by the fuel-containing
fluid guide plates (19) in the interior of the fuel-
containing fluid supply nozzle (12), the fuel-containing
fluid (11) is supplied uniformly in the direction in which
12

. ,75870-16 CA 02664769 2009-03-26
the fuel-containing fluid supply nozzle (12) expands from
the fuel-containing fluid connecting part (10a) toward the
outlet part of the nozzle (12), and the effects of NOx
reduction, improvement in combustion efficiency, suppression
of flow velocity increase, minimization of pressure loss,
and suppression of wear of component parts are improved in
comparison with other those of the first aspect of the
present invention.
According to the sixth aspect of the present
invention, effects of promoting dispersion of a fuel-
containing fluid ejection flow (20) inside the furnace (4)
and promoting combustion at a wake part of the furnace (4)
are provided.
According to the seventh aspect of the present
invention, because the fuel-containing fluid guide plates
(19) are respectively disposed in mutually opposing
directions with respect to the planes parallel to the plane
passing along the line extending the central axis of the
fuel-containing fluid supply nozzle (12) toward the furnace
(4) and passing through the longest axis of the major axis
part of the nozzle (12), the fuel-containing fluid (11) can
be ejected into the furnace (4) in two or more groups and
the fuel-containing fluid ejection flow (20) can thereby be
divided into groups by a simple structure to provide the
effects of promoting the dispersion of the fuel-containing
fluid ejection flow (20) inside the furnace (4) and
promoting the combustion at the wake part of the furnace
(4).
According to the eighth aspect of the present
invention, by dividing four fuel-containing fluid ejection
flows (20), formed by the fuel-containing fluid supply
nozzle (12) and the fuel-containing fluid guide plates (19)
13

. .75870-16 CA 02664769 2009-03-26
into two groups (20a, 20b) and thereby making, for example,
fuel-containing fluid ejection flows (20a), adjacent a
furnace side wall, rectilinear flows and making fuel-
containing fluid ejection flows (20b), not adjacent the
furnace side wall, be ejected upon applying an inclination
with respect to a horizontal direction, an effect of
preventing ash deposition by suppressing flame inflow to a
vicinity of the furnace side wall while maintaining
promotion of combustion at the furnace wake part by
dispersion of the fuel is provided.
According to the ninth aspect of the present
invention, because the fuel-containing fluid (11) can be
ejected into the furnace (4) at mutually different angles
with respect to the horizontal direction or the vertical
direction from the fuel-containing fluid supply nozzle (12)
and the fuel-containing fluid ejection flow (20) can be
varied in direction without using parts inside the fuel-
containing fluid supply nozzle (12) with which pulverized
coal or other solid fuel collides directly, wear of parts
can be suppressed effectively.
14

75870-16 CA 02664769 2009-03-26
According to the tenth aspect of the present invention,
the fuel-containing fluid ejection flow (20) is partitioned
by the fuel-containing fluid partitioning plates (22) to be
increased in surface area, and radiant heat inside the furnace
(4) is thereby increased and a negative pressure region is
formed at the wake side of the fluid partitioning plates (22),
thereby making a high temperature gas in a periphery flow into
the negative pressure region to contribute to early ignition
of the fuel, promote combustion at a reducing region in the
vicinity of the burner, and effectively contribute to the
reduction of the NOx concentration in the combustion gas and
the improvement in the combustion efficiency.
According to the eleventh aspect of the present invention,
by disposing the flame stabilizer (17) with the L-shaped cross
section at the outlet part of the fuel-containing fluid supply
nozzle (12), a circular vortex is formed at the wake of the
flame stabilizer (17) and draws back the high-temperature
combustion gas to a vicinity of the flame stabilizer (17) to
contribute to early ignition of the fuel, promote combustion
at the reducing region in the vicinity of the burner, and
effectively contribute to the reduction of the NOx
concentration in the combustion gas and the improvement in the
combustion efficiency in compassion with the eleventh aspect
15

75870-16 CA 02664769 2009-03-26
of the invention.
According to the twelfth aspect of the present invention,
by the secondary air guide plate (17a) at the front end of the
flame stabilizer (17) of L-shaped cross section, the secondary
air is spread outward and the circular vortex at the wake of
the flame stabilizer (17) is enlarged, thereby increasing a
recirculation amount of the high-temperature combustion gas
to further quicken ignition of the fuel, promote combustion
at the reducing region near the burner, and effectively
contribute to the reduction of the NOx concentration in the
combustion gas and the improvement in the combustion efficiency
in comparison with the eleventh aspect of the invention.
According to the thirteenth aspect of the present
invention, by provision of the combustion air guide plate (15a)
that spreads the combustion air ejection direction at the outer
side of the combustion air supply nozzles (15) outward with
respect to the fuel-containing fluid ejection direction, the
combustion air is spread outward, thereby enlarging the
reducing region at a central part of the flame and effectively
contributing to the reduction of the NOx concentration in the
combustion gas and the improvement in the combustion
efficiency.
According to the fourteenth aspect of the present
16

. .75870-16 CA 02664769 2009-03-26
invention, the fuel in the vicinity of the flame stabilizer
(17) is condensed by the condenser (23) thereby contributing
to early ignition of the fuel to promote combustion at a
reducing region in the vicinity of the burner and
effectively contributing to the reduction of the NOx
concentration in the combustion gas and the improvement in
the combustion efficiency.
According to the fifteenth aspect of the present
invention, the fuel concentration at the inlet part of the
fuel-containing fluid supply nozzle (12) is made uniform by
the fluid distribution plate (24) to suppress imbalance of
concentration of the fuel flowing into the respective flow
passages partitioned by the fuel-containing fluid guide
plates (19), and this is effective for NOx reduction and
improvement in the combustion efficiency.
According to the sixteenth aspect of the present
invention, because the liquid fuel or the gas fuel is
ejected to the burner outlet, the fuel-containing fluid (11)
that contains the solid fuel can be ignited reliably.
According to the seventeenth aspect of the present
invention, by the burners according to any of the first and
fourth to sixteenth aspects being disposed in the plurality
of stages in the up/down direction at each of the opposing
furnace walls of the opposed firing type furnace (4) and by
disposing the plurality of burners of each stage
respectively symmetrically at the wall surface regions
divided in two at the central part of width in the
horizontal direction of the same furnace wall, the
directions of the fluid ejection flows (20a, 20b) can be
made left/right symmetrical at a single furnace wall surface
and good left/right balance of flow and combustion states
can be maintained in the furnace (4).
17

. ,75870-16 CA 02664769 2009-03-26
According to the eighteenth aspect of the present
invention, by the burners according to any of the first and
fourth to sixteenth aspects being disposed in the plurality
of stages in the up/down direction at each of the two
opposing furnace walls of the opposed firing type furnace
(4) and by making the burners, which, among the plurality of
burners disposed in each stage of the same furnace wall, are
adjacent each other in the horizontal direction, burners of
the same structure, collision of the fuel-containing fluid
ejection flows (20a, 20b) can be avoided, especially in a
furnace (4) of small capacity, to suppress localized
concentration of fuel and provide the effects of reducing
the NOx concentration in the combustion gas and improving
the combustion efficiency.
According to the nineteenth aspect of the present
invention, by aligning a longitudinal direction of the water
wall tubes (25) with a longitudinal direction of the major
axis parts of the openings (26), a number of the spiral
water wall tubes (25) necessary for forming the openings
(26) can be made small and an economical boiler can be
constructed with few processed and bent parts in the water
wall tubes (25). The number of the spiral water wall tubes
(25) necessary for forming the openings (26) can be
minimized to improve economy. Also, because the fuel-
containing fluid (11) spreads in the horizontal (width)
direction of the furnace (4), distribution of the fuel-
containing fluid (11) in the horizontal (width) direction of
the furnace (4) is made uniform, the practical furnace
retention time is made longer, and the effects of reducing
the NOx concentration in the combustion gas and improving
the combustion efficiency are provided.
According to the twentieth aspect of the present
invention, because the rectangular openings (26) are
18

. ,75870-16 CA 02664769 2009-03-26
installed on the furnace wall along the arrangement of the
water wall tubes (25) in the vertical direction, by aligning
the longitudinal direction of the water wall tubes (25) with
the longitudinal direction of the major axis parts of the
openings (26), an economical boiler can be constructed with
few processed and bent parts in the water wall tubes (25).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows explanatory diagrams of ignited
regions of burner outlets according to the present invention
and a conventional art.
FIG. 2 shows explanatory diagrams of unignited
regions of the burner outlets according to the present
invention and the conventional art.
FIG. 3 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 3A
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 3B is a sectional view taken on line A-A of FIG.
3A, and FIG. 3C is a front view of the outlet part of the
burner as viewed from the furnace side).
FIG. 4 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 4A
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 4B is a sectional view taken on line A-A of FIG.
4A, and FIG. 4C is a front view of the outlet part of the
burner as viewed from the furnace side).
FIG. 5 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 5A
19

. .75870-16 CA 02664769 2009-03-26
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 5B is a sectional view taken on line A-A of
FIG. 5A, and FIG. 5C is a front view of the outlet part of
the burner as viewed from the furnace side).
FIG. 6 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 6A
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 6B is a sectional view taken on line A-A of
FIG. 6A, and FIG. 6C is a front view of the outlet part of
the burner as viewed from the furnace side).
FIG. 7 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 7A
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 7B is a sectional view taken on line B-B of
FIG. 7A, and FIG. 7C is a sectional view taken on line A-A
of FIG. 7A).
FIG. 8 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 8A
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 8B is a sectional view taken on line B-B of
FIG. 8A, and FIG. 8C is a sectional view taken on line A-A
of FIG. 8A).
FIG. 9 shows a configuration example of a burner
according to an embodiment of the present invention (FIG. 9A
20

. .75870-16 CA 02664769 2009-03-26
is a sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 9B is perspective view of the burner, FIG. 9C is
a sectional view taken on line B-B of FIG. 9A, and FIG. 9D
is a sectional view taken on line A-A of FIG. 9A).
FIG. 10 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 10A is a sectional view taken in a direction parallel
to a plane passing along a line, passing through a central
axis of the burner and extending toward the furnace, and
passing through a longest axis of a major axis part of an
outlet part, FIG. 10B is a sectional view taken on line A-A
of FIG. 10A, and FIG. 10C is a front view of the outlet part
of the burner as viewed from the furnace side).
FIG. 11 is an explanatory diagram of effects of
the invention shown in FIG. 10.
FIG. 12 shows a configuration example of a burner
according to an embodiment of the present invention shown in
FIG. 10 (FIG. 12A is a sectional view taken in a direction
parallel to a plane passing along a line, passing through a
central axis of the burner and extending toward the furnace,
and passing through a longest axis of a major axis part of
an outlet part, FIG. 12B is a sectional view taken on line
A-A of FIG. 12A, and FIG. 12C is a front view of the outlet
part of the burner as viewed from the furnace side).
FIG. 13 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 13A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 13B is a sectional view taken on line A-A
21

75870-16 CA 02664769 2009-03-26
of FIG. 13A, and FIG. 130 is a front view of the outlet part
of the burner as viewed from the furnace side).
FIG. 14 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 14A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 14B is a sectional view taken on line A-A
of FIG. 14A, and FIG. 140 is a front view of the outlet part
of the burner as viewed from the furnace side).
FIG. 15 shows a configuration example of a burner according
to an embodiment of the present invention (FIG. 15A is a
sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part, FIG. 15B is a sectional view taken on line A-A of
FIG. 15A, and FIG. 150 is a front view of the outlet part of
the burner as viewed from the furnace side).
FIG. 16 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 16A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 16B is a sectional view taken on line A-A
of FIG. 16A, and FIG. 160 is a front view of the outlet part
of the burner as viewed from the furnace side).
FIG. 17 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 17A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 17B is a sectional view taken on line A-A
22

75870-16 CA 02664769 2009-03-26
of FIG. 17A, and FIG. 170 is a front view of the outlet part
of the burner as viewed from the furnace (4) side).
FIG. 18 shows a configuration example of a burner
according to an embodiment of the present invention
(FIG. 18A is a sectional view parallel to a fuel-containing
fluid supply nozzle (12) surface formed through a long edge
of an outlet part of the nozzle (12) (sectional view taken
on line B-B of FIG. 18B), FIG. 18B is a sectional view taken
on line A-A of FIG. 18A, and FIG. 180 is a front view of the
outlet part of the burner as viewed from the furnace side).
FIG. 19 shows an example where an oil supply
nozzle is installed at a central part of a fuel-containing
fluid supply nozzle.
FIG. 20 shows an example where gas supply nozzles
are installed in a periphery of a flame stabilizer.
FIG. 21 shows a front view (FIG. 21A) and a plan
view (FIG. 21B) of a fuel-containing fluid supply nozzle.
FIG. 22 shows a front view (FIG. 22A) and a plan
view (FIG. 22B) of a fuel-containing fluid supply nozzle of
another configuration.
FIG. 23 shows an example where a plurality of the
fuel-containing fluid supply nozzles, shown in FIG. 21, are
positioned in three stages in an up/down direction and four
columns in a horizontal direction on a single furnace wall
surface.
FIG. 24 shows an example where a plurality of the
fuel-containing fluid supply nozzles, shown in FIGS. 21 and
22, are positioned in three stages in an up/down direction
and four columns in a horizontal direction on a single
furnace wall surface.
23

75870-16 CA 02664769 2009-03-26
FIG. 25 shows another embodiment where a plurality
of the fuel-containing fluid supply nozzles, shown in
FIG. 21, are positioned in three stages in an up/down
direction and four columns in a horizontal direction on a
single furnace wall surface.
FIG. 26 is a plan view of a furnace wall of a
boiler in which burners according to an embodiment of the
present invention are disposed.
FIG. 27 is a plan view of a furnace wall of a
boiler in which burners according to an embodiment of the
present invention are disposed.
FIG. 28 shows an example of a solid fuel burner
according to a conventional art (FIG. 28A is a side
sectional view of the burner, and FIG. 28B is a front view
of the burner as viewed from a furnace side).
FIG. 29A is a sectional view taken in a direction
along an ejection flow of a fuel-containing fluid at a fuel-
containing fluid supply nozzle in the burner of the
conventional art, and FIG. 29B is a front view of an outlet
part of a fuel-containing fluid supply nozzle as viewed from
the furnace side.
FIG. 30 is schematic diagram of a flame
propagation behavior inside the furnace in a cross-sectional
direction along the ejection flow of the fuel-containing
fluid at the fuel-containing fluid supply nozzle in the
burner of the conventional art.
BEST MODE(S) FOR CARRYING OUT THE INVENTION
Embodiments of the present invention shall now be
described along with the drawings.
24

75870-16 CA 02664769 2009-03-26
Basic concepts of the present invention shall now
be described using FIGS. 1 and 2. In FIG. 1, an ignition
position (33) in a furnace (4) using a fuel-containing fluid
supply nozzle (12) of a burner according to an embodiment
shown in FIGS. lA and 1B is compared with that in a
conventional art shown in FIGS. 1C and 1D. FIG. 1A is a
sectional view of the fuel-containing fluid supply nozzle
(12) of the burner according to the present embodiment taken
in an ejection flow direction of a fuel-containing fluid
(11), FIG. 1B is a front view of an outlet part of the fuel-
containing fluid supply nozzle (12) of FIG. 1A as viewed
from the furnace (4) side, FIG. 1C is a sectional view of
the fuel-containing fluid supply nozzle (12) of the burner
according to the conventional art taken in the ejection flow
direction of the fuel-containing fluid, and FIG. 1D is a
front view of the outlet part of the fuel-containing fluid
supply nozzle (12) as viewed from the furnace (4) side.
25

, .75870-16 CA 02664769 2009-03-26
As shown in FIG. 1D, in the conventional art, the
ring-shaped ignition position (33) is present in a periphery
of the ejection flow of circular cross section of the
fuel-containing fluid (11) that is ejected from the
fuel-containing fluid supply nozzle (12) of the burner.
Meanwhile, in the present embodiment, the ignition position
(33) is present in a periphery of the ejection flow of
rectangular cross section of the fuel-containing fluid (11)
that is ejected from the fuel-containing fluid supply nozzle
(12) of the burner as shown in FIG. 1B.
In the present embodiment, by making the shape of the
outlet part of the fuel-containing fluid supply nozzle (12)
of the burner a rectangular shape and reducing a length of a
short edge, a length L2 (FIG. 1B) from the ignition position
(33) to a central part of the ejection flow of the
fuel-containing fluid (11) inside the furnace (4) in a
direction perpendicular to the ejection flow of rectangular
cross section of the fuel-containing fluid (11) is reduced
significantly in comparison with the length L2' (FIG. 1D) from
the ignition position (33) to the central part of the ejection
flow of the fuel-containing fluid (11) in the direction
perpendicular to the ejection flow of circular cross section.
FIG. 2 shows sectional views of the fuel-containing fluid
26

, .75870-16 CA 02664769 2009-03-26
supply nozzle (12) of the burner showing that a distance
(unignited distance) Ll (FIG. 2A) that a flame propagates
from the ignition position (33) to the central part of the
fuel ejection flow in an ejection flow direction of the
fuel-containing fluid (11) from the fuel-containing fluid
supply nozzle (12) in the embodiment is reduced in
comparison with the unignited distance Ll' (FIG. 2B) in the
conventional art. In the present embodiment, in accordance
with the reduction of the distance L2 from the ignition
position (33) to the central part of the ejection flow of
the fuel-containing fluid (11) in the direction
perpendicular to the ejection flow of rectangular cross
section in comparison with the distance L2' of the
conventional art, the unignited distance Ll is reduced
significantly in comparison with the unignited distance Ll'
of the conventional art.
FIG. 3 shows a structural example of a burner
according to an embodiment of the present invention. FIG.
3A is a sectional view taken in a direction parallel to a
plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 3B),
FIG. 3B is a sectional view taken on line A-A of FIG. 3A,
and FIG. 3C is a front view of the outlet part of the burner
as viewed from the furnace (4) side.
A cylindrical fuel-containing fluid flow passage
(10) is connected via a connecting part (10a) of circular
cross section to the fuel-containing fluid supply nozzle
(12) having a rectangular cross section and has an adequate
configuration for forming the ejection flow of rectangular
cross section from the fuel-containing fluid supply nozzle
(12) into the furnace (4). Even after the fuel-containing
fluid (11) is loaded into the furnace (4), the fuel-
27

. .75870-16 CA 02664769 2009-03-26
containing fluid (11) spreads along the ejection flow
directions and a cross-sectional area of the ejection flow
of the fuel-containing fluid (11) expands while a flow
velocity decreases, thereby effectively reducing the
unignited distance Li shown in FIG. 2 further. Also,
because the fuel-containing fluid (11) spreads inside the
furnace (4), a combustion space can be utilized effectively
and a practical furnace retention time is made long, thereby
contributing effectively to reduction of NOx concentration
in a combustion gas and improvement in combustion
efficiency. A combustion air sleeve (15) of rectangular
cross section and a burner throat (16) of rectangular cross
section are disposed in a periphery of the fuel-containing
fluid supply nozzle (12).
FIG. 4 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 4A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 48),
FIG. 4B is a sectional view taken on line A-A of FIG. 4A,
and FIG. 4C is a front view of the outlet part of the burner
as viewed from the furnace (4) side.
In the burner shown in FIG. 4, the cross section
of the burner in the direction perpendicular to the ejection
flow of the fuel-containing fluid (11) has an elliptical
shape, and configurations of other parts are the same as
those of the burner shown in FIG. 3.
Although as cross-sectional shapes in a vertical
direction of the burner (direction perpendicular to the
ejection flow of the fuel-containing fluid (11)), the
representative shapes of rectangular and elliptical were
28

75870-16 CA 02664769 2009-03-26
shown in FIGS. 3 and 4, respectively, the same effects as
those mentioned above can be obtained even when a similar
shape, such as a shape with which short sides of a rectangle
have an arcuate shape, an expanded rhombus, etc., is
employed.
FIG. 5 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 5A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 5B),
FIG. 5B is a sectional view taken on line A-A of FIG. 5A,
and FIG. 5C is a front view of the outlet part of the burner
as viewed from the furnace (4) side.
In the burner shown in FIG. 5, whereas a size of
the major axis part gradually increases along the flow
direction of the fuel-containing fluid (11) from the fuel-
containing fluid connecting part (10a) of the fuel-
containing fluid supply nozzle (12) toward the outlet part,
a size of a minor axis part gradually decreases along the
direction of flow of the fuel-containing fluid (11), and
configurations of other parts are the same as those of the
burner shown in FIG. 3.
A characteristic of the burner structure shown in
FIG. 5 is that increase of the flow velocity of the fuel-
containing fluid (11) from the fuel-containing fluid
connecting part (10a) toward the outlet part of the fuel-
containing fluid supply nozzle (12) can be suppressed to
minimize pressure loss and suppress wear of component parts
inside the fuel-containing fluid supply nozzle (12).
FIG. 6 shows a structural example of a burner
according to an embodiment of the present invention.
29

. . 75870-16
CA 02664769 2009-03-26
FIG. 6A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 6B),
FIG. 6B is a sectional view taken on line A-A of FIG. 6A,
and FIG. 6C is a front view of the outlet part of the burner
as viewed from the furnace (4) side.
In the burner shown in FIG. 6, fuel-containing
fluid guide plates (19) are disposed so that the fuel-
containing fluid (11) flowing inside the fuel-containing
fluid supply nozzle (12) is uniformly supplied in directions
in which the fuel-containing fluid supply nozzle (12)
expands along the ejection flow direction, and
configurations of other parts are the same as those of the
burner shown in FIG. 5. In the present example, three fuel-
containing fluid guide plates (19) are installed, and to
make the fuel-containing fluid (11) spread uniformly in
accordance with the spreading of the fuel-containing fluid
supply nozzle (12), a central guide plate (19) is disposed
along the central axis and guide plates (19) at both sides
that sandwich the central guide plate (19) are disposed at
angles a and p with respect to a vertical section passing
through the central axis.
flowing inside the fuel-containing fluid supply nozzle (12) Because the flow
of the fuel-containing fluid (11)
is partitioned plurally by the fuel-containing fluid guide
plates (19), the fuel-containing fluid (11) is spread
uniformly according to the spreading of the fuel-containing
fluid supply nozzle (12) from the fuel-containing fluid
connecting part (10a) toward the outlet part of the fuel-
containing fluid supply nozzle (12) and can be combusted
without imbalance. Also, by the fuel-containing fluid (11)
being spread uniformly, the effects of suppression of
30

75870-16 CA 02664769 2009-03-26
localized increase of flow velocity, minimization of
pressure loss, and suppression of wear of component parts
are improved over those of the configuration shown in
FIG. 5.
FIG. 7 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 7A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 73 is a sectional view taken on line B-B
of FIG. 7A, and FIG. 70 is a sectional view taken on
line A-A of FIG. 7A.
In the burner shown in FIG. 7, the fuel-containing
fluid guide plates (19) are disposed in the same manner as
in the burner shown in FIG. 6 so that the fuel-containing
fluid (11) flowing inside the fuel-containing fluid supply
nozzle (12) is uniformly supplied in directions in which the
fuel-containing fluid supply nozzle (12) expands along the
flow direction, and in the section taken on line A-A of
FIG. 7A, fuel-containing fluid direction changing guide
plates (21a) that change the flow of the fluid (11) downward
with respect to a plane along a line, passing through the
central axis of the fuel-containing fluid supply nozzle (12)
and extending toward the furnace (4), and passing through
the longest axis of the major axis part of the outlet part
are installed at the burner outlet part, and in the section
taken on line B-B of FIG. 7A, fuel-containing fluid
direction changing guide plates (21b) that change the flow
of the fluid (11) upward with respect to the abovementioned
plane are installed at the burner outlet part. Four fuel-
containing fluid ejection flows 20 (20a, 20b) formed by the
fuel-containing fluid supply nozzle (12) and the fuel-
containing fluid guide plates (19) are formed to downwardly
31

. ,
75870-16



CA 02664769 2009-03-26
inclining fuel-containing fluid ejection flows (20a) and
upwardly inclining fuel-containing fluid ejection flows
(20b) by the above-mentioned fuel-containing fluid direction
changing guide plates (21a, 21b). By the burner
5 configuration shown in FIG. 7, dispersion of the fuel-
containing fluid ejection flow (20) inside the furnace (4)
is promoted to provide an effect of promoting combustion at
a wake part of the furnace (4).
FIG. 8 shows a structural example of a burner
10 according to an embodiment of the present invention.
FIG. 8A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 8B is a sectional view taken on line B-B
15 of FIG. 8A, and FIG. 80 is a sectional view taken on
line A-A of FIG. 8A.
In the burner shown in FIG. 8, the fuel-containing
fluid guide plates (19) are disposed in the same manner as
in the burner shown in FIG. 7 so that the fuel-containing
20 fluid (11) flowing inside the fuel-containing fluid supply
nozzle (12) is uniformly supplied in directions in which the
fuel-containing fluid supply nozzle (12) expands along the
flow direction, and in the section taken on line A-A of
25 plates (21a) that rectify and make the flow of the fluid FIG. 8A, fuel-
containing fluid direction changing guide
(11) rectilinear with respect to a plane along a line,
passing through the central axis of the fuel-containing
fluid supply nozzle (12) and extending toward the furnace
(4), and passing through the longest axis of the major axis
30 part of the outlet part are installed at the burner outlet
part, and in the section taken on line B-B of FIG. 8A, fuel-
containing fluid direction changing guide plates (21b) that
change the flow of the fluid (11) upward with respect to the
32

. ,75870-16 CA 02664769 2009-03-26
abovementioned plane are installed at the burner outlet
part. Four fuel-containing fluid ejection flows 20 (20a,
20b) formed by the fuel-containing fluid supply nozzle (12)
and the fuel-containing fluid guide plates (19), are formed
to fuel-containing fluid ejection flows (20a) in a
rectilinear direction and fuel-containing fluid ejection
flows (20b) that are upwardly directed ejection flows by
installation of the above-mentioned fuel-containing fluid
direction changing guide plates (21a, 21b).
In a case where the fuel-containing fluid
direction changing guide plates (21a) are not installed and
only the guide plates (21b) that change the direction are
installed, the same fuel-containing fluid ejection flows
(20a, 20b) are formed.
For example, by making fuel-containing fluid
ejection flows, close to a water wall side at a side wall
side of the furnace (4), rectilinear flows and making fuel-
containing fluid that are not close to the water wall side
at the side wall side of the furnace (4) flows that are
oblique with respect to a central side of the furnace by the
burner configuration shown in FIG. 8, the dispersion of the
fuel-containing fluid ejection flow (20) inside the furnace
(4) is promoted to maintain the effect of promoting the
combustion at the wake part of the furnace (4) and provide
an effect of suppressing inflow of a flame to a vicinity of
the side wall of the furnace (4) to prevent ash deposition.
FIG. 9 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 9A is a sectional view taken in a direction parallel to
a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part, FIG. 9B is perspective view of the burner,
33

, 75870-16 CA 02664769 2009-03-26
FIG. 90 is a sectional view taken on line B-B of FIG. 9A,
and FIG. 9D is a sectional view taken on line A-A of
FIG. 9A.
In the burner shown in FIG. 9, the fuel-containing
fluid guide plates (19) are disposed in the same manner as
in the burner shown in FIG. 7 so that the fuel-containing
fluid (11) flowing inside the fuel-containing fluid supply
nozzle (12) is uniformly supplied in directions in which the
fuel-containing fluid supply nozzle (12) expands along the
flow direction. A front side of an inlet part of the fuel-
containing fluid supply nozzle (12) has a parallelepiped
shape, one side surface (12a) of the fuel-containing fluid
supply nozzle (12) leads to the outlet of the fuel-
containing fluid supply nozzle (12) while being disposed
obliquely downward along the flow direction and the other
side surface (12b) leads to the outlet while being disposed
obliquely upward along the flow direction.
By this configuration, an obliquely downwardly
directed fuel-containing fluid ejection flow (20a) is formed
at a portion close to the side surface (12a) of the fuel-
containing fluid supply nozzle (12) as shown in FIG. 9D, and
an obliquely upwardly directed fuel-containing fluid
ejection flow (20d) is formed at a portion close to the side
surface (12b) of the fuel-containing fluid supply nozzle
(12) as shown in FIG. 90. From two central flow passages
into which the fuel-containing fluid supply nozzle (12) is
partitioned by the fuel-containing fluid guide plates (19),
a fuel-containing fluid ejection flow (20b) having an
ejection flow direction intermediate the fuel-containing
fluid ejection flow (20a) and the central line and a fuel-
containing fluid ejection flow (20c) having an ejection flow
direction intermediate the fuel-containing fluid ejection
flow (20d) and the central line are formed.
34

. ,75870-16 CA 02664769 2009-03-26
Although the effects of the burner configuration
of FIG. 9 are equivalent to those of the burner shown in
FIG. 7, because the fuel-containing fluid direction changing
guide plates (21) are not used to change the ejection
direction of the fuel-containing fluid (11), a problem of
wear that is of concern with the guide plates (21) does not
occur.
FIG. 10 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 10A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 10B),
FIG. 10B is a sectional view taken on line A-A of FIG. 10A,
and FIG. 10C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
Fuel-containing fluid partitioning plates 22,
perpendicular to the flow of the fuel-containing fluid (11)
and partially blocking the flow, are disposed at the outlet
part of the fuel-containing fluid supply nozzle (12). The
fuel-containing fluid ejection flow (20) is partitioned into
four by the fuel-containing fluid partitioning plates (22)
as shown in FIG. 11. By the partitioning, the fuel-
containing fluid ejection flow (20) increases in surface
area, the radiant heating inside the furnace (4) increases,
negative pressure regions (22a) are formed at the wake side
of the fuel-containing fluid partitioning plates (22), and
high-temperature gas in the periphery flows into the
negative pressure regions (22a) as indicated by arrows in
the figure. Increase of the radiant heating and inflow of
the high-temperature gas into the negative pressure regions
(22a) both contribute to early ignition of the fuel, and
combustion in a reducing region in a vicinity of the burner
35

75870-16 CA 02664769 2009-03-26
is promoted to contribute effectively to reduction of the
NOx concentration of the combustion gas and improvement in
the combustion efficiency.
FIG. 12 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 12A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 12B),
FIG. 12B is a sectional view taken on line A-A of FIG. 12A,
and FIG. 12C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
The fuel-containing fluid partitioning plates
(22), perpendicular to the flow of the fuel-containing fluid
(11) and partially blocking the flow, are disposed at the
outlet parts of the fuel-containing fluid guide plates (19)
at the outlet part of the fuel-containing fluid supply
nozzle (12). Because the fuel-containing fluid (11) is
supplied uniformly inside the fuel-containing fluid supply
nozzle (12) by the fuel-containing fluid guide plates (19),
the reduction of NOx and improvement in the combustion
efficiency are realized more effectively.
FIG. 13 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 13A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 132),
FIG. 132 is a sectional view taken on line A-A of FIG. 13A,
and FIG. 13C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
36

. ,75870-16 CA 02664769 2009-03-26
A flame stabilizer (17) with an L-shaped cross
section is installed at the outlet part of the fuel-
containing fluid supply nozzle (12). Because a circular
vortex (not shown) is formed at a wake of the flame
stabilizer (17) and draws back the high-temperature
combustion gas to the vicinity of the flame stabilizer (17),
the configuration contributes to early ignition of the fuel
and promotes combustion in the reducing region in the
vicinity of the burner to effectively contribute to
reduction of the NOx concentration in the combustion gas and
improvement in the combustion efficiency.
FIG. 14 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 14A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 14B),
FIG. 14B is a sectional view taken on line A-A of FIG. 14A,
and FIG. 14C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
A secondary air guide plate (17a) that outwardly
spreads ejection directions of a secondary air is installed
at a front end of the flame stabilizer (17) of L-shaped
cross section shown in FIG. 14. By the secondary air being
spread outward by the guide plate (17a), the vortex flow
(not shown) at the wake of the flame stabilizer (17) is
enlarged, a recirculation amount of the high-temperature gas
is increased, ignition of the fuel is quickened further, and
combustion in the reducing region in the vicinity of the
burner is promoted to effectively contribute to reduction of
the NOx concentration in the combustion gas and improvement
in the combustion efficiency.
37

. ,75870-16 CA 02664769 2009-03-26
FIG. 15 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 15A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 15B),
FIG. 15B is a sectional view taken on line A-A of FIG. 15A,
and FIG. 15C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
In the burner shown in FIG. 15, a tertiary air
guide plate (15a) that outwardly spreads ejection directions
of a tertiary air is installed at a front end of a secondary
air sleeve (15). By the tertiary air being spread outward,
a reducing region at a center part of the flame is enlarged
to effectively contribute to reduction of the NOx
concentration in the combustion gas and improvement in the
combustion efficiency.
FIG. 16 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 16A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 16B),
FIG. 16B is a sectional view taken on line A-A of FIG. 16A,
and FIG. 16C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
In the burner shown in FIG. 16, a fuel-containing
fluid condenser (23), combining a triangular prism gradually
increasing in cross-sectional area from an upstream side and
an oppositely directed triangular prism gradually decreasing
in cross-sectional area at a downstream side, is installed
inside the fuel-containing fluid supply nozzle (12). The
38

75870-16 CA 02664769 2009-03-26
fuel in the vicinity of the flame stabilizer (17) is
condensed by the fuel-containing fluid condenser (23) and
this contributes to early ignition of the fuel, promotes
combustion in the reducing region near the burner, and
thereby effectively contributes to reduction of the NOx
concentration in the combustion gas and improvement in the
combustion efficiency.
FIG. 17 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 17A is a sectional view taken in a direction parallel
to a plane passing through a central axis of the burner and
passing through a longest axis of a major axis part of an
outlet part (sectional view taken on line B-B of FIG. 17B),
FIG. 17B is a sectional view taken on line A-A of FIG. 17A,
and FIG. 17C is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
A fuel-containing fluid condenser (23') combining
a triangular prism gradually increasing in cross-sectional
area at an upstream side, a quadrangular prism at an
intermediate part, and an oppositely directed triangular
prism gradually decreasing in cross-sectional area at a
downstream side, is installed inside the fuel-containing
fluid supply nozzle (12). In the present configuration,
delamination is suppressed by making an angular variation
around the condenser (23') small and a fuel condensing
effect is thereby promoted to heighten the NOx reducing
effect and improve the combustion efficiency.
Although effective configuration examples of the
condenser (23, 23') are shown in FIGS. 16 and 17, the same
effects are obtained even when a condenser with a similar
structure, such as a triangular prism, etc., is employed.
39

75870-16 CA 02664769 2009-03-26
FIG. 18 shows a structural example of a burner
according to an embodiment of the present invention.
FIG. 18A is a sectional view parallel to a fuel-containing
fluid supply nozzle (12) surface formed through a long edge
of an outlet part of the nozzle (12) (sectional view taken
on line B-B of FIG. 18B), FIG. 18B is a sectional view taken
on line A-A of FIG. 18A, and FIG. 18C is a front view of the
outlet part of the burner as viewed from the furnace (4)
side.
In FIG. 18, a dam-like fluid distribution plate
(24) is disposed at an inlet part of the fuel-containing
fluid supply nozzle (12). The fuel-containing fluid (11)
collides once with an upstream side of the dam-like fluid
distribution plate (24) and, after being dispersed uniformly
in the direction of a long edge of the fuel-containing fluid
supply nozzle (12), is guided uniformly into the four flow
passages partitioned by the fuel-containing fluid guide
plates (19) inside the fuel-containing fluid supply nozzle
(12) and supplied into the furnace (4) while being
maintained in a uniform state.
FIG. 19 shows an example where an oil supply
nozzle (41) is installed at a central part of the fuel-
containing fluid supply nozzle (12). FIG. 19A is a
sectional view taken in a direction parallel to a plane
passing through a central axis of the burner and passing
through a longest axis of a major axis part of an outlet
part (sectional view taken on line B-B of FIG. 19B),
FIG. 19B is a sectional view taken on line A-A of FIG. 19A,
and FIG. 190 is a front view of the outlet part of the
burner as viewed from the furnace (4) side.
FIG. 20 shows an example where a gas ejection
part, connected from a gas introduction tube (42) to gas
40

75870-16 CA 02664769 2009-03-26
supply nozzles (44) via a horizontal tube (43), is installed
in a periphery of the flame stabilizer (17).
FIG. 20A is a sectional view taken in a direction
parallel to a plane passing through a central axis of the
burner and passing through a longest axis of a major axis
part of an outlet part (sectional view taken on line B-B of
FIG. 20B), FIG. 20B is a sectional view taken on line A-A of
FIG. 20A, and FIG. 200 is a front view of the outlet part of
the burner as viewed from the furnace (4) side.
FIG. 21 shows, for a burner structure, a front
view as viewed from the furnace (4) side (FIG. 21A) and a
plan view (FIG. 21B) of the fuel-containing fluid supply
nozzle (12), with which the cross-sectional shape
perpendicular to the flow of the fuel-containing fluid (11)
flowing inside the fuel-containing fluid supply nozzle (12)
of the burner is rectangular, in a case where the fuel-
containing fluid supply nozzle (12) is positioned with its
long edge side directed in an up/down direction.
As viewed from the furnace (4) front side, the
fuel-containing fluid ejection flows (20a, 20b) from the
fuel-containing fluid supply nozzle (12) shown in FIG. 21
are formed obliquely toward mutually opposite sides in the
horizontal direction to the left and right with respect to a
plane perpendicular to the furnace wall surface in upper and
lower directions of the long edge side of the nozzle (12).
The forming of the present fuel-containing fluid ejection
flows is achieved by applying the burner structure of FIG. 7
or FIG. 9.
FIG. 22 shows, for a burner structure, a front
view as viewed from the furnace (4) side (FIG. 22A) and a
plan view (FIG. 22B) of the fuel-containing fluid supply
nozzle (12), with which the cross-sectional shape
41

75870-16 CA 02664769 2009-03-26
perpendicular to the flow of the fuel-containing fluid (11)
flowing inside the fuel-containing fluid supply nozzle (12)
of the burner is rectangular, in a case where the fuel-
containing fluid supply nozzle (12) is positioned with its
long edge side directed in an up/down direction.
As viewed from the furnace (4) front side, one
fuel-containing fluid ejection flow (20b) from the fuel-
containing fluid supply nozzle (12) shown in FIG. 22 is
formed obliquely to the horizontal direction with respect to
a plane perpendicular to the furnace wall surface in upper
and lower directions of the long edge side of the nozzle
(12) and the other fuel-containing fluid ejection flow (20c)
is formed perpendicular to the furnace wall surface. The
forming of the present fuel-containing fluid ejection flows
is achieved by applying the burner structure of FIG. 8.
FIG. 23 shows an example where a plurality of the
fuel-containing fluid supply nozzles (12), shown in FIG. 21,
are positioned in three stages in the up/down direction and
four columns in the horizontal direction on a single furnace
wall surface. Fuel-containing fluid supply nozzles (12)
forming ejection flows (20a, 20b) in the same directions as
the nozzles (12) shown in FIG. 21 are disposed at a right
half of the single furnace wall, and fuel-containing fluid
supply nozzles (12) forming ejection flows (20a, 20b) at
mirror symmetric positions with respect to the fuel-
containing fluid supply nozzles (12) shown in FIG. 21 are
disposed at a left half of the furnace wall. By configuring
the directions of the fuel-containing fluid ejection flows
(20a, 20b) to be left/right symmetrical on the single
furnace wall surface, a good left/right balance of flow and
combustion states can be maintained in the furnace (4).
42

. ,75870-16 CA 02664769 2009-03-26
As long as the ejection flows (20a, 20b) from the
fuel-containing fluid supply nozzles (12), disposed
distributedly at left and right halves of a single furnace
wall, are formed at mirror symmetrical positions, the
directions of
43

=75870-16 CA 02664769 2009-03-26
the fuel-containing fluid ejection flows (20a, 20b) from the
nozzles (12) do not necessary have to be as illustrated.
FIG. 24 shows an example where a plurality of the
fuel-containing fluid supply nozzles (12) are positioned in
three stages in the up/down direction and four columns in the
horizontal direction on a single furnace wall surface, with
the fuel-containing fluid supply nozzles (12) shown in FIG.
22 being disposed mirror symmetrically at respective end
columns at the left and right sides and the fuel-containing
fluid supplynozzles (12) shown in FIG. 21 being disposedmirror
symmetrically at two central columns. By aligning the burners
with the rectilinear fuel-containing fluid ejection flows
(20c) and the oblique fuel-containing fluid ejection flows
(20b) along and adjacent the water walls of the side wall of
the furnace (4), and aligning the fuel-containing fluid
ejection flows (20a, 20b), which are inclined obliquely to the
respective sides, along and adjacent the center, the dispersion
within the furnace (4) is promoted to maintain the effect of
promoting the combustion at the wake part of the furnace (4)
while providing the effect of suppressing inflow of the flame
to the vicinity of the side wall of the furnace (4) to prevent
ash deposition.
FIG. 25 shows an example where the fuel-containing fluid
44

75870-16 CA 02664769 2009-03-26
supply nozzles (12) that are all the same and form the
fuel-containing fluid ejection flows (20a, 20b) shown in FIG.
21 are disposed as the fuel-containing fluid supply nozzles
(12) of all of the burners on the single furnace wall. The
present embodiment provides a configuration with which
collision of the fuel-containing fluid ejection flows (20a,
20b) can be avoided, especially in a furnace (4) of small
capacity, and localized concentration of fuel is suppressed
to effectively reduce the NOx concentration in the combustion
gas and improve the combustion efficiency.
By selecting appropriately from the burner structures
of FIGS. 21 to 25 in accordance with furnace dimensions, burner
configurations, and other conditions, optimal combustion
characteristics can be realized.
FIG. 26 is a plan view of a furnace wall of a boiler in
which burners according to an embodiment of the present
invention are disposed. In FIG. 26, in a boiler having spiral
water wall tubes (25) on the furnace wall, rectangular openings
(26) are installed and the various burners described as the
embodiments of the present invention are mounted along an
arrangement of the water wall tubes (25) that is oblique with
respect to the horizontal direction. By disposing the
openings (26) along the spiral water wall tubes (25), a number
45

75870-16 CA 02664769 2009-03-26
of the water wall tubes (25) necessary for forming the openings
(26) can be minimized to improve economy.
As described above, a combustion equipment configured
from the respective embodiments of the present invention has
a characteristic of enabling the combustion space to be
utilized effectively because the fuel-containing fluid
ejection flows (20) spread inside the furnace (4), and with
the configuration shown in FIG. 26, because the fuel-containing
fluid ejection flows (20a, 20b) spread in the horizontal
(width) direction of the furnace (4), a distribution of the
fuel-containing fluid (11) in the horizontal (width) direction
of the furnace (4) is made uniform and the practical furnace
retention time is made even longer, thereby effectively
contributing to the reduction of NOx concentration in the
combustion gas and improvement in combustion efficiency.
FIG. 27 is a plan view of a furnace wall of a boiler in
which burners according to an embodiment of the present
invention are disposed. In FIG. 27, in a boiler having water
wall tubes (25) extending in the vertical direction on the
furnace wall, rectangular openings (26) are installed and the
various burners described as the embodiments of the present
invention are mounted along the arrangement of the water wall
tubes (25). By disposing the openings (26) along the water
46

75870-16 CA 02664769 2009-03-26
wall tubes (25) , the number of the water wall tubes (25)
necessary for forming the openings (26) can be minimized to
improve economy.
In the present configuration, by using the burners shown
in FIGS. 7 to 9 so that the directions of the fuel-containing
fluid ejection flows (20a, 20b) are directed in mutually
different directions to promote the dispersion of the
fuel-containing fluid (11) even in the horizontal (width)
direction of the furnace (4) , the dispersion of the
fuel-containing fluid (11) in the entirety of the furnace is
promoted, thereby effectively contributing to NOx reduction
and improvement in combustion efficiency.
An oil or a gas is generally used as an auxiliary fuel
in a burner, and even when supply nozzles for such fuels are
installed at a part of the burners according to the embodiments
of the present invention, the characteristics and effects of
the burners according to the embodiments of the present
invention are maintained.
INDUSTRIAL APPLICABILITY
As a burner structure capable of following a trend toward
burners of large capacity while reducing cost without lowering
combustion performance, the present invention is high in future
47

75870-16 CA 02664769 2009-03-26
industrial applicability.
DESCRIPTION OF THE SYMBOLS
3 windbox, 4 furnace, 10 fuel-containing fluid flow passage,
10a fuel-containing fluid connecting part, 11
fuel-containing fluid, 12 fuel-containing fluid supply
nozzle
13 secondary air, 14 tertiary air, 15 combustion air sleeve,
15a tertiary air guide plate, 16 burner throat, 17 flame
stabilizer, 17a secondary air guide plate, 19
fuel-containing fluid guide plate, 20, 20a, 20b, 20c, 20d
fuel-containing fluid ejection flow, 21a, 21b
fuel-containing fluid direction changing guide plate, 22
fuel-containing fluid partitioning plate, 22a negative
pressure region, 23, 23' condenser, 24 fluid distribution
plate, 25 water wall tube, 26 opening, 31 unignited region,
32 ignited region, 33 ignition position, 41 oil supply
nozzle, 42 gas introduction tube, 43 horizontal tube, 44
gas supply nozzle, Li unignited distance, L2 distance from
ignition position to central part of fuel-containing fluid
ejection flow
48

Dessin représentatif