FI126037B

FI126037B - Spray nozzle, burner with spray nozzle, and combustor with burner

Info

Publication number: FI126037B
Application number: FI20145014A
Authority: FI
Inventors: Hirofumi Okazaki; Koji Kuramashi; Hideo Okimoto; Akihito Orii; Kenichi Ochi; Yuuki KONDOU
Original assignee: Mitsubishi Hitachi Power Sys
Priority date: 2012-11-16
Filing date: 2014-01-09
Publication date: 2016-06-15
Also published as: FI20145014A; JP6053815B2; JPWO2014076812A1; KR101587744B1; WO2014076812A1; KR20140085412A; MY183923A

Description

{DESCRIPTION} {Title of Invention}

ATOMIZING NOZZLE, BURNER WITH ATOMIZING NOZZLE, AND COMBUSTION APPARATUS WITH BURNER

{Technical Field} {0001} The present invention relates to a twin-fluid atomizing nozzle that uses a spray medium (gas) to convert a spray fluid (liquid) to fine particles, and more particularly to an atomizing nozzle that uses a spray medium to convert a spray fluid of a liquid fuel to fine particles, a burner equipped with the atomizing nozzle, and a combustion apparatus equipped with the burner.

{Background Art} {0002} In many combustion apparatuses that produce a high output under a high load, such as a power generation boiler, a suspension firing method is used in which a fuel is expelled in a horizontal direction toward a furnace space (referred to below as a furnace) provided in a combustion apparatus to burn the fuel.

{0003} When a liquid fuel is burned, an atomizing nozzle is used to convert the fuel to fine particles by using a fluid medium to suspend the fine particles in a furnace to burn the fuel.

{0004} This atomizing nozzle is not only used in a combustion apparatus that uses a liquid fuel as the main fuel but also is often attached to a combustion apparatus that uses a solid fuel of pulverized coal as the main fuel to activate the combustion apparatus and burn a liquid fuel that supports combustion.

{0005} In liquid fuel combustion, the following three items are mainly demanded.

{0006} (1) High combustion efficiency (2) Reduction in combustion emissions typified by particle matter, carbon monoxide, and nitrogen oxides (NOx) (3) Increase in the capacity of the atomizing nozzle to suit enlarged combustion apparatuses.

For the demands in (1) and (2) above, adjustment of the amount of air used for combustion and conversion of a spray of a liquid fuel to fine particles are desirable.

{0007} For adjustment of the amount of air used for combustion, it is desirable to reduce the amount of air in order to increase the combustion efficiency and reduce sensible heat that is dissipated together with an exhaust gas generated after combustion.

{0008} However, when the amount of air is reduced, imperfect combustion occurs and particulate matter and carbon monoxide are likely to be generated. Therefore, extra air is generally given by an amount equal to at least 5% of a theoretical amount of air required for liquid fuel combustion. This is described in Combustion Handbook, the Japan Society of Mechanical Engineers, pp. 167-169, 272 (Non-patent Literature 1).

{0009} As for conversion of a spray of a liquid fuel to fine particles, conversion of the liquid fuel to fine particles hastens a combustion reaction, so even if the amount of combustion air is less, particulate matter and carbon monoxide are less likely to be generated. In addition, when the combustion reaction is hastened, an atmosphere of a high oxygen density at high temperature is less likely to be formed and thereby nitrogen oxides are also less likely to be generated.

{0010} For this reason, an atomizing nozzle used in a burner of a combustion apparatus requires both conversion of a liquid fuel to fine particles and a large capacity of the combustion apparatus to be satisfied.

{0011} It is described in Non-patent Literature 1 that combustion apparatuses such as boilers having a large capacity and heating furnaces generally use an internal-mixing type twin-fluid atomizing nozzle (referred to below as a conventional atomizing nozzle) as an atomizing nozzle of a burner, by which a liquid fuel mixed with a spray medium, such as air or water vapor, is expelled to convert the liquid fuel to fine particles.

{0012} The problems with the above conventional atomizing nozzle are to reduce the amount of spray medium used to convert the liquid fuel to fine particles and to reduce an amount by which a spray fluid and the spray medium are pressurized during spraying.

{0013} If water vapor, for example, is used as the spray medium used to convert a liquid fuel, which is a spray fluid, to fine particles, the water vapor supplied into the combustion apparatus as the spray medium becomes moisture in an exhaust combustion gas generated in the combustion apparatus. If the amount of exhaust gas is increased due to this moisture, the combustion efficiency of the combustion apparatus is reduced. Therefore, it is desirable to reduce the amount of water vapor used as the spray medium in a range in which conversion of the liquid fuel to fine particles is not impeded.

{0014} The spray fluid and spray medium are pressurized when a spray medium used to convert a liquid fuel, which is a spray fluid, to fine particles is expelled. If an amount by which the spray fluid and spray medium are pressurized is reduced, the amount of energy consumed for the pressurization can be reduced.

{0015} To solve the problems described above, methods of mixing a spray medium used to convert a liquid fuel to fine particles have been considered. As one of these, an example of a technology is disclosed in, for example, Japanese Patent Laid-open No. Hei 9(1997)-239299 (Patent Literature 1); in the technology, conversion of the liquid fuel to fine particles is facilitated by supplying mixed fluids of a spray fluid and a spray medium so as to face each other in the vicinity of the outlet of an atomizing nozzle and causing the opposite mixed fluids to strike against each other.

{0016} Since, in the above technology, a spray is formed in a fan shape from the outlet of the atomizing nozzle, the technology is also referred to as the fan spray atomizing nozzle.

{0017} In the technology of the fan spray atomizing nozzle disclosed in Japanese Patent Laid-open No. Hei 9(1997)-239299, a spray medium is mixed with a spray fluid such as a liquid fuel in a flow path on the upstream side of the outlet of the atomizing nozzle and the mixed fluids are made to strike against each other.

{0018} The liquid fuel is converted to fine particles due to mixing with the spray medium and the strike of the mixed fluids in the vicinity of the outlet of the atomizing nozzle. It is disclosed that even if the amount of spray medium to be used is reduced, conversion to fine particles at these two stages prevents the particle diameters of the expelled liquid fuel from becoming large.

{Citation List} {Patent Literature} {0019} {Patent Literature 1} Japanese Patent Laid-open No. Hei 9(1997)-239299 {Non-patent Literature} {0020} {Non-patent Literature 1} Combustion Handbook, the Japan Society of Mechanical Engineers, pp. 167-169, 272 {Summary of Invention} {Technical Problem} {0021} With the fan spray atomizing nozzle disclosed in Japanese Patent Laid-open No. Hei 9(1997)-239299, a flow path for a spray fluid (liquid) is formed in the atomizing nozzle and a flow path for a spray medium (gas) is also formed along the outer circumference of the flow path for the spray fluid.

{0022} The flow directions of the flow path for the spray fluid and the flow path for the spray medium are changed by a partition wall that encloses an outlet at the top of the atomizing nozzle. Both flow paths cross each other, so the spray fluid and spray medium are mixed. Flow paths for the mixed fluid are formed in the vicinity of the outlet so as to face each other.

{0023} With the fan spray atomizing nozzle described above, the mixed fluids flowing so as to face each other strike against each other in the vicinity of the outlet, converting the spray fluid to fine particles. When this occurs, the mixed fluid ejected from the outlet of the atomizing nozzle forms a fan-shaped spray that extends along a plane orthogonal to a flow direction before the strike.

{0024} In general, the fan-shaped spray of the spray fluid expelled from the outlet of the atomizing nozzle has a large amount of flow in the central portion of the spray and a small amount of flow in an outer peripheral portion of the spray. In addition, according to results of measurements by the inventor, the diameters of particles in the spray of the spray fluid expelled from the fan spray atomizing nozzle are relatively large in the central portion of the fan-shaped spray and are small in the outer peripheral portion of the fanshaped spray.

{0025} Since the amount of fluid in the central portion of the fanshaped spray of the spray fluid is larger than in the outer peripheral portion of the spray, the fluid in the central portion is less likely to be mixed with air used for combustion. Furthermore, the particle diameters in the central portion of the spray are large, so the combustion reaction is slow and combustion emissions are thereby likely to be generated.

{0026} This involves a problem in that to facilitate conversion of the spray fluid to fine particles, it is necessary to increase the amount of spray medium to be used or increase pressure to be applied; if the amount of spray medium to be used is increased or pressure to be applied is increased, however, the amount of energy consumed to supply the spray medium or apply pressure is increased, lowering combustion efficiency of the combustion apparatus.

{0027} An object of the present invention is to provide an atomizing nozzle that has improved combustion efficiency by facilitating conversion to fine particles in the central portion of a spray in which particles of the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied, and to provide a burner equipped with the atomizing nozzle and a combustion apparatus equipped with the burner.

{Solution to Problem} {0028} An atomizing nozzle of the present invention to spray a mixed fluid obtained by mixing a spray fluid with a spray medium and converting to fine particles, which is formed with a partition wall forming an outer wall of the atomizing nozzle and a structural body accommodated inside the partition wall. The atomizing nozzle is characterized in that: a plurality of spray fluid flow paths, through which the spray fluid is supplied, are formed with the inner wall of the partition wall and a plurality of grooves formed in the outer surface of the structural body, the outer surface being on the inlet side of the atomizing nozzle; a plurality of spray medium flow paths, through which the spray medium is supplied, are formed in the interior of the structural body on the inlet side of the atomizing nozzle; a first joining part is formed at an intermediate point in each of the plurality of spray fluid flow paths, through which the spray fluid is supplied, so that the spray medium flow path communicates with the spray fluid flow path and the spray fluid and the spray medium supplied from the spray medium flow path join to form a mixed fluid; mixed fluid flow paths are placed in the plurality of spray medium flow paths on a downstream side of the first joining part so as to face each other and communicate with the spray fluid flow paths so that mixed fluids that have flowed down through the spray fluid flow paths flow so as to face each other; a second joining part is formed, in the mixed fluid flow paths, in the vicinity of the end of the atomizing nozzle at which the mixed fluids that have flowed down through the mixed fluid flow paths disposed so as to face each other and strike against each other; an outlet is provided in the partition wall at the end, facing the second joining part, of the atomizing nozzle, the mixed fluid being expelled from the atomizing nozzle through the outlet to the outside; and a contracted portion is formed in the mixed fluid flow paths so that the cross sectional area of the mixed fluid flow paths facing the second joining part is smaller than the cross sectional area of the mixed fluid flow paths on the upstream sides of the second joining part.

{0029} An atomizing nozzle of the present invention that mixes a spray fluid with a spray medium to obtain fine particles which is formed with a partition wall forming an outer wall of the atomizing nozzle and a structural body accommodated inside the partition wall, wherein: a plurality of spray fluid flow paths, through which the spray fluid is supplied, are formed with the inner wall of the partition wall and a plurality of grooves formed in the outer surface of the structural body on an inlet side of the atomizing nozzle; a plurality of spray medium flow paths, through which the spray medium is supplied, are formed in the interior of the structural body on the inlet side of the atomizing nozzle; a first joining part is formed at an intermediate point in each of the plurality of spray fluid flow paths, through which the spray fluid is supplied, so that the spray medium flow path communicates with the spray fluid flow path and the spray fluid and the spray medium supplied from the spray medium flow path join to form a mixed fluid; mixed fluid flow paths are placed in the plurality of spray medium flow paths on a downstream side of the first joining part so as to face each other and communicate with the spray fluid flow paths so that mixed fluids that have flowed down through the spray fluid flow paths flow so as to face each other; a second joining part is formed, in the mixed fluid flow paths, in the vicinity of the end of the atomizing nozzle at which the mixed fluids that have flowed down through the mixed fluid flow paths disposed so as to face each other and strike against each other; an outlet is provided in the partition wall at the end, facing the second joining part, of the atomizing nozzle, the mixed fluid being expelled from the atomizing nozzle through the outlet to the outside; and a contracted portion is formed in the mixed fluid flow paths facing the second joining part so that the cross sectional area of the mixed fluid flow paths facing the second joining part, which cross sectional area is perpendicular to the flow directions of the mixed fluids, is smaller in the central portion in the width direction of the flow paths than at ends in the width direction.

{0030} A burner of the present invention equipped with an atomizing nozzle that uses a liquid fuel as a fuel, wherein the atomizing nozzle described above as the atomizing nozzle, the liquid fuel is supplied to the atomizing nozzle as the spray fluid, and water vapor or compressed air is supplied to the atomizing nozzle as the spray medium.

{0031} A burner of the present invention equipped with a fuel nozzle through which a solid fuel and a gas that conveys the solid fuel are expelled, an atomizing nozzle through which a liquid fuel is expelled, and a combustion gas nozzle through which a combustion gas that burns the solid fuel and the liquid fuel is expelled, wherein the atomizing nozzle described above as the atomizing nozzle, the liquid fuel is supplied to the atomizing nozzle as the spray fluid, and water vapor or compressed air is supplied to the atomizing nozzle as the spray medium.

{0032} A combustion apparatus of the present invention equipped with a burner that burns a fossil fuel comprising: a combustion furnace in which a fossil fuel is burned, a fuel supply system through which a fossil fuel is supplied to the combustion furnace, a combustion gas supply system through which a combustion gas is supplied to the combustion furnace, a burner connected to the fuel supply system and combustion gas supply system and disposed on a furnace wall of the combustion furnace burns the fossil fuel, a heat exchanger that collects heat from an exhaust combustion gas generated in the combustion furnace, and a flue through which the exhaust combustion gas, from which heat has been collected, is released to the outside of the combustion furnace; and the burner of the present invention described above, the burner using a liquid fossil fuel, is used as the burner of the combustion apparatus.

{0033} A combustion apparatus of the present invention equipped with a burner to burn a solid fuel and a liquid fuel comprising: a combustion furnace in which a fuel is burned, a solid fuel supply system through which a solid fuel is supplied to the combustion furnace, a liquid fuel supply system through which a liquid fuel is supplied to the combustion furnace, a combustion gas supply system through which a combustion gas is supplied to the combustion furnace, a plurality of burners connected to the fuel supply systems and combustion gas supply system and disposed on a furnace wall of the combustion furnace, the burners that burns the solid fuel and the liquid fuel, a heat exchanger that collects heat from an exhaust combustion gas generated in the combustion furnace, and a flue through which the exhaust combustion gas, from which heat has been collected, is released to the outside of the combustion furnace; and the burner of the present invention described above is used as the burner of the combustion apparatus.

{Advantageous Effects of Invention} {0034} According to the present invention, it is possible to achieve an atomizing nozzle that has improved combustion efficiency by facilitating conversion to fine particles in the central portion of a spray in which particles in the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied, and to provide a burner equipped with the atomizing nozzle and a combustion apparatus equipped with the burner.

{Brief Description of Drawings} {0035} {Fig. 1} Fig. 1 is a cross sectional view of the end of an atomizing nozzle in a first embodiment of the present invention, illustrating the structure of the atomizing nozzle at a cross section taken along line A-A in Fig. 3.

{Fig. 2} Fig. 2 is a cross sectional view of the end of the atomizing nozzle, illustrated in Fig. 1, in the first embodiment of the present invention when viewed from another direction, as taken along line B-B in Fig. 3.

{Fig. 3} Fig. 3 is a plan view of the end of the atomizing nozzle, illustrated in Fig. 1, in the first embodiment of the present invention when viewed from an outlet.

{Fig. 4} Fig. 4 illustrates an example of performance for conversion to fine particles by the atomizing nozzle in an embodiment of the present invention.

{Fig. 5} Fig. 5 is a cross sectional view of the end of an atomizing nozzle in a second embodiment of the present invention, illustrating the structure of the atomizing nozzle at a cross section taken along line A-A in Fig. 7.

{Fig. 6} Fig. 6 is a cross sectional view of the end of the atomizing nozzle in the second embodiment of the present invention in Fig. 5, illustrating the structure of the atomizing nozzle end at a cross section taken along line B-B in Fig. 7.

{Fig. 7} Fig. 7 is a plan view of the end of the atomizing nozzle, illustrated in Fig. 5, in the second embodiment of the present invention when viewed from an outlet.

{Fig. 8} Fig. 8 schematically illustrates the structure of a burner, in a third embodiment of the present invention, that has the atomizing nozzle in the first embodiment in Fig. 1 or the atomizing nozzle in the second embodiment in Fig. 5.

{Fig. 9} Fig. 9 schematically illustrates the structure of a combustion apparatus, in a fourth embodiment of the present invention, that has the burner in the third embodiment in Fig. 8.

{Description of Embodiments} {0036} An atomizing nozzle in an embodiment of the present invention, a burner equipped with the atomizing nozzle, and a combustion apparatus equipped with the burner will be described with reference to the drawings.

{Embodiment 1} {0037} The structure of an atomizing nozzle in a first embodiment of the present invention will be described with reference to Figs. 1 to 4. The atomizing nozzle 1 in this embodiment is structured so that a spray fluid 2, which is a liquid fuel, and a spray medium 3, which is used to convert the spray fluid 2 to fine particles, join at a first joining part 91 in a spray fluid flow path 4 and are mixed, the cross sectional areas of a mixed fluid flow path 9 and a mixed fluid flow path 10 are narrowed in the vicinity of an outlet 11 of the atomizing nozzle 1 from which mixed fluids 8, obtained by mixing the spray fluid 2 and spray medium 3 together in the mixed fluid flow path 9 and mixed fluid flow path 10 between the first joining part 91 and the outlet 11, are ejected to the outside of the atomizing nozzle 1, and the mixed fluids 8 are made to strike against each other in the vicinity of the outlet 11 and are expelled from the outlet 11 to the outside of the atomizing nozzle 1.

{0038} Figs. 1 to 3 illustrate the end of the atomizing nozzle 1 in this embodiment. Fig. 1 is a cross sectional view of the end of the atomizing nozzle 1, the upstream side of which is connected to a supply system (not illustrated) of the spray fluid 2 (liquid fuel) and to another supply system (not illustrated) of the spray medium 3 (water vapor or compressed air) used to convert the spray fluid 2 to fine particles, as taken along line A-A in Fig. 3. Fig. 2 is a cross sectional view of the end of the atomizing nozzle 1, illustrated in Fig. 1, in this embodiment when the atomizing nozzle end is viewed from another direction, as taken along line B-B in Fig. 3. Fig. 3 is a plan view of the atomizing nozzle end, illustrated in Fig. 1, in this embodiment when the atomizing nozzle is viewed from the outlet. The X direction is a direction of spraying from the atomizing nozzle 1.

{0039} As illustrated in Fig. 1, the end of the atomizing nozzle 1 in this embodiment has a partition wall 15, which is cylindrical wall forming the outer surface at the top of the atomizing nozzle 1 and also includes a structural body 16, which is a columnar body accommodated inside the cylindrical partition wall 15.

{0040} On the outer peripheral side of the structural body 16, grooves are provided which form a plurality of spray fluid flow paths 4 and 5, through which the spray fluid 2, which is a liquid fuel, is supplied. The spray fluid flow paths 4 and 5 are formed between the inner circumferential wall of the cylindrical partition wall 15 and the grooves formed in the structural body 16. An even number (two or four) of spray fluid flow paths 4 and 5 are formed at, for example, symmetric positions in a circumferential direction.

{0041} A plurality of spray medium flow paths 6 and 7 are provided in the structural body 16, independently of the spray fluid flow paths 4 and 5. The spray medium 3 is supplied through the spray medium flow paths 6 and 7, the spray medium 3 being used to convert the spray fluid 2 that has flowed down through the spray fluid flow paths 4 and 5 to fine particles.

{0042} Since the spray medium 3 is supplied through the spray medium flow path 6, which communicates with the spray fluid flow path 4 formed in the outer surface of the structural body 16, the spray fluid 2 flowing in the spray fluid flow path 4 and the spray medium 3 flowing in the spray medium flow path 6 join at the first joining part 91 in the spray fluid flow path 4 and are mixed and the resulting mixed fluid 8 flows toward the downstream of the spray fluid flow path 4. Similarly, since the spray medium 3 is supplied through a spray medium flow path 7, which communicates with the spray fluid flow path 5 formed in the outer surface of the structural body 16, the spray fluid 2 flowing in the spray fluid flow path 5 and the spray medium 3 flowing in the spray medium flow path 7 join at the first joining part 91 in the spray fluid flow path 5 and are mixed and the resulting mixed fluid 8 flows toward the downstream of the spray fluid flow path 5.

{0043} The spray fluid flow paths 4 and 5 respectively communicate with the mixed fluid flow paths 9 and 10 formed in the outer surface of the structural body 16 so as to face each other, the outer surface facing the inner circumference of the partition wall 15, on the downstream side of the spray fluid flow paths 4 and 5.

{0044} The mixed fluid 8 of the spray fluid 2 and spray medium 3 further flows down through the spray fluid flow path 4 and mixed fluid flow path 9, and the other mixed fluid 8 of the spray fluid 2 and spray medium 3 further flows down through the spray fluid flow path 5 and mixed fluid flow path 10. The mixed fluid 8 flowing through the mixed fluid flow path 9 disposed so as to face the mixed fluid flow path 10 and the other mixed fluid 8 flowing through the mixed fluid flow path 10 flow in opposite directions and strike against each other at a second joining part 92.

{0045} The mixed fluids 8 that have flowed down through the mixed fluid flow paths 9 and 10, disposed so as to face each other, strike against each other at the second joining part 92 formed in the vicinity of the outlet 11, which is formed at the end of the atomizing nozzle 1 and communicates with the mixed fluid flow paths 9 and 10. The mixed fluid 8 is then expelled in a fan shape from the outlet 11, which is formed in the partition wall 15 at the end of the atomizing nozzle 1, to the outside, the outlet facing the second joining part 92.

{0046} In this case, the mixed fluid flow path 9 has a bent portion 13 formed on the upstream side of the mixed fluid flow path 9, which communicates with the spray fluid flow path 4, to change the flow direction of the mixed fluid 8 by 90 degrees, and the mixed fluid flow path 10 has a bent portion 14 formed on the upstream side of the mixed fluid flow path 10, which communicates with the spray fluid flow path 5, to change the flow direction of the mixed fluid 8 by 90 degrees, facilitating conversion of the mixed fluid 8 of the spray fluid 2 and spray medium 3 to fine particles in the mixed fluid flow paths 9 and 10.

{0047} With the atomizing nozzle 1 in this embodiment, a contracted portion 17 is formed, in the mixed fluid flow paths 9 and 10 facing the second joining part 92, by which the cross sectional areas of the mixed fluid flow paths 9 and 10 facing the second joining part 92 become smaller than the cross sectional areas of the mixed fluid flow paths 9 and 10 on the upstream sides of the second joining part 92 by providing a convex part 16a protruding to the interior of the mixed fluid flow paths 9 and 10, which becomes an obstacle, is formed on a wall surface, of the structural body 16, that faces the second joining part 92 on a side opposite to the expelling side of the outlet 11, from which the mixed fluid 8 is expelled to the outside, the convex part 16a being formed so as to be integral with the structural body 16 in the mixed fluid flow paths 9 and 10.

{0048} As to the contracted portion 17, it can also be stipulated that the contracted portion 17 is formed in the mixed fluid flow paths 9 and 10 facing the second joining part 92 in the mixed fluid flow paths 9 and 10 so that the cross section area, perpendicular to the flow direction of the mixed fluid, of the mixed fluid flow paths is smaller in the central portion in the width direction of the flow paths 9 and 10 than at ends in the width direction.

{0049} As a means for forming the contracted portion 17 so that the cross section area of the mixed fluid flow paths 9 and 10 facing the second joining part 92, the convex part 16a protruding to the interior of the flow paths 9 and 10, which becomes an obstacle to the mixed fluid 8 flowing in the mixed fluid flow paths 9 and 10, is formed on a wall surface of the structural body 16 that is opposite to the outlet 11 formed in the partition wall 15 facing the second joining part 92.

{0050} The convex part 16a, which is a protruding part protruding to the interior of the mixed fluid flow paths 9 and 10 and by which the contracted portion 17 is formed, is detachably attached to a wall surface of the structural body 16 facing the second joining part 92 so as to be replaceable.

{0051} Since the mixed fluids 8 that have flowed down through the mixed fluid flow paths 9 and 10, disposed so as to face each other, strike against each other at the second joining part 92 formed in the vicinity of the outlet 11 and are expelled from the outlet 11, which is formed at the end of the atomizing nozzle 1, to the outside, the mixed fluid 8 converted to fine particles is expelled to the outside in a fan shape, illustrated in Fig. 2, oriented in a direction (direction of line B-B in Fig. 3) orthogonal to the flow directions in the mixed fluid flow paths 9 and 10 (directions in which the mixed fluid flow paths 9 and 10 are disposed).

{0052} A groove 12 is formed, in the same direction as the direction in which the fan-shaped spray is formed, in the partition wall 15 at the end of the atomizing nozzle 1, at which the outlet 11 of the atomizing nozzle 1, from which the mixed fluid 8 is expelled to the outside, is formed. The groove 12 is oriented in a direction orthogonal to the flow directions of the mixed fluids 8 that flow down through the mixed fluid flow paths 9 and 10, disposed so as to face each other, toward the second joining part 92. A portion at which the groove 12 and the mixed fluid flow paths 9 and 10 cross each other is the outlet 11, through which the mixed fluid 8 is expelled to the outside.

{0053} In the atomizing nozzle 1, illustrated in Fig. 1, in this embodiment, the end of the atomizing nozzle 1 is structured so that the partition wall 15 on the outer side and the structural body 16 inside the partition wall 15 are combined.

{0054} The structure in which the partition wall 15 on the outer side of the atomizing nozzle 1 and the structural body 16, on the inner side, in which the fluid flow paths and spray medium flow paths are formed, are combined is advantageous in that the fluid flow paths and the like can be easily machined.

{0055} With the atomizing nozzle 1 in this embodiment, as for the mixed fluid 8 expelled from the outlet 11 formed at the end of the atomizing nozzle 1, conversion of the spray fluid to fine particles are facilitated mainly by the following three actions.

{0056} (1) Since the flow paths of the spray fluid and spray medium join and the spray fluid and spray medium are thereby mixed, the mixed fluid is converted to fine particles.

{0057} (2) Since the mixed fluid flow path after the flow paths of the spray fluid and spray medium join is bent, the mixed fluid obtained by mixing the spray fluid and spray medium in the mixed fluid flow path is converted to fine particles.

(3) Since the mixed fluids flowing so as to face each other strike against each other in the vicinity of the outlet, the mixed fluid is converted to fine particles.

{0058} The mixed fluid 8 expelled from the outlet 11 due to the strike in (3) above expands, just like a fan-shaped spray illustrated in Fig. 2, along the line indicated by line B-B in Fig. 3, which is orthogonal to the flow direction, indicated by line A-A in Fig. 3, before the strike.

{0059} Since the mixed fluid 8 expelled from the outlet 11 of the atomizing nozzle 1 in this embodiment forms a fan-shaped spray illustrated in Fig. 2, the atomizing nozzle as described above is generally referred to as the fan spray atomizing nozzle.

{0060} As for a spray generated by the fan spray atomizing nozzle, the amount of flow is generally large in a central portion 18 of the fan-shaped spray and is small in an outer peripheral portion 19 of the fan-shaped spray, the outer peripheral portion 19 being disposed around the central portion 18 of the fan-shaped spray.

{0061} In addition, according to results of measurements by the inventor, the diameters of particles of the spray are relatively large in the central portion 18 of the fan-shaped spray and small in the outer peripheral portion 19 of the fan-shaped spray.

{0062} In the outer peripheral portion 19 of the fan-shaped spray, the spray is easily expanded and a thin liquid film is thereby formed, so fine particles with diameters of less than 100 pm are increased. In addition, since kinetic momentum of fine particles is small, fine particles are likely to stay in the vicinity of the atomizing nozzle 1.

{0063} Particles converted to fine particles with diameters of less than 100 pm, preferably 50 pm or less (these particles are simply referred to below as fine particles) have a large surface area with respect to the volume, so they are likely to be heated and burned due to heat radiation from the interior of a furnace, which is a combustion apparatus.

{0064} Accordingly, when these fine particles are made to stay in the vicinity of the atomizing nozzle 1, the spray is fired at an earlier time, contributing to flame stabilization and facilitation of combustion reaction.

{0065} The degree of fine particles can be adjusted by adjusting the pressure of the mixed fluid 8 or the amount of spray medium (the ratio of the spray medium 3 to the spray fluid 2).

{0066} The amount of flow in the central portion 18 of the fanshaped spray is larger than the amount of flow in the outer peripheral portion 19 of the fan-shaped spray. In the central portion 18, therefore, the spray is not easily expanded and a thicker film than in the outer peripheral portion is formed, causing many large particles (with diameters of 100 to 300 μηπ) to be present.

{0067} Large particles have larger kinetic momentum than fine particles and are thereby likely to be mixed with combustion air flowing at a distance. However, the combustion reaction of large particles is slower than the combustion reaction of fine particles.

{0068} To facilitate combustion reaction, it is desirable to reduce the diameters of particles in the central portion 18 of the fan-shaped spray by reducing the amount of flow in the central portion 18 of the fan-shaped spray. Accordingly, it is desirable to increase the action in (3) above by increasing the speed at which the mixed fluids 8 strike against each other.

{0069} If the cross sectional areas of the mixed fluid flow paths 9 and 10 are uniformly narrowed to increase the striking speed, the flow speed of the mixed fluid 8 is raised but there is a problem in that the pressure loss is increased and energy required to pressurize the spray fluid 2 and spray medium 3 is increased.

{0070} In the atomizing nozzle 1 in this embodiment, therefore, in the flow path structure formed by the inner wall of the partition wall 15 and on the outer surface of the structural body 16 disposed inside the partition wall 15, the partition wall 15 and structural body 16 constituting the atomizing nozzle 1, the contracted portion 17 is formed so that the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed by providing the convex part 16a integrally with the structural body 16 so as to protrude to the interior of the mixed fluid flow paths 9 and 10 on a wall of the structural body 16 on a side opposite to the expelling side of the outlet 11 in the central portion in the width direction of the mixed fluid flow paths 9 and 10 facing the second joining part 92 in the cross section of the mixed fluid flow paths 9 and 10 disposed so as to face each other in the vicinity of the outlet 11 so that the mixed fluids 8 strike against each other, as illustrated in Figs. 1 to 3.

{0071} That is, in the atomizing nozzle 1 in this embodiment, the above problems are solved by providing two structures indicated in (A) and (B) below.

{0072} (A) The cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed only in the vicinity of the outlet 11.

{0073} (B) The cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed particularly in the central portion in the width direction of the flow paths.

{0074} In this atomizing nozzle 1 in the present embodiment, the structure in (A) above is used, so the flow speed of the mixed fluid 8 in the vicinity of the outlet 11 of the atomizing nozzle 1 is high, but a portion at high flow speed is smaller than a case in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are uniformly narrowed. Accordingly, an increase in pressure loss can be suppressed.

{0075} When the flow speed is changed so as to be raised, the static pressure of the mixed fluid 8 is lowered in the contracted portion 17 of the flow path cross sectional area formed in the mixed fluid flow paths 9 and 10. At this time, the spray medium 3 in the mixed fluid 8 is a gas, so its volume is increased as the static pressure is lowered. When the volume is increased, the spray fluid 2 (liquid) is split and is converted to fine particles, facilitating conversion of the mixed fluid 8 to fine particles.

{0076} As for the contracted portion 17 formed in the mixed fluid flow paths 9 and 10, which narrows the cross sectional areas of the flow paths by providing the convex part 16a integrally with the structural body 16 so as to protrude to the interior of the mixed fluid flow paths 9 and 10 on a wall of the structural body 16 on a side opposite to the expelling side of the outlet 11, the shape of the convex part 16a is preferably, for example, a curved shape so that the flow path cross sectional area of the contracted portion 17 is smoothly changed, as illustrated in Fig. 1.

{0077} When the shape of the convex part 16a has a curved shape and the contracted portion 17 provided in the mixed fluid flow paths 9 and 10 is formed so that its flow path cross sectional area is smoothly changed, an increase in pressure loss can be reduced when compared with a case in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are changed stepwise.

{0078} When the static pressure is lowered in the portion in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed, conversion of the mixed fluid 8 to fine particles is facilitated.

{0079} In the atomizing nozzle 1 in this embodiment, since the structure in (B) above is used, in the vicinity of the outlet 11 of the atomizing nozzle 1, the amount of flow of the mixed fluid 8 flowing in the central portion in the width direction of the mixed fluid flow paths 9 and 10 is reduced and the amount of flow of the mixed fluid 8 flowing at the ends in the width direction of the mixed fluid flow paths 9 and 10 is increased.

{0080} After the mixed fluids 8 have struck against each other at the second joining part 92 in the mixed fluid flow paths 9 and 10 in the vicinity of the outlet 11, the mixed fluid 8 is expelled, in the form of a fan-shaped spray illustrated in Fig. 2, from the outlet 11 to the outside of the atomizing nozzle 1 in a direction (direction indicated by line B-B in Fig. 3) orthogonal to the direction in which the mixed fluid flow paths 9 and 10 are disposed.

{0081} In this case, the mixed fluids 8 flowing at the ends in the width direction of the mixed fluid flow paths 9 and 10 receive more restrictions in the flow direction than the mixed fluids 8 flowing in the central portion in the width direction of the flow paths, so the mixed fluids 8 flowing at the ends are bent at right angles (in the direction indicated by line B-B in Fig. 3) and is likely to flow in the outer peripheral portion 19 of the fan-shaped spray illustrated in Fig. 2.

{0082} In the atomizing nozzle 1 in this embodiment, therefore, since the mixed fluids 8 flowing at the ends in the width direction of the mixed fluid flow paths 9 and 10 are increased in the vicinity of the outlet 11, the mixed fluid 8 is expelled from the outlet 11 of the atomizing nozzle 1 in such a way that the amount of flow of the mixed fluid 8 flowing in the outer peripheral portion 19 of the fan-shaped spray is increased and the amount of flow of mixed fluid 8 flowing in the central portion 18 of the fan-shaped spray is decreased.

{0083} Accordingly, the liquid film is thin in the central portion 18 of the fan-shaped spray. This liquid film is split due to surface tension or the like and the diameters of the resulting spray particles also become small. As a result, performance to convert to fine particles is improved in the central portion 18 of the fan-shaped spray.

{0084} Fig. 4 illustrates an example of performance for conversion to fine particles by the atomizing nozzle in a first embodiment of the present invention. The vertical axis in the drawing indicates the average particle diameter of the spray, and the horizontal axis indicates the angel of the spray. As the average particle diameter of the spray, particle diameters were optically measured for a fan-shaped spray expelled from the outlet 11 at a position 300 mm downstream of the spray in the longitudinal direction (direction indicated by line B-B in Fig. 3) passing through the central axis of the fan-shaped spray; the average particle diameter of the spray is indicated as a volume-surface mean diameter. In the drawing, a distribution of particle diameters obtained with the atomizing nozzle in this embodiment is indicated by using relative values with respect to a volume-surface mean diameter obtained with an atomizing nozzle in a comparative embodiment.

{0085} As illustrated in Fig. 4, with the atomizing nozzle in the comparative embodiment, the central portion of the spray has a larger average particle diameter than the outer peripheral portion.

{0086} In contrast, with the atomizing nozzle in this embodiment, the average particle diameter of the central portion of spray can be made smaller than that of the central portion with the atomizing nozzle in the comparative embodiment.

{0087} In contrast, with the atomizing nozzle in this embodiment, the outer peripheral portion of the spray has slightly large diameters. However, in the central portion of the spray, in which the average particle diameter becomes large with the atomizing nozzle in the comparative embodiment, the atomizing nozzle in this embodiment can reduce particle diameters, so the entire performance of the mixed fluid 8 for conversion to fine particles is improved.

{0088} With the atomizing nozzle 1 in this embodiment illustrated in Figs. 1 to 3, to form the contracted portion 17, which narrows the cross sectional areas of the mixed fluid flow paths 9 and 10, the protruding convex part 16a, which becomes an obstacle, is provided inside the mixed fluid flow paths 9 and 10 on the wall surface at the end of the structural body 16 on a side opposite to the expelling side of the outlet 11. However, it is also possible to form the contracted portion 17 so that it narrows the cross sections of the flow paths by changing the depths of the grooves of the mixed fluid flow paths 9 and 10, instead of providing the convex part 16a.

{0089} When the convex part 16a, which becomes an obstacle, is attached to the wall surface at the end of the structural body 16, the convex part 16a is desirably attached with screws, pins, or other fasteners.

{0090} If the convex part 16a in the mixed fluid flow paths 9 and 10 is subject to wear in a high flow speed portion, it is only necessary to replace the convex part 16a which becomes a target.

{0091} If the convex part 16a, which becomes an obstacle, is formed with a wear-resistant material, durable time is prolonged and a portion in which a wear-resistance material is used is reduced when compared with a case in which the entire mixed fluid flow paths 9 and 10 are formed with a wear-resistance material; this is advantageous from the viewpoint of costs.

{0092} Wear-resistance materials generally have higher wear resistance than other materials, but their resistance to heat and thermal deformation is often low. If the convex part 16a is formed with a wear-resistance material, therefore, a portion in which a wear-resistance material is used can be reduced and resistance to heat and thermal deformation is improved due to a small amount of displacement by thermal deformation. Accordingly, durable time is prolonged when compared with a case in which the entire mixed fluid flow paths 9 and 10 in the atomizing nozzle 1 are formed with a wear-resistance material.

{0093} Although a case in which the atomizing nozzle 1 in this embodiment has only a single outlet 11 has been described, even if a plurality of outlets 11 are provided, an effect of converting the mixed fluid 8 expelled to fine particles was obtained by forming, in the atomizing nozzle 1 in this embodiment, the contracted portion 17, which narrows the cross sectional areas of the mixed fluid flow paths 9 and 10, through which the mixed fluid 8 flows down, in the central portion in the width direction of the mixed fluid flow paths 9 and 10 in the vicinity of the outlet 11 facing the second joining part 92, that is, by forming the contracted portion 17 by which the cross sectional areas of the mixed fluid flow paths 9 and 10 in the central portion in their width direction are made narrower than the cross sectional areas of the mixed fluid flow paths 9 and 10 at the ends in their width direction as indicated by the broken lines in Fig. 3.

{0094} If the atomizing nozzle 1 has a so-called porous structure in which an increased number of outlets 11 are formed, it is also possible to increase the amount of mixed fluid 8 expelled from the atomizing nozzle 1 without increasing the amount of mixed fluid 8 expelled from a single outlet 11. That is, the atomizing nozzle 1 can have a large capacity by increasing the number of outlets 11 while performance to convert to fine particles is maintained.

{0095} According to the atomizing nozzle 1 in this embodiment, since the contracted portion 17 is formed so that the cross sectional areas of the mixed fluid flow paths 9 and 10, through each of which the mixed fluid 8 obtained by mixing the spray fluid 2 and spray medium 3 flows down, are narrowed in the mixed fluid flow paths 9 and 10 in the vicinity of the outlet 11 facing the second joining part 92, the flow speeds of the mixed fluids 8 are accelerated in the vicinity of the outlet 11.

{0096} Then, in the vicinity of the outlet 11, the accelerated flows of the mixed fluids 8 strike against each other at the second joining part 92 formed in the mixed fluid flow paths 9 and 10 as opposite flows, and are expelled from the outlet 11 to the outside of the atomizing nozzle 1. As a result, the spray of the mixed fluids 8 expelled from the outlet 11 due to the strike of the opposite flows of the mixed fluids 8 has a thin fan-shaped film, and the particle diameters of the spray formed by the thin liquid film become small.

{0097} Since the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed only in the contracted portion 17 in the vicinity of the outlet 11, the pressure loss of the mixed fluids 8 flowing through the mixed fluid flow paths 9 and 10 can be reduced while flow speeds necessary for the mixed fluids 8 to strike against each other are maintained.

{0098} Since the flow speeds of the mixed fluids 8 flowing down through the mixed fluid flow paths 9 and 10 are increased in the vicinity of the outlet 11 facing the second joining part 92, the mixing of the spray fluid 2 and spray medium 3, which form the mixed fluid 8, is facilitated and conversion of the mixed fluid 8 to fine particles is facilitated by the facilitated mixing.

{0099} In addition, in narrowing the cross sectional areas of the mixed fluid flow paths 9 and 10 in the contracted portion 17 in the vicinity of the outlet 11 facing the second joining part 92, the contracted portion 17 is formed so that the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed only in the central portion in their width direction as compared with the cross sectional areas at the ends, which are the peripheral portions of the mixed fluid flow paths 9 and 10, in the width direction. Accordingly, the amount of flow of the mixed fluid 8 flowing in the central portion of the mixed fluid flow paths 9 and 10 in their width direction is reduced and the amount of flow flowing at the ends of the mixed fluid flow paths 9 and 10 in their width direction is increased.

{0100} As a result, the thickness of the liquid film of the fan-shaped spray, which is the spray of the mixed fluids 8 expelled from the outlet 11 to the outside of the atomizing nozzle 1 after the mixed fluids 8 have struck against each other at the second joining part 92 in the mixed fluid flow paths 9 and 10 in the vicinity of the outlet 11, becomes thin in the central portion 18 of the fan-shaped spray illustrated in Fig. 2 and the particle diameters of the spray become small therein.

{0101} The amount of flow of the fan-shaped spray is reduced in the central portion 18 of the fan-shaped spray. In contrast, the amount of flow is increased in the outer peripheral portion 19, of the fan-shaped spray, which is around the central portion 18 of the fan-shaped spray, but the amount of flow in the outer peripheral portion 19 of the fan-shaped spray is smaller than or equal to the amount of flow in the central portion 18 of the fan-shaped spray, so mixing with the surrounding gas is more likely to be facilitated in the outer peripheral portion 19 of the fan-shaped spray than in the central portion 18 of the fan-shaped spray. Accordingly, the particle diameters of the spray are almost the same.

{0102} With the atomizing nozzle 1 in this embodiment, the amount of flow is reduced in the central portion 18 of the fan-shaped spray and is increased in the outer peripheral portion 19. Particle diameters are small in the central portion 18 of the fan-shaped spray and remain almost unchanged in the outer peripheral portion 19. Accordingly, particle diameters of the whole spray including the central portion 18 and outer peripheral portion 19 of the fan-shaped spray become small.

{0103} That is, when the atomizing nozzle in this embodiment is used, conversion to fine particles can be facilitated by using the same amount of spray medium. It is also possible to suppress the amount of spray medium necessary to obtain performance for conversion to fine particles or to reduce pressure to be applied to the spray fluid and spray medium.

{0104} In addition, with the atomizing nozzle in this embodiment, the amount of flow is reduced in the central portion 18 of the fan-shaped spray, so the spray evenly expands in the space, facilitating mixing with combustion air.

{0105} Conversion to fine particles and facilitated mixing with combustion air hasten combustion reaction, reducing unburned fuel, particulate matter, and carbon monoxide at the outlet of the combustion apparatus and thereby increasing combustion efficiency. Since combustion reaction is hastened, more oxygen is consumed. This makes it possible to suppress generation of nitrogen oxides. Furthermore, since unburned fuel, particulate matter, and carbon monoxide are reduced, an extra amount of air to be supplied to the combustion apparatus can be reduced.

{0106} When an extra amount of air is reduced, the amount of exhaust combustion gas is also reduced, so sensible heat released to the outside of the combustion apparatus together with the exhaust combustion gas is reduced. This makes it possible to increase thermal efficiency.

{0107} With a combustion apparatus that uses the atomizing nozzle in this embodiment, since the amount of spray medium to be used is suppressed or its pressure is reduced, energy consumed for each supply or to apply pressure can be reduced.

{0108} If water vapor is used as the spray medium, the water vapor supplied into the combustion apparatus reduces thermal efficiency of the combustion apparatus. If the atomizing nozzle in this embodiment is used, however, even if the amount of water vapor to be used is reduced, conversion to fine particles can be maintained. This makes it possible to prevent thermal efficiency from being lowered.

{0109} According to this embodiment, it is possible to achieve an atomizing nozzle that has improved combustion efficiency by facilitating conversion to fine particles in the central portion of a spray in which particles in the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied.

{Embodiment 2} {0110} The structure of an atomizing nozzle in a second embodiment of the present invention will be described with reference to Figs. 5 to 7.

{0111} The atomizing nozzle 61, illustrated in Figs. 5 to 7, in this embodiment has a basic structure common to the atomizing nozzle 1, illustrated in Figs. 1 to 4, in the first embodiment, so descriptions of the structure common to the first and second embodiments will be omitted.

{0112} Figs. 5 to 7 illustrate the end of the atomizing nozzle 61 in this embodiment. Fig. 5 is a cross sectional view of the end of the atomizing nozzle 61, the upstream side of which is connected to a supply system (not illustrated) of the spray fluid 2 (liquid fuel) and to another supply system (not illustrated) of the spray medium 3 (such as water vapor or compressed air) used to convert the spray fluid 2 to fine particles, as taken along line A-A in Fig. 7. Fig. 6 is a cross sectional view of the end of the atomizing nozzle 61, illustrated in Fig.5, in this embodiment when the end of the atomizing nozzle 61 is viewed from another direction, as taken along line B-B in Fig. 7. Fig. 7 is a plan view of the end of the atomizing nozzle 1, illustrated in Fig. 5, in this embodiment when the atomizing nozzle 61 is viewed from the outlet. The X direction is a direction of spraying from the atomizing nozzle 61.

{0113} The atomizing nozzle 61, illustrated in Figs. 5 to 7, in this embodiment is a fan spray atomizing nozzle that has basically the same structure as the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4.

{0114} The atomizing nozzle 61 in this embodiment has a flow path structure common to the atomizing nozzle 1, illustrated in Figs. 1 to 4, in the first embodiment; the atomizing nozzle 61 is structured so as to have the contracted portion 17 by which the cross sectional areas of the mixed fluid flow paths 9 and 10 disposed opposite to each other is narrowed in the vicinity of the outlet 11, which becomes the second joining part 92.

{0115} With the atomizing nozzle 61 in this embodiment, the contracted portion 17 by which the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed only in the vicinity of the outlet 11 facing the second joining part 92 is formed over the entire width of the flow paths including the ends in the width direction rather than only in the central portion in the width direction of the flow paths, as illustrated in Fig. 7. Therefore, the flow speed of the mixed fluid 8 is increased in the vicinity of the outlet 11.

{0116} In contrast, a portion at high speed is smaller than in a case in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are uniformly narrowed. Accordingly, an increase in pressure loss can be suppressed.

{0117} When the flow speed of the mixed fluid 8 flowing down through the mixed fluid flow paths 9 and 10 is changed so as to be raised, the static pressure of the mixed fluid 8 is lowered in the vicinity of the contracted portion 17. At this time, the spray medium 3 in the mixed fluid 8 is a gas, so its volume is increased as the static pressure is lowered.

{0118} When the volume is increased, the spray fluid 2 (liquid) is split and is converted to fine particles, facilitating conversion of the mixed fluid 8 to fine particles.

{0119} Although, as illustrated in Fig. 5, a convex part 16b in a curved shape is provided so as to protrude to the interior of the mixed fluid flow paths 9 and 10 on a wall, of the structural body 16, facing a side opposite to the expelling side of the outlet 11 in the vicinity of the outlet 11 facing the second joining part 92 in the mixed fluid flow paths 9 and 10, and the contracted portion 17, which narrows the cross sectional areas of the mixed fluid flow paths 9 and 10, is formed, the convex part 16b is attached to the structural body 16 as a body separated from the structural body 16. Accordingly, the convex part 16b is replaceable.

{0120} Since the convex part 16b is formed in a curvature shape so that the contracted portion 17 smoothly changes the cross sectional areas of the mixed fluid flow paths 9 and 10, an increase in pressure loss can be reduced when compared with a case in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are changed stepwise.

{0121} When the static pressure is lowered in the portion in which the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed, conversion of the mixed fluid 8 to fine particles is facilitated.

{0122} With the atomizing nozzle 61, illustrated in Figs. 5 to 7, in this embodiment, the contracted portion 17 by which the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed by forming the convex part 16b protruding to the interior of the mixed fluid flow paths 9 and 10 on a wall surface, of the structural body 16, that faces the second joining part 92 on a side opposite to the expelling side of the outlet 11 from which the mixed fluid 8 is expelled to the outside.

{0123} When the convex part 16b in a curvature shape is provided on a wall surface, of the structural body 16, on a side opposite to the outlet 11, which is an expelling side, in this way, the mixed fluids 8 flowing through the mixed fluid flow paths 9 and 10 induce a flow directed toward an expelling direction (X direction in Fig. 5) in the vicinity of the outlet 11.

{0124} Accordingly, although the mixed fluids 8 strike against each other at high speed, the speed components of the mixed fluids 8 in the expelling direction (X direction) become high, so the flow speeds of expelled particles of the mixed fluid 8 expelled from the atomizing nozzle 61 are increased, enabling particles with small diameters to be expelled at high speed.

{0125} In the atomizing nozzle 61 in this embodiment, the mixed fluids 8 that have flowed down through the mixed fluid flow paths 9 and 10 disposed opposite to each other strike against each other at the second joining part 92 disposed in the vicinity of the outlet 11, after which the mixed fluid 8 is expelled from the outlet 11 formed at the top of the atomizing nozzle 61 to the outside. Then, the mixed fluid 8 converted to fine particles is expelled to the outside by forming a fan-shaped spray, illustrated in Fig. 8, in a direction (direction indicated by line B-B in Fig. 7) orthogonal to the flow direction (direction in which the mixed fluid flow paths 9 and 10 are disposed) in the mixed fluid flow paths 9 and 10.

{0126} A groove 12 is formed, in the same direction as the direction in which the fan-shaped spray is formed, in the partition wall 15 at the end of the atomizing nozzle 61, at which the outlet 11 of the atomizing nozzle 61, from which the mixed fluid 8 is expelled to the outside, is formed. A portion in which the groove 12 and the mixed fluid flow paths 9 and 10 cross each other is the outlet 11, through which the mixed fluid 8 is expelled to the outside.

{0127} When the convex part 16b, which becomes an obstacle, is attached to the wall surface at the end of the structural body 16, the convex part 16b is desirably attached with screws, pins, or other fasteners.

{0128} If the convex part 16b in the mixed fluid flow paths 9 and 10 is subject to wear in a high flow speed portion, it is only necessary to replace the convex part 16b which becomes a target.

{0129} If the convex part 16b is formed with a wear-resistant material, durable time is prolonged and a portion in which a wear-resistance material is used is reduced when compared with a case in which the entire mixed fluid flow paths 9 and 10 are formed with a wear-resistance material; this is advantageous from the viewpoint of costs.

{0130} Wear-resistance materials generally have higher wear resistance than other materials, but their resistance to heat and thermal deformation is often low. If the convex part 16b is formed with a wear-resistance material, therefore, a portion in which a wear-resistance material is used can be reduced and resistance to heat and thermal deformation is improved due to a small amount of displacement by thermal deformation. Accordingly, durable time is prolonged when compared with a case in which the entire mixed fluid flow paths 9 and 10 in the atomizing nozzle 1 are formed with a wear-resistance material.

{0131} With the atomizing nozzle 61 in this embodiment, to form the contracted portion 17, which narrows the cross sectional areas of the mixed fluid flow paths 9 and 10, the convex part 16b with a curved surface, which protrudes so as to become an obstacle, is provided inside the mixed fluid flow paths 9 and 10 on the wall surface at the end of the structural body 16 on a side opposite to the expelling side of the outlet 11. However, it is also possible to form the contracted portion 17 so that it narrows the cross sections of the flow paths by changing the depths of the grooves of the mixed fluid flow paths 9 and 10, instead of providing the convex part 16b.

{0132} Although, with the atomizing nozzle 61 in this embodiment, the convex part 16b, which becomes an obstacle, has been provided on the front surface of the wall at the end of the structural body 16, the wall being opposite to the outlet 11 in the mixed fluid flow paths 9 and 10, even if the convex part 16b with a curved surface, which protrudes so as to become an obstacle, is provided inside the mixed fluid flow paths 9 and 10 on a side surface of the wall at the end of the structural body 16 instead of the front surface of the wall at the end of the structural body 16, the cross sectional areas of the mixed fluid flow paths 9 and 10 are narrowed, so the effect described above can be obtained.

{0133} If the atomizing nozzle 61 in this embodiment is used, the amount of spray medium to be used is suppressed or its pressure is reduced, energy consumed for each supply or to apply pressure can be reduced. If water vapor is used as the spray medium, the water vapor supplied into the combustion apparatus reduces thermal efficiency of the combustion apparatus. If the atomizing nozzle in this embodiment is used, however, even if the amount of water vapor to be used is reduced, conversion to fine particles can be maintained. This makes it possible to prevent thermal efficiency from being lowered.

{0134} Although a case in which the atomizing nozzle 61 in this embodiment has only a single outlet 11, through which the mixed fluid 8 is expelled to the outside of the atomizing nozzle 61, has been described, even if a plurality of outlets 11 are provided, an effect of converting the mixed fluid 8 to fine particles is obtained by forming, in the atomizing nozzle 61 in this embodiment, the convex part 16b in a curved shape, which protrudes to the interior of the mixed fluid flow paths 9 and 10, on a wall surface, of the structural body 16, that faces the second joining part 92 in the mixed fluid flow paths 9 and 10 in the vicinity of the outlet 11 to form the contracted portion 17, which narrows the cross sectional areas of the mixed fluid flow paths 9 and 10 over their entire width direction as illustrated in Figs. 5 to 7.

{0135} If the atomizing nozzle 61 has a so-called porous structure in which an increased number of outlets 11 are formed, it is also possible to increase the amount of mixed fluid 8 expelled from the atomizing nozzle 1 without increasing the amount of mixed fluid 8 expelled from a single outlet 11. That is, the atomizing nozzle 1 can have a large capacity by increasing the number of outlets 11 while performance to convert to fine particles is maintained.

{0136} According to this embodiment, as illustrated in Fig. 6, it is possible to achieve an atomizing nozzle that has improved combustion efficiency by facilitating conversion to fine particles in the central portion 18 of a fan-shaped spray in which particles in the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied.

{Embodiment 3} {0137} Next, a burner, in a third embodiment of the present invention, equipped with an atomizing nozzle will be described with reference to Fig. 8, the burner including the atomizing nozzle 1 in the first embodiment of the present invention or the atomizing nozzle 61 in the second embodiment.

{0138} The atomizing nozzle 1 or 61 used in the burner equipped with an atomizing nozzle, illustrated in Fig. 8, in this embodiment is the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7. Therefore, structures common to the atomizing nozzles 1 and 61 in the first and second embodiments will be omitted.

{0139} Fig. 8 illustrates an embodiment of a burner, in this embodiment, equipped with an atomizing nozzle. In the burner 20, in this embodiment illustrated in Fig. 8, equipped with the atomizing nozzle 1 or 61, the burner 20 in this embodiment has the atomizing nozzle 1, illustrated in Figs. 1 to 3, through which the mixed fluid 8 of a spray fluid and a spray medium is expelled, or the atomizing nozzle 61, illustrated in Figs. 5 to 7, through which the mixed fluid 8 of a spray fluid and a spray medium is expelled, at the end of a central axis 21 of the burner 20. An obstacle 22 used to stabilize a flame is provided in the vicinity of the end of the central axis 21.

{0140} The obstacle 22 disposed on the central axis 21 is generally a swirl vane, which generates a swirl flow, or a baffle plate with slots. When the mixed fluid 8 obtained by mixing the spray fluid 2 and spray medium 3 is expelled from the atomizing nozzle 1 or 61, a spray 23 in a fan shape is formed, like the spray, illustrated in Fig. 2, obtained with the atomizing nozzle 1 in the first embodiment or the spray, illustrated in Fig. 6, obtained with the atomizing nozzle 61 in the second embodiment.

{0141} Combustion air in the burner 20 is supplied from a wind box 24 through three flow paths: a primary flow path 25, a secondary flow path 26 and a tertiary flow path 27, which are disposed in that order from the vicinity of the atomizing nozzle 1 at the center. Primary air 28, secondary air 29, and tertiary air 30 are respectively supplied through the primary flow path 25, secondary flow path 26, and tertiary flow path 27 and are expelled into the furnace 31.

{0142} The directions in which these combustion airs are expelled are changed by swirl generators 32 and 33, which are respectively provided in the secondary flow path 26 and tertiary flow path 27 in the wind box 24 and by a guide plate 34 provided near the outlet between the secondary flow path 26 and the tertiary flow path 27, after the combustion airs are supplied into the furnace 31. Thus, generation of particulate matter and nitrogen oxides is suppressed.

{0143} The amounts of flows of these combustion airs are controlled by dampers (not illustrated) provided in the primary flow path 25, secondary flow path 26, and tertiary flow path 27.

{0144} The burner 20 is attached to a furnace wall 35 of the furnace 31. A heat exchanger tube 36 is attached to the furnace wall 35 to collect heat.

{0145} Combustion air to be supplied to the burner 20, in this embodiment, equipped with the atomizing nozzle 1 or 61 is branched from a combustion air supply system 41 to pipes 45 and 46 as illustrated in Fig. 9, which illustrates a combustion apparatus, in a fourth embodiment described later, equipped with a burner. The branched air is expelled from the burner 20 and an air supply port 44 into the furnace 31. Since the combustion air is supplied separately from the burner 20 and air supply port 44 into the furnace 31, the temperature of a flame formed in the burner 20 is lowered.

{0146} In addition, if a fuel is burned with insufficient air in the furnace 31 in the vicinity of the burner 20, part of nitrogen components included in the fuel is generated as a reducing agent, causing a reaction in which nitrogen oxides generated during combustion are reduced to nitrogen. Therefore, the nitrogen oxide density at the outlet of the furnace 31 can be reduced when compared with a case in which all combustion air is supplied from the burner 20.

{0147} To reduce unburned components of a fuel, remaining combustion air is supplied from the air supply port 44 into the furnace 31 to completely burn the fuel. A combustion gas 47 mixed with the combustion air supplied from the air supply port 44 undergoes heat exchange by a heat exchanger 48 provided above the furnace 31, passes through a flue 49, and is then released from the chimney 50 to the atmosphere.

{0148} Since the atomizing nozzle 1 included in the burner 20 in this embodiment is the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7, the surface area of a liquid fuel per unit weight is increased due to conversion of a spray fluid, which is a liquid fuel, to fine particles. Therefore, combustion reaction is hastened, reducing unburned fuel, particulate matter, and carbon monoxide at the outlet of the combustion apparatus, so combustion efficiency of the combustion apparatus can be increased.

{0149} Since combustion reaction is hastened, more oxygen is consumed. This makes it possible to suppress generation of nitrogen oxides. Furthermore, since unburned fuel, particulate matter, and carbon monoxide are reduced, an extra amount of air to be supplied to the combustion apparatus can be reduced.

{0150} When an extra amount of air is reduced, the amount of exhaust combustion gas is also reduced, so sensible heat released to the outside of the combustion apparatus together with the exhaust combustion gas is reduced. This makes it possible to increase thermal efficiency of the combustion apparatus.

{0151} In the burner 20, in this embodiment, equipped with an atomizing nozzle, when the amount of spray medium to be supplied to the burner 20 is suppressed or its pressure is reduced, energy consumed to supply the spray medium or apply pressure to it can be reduced.

{0152} If water vapor is used as the spray medium, the water vapor supplied into the combustion apparatus reduces thermal efficiency of the combustion apparatus. If the atomizing nozzle of the present invention used, however, even if the amount of water vapor to be used is reduced, conversion to fine particles can be maintained as conventionally done. This makes it possible to prevent thermal efficiency from being lowered.

{0153} Although a case in which the burner 20, in this embodiment, equipped with an atomizing nozzle uses a liquid fuel as a fuel has been described, a case in which a solid fuel such as powdered coal is used as the main fuel and a liquid fuel is used as an auxiliary fuel is also applicable. In this case, when the liquid fuel is expelled from the atomizing nozzle 1 or 61 into the furnace, the effect described above is obtained.

{0154} According to this embodiment, it is possible to achieve a burner, equipped with an atomizing nozzle, that has improved combustion efficiency by facilitating conversion to fine particles in the central portion of a spray in which particles in the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied.

{Embodiment 4} {0155} Next, a combustion apparatus, in a fourth embodiment of the present invention, equipped with a burner will be described with reference to Fig. 9.

{0156} The atomizing nozzle 1 or 61 used in a combustion apparatus 60 equipped with the burner 20, illustrated in Fig. 9, in this embodiment is the same as the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7, and the burner 20 equipped with the atomizing nozzle 1 or 61 is the same as the burner 20, illustrated in Fig. 8, in the second embodiment. Structures common to these embodiments will be omitted.

{0157} Fig. 9 illustrates an embodiment of a combustion apparatus, in this embodiment, equipped with a burner. In the combustion apparatus 60, in this embodiment illustrated in Fig. 9, equipped with the burner 20, the combustion apparatus 60 in this embodiment has a plurality of burners 20, each of which is equipped with the atomizing nozzle 1 or 61, on the furnace wall 35 of the furnace 31, as illustrated in Fig. 9.

{0158} The combustion air supply system 41, a liquid fuel supply system 42, and a spray medium supply system 43 are connected to each burner 20 equipped with the atomizing nozzle 1 or 61.

{0159} When a solid fuel is supplied to the burner 20 as a fuel, a solid fuel supply system (not illustrated) is further provided.

{0160} The burner 20 included in the combustion apparatus 60, in this embodiment, equipped with burner 20 has the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7. The pipe 45 branches from the combustion air supply system 41, through which combustion air is supplied to the burner 20, and is connected to the burner 20. The pipe 46 branches from the combustion air supply system 41 and is connected to the air supply port 44 attached to the furnace wall 35 of the furnace 31, which is disposed downstream of the burner 20.

{0161} The pipe 45 and pipe 46 branching from the combustion air supply system 41 are each equipped with a flow rate adjustment valve (not illustrated), which adjusts the amount of flow of air to be supplied.

{0162} A supply unit (not illustrated), which adjusts the pressure of the liquid fuel and spray medium and also adjusts the amounts of their flows, is connected to the liquid fuel supply system 42 and spray medium supply system 43 on their upstream sides. The atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7 is disposed at the downstream ends of the liquid fuel supply system 42 and spray medium supply system 43.

{0163} To the burner 20 included in the combustion apparatus 60 in this embodiment, the combustion air to be supplied is branched from the combustion air supply system 41 to the pipe 45 and pipe 46 and is expelled from the burner 20 and air supply port 44 into the furnace 31.

{0164} Since the combustion air is supplied from the pipe 45 and pipe 46 branching from the combustion air supply system 41, the temperature of a flame formed in the furnace 31 by a spray from the burner 20 is lowered.

{0165} In addition, in the combustion apparatus 60, in this embodiment, equipped with the burner 20, if a spray fluid of a fuel is burned with insufficient air in the furnace 31 in the vicinity of the burner 20, part of nitrogen components included in the fuel is generated as a reducing agent, causing a reaction in which nitrogen oxides generated during combustion are reduced to nitrogen.

{0166} Therefore, the nitrogen oxide density at the outlet of the furnace 31 can be reduced when compared with a case in which all combustion air is supplied from the burner 20 to the interior of the furnace 31.

{0167} In addition, remaining combustion air is supplied from the air supply port 44 through the pipe 46 branching from the combustion air supply system 41 into the furnace 31 to completely burn the spray fluid of the fuel, thereby reducing unburned components of a fuel.

{0168} The combustion gas 47 mixed with the combustion air supplied from the air supply port 44 undergoes heat exchange by the heat exchanger 48 provided above the furnace 31, passes through the flue 49, and is then released from the chimney 50 to the atmosphere.

{0169} Since the atomizing nozzle 1 in the first embodiment illustrated in Figs. 1 to 4 or the atomizing nozzle 61 in the second embodiment illustrated in Figs. 5 to 7 is used in the burner 20 included in the combustion apparatus 60 in this embodiment, the surface area of a liquid fuel per unit weight is increased because the fuel fluid, which is a liquid fuel, is converted to fine particles before the fuel fluid is expelled. Therefore, combustion reaction is hastened, reducing unburned fuel, particulate matter, and carbon monoxide at the outlet of the combustion apparatus 60, so combustion efficiency of the combustion apparatus can be increased.

{0170} When combustion reaction is hastened, more oxygen is consumed. This makes it possible to suppress generation of nitrogen oxides. Furthermore, since unburned fuel, particulate matter, and carbon monoxide are reduced, an extra amount of air to be supplied to the combustion apparatus can be reduced. When an extra amount of air is reduced, the amount of exhaust combustion gas is also reduced, so sensible heat released to the outside of the combustion apparatus together with the exhaust combustion gas is reduced. This makes it possible to increase thermal efficiency of the combustion apparatus.

{0171} Since the amount of spray medium to be used is suppressed or its pressure is reduced, energy consumed for each supply or apply can be reduced. If water vapor is used as the spray medium, the water vapor supplied into the combustion apparatus reduces thermal efficiency of the combustion apparatus. If the atomizing nozzle 1 in the first embodiment or the atomizing nozzle 61 in the second embodiment, described above, is used in the burner 20, however, even if the amount of water vapor to be used is reduced, conversion to fine particles can be maintained. This makes it possible to prevent thermal efficiency of the combustion apparatus from being lowered.

{0172} In the combustion apparatus 60 in this embodiment, illustrated in Fig. 9, equipped with the burner 20, an embodiment has been described in which combustion air is supplied, into the furnace 31, from the burner 20 through the pipe 45 branching from the combustion air supply system 41 and from the air supply port 44 through the pipe 46 branching from the combustion air supply system 41. In a case as well in which combustion air is supplied only from the burner 20 into the furnace 31, the burner 20, illustrated in Fig. 8, equipped with the atomizing nozzle 1 in the first embodiment or the atomizing nozzle 61 in the second embodiment can be used.

{0173} Although a case in which the combustion apparatus in this embodiment illustrated in Fig. 9 has the burner 20 in the third embodiment illustrated in Fig. 8 on a single furnace wall 35 of the furnace 31 has been described, the combustion apparatus can also be applied to a case in which the burner 20 is attached to a plurality of furnace walls 35 of the furnace 31 or to a case in which the burner 20 is attached to a corner of the furnace wall 35 of the furnace 31.

{0174} According to the this embodiment, it is possible to achieve a combustion apparatus, equipped with a burner, that has improved combustion efficiency by facilitating conversion to fine particles in the central portion of a spray in which particles in the spray fluid have relatively large diameters so that conversion of the entire spray fluid to fine particles is facilitated and also enabling reduction in the amount of spray medium to be used to convert the spray fluid to fine particles or in pressure to be applied.

{Industrial Applicability} {0175} The present invention can be applied to an atomizing nozzle that uses a spray medium to convert a spray fluid to fine particles, to a burner equipped with this atomizing nozzle, and to a combustion apparatus equipped with this burner.

{Reference Sings List} {0176} 1: atomizing nozzle, 2: spray fluid, 3: spray medium, 4, 5: spray fluid flow path, 6, 7: spray medium flow path, 8: mixed fluid, 9, 10: mixed fluid flow path, 11: outlet, 12: groove, 13, 14: bent portion, 15: partition wall, 16: structural body, 16a, 16b: convex part, 17: contracted portion, 18: central portion of fan-shaped spray, 19: outer peripheral portion of fan-shaped spray, 20: burner, 21: coaxial flow path component, 22: obstacle, 23: spray, 24: wind box, 25: primary flow path, 26: secondary flow path, 27: tertiary flow path, 28: primary air flow, 29: secondary air flow, 30: tertiary air flow, 31: furnace, 32, 33: swirl generator, 34: guide plate, 35: furnace wall, 36: heat exchanger tube, 41: combustion air supply system, 42: liquid fuel supply system, 43: spray medium supply system, 44: air supply port, 45, 46: pipe, 47: combustion gas flow, 48: heat exchanger, 49: flue, 50: chimney, 60: combustion apparatus, 61: atomizing nozzle, 91: first joining part, 92: second join part

Claims

A spray nozzle for spraying a mixed fluid obtained by mixing the fluid spray and the spray medium into fine particles, wherein the spray nozzle is formed by a partition (15) forming an outer wall and a component (16) of the spray nozzle (1,61). is disposed within the septum (15), wherein: a plurality of fluid spray fluid passages (4,5) are provided through the inlet side of the spray nozzle (1,61), the inner surface of the septum (15) and a plurality of grooves formed on the outer surface of the component (16) (2) feeding; on the inlet side of the spray nozzle (1,61), a plurality of spray fluid flow paths (6,7) are formed within the component (16) through which the spray fluid (3) is supplied; the first junction (91) being formed in the intermediate region of each flow jet of fluid jets (4,5) through which jets of fluid jet (2) are fed so that the jet fluid path (6,7) is in contact with the fluid jet (4,5) and the spraying medium (2) and the spraying medium (3) fed through the spraying medium bus (6,7) to form a mixed fluid (8); after the first junction, the downstream side of the jet flow paths (4.5) with respect to the first junction (91) are arranged to open the mixed fluid flow paths (9,10) and communicate with the jet fluid jet flow paths (4.5) so that the mixed fluid (8) which have flowed through the fluid flow paths (4,5) to be sprayed, are adapted to open to each other; a second junction (92) is formed in the mixed fluid flow paths (9,10) near the end of the spray nozzle (1,61), where the mixed fluids (8) have flowed through the mixed flow flow paths (9,10), open to one another and strike each other and partition (15) near the end of the spray nozzle (1,61), an outflow point (11) is arranged at the second junction (92), whereby a mixed fluid (8) is discharged from the spray nozzle (1,61), is led via an outflow point (11) to the environment; characterized in that an inflection point (17) is disposed in the mixed fluid flow paths (9,10) such that the cross-sectional area of the mixed fluid flow paths (9,10) towards the second junction (92) is smaller than that of the mixed fluid flow paths (92). a cross-sectional area of the fluid flow paths (9,10) upstream of the second junction (92).

A spray nozzle which mixes a fluid spray with a spray medium to produce small particles, the spray nozzle being formed by a partition wall (15) forming an outer wall of a spray nozzle (1,61) and a structural member (16) disposed within the partition wall; a plurality of fluid spray fluid flow paths (4,5) are formed on the inlet side of the spray nozzle (1,61), the inner surface of the partition wall (15) and a plurality of grooves formed on the outer surface of the component (16) through which the fluid spray fluid (2) is supplied; on the inlet side of the spray nozzle, a plurality of spray fluid flow paths are formed within the component through which the spray fluid is fed; a first junction (91) is formed in the intermediate region of each flow jet of flow jet (4,5) through which flow jet (2) is fed so that the jet fluid path (6,7) contacts the fluid jet (4,5) and the fluid spray (2) and the spray fluid (3) fed through the spray medium (6,7) combine to form a mixed fluid (8); after the first junction, downstream side of the jet flow paths (4,5) with respect to the first junction (91) are arranged to open the mixed fluid flow paths (9,10) and communicate with the fluid jets (4,5) to be sprayed so that the mixed fluids (8) flowing through the fluid flow paths (4,5) to be sprayed are arranged to open to one another and a second junction (92) is formed near the end of the spray nozzle (1,61) in the mixed fluid flow paths (9,10), wherein the mixed fluids (8) that have flowed through the mixed flow flow paths (9,10) open to one another and strike each other, characterized in that the partition (15) near the end of the spray nozzle (1,61), 92) is provided with an outflow point (11), whereby the fluid (8) which discharges into the spray mouth the emitter (1,61) is led via an outflow point (11) to the environment; and a throttle point (17) is provided in the flow paths (9,10) facing the second fluid connection point (92) of the mixed fluid such that a cross-sectional area perpendicular to the fluid flow paths (92) of the mixed fluid flow paths (9,10) (8) relative to the flow directions, is smaller at the center of the flow paths as seen in the width direction than at the edges as seen in the width direction.

Atomising nozzle according to claim 1 or 2, wherein the throttling point (17) formed in the mixed fluid flow paths (9,10) facing the second junction (92) is formed by a protruding portion (16a, 16b) adapted to protrude into the mixed fluid flow path. inside the passageways (9,10), wherein the protruding portion (16a, 16b) forms a barrier at a point in the wall of the structural member (16) opposite the outflow formed at the partition wall (15) at the second junction (92).

Spray nozzle according to claim 1 or 2, wherein the projecting portion (16b) fitted to the wall surface of the component (16), which is disposed within the interior of the fluid flow paths (9,10) mixed with the component, is removably attached to the component (16).

Spray nozzle according to claim 1 or 2, wherein a second groove (12) is formed in the partition wall (15) formed by an outflow point (11) facing the second junction (92) at the mixed fluid flow paths (9,10). ) in a direction perpendicular to the flow direction of the mixed fluids (8) flowing to the second junction (92) via the mixed fluid flow paths (9,10) which are arranged to open to one another and the second junction (92) and the other the groove (12) is formed at the outflow point (11).

Spray nozzle according to claim 1 or 2, wherein a curved portion (13,14) is formed in the cooperating portion of the mixed fluid flow path (9,10), wherein the mixed fluid flow path (9,10) cooperates with the sprayable fluid flow path (4,5). ) to change the flow direction of the hate agent (8).

A burner equipped with an atomizing nozzle using liquid fuel as fuel, characterized in that the atomizing nozzle according to any one of claims 1 to 6 is used as an atomizing nozzle (1,61), wherein the liquid fuel is supplied to the atomizing nozzle (1,61). the sprayable fluid (2) and the water vapor or compressed air are supplied to the spray nozzle (1,61) as the spray medium (3).

8. A burner equipped with a fuel nozzle for supplying solid fuel and gas for conveying solid fuel, a spray nozzle for supplying liquid fuel, and a fuel gas nozzle for supplying fuel gas for the solid fuel and the liquid fuel, a spray nozzle (1,61) as described in any one of claims 1 to 6, the liquid fuel is supplied to the spray nozzle (1,61) as a fluid spray (2), and water vapor or compressed air is supplied to the spray nozzle (1,61) as the spray medium (3).

An incinerator provided with a burner for burning fossil fuel, comprising: an incinerator (31) in which the fossil fuel is incinerated, a fuel supply system (42) through which the fossil fuel is fed to the incinerator (31), a fuel gas supply system (41); the fuel gas is fed to the combustion furnace (31), a burner (20) connected to the fuel supply system (42) and the fuel gas supply system (41) and mounted on the wall of the fossil fuel combustion furnace (31) to recover heat from the heat exchanger (48); combustion gas generated in and exiting the furnace (31), and the flue gas (49) through which the heat from which the heat is recovered is discharged to the outside of the furnace (31), characterized in that the combustion device uses the liquid fossil fuel described in claim 7 or 8; open the burner. (20)

A combustion device provided with a burner for combustion of solid fuel and liquid fuel, comprising: an incinerator (31) in which the fuel is incinerated, a solid fuel supply system through which solid fuel is fed to the incinerator (31), a liquid fuel supply system (42); a plurality of burners (20) connected to the fuel supply systems (42) and the fuel gas supply systems (41) and fitted to the combustion furnace (31), the fuel gas supply system (41) through which the fuel gas is fed to the combustion furnace (31); ) on the wall and which burners (20) burn solid fuel and liquid fuel, a heat exchanger (48) for recovering heat from the combustion gas from and to the furnace (31), and a flue gas (49) for recovering the recovered combustion gas,is conducted outside the incinerator (31), characterized in that the burner (20) described in claim 7 or 8 is used as the burner in the incinerator.