JP2013174370A - Burner exclusive for biomass burning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner exclusive for biomass burning that can burn only biomass fuel without the need for a classification mens for classifying the biomass fuel.SOLUTION: A burner 4 exclusive for biomass burning for supplying pulverized biomass fuel in a furnace together with air to be combusted includes: an inner cylinder 42 that is formed so that a flow path cross section area is gradually reduced from an upstream side toward a downstream side and in which the biomass fuel and the air to be combusted are supplied; and an outer cylinder 41 that is disposed to enclose the entire outside of the inner cylinder 42.

Description

  The present invention relates to woody biomass originating from organisms such as plants, other types of renewable fuels such as waste materials and wastes (hereinafter these fuels are referred to as “biomass fuels”), and nitrogen oxides in exhaust gas. The present invention relates to a biomass-burning burner suitable for low NOx combustion with low concentration and co-firing with high efficiency.

  Now, when burning biomass fuel at a high co-firing rate in a coal fired boiler, a dedicated pulverizer for pulverizing the biomass fuel and a dedicated burner for burning the biomass fuel are required. Although biomass fuel is easier to burn than coal, in order to pulverize biomass fuel to the level of coal (equivalent to pulverized coal of several hundred μm or less), the power consumed in the pulverizer becomes large. Therefore, it is necessary to pulverize the biomass fuel to about several mm. However, there is a problem that biomass fuel pulverized to several millimeters is harder to ignite than pulverized coal.

  In addition, when pulverizing biomass fuel, a large amount of air is required to dry, stably pulverize, and stably transport the biomass fuel. As a result, the amount of primary air becomes excessive and the fuel concentration is low. As a result, ignition of biomass fuel is even more difficult.

  Therefore, conventionally, pulverized coal is supplied from the pulverized coal pipe constituting the burner, biomass fuel is supplied from the conveying pipe constituting the burner pulverized to about several mm, and the pulverized coal and biomass fuel are combusted. (See Patent Document 1). In this case, first, pulverized coal with good ignitability is ignited to form a stable flame, and then the biomass fuel having poor ignitability is ignited by the radiant heat of the flame.

  Further, the biomass fuel pulverized by the pulverizer is classified into a biomass fuel of 1 mm or more (large particle size) and a biomass fuel of less than 1 mm (small particle size) by classification means, and the biomass fuel of 1 mm or more is classified. Supplying to the center side of a burner, supplying biomass fuel of less than 1 mm to the periphery (outside), and burning these biomass fuels were also performed (refer patent document 2). In this case, first, a biomass fuel of less than 1 mm having good ignitability is ignited to form a stable flame, and then the biomass fuel of 1 mm or more having poor ignitability is ignited by the radiant heat of this flame.

Japanese Patent No. 4056752 Japanese Patent No. 389958

However, the burner disclosed in Patent Document 1 requires pulverized coal (fuel other than biomass fuel), and has a problem that only biomass fuel cannot be combusted.
Moreover, in the burner disclosed in the above-mentioned Patent Document 2, classification means for classifying into a biomass fuel of 1 mm or more and a biomass fuel of less than 1 mm is required, which complicates the equipment and increases the equipment cost. There was also a problem.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a biomass-burning burner that does not require classification means for classifying biomass fuel and can burn only biomass fuel.

The present invention employs the following means in order to solve the above problems.
The biomass-burning burner according to the present invention is a biomass-burning burner that supplies pulverized biomass fuel together with combustion air into the furnace, and the flow passage cross-sectional area gradually decreases from the upstream side toward the downstream side. And an inner cylinder that collects the biomass fuel supplied to the inside in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner, and is arranged so as to surround the entire outside of the inner cylinder An outer cylinder.

According to the biomass-burning burner according to the present invention, the biomass fuel supplied into the inner cylinder is gathered in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner as it proceeds downstream in the inner cylinder. Thus, the concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner is increased. Further, the combustion air supplied into the inner cylinder is supplied into the furnace so as to surround the outside (periphery) of the biomass fuel as it proceeds downstream in the inner cylinder.
At this time, the biomass fuel supplied into the furnace is heated and burned by the radiant heat in the furnace as it goes downstream in the furnace (becomes easy to ignite).
Thereby, the classification means which classifies biomass fuel is not required, and only biomass fuel can be burned.
Moreover, since the concentration of the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner is increased, the concentration of combustion air for burning the biomass fuel is reduced. Can be suppressed.

  In the biomass-burning burner, the inner cylinder has a large number of holes extending in the circumferential direction and the axial direction that connect the space formed inside through the plate thickness direction and the space formed outside. It is more preferable that the porous body has a large number of holes communicating with the space formed on the inner side and the space formed on the inner side through the plate thickness direction.

According to such a biomass burning burner, a part of the combustion air supplied into the inner cylinder is led to the outside of the inner cylinder (between the inner cylinder and the outer cylinder) through the hole, and the biomass burning only The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the burner will be further increased, and the concentration of combustion air for burning the biomass fuel will be further decreased.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
In addition, since the concentration of biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner is further increased, the biomass fuel becomes more susceptible to radiant heat in the furnace and is more effective. Can be ignited.

  In the biomass-burning burner, it is more preferable that the number of the holes is dense on the upstream side and sparse on the downstream side and gradually decreases from the upstream side to the downstream side.

According to such a biomass-burning burner, the combustion air for burning the biomass fuel is more effectively separated from the biomass fuel, and the concentration of the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner is more In addition to being further increased, the concentration of combustion air for burning the biomass fuel is further reduced.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
In addition, since the concentration of biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner is further increased, the biomass fuel becomes more susceptible to radiant heat in the furnace and is more effective. Can be ignited.

  In the biomass-burning burner, it is more preferable that the hole is formed so that air passing through the hole slightly returns to the upstream side of the inner cylinder.

According to such a biomass-burning burner, only a part of the combustion air supplied into the inner cylinder through the hole is guided to the outside of the inner cylinder (between the inner cylinder and the outer cylinder).
Thereby, it is possible to prevent the biomass fuel supplied into the inner cylinder from being guided to the outside of the inner cylinder (between the inner cylinder and the outer cylinder) through the hole, and the longitudinal direction of the biomass burning burner. The concentration of biomass fuel in the vicinity of the central axis along the line can be further increased.

  In the biomass-burning burner, a round portion that smoothly connects the inner wall surface of the inner cylinder and the inner peripheral surface of the hole is provided around the inlet of the hole so as to be continuous along the circumferential direction. It is more preferable that it is used.

According to such a biomass-burning burner, even if the biomass fuel collides with the periphery of the hole inlet, the biomass fuel flows downstream without being caught around the hole inlet.
Thereby, it is possible to prevent the biomass fuel from being caught in the hole or being blocked by the biomass fuel caught in the hole.

  In the biomass-burning burner, it is more preferable that the outlet end of the inner cylinder is connected to the inlet end of a diffuser formed so that the flow passage cross-sectional area rapidly increases from the upstream side toward the downstream side. is there.

  According to such a biomass-burning burner, for example, as shown by a broken line in FIG. 8, a circulating flow of biomass fuel is formed in the vicinity of the outlet of the diffuser, and heating by radiant heat in the outer cylinder, Since heating by radiant heat is further promoted, the ignitability of the biomass fuel can be further improved.

  In the biomass-burning burner, the inner cylinder is a hollow formed so as to taper from the upstream side toward the downstream side, and includes a plurality of cylinders. It is more preferable that a predetermined distance is provided in the axial direction, and a gap is formed between the cylinder and the cylinder along the circumferential direction.

According to such a biomass burning burner, a part of the combustion air supplied into the inner cylinder is led to the outside of the inner cylinder (between the inner cylinder and the outer cylinder) through the gap, and the biomass burning only The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the burner will be further increased, and the concentration of combustion air for burning the biomass fuel will be further decreased.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
In addition, since the concentration of biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner is further increased, the biomass fuel becomes more susceptible to radiant heat in the furnace and is more effective. Can be ignited.

  In the biomass-burning burner, the inner cylinder is a hollow formed so as to taper from the upstream side toward the downstream side, and includes a plurality of cylinders. More preferably, a predetermined distance is provided in a direction orthogonal to the axial direction, and a gap is formed between the cylinder and the cylinder along the circumferential direction.

According to such a biomass burning burner, a part of the combustion air supplied into the inner cylinder is led to the outside of the inner cylinder (between the inner cylinder and the outer cylinder) through the gap, and the biomass burning only The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the burner will be further increased, and the concentration of combustion air for burning the biomass fuel will be further decreased.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
In addition, since the concentration of biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner is further increased, the biomass fuel becomes more susceptible to radiant heat in the furnace and is more effective. Can be ignited.

  The combustion apparatus according to the present invention includes any one of the above-described biomass-burning burners.

  According to the combustion apparatus according to the present invention, since there is no need for classification means for classifying the biomass fuel and the biomass exclusive burning burner capable of burning only the biomass fuel is provided, the equipment cost and running Cost can be reduced.

  According to the biomass-burning burner according to the present invention, there is an effect that no classification means for classifying biomass fuel is required and only biomass fuel can be burned.

It is a schematic block diagram which shows one specific example of the combustion apparatus provided with the biomass exclusive combustion burner which concerns on this invention. 1 is a cross-sectional view of a biomass-burning burner according to a first embodiment of the present invention. It is the front view which looked at the biomass-burning burner which concerns on 1st Embodiment of this invention from the right side of FIG. It is a figure which expands and shows a part of inner cylinder shown in FIG. 2 and FIG. It is a figure which expands and shows a part of inner cylinder shown in FIG. It is sectional drawing of the biomass exclusive combustion burner which concerns on 2nd Embodiment of this invention. It is the front view which looked at the biomass exclusive combustion burner which concerns on 2nd Embodiment of this invention from the right side of FIG. FIG. 8 is a perspective view of the inner cylinder shown in FIGS. 6 and 7. It is sectional drawing of the biomass exclusive combustion burner which concerns on 3rd Embodiment of this invention. It is the front view which looked at the biomass exclusive combustion burner which concerns on 3rd Embodiment of this invention from the right side of FIG. It is sectional drawing of the biomass exclusive combustion burner which concerns on 4th Embodiment of this invention. It is the front view which looked at the biomass exclusive combustion burner which concerns on 4th Embodiment of this invention from the right side of FIG. It is sectional drawing of the biomass exclusive combustion burner which concerns on 5th Embodiment of this invention. It is the front view which looked at the biomass exclusive combustion burner which concerns on 5th Embodiment of this invention from the right side of FIG. It is sectional drawing of the biomass exclusive combustion burner which concerns on 6th Embodiment of this invention. It is the front view which looked at the biomass exclusive combustion burner which concerns on 6th Embodiment of this invention from the right side of FIG.

[First Embodiment]
Hereinafter, the biomass burning burner according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 is a schematic configuration diagram showing a specific example of a combustion apparatus equipped with a biomass-burning burner according to this embodiment, FIG. 2 is a cross-sectional view of the biomass-burning burner according to this embodiment, and FIG. 3 is a biomass according to this embodiment. FIG. 4 is an enlarged view of a part of the inner cylinder shown in FIGS. 2 and 3, and FIG. 5 is an enlarged view of a part of the inner cylinder shown in FIG. It is a figure shown.

The biomass-burning burner according to the present invention can be applied to, for example, the furnace body 2 of the combustion apparatus 1 in which pulverized coal (solid fossil fuel) and biomass fuel are co-fired.
As shown in FIG. 1, the furnace body 2 of the combustion apparatus 1 includes a burner 3 that cooperates with a pulverized coal nozzle (not shown) and an air nozzle (not shown), and a biomass-burning burner 4 according to the present embodiment. In the furnace 5, a heat transfer tube group 6 corresponding to a heater, an evaporator, a economizer, and the like is installed. The combustion exhaust gas 7 generated by the combustion of the pulverized coal and biomass fuel in the furnace 5 heats the heat transfer tube group 6 and is sent to the flue 8. In the middle of the flue 8, an air heater (AH) 9 is arranged, and the combustion exhaust gas 7 in the flue 8 is drawn by an induction fan (IDF) 10 to be air heater (AH) 9, ash It is emitted from the chimney 12 through the collection device 11 to the atmosphere.

  In order to burn the coal, coal 14 supplied from an external facility (not shown) via the coal supply line 13 is supplied from the coal bunker 15 to the coal pulverizer 16. Is pulverized into pulverized coal and dried with hot air 17 heated by an air heater 9. Thereafter, the pulverized pulverized coal is conveyed from the coal pulverizer 16 by hot air 17, supplied as a pulverized coal mixture 18 from the pulverized coal supply line 19 to the pulverized coal nozzle in the burner 3, and burned in the furnace 5. The

  On the other hand, in order to burn biomass fuel, biomass fuel supplied from an external facility (not shown) via a biomass supply line (not shown) is supplied from a biomass fuel bunker (not shown) to a biomass fuel pulverizer (see FIG. The biomass fuel is pulverized to about several millimeters by this biomass fuel pulverizer and dried by hot air 17 heated by the air heater 9. Thereafter, the pulverized biomass fuel is conveyed from the biomass fuel pulverizer by hot air 17, supplied as a biomass fuel mixture 25 into the biomass-burning burner 4 from the biomass fuel supply line 26, and burned in the furnace 5.

  Reference numeral 31 in FIG. 1 branches from the middle of the flue 8 and a part of the combustion exhaust gas 7 passing through the flue 8 is used as a furnace bottom recirculation gas (GR) 32 at the bottom of the furnace body 5. A recirculation gas line for the furnace bottom that is led, and a reference numeral 33 is provided in the middle of the recirculation gas line 31 for the furnace bottom, and a part of the combustion exhaust gas 7 passing through the flue 8 is recirculated for the furnace bottom. A furnace bottom recirculation gas blower (GRF) that sucks in through the circulation gas line 31 and supplies (sends) to the bottom of the furnace body 5.

  Further, reference numeral 34 in FIG. 1 is drawn by a forced air blower (FDF) 35 and is heated by an air heater (AH) 9 from a combustion air line 36 via a main burner air line 37 to be heated by a main burner. Combustion air is supplied into the furnace 5 from the air nozzle in the burner 3 and the air nozzle in the biomass-burning burner 4 as combustion air.

  Further, reference numeral 38 in FIG. 1 branches from the middle of the combustion air line 36 and a part of the combustion air 34 that passes through the combustion air line 36 is used as hot air 17 to pulverize the coal pulverizer 16 and biomass fuel. The reference numeral 39 is a hot air line that leads to the machine, and 39 is provided in the middle of the hot air line and sucks a part of the combustion air 34 that passes through the combustion air line 36 via the hot air line 38, A blower (PAF) that supplies (sends) to the pulverizer 16 and the biomass fuel pulverizer.

  Furthermore, the hot air 17 passing through the hot air line 38 located downstream of the air heater (AH) 9 is mixed with cold air for temperature control and supplied to the coal pulverizer 16 and the biomass fuel pulverizer. Is done.

Now, as shown in FIGS. 2 and 3, the biomass-burning burner 4 according to this embodiment includes an outer cylinder 41 and an inner cylinder 42.
The outer cylinder 41 is a member having a cylindrical shape arranged so as to surround the entire outer side of the inner cylinder 42.

The inner cylinder 42 is a hollow and frustoconical shape formed so as to taper from the proximal end side (upstream side) to the distal end side (downstream side) (the cross-sectional area of the flow path gradually decreases). It is a member exhibiting. In the present embodiment, the radius d ₁ at the proximal end of the inner cylinder 42 is three times the radius d _{2 at} the distal end, that is, d ₁ / d ₂ = 3, π (d ₁ ) ² / π (d ₂ ). ² = 9, and the angle θ ₁ formed by the inner wall 42a and the outer wall 42b forming the inner cylinder 42 and the longitudinal axis C1 of the inner cylinder 42 is 5 ° to 60 °. It is set to be within the range of ° (smallest possible).

As shown in FIGS. 4 and 5, the inner cylinder 42 has a hole that penetrates in the plate thickness direction and communicates a space formed inside the inner wall surface 42 a and a space formed outside the outer wall surface 42 b. A large number of holes 43 are formed along the circumferential direction and the axial direction of the inner cylinder 42. The hole 43 is a hole having a diameter of about 0.1 mm to 1 mm, and the number of holes 43 is provided so that the number is dense on the proximal end side, is sparse on the distal end side, and gradually decreases from the proximal end side to the distal end side. Further, in the present embodiment, the (smaller) angle θ ₂ formed by the center line C2 of the hole 43 and the outer wall surface 42b is within a range of 5 ° to 90 ° (reference numeral 44 in FIG. 4). Only the air (and the minute biomass fuel particles of several hundred μm or less) can escape to the space formed outside the outer wall surface 42 b without being caught by the inlet 43 a of the hole 43. In other words, the air passing through the hole 43 (and the minute biomass fuel particles of several hundred μm or less) is set to return slightly to the base end side of the inner cylinder 42. Furthermore, as shown in FIG. 5, around the inlet 43 a of the hole 43, there is a round portion 45 that smoothly connects the inner wall surface 42 a of the inner cylinder 42 and the inner peripheral surface 43 b of the hole 43 along the circumferential direction. It is provided to be continuous.

According to the biomass-burning burner 4 according to the present embodiment, the biomass fuel supplied into the inner cylinder 42 proceeds along the inner cylinder 42 to the downstream side, and the central axis along the longitudinal direction of the biomass-burning burner 4 concerned. The biomass fuel concentration in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 4 is increased. Further, the combustion air supplied into the inner cylinder 42 is supplied to the furnace 5 so as to surround the outside (periphery) of the biomass fuel as it proceeds downstream in the inner cylinder 42. .
At this time, the biomass fuel supplied to the furnace 5 is heated by the radiant heat in the furnace 5 and burned as it travels downstream in the furnace 5 (becomes easy to ignite).
Thereby, the classification means which classifies biomass fuel is not required, and only biomass fuel can be burned.
Moreover, since the concentration of the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 4 is increased, the concentration of combustion air for burning the biomass fuel is reduced, so that NOx and the like are generated. Can be suppressed.

In addition, according to the biomass-burning burner 4 according to the present embodiment, a part of the combustion air supplied into the inner cylinder 42 is outside the inner cylinder 42 (the inner cylinder 42 and the outer cylinder 41 through the hole 43. The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass burning burner 4 is further increased, and the concentration of combustion air for burning the biomass fuel is further decreased. Will do.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
Moreover, since the density | concentration of the biomass fuel gathered to the vicinity of the center axis line along the longitudinal direction of the said biomass exclusive combustion burner 4 will be raised more, biomass fuel becomes much more easy to receive the radiant heat of the furnace 5, It can be ignited effectively.

Furthermore, according to the biomass-burning burner 4 according to this embodiment, the number of holes 43 is dense on the base end side (upstream side) and sparse on the tip end side (downstream side), and gradually decreases from the base end side to the tip end side. Therefore, the combustion air for burning the biomass fuel is more effectively separated from the biomass fuel, and the concentration of the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner is more In addition to being further increased, the concentration of combustion air for burning the biomass fuel is further reduced.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
In addition, since the concentration of biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner is further increased, the biomass fuel becomes more susceptible to radiant heat in the furnace and is more effective. Can be ignited.

Furthermore, according to the biomass-burning burner 4 according to the present embodiment, the hole 43 is formed so that the air passing through the hole 43 slightly returns to the upstream side of the inner cylinder 42, and the inside through the hole 43. Only a part of the combustion air supplied into the cylinder 42 is guided to the outside of the inner cylinder 42 (between the inner cylinder 42 and the outer cylinder 41).
Thereby, it is possible to prevent the biomass fuel supplied into the inner cylinder 42 from being guided to the outside of the inner cylinder 42 (between the inner cylinder 42 and the outer cylinder 41) through the hole 43, and the biomass. The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the exclusive burning burner 4 can be further increased.

Furthermore, according to the biomass-burning burner 4 according to the present embodiment, the round portion that smoothly connects the inner wall surface 42a of the inner cylinder 42 and the inner peripheral surface 43b of the hole 43 around the inlet 43a of the hole 43. 45 is provided so as to be continuous along the circumferential direction, and even if the biomass fuel collides with the periphery of the inlet 43a of the hole 43, the biomass fuel is not caught around the inlet 43a of the hole 43, It will flow downstream.
Thereby, it is possible to prevent the biomass fuel from being caught in the hole 43 or the hole 43 from being blocked by the biomass fuel caught in the hole 43.

  According to the combustion apparatus 1 including the biomass-burning burner 4 according to the present embodiment, the biomass-burning burner 4 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

[Second Embodiment]
A biomass-burning burner according to a second embodiment of the present invention will be described with reference to FIGS.
6 is a cross-sectional view of the biomass-burning burner according to this embodiment, FIG. 7 is a front view of the biomass-burning burner according to this embodiment, as viewed from the right side of FIG. 6, and FIG. 8 is the inner cylinder shown in FIGS. FIG.
The biomass-burning burner 51 according to the present embodiment is different from that of the first embodiment described above in that an inner cylinder 52 is provided instead of the inner cylinder 42. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

As shown in FIGS. 6 to 8, the biomass-burning burner 51 according to the present embodiment includes an outer cylinder 41 and an inner cylinder 52.
The inner cylinder 52 is made thicker at the distal end of the inner cylinder 42 from the proximal end side (upstream side) toward the distal end side (downstream side) (the cross-sectional area (inner diameter) is rapidly increased). The base end of the formed hollow diffuser 53 having a trumpet shape is connected.

  As shown in FIG. 8, the diffuser 53 has a hole (hole) communicating with a space formed inside the inner wall surface and penetrating in the plate thickness direction and a space formed outside the outer wall surface. The hole corresponding to 43) is not drilled.

According to the biomass-burning burner 51 according to the present embodiment, for example, as shown by a broken line in FIG. 8, a circulating flow of biomass fuel is formed in the vicinity of the outlet of the diffuser 53, and due to the radiant heat in the outer cylinder 41. Since the heating and the heating by the radiant heat in the furnace 5 are further accelerated, the ignitability of the biomass fuel can be further improved.
Other functions and effects are the same as those of the above-described first embodiment, and thus description thereof is omitted here.

  According to the combustion apparatus 1 including the biomass-burning burner 51 according to the present embodiment, the biomass-burning burner 51 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

[Third Embodiment]
A biomass-burning burner according to a third embodiment of the present invention will be described with reference to FIGS. 9 and 10.
9 is a cross-sectional view of the biomass-burning burner according to the present embodiment, and FIG. 10 is a front view of the biomass-burning burner according to the present embodiment as viewed from the right side of FIG.
The biomass-burning burner 61 according to the present embodiment includes the outer cylinder 62 instead of the outer cylinder 41, and the first described above in that a duct 63 is provided between the outer cylinder 62 and the inner cylinder 52. Different from that of the second embodiment. Since other components are the same as those of the second embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 2nd Embodiment mentioned above.

As shown in FIGS. 9 and 10, the biomass-burning burner 61 according to this embodiment includes an inner cylinder 52 and a duct 63.
The duct 63 is a hollow member formed to taper from the base end side (upstream side) to the tip end side (downstream side) and has a rectangular shape in cross section. It is composed of two sets of plate-like members (one set for the upper and lower sides and one set for the left and right) exhibiting a shape. The two sets of plate-like members extend so that the inner wall surface and the outer wall surface thereof are parallel to the inner wall surface and the outer wall surface of the inner cylinder 42. On the other hand, the front ends (downstream ends) of a pair of plate-like members arranged above and below the inner cylinder 52 are connected to the front end of the diffuser 53.

  As shown in FIG. 10, the front ends (downstream ends) of the pair of plate-like members arranged on the left and right of the inner cylinder 52 are not connected to the front end of the diffuser 53, and the front end of the duct 63, Two gaps 64 are formed between the tip of the diffuser 53.

According to the biomass-burning burner 61 according to the present embodiment, the duct 63 prevents the combustion air from diffusing in the vertical direction, and the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 61. The concentration will remain high.
Thereby, the classification means which classifies biomass fuel is not required, and only biomass fuel can be burned.
Moreover, since the concentration of the biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 4 is increased, the concentration of combustion air for burning the biomass fuel is reduced, so that NOx and the like are generated. Can be suppressed.
Other functions and effects are the same as those of the above-described second embodiment, and thus description thereof is omitted here.

  According to the combustion apparatus 1 including the biomass-burning burner 61 according to the present embodiment, the biomass-burning burner 61 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

[Fourth Embodiment]
A biomass-burning burner according to a fourth embodiment of the present invention will be described with reference to FIGS. 11 and 12.
FIG. 11 is a cross-sectional view of the biomass-burning burner according to this embodiment, and FIG. 12 is a front view of the biomass-burning burner according to this embodiment as viewed from the right side of FIG.
The biomass-burning burner 71 according to this embodiment is different from that of the third embodiment described above in that an inner cylinder 72 is provided instead of the inner cylinder 52 and the duct 63. Since other components are the same as those of the third embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 3rd Embodiment mentioned above.

As shown in FIGS. 11 and 12, the biomass-burning burner 71 according to the present embodiment includes an outer cylinder 62 and an inner cylinder 72.
The outer cylinder 62 is a hollow and square member that is disposed so as to surround the entire outer side of the inner cylinder 72.
The inner cylinder 72 is a plurality of hollow cylinders formed in a taper shape from the base end side (upstream side) to the distal end side (downstream side) and having a rectangular shape in cross section (four in this embodiment). Each of the cylinders 73, 74, 75, and 76, and each of the cylinders 73, 74, 75, and 76 has two plate-like (upper and lower, one set on the left and right) plate-like shapes in plan view. It is comprised by the member. Further, a plate-like member disposed above to form each cylinder 73, 74, 75, 76, a plate-like member disposed below to form each cylinder 73, 74, 75, 76, arranged to the left The plate-like members that form the cylinders 73, 74, 75, and 76, and the plate-like members that are arranged on the right and form the cylinders 73, 74, 75, and 76 are inclined along the axial direction. Are arranged on the same plane.

  11 and 12, the cylindrical body 73 and the cylindrical body 74, the cylindrical body 74 and the cylindrical body 75, and the cylindrical body 75 and the cylindrical body 76 are separated from each other by a predetermined distance in the axial direction. A gap 77 is formed along the circumferential direction between the cylinder 73 and the cylinder 74, between the cylinder 74 and the cylinder 75, and between the cylinder 75 and the cylinder 76, respectively. It has become.

According to the biomass-burning burner 71 according to the present embodiment, part of the combustion air supplied into the inner cylinder 72 is outside the inner cylinder 72 (between the inner cylinder 72 and the outer cylinder 62 through the gap 77). ), The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 71 is further increased, and the concentration of combustion air for burning the biomass fuel is further decreased. become.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
Moreover, since the concentration of the biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner 71 is further increased, the biomass fuel becomes more susceptible to the radiant heat in the furnace 5, and more It can be ignited effectively.

  According to the combustion apparatus 1 including the biomass-burning burner 71 according to the present embodiment, the biomass-burning burner 71 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

[Fifth Embodiment]
A biomass burning burner according to a fifth embodiment of the present invention will be described with reference to FIGS. 13 and 14.
13 is a cross-sectional view of the biomass-burning burner according to this embodiment, and FIG. 14 is a front view of the biomass-burning burner according to this embodiment as viewed from the right side of FIG.
The biomass-burning burner 81 according to this embodiment is different from that of the fourth embodiment described above in that an inner cylinder 82 is provided instead of the inner cylinder 72. Since other components are the same as those of the fourth embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 4th Embodiment mentioned above.

As shown in FIGS. 13 and 14, the biomass-burning burner 81 according to this embodiment includes an outer cylinder 62 and an inner cylinder 82.
The inner cylinder 82 is hollow and formed in a tapered shape from the base end side (upstream side) to the distal end side (downstream side), and has a plurality of rectangular shapes (four in the present embodiment). Each of the cylinders 83, 84, 85, and 86, and each of the cylinders 83, 84, 85, and 86 has a plate shape of two sets (one set on the upper and lower sides and one set on the left and right) each having an isosceles trapezoidal shape in plan view It is comprised by the member. Further, the inner cylinder 82 is configured such that adjacent cylinders 83, 84, 85, 86 overlap (overlap), that is, the base end of the cylinder 84 surrounds the entire outside of the distal end of the cylinder 83. Arranged so that the base end of the cylinder 85 surrounds the entire outside of the tip of the cylinder 84, and the base end of the cylinder 86 surrounds the entire outside of the tip of the cylinder 85. Has been.

As shown in FIG. 13, the distal end of the cylinder 83 and the proximal end of the cylinder 84, the distal end of the cylinder 84 and the proximal end of the cylinder 85, and the distal end of the cylinder 85 and the proximal end of the cylinder 86 Are spaced apart from each other by a predetermined distance in a direction orthogonal to the axial direction, between the distal end of the tubular body 83 and the proximal end of the tubular body 84, between the distal end of the tubular body 84 and the proximal end of the tubular body 85, and A gap 87 is formed along the circumferential direction between the distal end of the cylindrical body 85 and the proximal end of the cylindrical body 86.
Further, the cylinders 83, 84, 85, 86 are overlapped so that the air passing through the gap 87 (and fine biomass fuel particles of several hundred μm or less) slightly returns to the base end side of the inner cylinder 82. (Overlapping).

According to the biomass-burning burner 81 according to the present embodiment, a part of the combustion air supplied into the inner cylinder 82 is outside the inner cylinder 82 (between the inner cylinder 82 and the outer cylinder 62 through the gap 87. ), The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the biomass burning burner 81 is further increased, and the concentration of combustion air for burning the biomass fuel is further decreased. become.
Thereby, generation | occurrence | production of NOx etc. can be suppressed further.
Moreover, since the concentration of the biomass fuel collected near the central axis along the longitudinal direction of the biomass-burning burner 81 is further increased, the biomass fuel becomes more susceptible to the radiant heat in the furnace 5, It can be ignited effectively.

Further, according to the biomass-burning burner 81 according to this embodiment, the gap 87 is formed so that the air passing through the gap 87 slightly returns to the upstream side of the inner cylinder 82, and the inner cylinder is interposed via the gap 87. Only a part of the combustion air supplied into the interior 82 is guided to the outside of the inner cylinder 82 (between the inner cylinder 82 and the outer cylinder 62).
Thereby, it is possible to prevent the biomass fuel supplied into the inner cylinder 82 from being guided to the outside of the inner cylinder 82 (between the inner cylinder 82 and the outer cylinder 62) through the gap 87. The concentration of biomass fuel in the vicinity of the central axis along the longitudinal direction of the exclusive burner can be further increased.

  According to the combustion apparatus 1 including the biomass-burning burner 81 according to the present embodiment, the biomass-burning burner 81 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

[Sixth Embodiment]
A biomass-burning burner according to a sixth embodiment of the present invention will be described with reference to FIGS. 15 and 16.
15 is a cross-sectional view of the biomass-burning burner according to this embodiment, and FIG. 16 is a front view of the biomass-burning burner according to this embodiment as viewed from the right side of FIG.
The biomass-burning burner 91 according to this embodiment is different from those of the third to fifth embodiments described above in that a kicker 92 is provided instead of the inner cylinders 52, 72, 82 and the duct 63. Since other components are the same as those in the third to fifth embodiments described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 3rd Embodiment mentioned above-5th Embodiment.

As shown in FIGS. 15 and 16, the biomass-burning burner 91 according to this embodiment includes an outer cylinder 62 and a kicker 92.
The kicker 92 collects biomass fuel passing through the outer cylinder 62 at the center in the height direction of the outer cylinder 62 (near the central axis along the longitudinal direction of the outer cylinder 62). As shown, it has a cross-sectional C-shape. Further, the kicker 92 is provided over the entire width direction of the outer cylinder 62 along the width direction of the outer cylinder 62 (the direction perpendicular to the paper surface in FIG. 15, the left-right direction in FIG. 16), and the kicker 92 located above. One end (upstream end) of 92 is connected to the ceiling surface 62 a of the outer cylinder 62, and one end (upstream end) of the kicker 92 positioned below is connected to the bottom surface 62 b of the outer cylinder 62.

According to the biomass-burning burner 91 according to the present embodiment, the biomass fuel supplied into the kicker 92 advances in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner 91 as it proceeds downstream in the kicker 92. The combustion air that has been collected in the air and supplied into the kicker 92 surrounds the outside (periphery) of the biomass fuel and is supplied to the furnace 5 as it proceeds downstream in the kicker 92.
At this time, the biomass fuel that has exited the kicker 92 is heated by the radiant heat in the outer cylinder 62 as it travels downstream in the outer cylinder 62, and then supplied to the furnace 5, and further by the radiant heat in the furnace 5. It is heated and burned (it becomes easy to ignite).
Thereby, the classification means which classifies biomass fuel is not required, and only biomass fuel can be burned.
Moreover, since the combustion air surrounding the outer side (surrounding) of the biomass fuel serves as secondary air, generation of NOx and the like can be suppressed.

  According to the combustion apparatus 1 including the biomass-burning burner 91 according to the present embodiment, the biomass-burning burner 91 that does not require classification means for classifying the biomass fuel and can burn only the biomass fuel is provided. Therefore, the equipment cost and running cost can be reduced.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.
For example, in the first to third embodiments described above, as the inner cylinder, a hole penetrating in the plate thickness direction and formed on the inner side and a space formed on the outer side communicates with the circumferential direction and Although a plurality of bores along the axial direction have been described as a specific example, the inner cylinder according to the present invention is not limited to this, but penetrates in the plate thickness direction to the inside. It may be produced from a porous body (sintered metal (sintered alloy) or the like) having a large number of holes communicating the formed space and the space formed outside.

  Further, the positional relationship between the inner cylinder and the outer cylinder is not limited to the above-described embodiment, and the inner cylinder is arranged so that the outlet end of the inner cylinder and the outlet end of the outer cylinder are located on the same plane. Alternatively, the inner cylinder may be arranged such that the outlet end of the inner cylinder is located farther from the outlet end of the outer cylinder (for example, the left side in FIG. 2).

  Furthermore, the numerical values shown in the above-described embodiments are merely specific examples, and can be changed as necessary.

DESCRIPTION OF SYMBOLS 1 Combustion device 4 Biomass burning burner 5 Furnace 41 Outer cylinder 42 Inner cylinder 42a Inner wall surface 43 Hole 43a Inlet 43b Inner peripheral surface 45 Ear part 51 Biomass burning furnace 52 Inner cylinder 53 Diffuser 61 Biomass burning furnace 62 Outer cylinder 71 Biomass burning burner 72 Inner cylinder 73 Cylinder 74 Cylinder 75 Cylinder 76 Cylinder 77 Crevice 81 Biomass exclusive burner 82 Inner cylinder 83 Cylinder 84 Cylinder 85 Cylinder 86 Cylinder 87 Crevice 91 Biomass exclusive burner 92 Kicker

Claims (9)

A biomass-burning burner that supplies pulverized biomass fuel together with combustion air into the furnace,
The flow path cross-sectional area is gradually reduced from the upstream side to the downstream side, and the biomass fuel supplied to the inside is gathered in the vicinity of the central axis along the longitudinal direction of the biomass-burning burner. An inner cylinder
A biomass-burning burner comprising: an outer cylinder disposed so as to surround the entire outer side of the inner cylinder.   The inner cylinder has a large number of holes extending in the circumferential direction and the axial direction through which the space formed on the inner side and the space formed on the outer side penetrates in the thickness direction. 2. The biomass-burning burner according to claim 1, wherein the burner is a porous body having a large number of holes that communicate with a space formed inside through a direction and a space formed outside.   3. The biomass-burning burner according to claim 2, wherein the number of the holes is dense on the upstream side and sparse on the downstream side and gradually decreases from the upstream side to the downstream side.   The biomass-burning burner according to claim 2 or 3, wherein the hole is formed so that air passing through the hole slightly returns to the upstream side of the inner cylinder.   Around the inlet of the hole, a round portion that smoothly connects the inner wall surface of the inner cylinder and the inner peripheral surface of the hole is provided so as to be continuous in the circumferential direction. The biomass-burning burner according to any one of claims 2 to 4.   6. The diffuser inlet end formed such that the flow passage cross-sectional area rapidly increases from the upstream side toward the downstream side is connected to the outlet end of the inner cylinder. A biomass-burning burner according to any one of the above.   The inner cylinder is a hollow formed so as to taper from the upstream side toward the downstream side, and includes a plurality of cylinders. The cylinders and the cylinders each have a predetermined distance in the axial direction. 2. The biomass-burning burner according to claim 1, wherein gaps are formed along the circumferential direction between the cylindrical body and the cylindrical body.   The inner cylinder is a hollow formed so as to taper from the upstream side toward the downstream side, and is composed of a plurality of cylinders, and the cylinders and the cylinders are each orthogonal to the axial direction. 2. The biomass-burning burner according to claim 1, wherein a gap is formed along the circumferential direction between the cylindrical body and the cylindrical body.   A combustion apparatus comprising the biomass-burning burner according to any one of claims 1 to 8.

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