JP2017036883A - Woody biomass boiler - Google Patents

Abstract

[Problem] To provide a pyrolysis-type woody biomass boiler that generates significantly less carbon dioxide than a combustion furnace type. SOLUTION: A pyrolysis furnace 2 for pyrolyzing a wood material fuel, a magnetizing device 3 that makes oxygen deficient by passing air sucked into the pyrolysis furnace 2, and a pyrolysis furnace 2 are provided. The boiler tank unit 4 that heats the stored water by the heat generated by the pyrolysis furnace 2 and a pipe that passes through the pyrolysis furnace 2, and the flowing water in the pipe is heated by the heat generated by the pyrolysis furnace 2. Generating hot air, comprising an exhaust pipe 30 for discharging heated air generated in the pyrolysis furnace 2, and a fan 31 for sucking the heated air from the pyrolysis furnace 2 in the exhaust pipe 30 Device 6. [Selection] Figure 1

Description

  The present invention relates to a thermal biomass wood biomass boiler using wood materials such as waste wood and waste bamboo as fuel.

  Conventionally, as fuel for boilers, fossil fuels such as A heavy oil, light oil, kerosene and LPG are mainly used. However, the fossil fuel boiler has problems such as rising raw material costs and carbon dioxide emissions, and is required to reduce energy costs and environmental burdens. Therefore, a biomass boiler that uses biomass fuel such as wood pellets and chips has attracted attention.

  For example, in Patent Document 1, a hot water tank is formed so as to surround the combustion chamber of a combustion furnace for burning biomass, and combustion is performed so that the upper edge is at a position equal to or less than ½ of the height of the combustion chamber. A biomass boiler is disclosed in which a smoke exhaust port is provided on the back wall of the chamber, and smoke is exhausted to a smoke cylinder provided through the hot water chamber of the hot water tank.

JP 2014-199174 A

However, the combustion boiler type biomass boiler as disclosed in Patent Document 1 has a problem that the amount of carbon dioxide emission is large.
Therefore, an object of the present invention is to provide a pyrolysis-type woody biomass boiler that generates significantly less carbon dioxide than a combustion furnace system.

  The woody biomass boiler of the present invention is provided so as to surround a pyrolysis furnace for pyrolyzing wood fuel, a magnetizing device that makes oxygen deficient by passing air sucked into the pyrolysis furnace, and a pyrolysis furnace. A heat exchanger that heats the running water in the pipe with heat generated by the pyrolysis furnace, and a boiler tank that heats the stored water with heat generated by the pyrolysis furnace and a pipe that passes through the pyrolysis furnace And an exhaust pipe for discharging heated air generated in the pyrolysis furnace, and a hot air generator provided with a fan for sucking the heated air from the pyrolysis furnace in the exhaust pipe.

  In the woody biomass boiler of the present invention, the air sucked into the pyrolysis furnace is passed through the magnetizing device, so that the oxygen deficient state, that is, the low oxygen state (nitrogen rich state), and oxygen molecules in the air are condensed. Form a conjugate. When the condensed low-oxygen conjugate collides with the wood material fuel, the wood material fuel undergoes a pyrolysis reaction, and is pyrolyzed by a dry distillation reaction without being flame-combusted to become magnetic ash. This magnetic ash serves as a heat source for the next adjacent fuel, whereby the dry distillation reaction continues. The heat generated in the pyrolysis furnace due to such pyrolysis of the wood fuel becomes the heated water or steam that is stored in the boiler tank, and the running water in the heat exchanger is heated to become hot water. The heated air generated in the cracking furnace is sucked through the exhaust pipe by the fan of the hot air generator and becomes hot air.

  Further, the woody biomass boiler of the present invention is a cylindrical body that extends in the vertical direction in the pyrolysis furnace, and has a plurality of vertical rectifying plates that protrude obliquely downward on the inner surface thereof in the vertical direction. It is desirable that the pipe of the heat exchanger section is disposed so as to wind around the cylindrical body. The convection generated by the pyrolysis of the wood-based material in the pyrolysis furnace varies and is turbulent, but this turbulent convection is received by an annular rectifying plate that projects obliquely downward on the inner surface of the cylindrical body. It becomes possible to adjust and to make uniform the radiant heat around the cylindrical body. Further, the thermal decomposition in the pyrolysis furnace is continued by the heat absorbed by the annular rectifying plate itself.

  In addition, the woody biomass boiler of the present invention desirably has a drying chamber for drying the wood material fuel to a moisture content of 30% or less, more preferably 20% or less at the top of the pyrolysis furnace. As a result, the wood material fuel can be dried by utilizing the exhaust heat from the top of the pyrolysis furnace. When using raw waste wood or waste bamboo material as the wood material fuel, these wood material fuels can be used. By making the mass moisture content of the water 30% or less, it becomes possible to always keep the heat of decomposition generated in the pyrolysis furnace constant. In particular, if the moisture content of the wood material fuel is dried to 20% or less, there is an advantage that thermal decomposition becomes easy and no harmful gas is generated.

  The hot air generator is preferably provided with a spraying device for spraying water against the heated air passing through the exhaust pipe. Thereby, harmful substances, white smoke and impurities in the heated air can be captured and purified by the water spray particles.

(1) A pyrolysis furnace that pyrolyzes wood fuel, a magnetizing device that is oxygen-deficient by allowing air to be sucked into the pyrolysis furnace, and a pyrolysis furnace provided to surround the pyrolysis furnace A boiler tank that heats the stored water with the heat generated by the pipe, a pipe that passes through the pyrolysis furnace, and a heat exchanger that heats the flowing water in the pipe with the heat generated by the pyrolysis furnace, and pyrolysis Compared to the combustion furnace system, the exhaust pipe that discharges the heated air generated in the furnace and the hot air generator that includes a fan that sucks the heated air from the pyrolysis furnace in the exhaust pipe has carbon dioxide compared to the combustion furnace method. It is possible to pyrolyze the wood material fuel by a pyrolysis method with significantly less generation of hot water and to obtain hot water (steam) and hot air by the heat of decomposition.

(2) Inside the pyrolysis furnace is a cylindrical body extending in the vertical direction, and has a cylindrical body with a plurality of vertical rectifying plates in the vertical direction projecting obliquely downward on the inner surface thereof, for heat exchange The piping of the vessel part is arranged so as to be wound around the cylindrical body, so that the radiant heat around the cylindrical body is made uniform, hot water (steam) and hot air at a desired temperature Can be stably obtained.

(3) The wood material fuel is dried by utilizing the exhaust heat from the top of the pyrolysis furnace by using a drying chamber for drying the wood fuel to a moisture content of 30% or less at the top of the pyrolysis furnace. The woody biomass boiler can be stably operated by always keeping the heat of decomposition generated in the pyrolysis furnace constant.

(4) Since the warm air generator is equipped with a spray device that sprays water against the heated air passing through the exhaust pipe, harmful substances, white smoke and impurities in the heated air are sprayed with water spray particles. It becomes possible to capture and purify, and it is possible to use harmless warm air.

It is a front view which shows the outline | summary of the woody biomass boiler in embodiment of this invention. It is a top view which shows the outline | summary of the woody biomass boiler of FIG. It is explanatory drawing explaining the adjustment effect of the convection by a baffle plate.

  FIG. 1 is a front view showing an outline of a woody biomass boiler in an embodiment of the present invention, and FIG. 2 is a plan view showing an outline of the woody biomass boiler in FIG.

  As shown in FIGS. 1 and 2, a wood biomass boiler 1 according to an embodiment of the present invention includes a pyrolysis furnace 2 that thermally decomposes a wood material fuel such as waste wood and waste bamboo material, and is sucked into the pyrolysis furnace 2. Heat exchanger composed of a magnetizing device 3 that is in an oxygen-deficient state by allowing air to pass through, a boiler tank unit 4 provided so as to surround the pyrolysis furnace 2, and piping passing through the pyrolysis furnace 2 And a hot air generator 6 for obtaining hot air from heated air generated in the pyrolysis furnace 2.

  The pyrolysis furnace 2 is formed by a cylindrical inner furnace shell 10 extending in the vertical direction and a furnace top plate 11. The inner furnace shell 10 is a boiler steel plate (carbon steel plate for boiler), and the furnace top plate 11 is a normal steel plate (carbon steel plate). An intermediate hearth 12 is provided in the lower part of the pyrolysis furnace 2. The intermediate hearth 12 is a grate (rooster) that receives the wood material fuel. In addition, a fuel input port 13 is provided on the front surface of the pyrolysis furnace 2 for supplying wood material fuel onto the intermediate hearth 12 of the pyrolysis furnace 2. Below the fuel inlet 13, an ash scraper outlet 14 is provided for scraping the ash under the intermediate hearth 12.

  Three air suction pipes 15A, 15B, and 15C and air suction pipes 16A, 16B, and 16C are provided on the upper and lower side surfaces of the intermediate hearth 12 of the pyrolysis furnace 2, respectively. As shown in FIG. 2, the air suction pipes 15A, 15B, and 15C are provided at intervals of 120 ° in plan view. The same applies to the air suction pipes 16A, 16B, and 16C. Further, the air suction pipes 15A, 15B, 15C and the air suction pipes 16A, 16B, 16C are arranged so as to be spaced from each other by 40 °. The magnetizing device 3 is provided in each of the air suction pipes 15A, 15B, 15C, 16A, 16B, and 16C.

  In the pyrolysis furnace 2, a cylindrical tubular body 17 extending in the vertical direction is provided. On the inner surface of the cylindrical body 17, an annular (inverted truncated cone) rectifying plate 18 projecting obliquely downward is provided in a plurality of stages in the vertical direction. FIG. 3 is an explanatory diagram for explaining the effect of adjusting the convection by the rectifying plate 18. As shown in FIG. 3, the convection C1 generated by the pyrolysis of the wood-based material in the pyrolysis furnace 2 has variations and is distorted. Is received and adjusted to make the radiant heat C2 around the cylindrical body 17 uniform.

  The magnetizing device 3 is a magnet in which strong magnets are arranged facing each other. When the thermal decomposition air passes through the magnetizing device 3, oxygen in the air is attracted to the strong magnet, and the inflowing air is in an oxygen-deficient state, that is, a low oxygen state (nitrogen-rich state). The molecules form a condensed conjugate. When the condensed low-oxygen conjugate collides with the wood material fuel, the wood material fuel undergoes a pyrolysis reaction, and is pyrolyzed by dry distillation without burning with flame to become magnetic ash. This magnetic ash serves as a heat source for the next adjacent fuel, so that dry distillation continues.

  The boiler tank unit 4 is a space formed by the aforementioned inner furnace shell 10 and a cylindrical outer furnace shell 20 that extends in the vertical direction and is provided so as to surround the inner furnace shell 10. A head tank 7 for supplying water is provided above the boiler tank unit 4. The water in the head tank 7 is supplied to the upper part of the boiler tank unit 4 by its own weight, stored in the boiler tank unit 4, and heated by the heat generated by the pyrolysis furnace 2. In addition, a discharge pipe 21 for discharging hot water or steam in the boiler tank unit 4 is provided below the boiler tank unit 4.

  The heat exchanger section 5 is a pipe formed by a heat exchanger steel pipe 5 </ b> A arranged so as to be wound around the cylindrical body 17. One end of the heat exchanger steel pipe 5 </ b> A is connected to the water injection port 19 </ b> A at the top of the pyrolysis furnace 2, and is disposed around the cylindrical body 17 so as to descend spirally around the cylindrical body 17 from the water injection port 19 </ b> A. The other end of the pyrolysis furnace 2 is connected to the lower discharge port 19B. The running water in the heat exchanger steel pipe 5 </ b> A is heated by the heat generated by the pyrolysis furnace 2.

  The hot air generator 6 includes an exhaust pipe 30 that discharges heated air generated in the pyrolysis furnace 2, and a fan 31 that sucks heated air from the pyrolysis furnace 2 in the exhaust pipe 30. The exhaust pipe 30 is connected to the top of the pyrolysis furnace 2. The fan 31 includes an impurity removal filter that removes impurities in the air. A sheathed heater 32 is provided between the exhaust pipe 30 and the fan 31. Further, in the middle of the exhaust pipe 30, a spray device 33 that sprays water on the heated air passing through the exhaust pipe 30 is provided.

  The spraying device 33 sprays warm water as water into the exhaust pipe 30 to capture and purify harmful substances, white smoke and impurities in the heated air generated in the pyrolysis furnace 2 by spray particles of warm water. . The harmful substances, white smoke and impurities trapped in the spray particles of the hot water are discharged from the drain 34. The sheathed heater 32 is for heating the heated air whose humidity has been increased by spraying warm water from the spraying device 33 to lower the humidity and to sterilize various germs in the moisture in the heated air.

  In the woody biomass boiler 1 in the present embodiment, the entire pyrolysis furnace 2 and boiler tank unit 4 and the periphery of the exhaust pipe 30 are covered with heat insulating materials 40 and 41. Moreover, the wood biomass boiler 1 in this embodiment has the drying chamber 8 which dries a wood material fuel to 30% or less of a mass moisture content at the top of the pyrolysis furnace 2.

  In the woody biomass boiler 1 having the above-described configuration, woody material fuel such as waste wood and waste bamboo is introduced into the pyrolysis furnace 2 from the fuel inlet 13. At this time, the wood material fuel is charged to a height that is less than half that of the pyrolysis furnace 2. Then, by driving the fan 31, the air for pyrolysis is drawn into the pyrolysis furnace 2 through the magnetizing device 3 and ignited by fire. At this time, the pyrolysis air is in an oxygen-deficient state as described above, and the condensed low-oxygen conjugate collides with the wood fuel, so that the wood fuel continues the pyrolysis reaction without flame burning. To do.

  Further, the wood fuel after pyrolysis becomes magnetic ash, and this magnetic ash becomes a heat source for the next adjacent fuel, so that dry distillation continues. On the other hand, the low oxygen combined body drawn into the pyrolysis furnace 2 becomes heated air, which is adjusted by the rectifying plate 18 in the cylindrical body 17 of the pyrolysis furnace 2 and circulates in the pyrolysis furnace 2. 18 itself absorbs heat. Thermal decomposition is also continued by the heat absorbed by the current plate 18. The pyrolyzed wood material fuel is finally reduced in volume to about 1/300, falls from the intermediate hearth 12 and is scraped out from the ash scraper 14.

  The temperature distribution in the pyrolysis furnace 2 is maintained at a low temperature dry distillation temperature in which the temperature of the dry distillation part is 350 to 400 ° C. The middle part from the lower part in the furnace is controlled to 400 to 900 ° C. (rise with time), and the upper part temperature is maintained at a low temperature of 300 to 480 ° C.

  The water in the boiler tank unit 4 is heated by this decomposition heat, and becomes hot water or steam at 90 to 100 ° C. The water in the head tank 7 is supplied to the boiler tank unit 4 by its own weight, and the hot water is discharged from the discharge pipe 21 below the boiler tank unit 4. In general, boiler water is supplied from the bottom by a pump, and the water inside the boiler is heated, resulting in a density difference, natural convection due to thermal convection, and hot water receiving buoyancy to the top. In the woody biomass boiler 1 in the embodiment, natural convection from the upper part to the lower part occurs by continuously discharging heated hot water.

  At the same time, the flowing water in the pipe of the heat exchanger section 5 is heated by the decomposition heat in the pyrolysis furnace 2 to become hot water of 90 to 95 ° C. Water injection into the heat exchanger unit 5 is performed from existing tap water piping. Water is poured from a water injection port 19 </ b> A at the top of the pyrolysis furnace 2, heated by the decomposition heat while descending spirally around the cylindrical body 17 in the pyrolysis furnace 2, and hot water is heated in the pyrolysis furnace 2. It is discharged from the pipe 22 connected to the lower discharge port 19B.

  The heated air generated inside the pyrolysis furnace 2 is sucked by the fan 31 and becomes hot air of 90 to 100 ° C. The heated air in the pyrolysis furnace 2 is purified by spraying hot water from a spray device 33 provided in the middle of the exhaust pipe 30. Although black smoke is generated immediately after the ignition of the wood material fuel, almost no smoke is generated in the pyrolyzed state, so that hot water is sprayed from the spray device 33 as necessary. Further, the sheathed heater 32 is driven as necessary to lower the humidity of the heated air and sterilize germs in the moisture.

  As described above, the hot water or steam obtained from the boiler tank unit 4 is used for hot water supply (for farmhouses, inns / hotels / hospitals, for reheating, etc.) and for heating (agricultural houses, hot water, inns, hotels, hotels, (Office, school, hospital, business use, etc.), generator for the temperature difference from the atmosphere, industrial, hot air (convert hot water into hot air with an existing heat exchanger), etc. The hot water obtained by the heat exchanger unit 5 is used for reheating the hot water in the boiler tank unit 4, for floor heating, in combination with the boiler tank unit 4 (in combination with hot water supply and heating), the atmosphere It can be used for generators due to temperature difference between the two and warm air (converting hot water into hot water using an existing heat exchanger). Furthermore, the warm air obtained by the warm air generator 6 can be used for agricultural houses, various greenhouses, for heating, for warm water (converting warm air into warm water with an existing heat exchanger), and the like.

  In addition, as wood material fuel used for the wood biomass boiler 1 in this embodiment, forest land residual materials (thinned wood, etc.), residual lumber, construction waste materials / remaining materials, waste wood such as firewood, wood chips, and abandoned bamboo forest Waste wood, etc. can be used. Further, in the case of a log-like or rod-like woody material fuel, one having a length of 50 to 60 cm × diameter (10 cm or less) is used. Further, when the mass moisture content of the wood material fuel exceeds 30%, it is used after being dried to a mass moisture content of 30% or less in the drying chamber 8.

  Further, in the present embodiment, the wood material fuel is manually input from the fuel input port 13, but may be configured to automatically input. In this case, the wood material fuel may be transported from the storage hopper to the drying chamber 8 by a screw conveyor or the like, and the furnace top plate 11 of the pyrolysis furnace 2 may be put into the pyrolysis furnace 2 as an automatic opening / closing type.

  The woody biomass boiler of the present invention is useful as a boiler capable of obtaining warm water (steam) and warm air using woody materials such as waste wood and waste bamboo as fuel.

DESCRIPTION OF SYMBOLS 1 Wood biomass boiler 2 Pyrolysis furnace 3 Magnetizer 4 Boiler tank part 5 Heat exchanger part 6 Hot air generator 10 Internal furnace shell 11 Furnace top plate 12 Intermediate hearth 13 Fuel inlet 14 Ash scraper outlet 15A, 15B, 15C, 16A, 16B, 16C Air suction pipe 17 Cylindrical body 18 Current plate 19A Water injection port 19B Discharge port 20 External furnace shell 30 Exhaust pipe 31 Fan 32 Seeds heater 33 Spraying device 34 Drain 40, 41 Heat insulating material

Claims (4)

A pyrolysis furnace for pyrolyzing wood fuel;
A magnetizing device that is in an oxygen-deficient state by passing air sucked into the pyrolysis furnace;
A boiler tank section that is provided so as to surround the pyrolysis furnace, and that heats the stored water by heat generated by the pyrolysis furnace;
A heat exchanger part configured by piping passing through the inside of the pyrolysis furnace, and heating the running water in the pipe by heat generated by the pyrolysis furnace;
A woody biomass boiler having an exhaust pipe for discharging heated air generated in the pyrolysis furnace, and a hot air generator having a fan for sucking the heated air from the pyrolysis furnace in the exhaust pipe. In the pyrolysis furnace, it is a cylindrical body extending in the vertical direction, and has a cylindrical body provided with a plurality of steps in the vertical direction on the inner surface of the annular rectifying plate protruding obliquely downward,
The woody biomass boiler according to claim 1, wherein the pipe of the heat exchanger section is disposed so as to wind around the cylindrical body.   The woody biomass boiler according to claim 1 or 2, further comprising a drying chamber for drying the woody fuel to a moisture content of 30% or less at a top of the pyrolysis furnace.   The woody biomass boiler according to any one of claims 1 to 3, wherein the warm air generating device includes a spraying device that sprays water on the heated air passing through the exhaust pipe.

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