JP4912003B2 - Wood pellet fuel combustion equipment - Google Patents

Description

  The present invention relates to a wood pellet fuel combustion apparatus for preventing adhesion of ash, soot and the like to heat-resistant glass such as a heater using wood pellets as combustion fuel.

  Conventionally, fossil fuel coal and oil, which have been used as fuel for heating and the like, have been converted to natural friendly resources instead of natural warming due to greenhouse gases such as carbon dioxide.

  Of the expected resources, biomass fuel, which is considered to be effective due to environmental problems, is attracting attention as fuel for rice husk or its pellets, firewood, etc., especially thinned wood, large sawdust, driftwood, etc. The wood material which has been used is granulated as wood pellets and used as a combustion fuel for a heater or the like, and its apparatus becomes known as a solid fuel stove described in Japanese Utility Model Publication No. 58-190301 (Patent Document 1). Yes.

  Among the wood pellet fuel combustion devices, the wood pellet stove has an effect of giving a peace of mind by producing a flame during combustion in addition to the effective use of the biomass fuel, and Japanese Patent Application Laid-Open No. 2004-293930 (Patent Publication 2). A wood pellet stove equipped with a transparent plate that can confirm the flame burning in the combustion chamber from the outside is also known.

  By the way, the amount of ash generated after burning the wood pellets, for example, the wood pellets formed in the wood part of the wood has an ash content of about 0.5 to 2.0%, but the pellets molded with bark In ash, the ash content increases to about 5 to 7%, and the amount of ash varies depending on the wood to be pelletized. Naturally, the ash deposited after burning the wood pellets molded from bark and the combustion wind The amount of ash that soars will also increase.

  In addition, the ignitability of wood pellets varies depending on the quality of the wood, and the ignitability of the pellets formed from bark is worse than the pellets formed from the xylem. There is a tendency not to ignite easily.

  Even in the combustion of wood pellets formed in the wood part of the wood, soot is likely to be generated along with the ash that rises or falls with the combustion wind to some extent, especially in the case of incomplete combustion, ignition, etc. When it adheres to the inner surface of the heat-resistant glass viewing window provided so that the flame can be seen, especially when the above-mentioned bark pellets are burnt, the observation window is fogged and the stove is managed especially due to ignitability problems. A person frequently needs to clean the sight glass.

  Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2004-191017 (Patent Document 3), a blowing unit that blows air toward the inner surface of the heat-resistant glass that serves as a viewing window, an air supply unit that takes in outside air, and air that connects both of them. A passage is provided so that a part of the combustion air taken in from the air supply part is guided to the air passage, and the air is blown from the blowing part toward the inside of the heat-resistant glass to be applied to the inner surface of the heat-resistant glass. Also known is an invention that prevents adhesion of ash and soot, promotes prevention of dirt on the heat-resistant glass, and eliminates periodic cleaning of the glass surface.

Japanese Utility Model Publication No. 58-190301 JP 2004-293930 A JP 2004-191017 A

  When wood pellets are burned, tar is generated in addition to the ash and soot, and tar generation increases when the combustion temperature is 150 ° C. or lower. In particular, when the aforementioned bark pellets are burned, the amount of tar generated increases due to the problem of ignitability.

  In Patent Document 3, it is possible to prevent soot and ash from adhering to the inner surface of the heat-resistant glass by blowing a part of the outside air from the air supply unit to the inside of the heat-resistant glass. The temperature near the heat-resistant glass is low because the outside air is blown at room temperature, which promotes the environment where tar is generated. In addition, the intake of outside air into the combustion chamber hinders the temperature rise of the combustion chamber, hinders the temperature rise, and hinders efficient combustion of the wood pellets.

  Furthermore, in the combustion chamber, rising air is generated by the combustion air from the combustion section, and combustion that forms a circulating convection in which the combustion air falls near the heat-resistant glass prevents the phenomenon of scattering or spreading in the left-right direction, and in the vertical direction. It has been found to form a straight flame. However, in Patent Document 3, since an air flow rising toward the inner surface of the heat-resistant glass is formed, the circulation convection in the combustion chamber is not formed, and the combustion flame tends to be disturbed.

Therefore, in the present invention, a part of the air after heat exchange that forcibly circulates in the heat radiating pipe of the heat exchanging portion is sprayed from the upper end to the obliquely downward direction over the substantially entire width of the inner surface of the heat-resistant glass in the combusting portion. Prevents the ash and soot scattered on the combustion air space from being blown down along the inner surface of the heat-resistant glass and attached to the combustion air. As the air is blown, the temperature in the combustion chamber is prevented from lowering, the efficient combustion of the wood pellet fuel is promoted, and the circulation convection of the combustion air in the combustion chamber is performed well, and a well-organized flame It is an object of the present invention to provide a wood pellet fuel combustion apparatus that can perform good combustion visually.

  In order to achieve the above object, the present invention proposes a wood pellet fuel combustion apparatus according to claim 1.

That is, the wood pellet fuel combustion apparatus according to claim 1 supplies the wood pellets from the fuel tank to the combustion tank storing the wood pellets, the combustion chamber having the combustion section and the heat exchange section, and the combustion section of the combustion chamber. A wood pellet fuel combustion apparatus comprising a fuel supply apparatus and an exhaust section for discharging combustion air combusted in a combustion section of a combustion chamber, the transparent or translucent heat-resistant glass disposed at least on the front side of the combustion chamber; In the combustion chamber, it is installed over the entire width of the heat-resistant glass adjacent to the vicinity of the upper end of the heat-resistant glass, and air is blown obliquely downward from the upper end over almost the entire inner surface facing the combustion part of the heat-resistant glass. provided with a with that blowoff unit, communicates with the distance blowing a short heat radiating pipe section to heat the glass of several of the heat dissipation tubes of the heat exchange section, is forced supplied to the heat exchanger outside air temperature heated by the combustion air From the upper end toward the inner surface of the heat-resistant glass from the blowing unit by blowing obliquely downward and it is characterized in blown Kudaro Succoth along the inner surface of the heat-resistant glass.

According to the present invention, a part of the air after heat exchange that forcibly circulates in the heat radiating pipe of the heat exchange part is sprayed obliquely downward from the upper end to the inner surface of the heat-resistant glass in the combustion part over the substantially entire width. As a result, it was possible to prevent ash and soot scattered on the combustion chamber from being blown down along the inner surface of the heat-resistant glass, and to exchange heat with the combustion wind at the heat exchange section . Since high-temperature air is blown, it is possible to prevent a temperature drop in the combustion chamber and promote efficient combustion of the wood pellet fuel.

And since the wind that blows to the inner surface of the heat-resistant glass in the combustion chamber is blowing from above, the air that circulates in the combustion chamber, that is, the flow that rises in the combustion section and descends in the vicinity of the heat-resistant glass, The shape of the flame of the part is formed vertically, and it has the effect of preventing the lateral spread and maintaining a visually good flame production.

  As an example of the wood pellet fuel combustion apparatus of the present invention, a pellet stove using wood pellets as fuel will be described below.

  FIG. 1 is a schematic side sectional view of a wood pellet stove showing an embodiment of the present invention. FIG. 2 is a perspective view of a wood pellet stove showing an embodiment of the present invention.

  In FIG. 1, 1 is a wood pellet stove. a is a wood pellet, and in the wood pellet stove 1, a combustion chamber 2 in which the wood pellet a burns, and a heat exchanging section 5 are provided from the middle to the top. A combustion wind exhaust port 7 is provided at the upper end of the combustion chamber 2 to circulate the combustion wind to the exhaust section 6. A fuel tank 3 is provided adjacent to the combustion chamber 2, and a fuel supply device 4 for supplying the wood pellets a from the fuel tank 3 to the combustion chamber 2 is provided in close contact with the fuel tank 3. Reference numeral 38 denotes a suction air passage, which is an air passage for taking outside air into the wood pellet stove 1, and the outside air sucked from the suction air passage 38 is used as hot air and combustion air for cooling and ignition of each part. The fuel tank 3 shown in FIG. 1 has a space up to the upper end of the wood pellet stove 1, and it is preferable that the wood pellet stove has an upper surface as a door so that the wood pellet a can be put into the fuel tank 3 ( Not shown).

  The bottom plate 10 constituting the lower end of the fuel tank 3 is inclined toward the fuel supply device 4 so that the wood pellets a can be input to the input port 9 of the screw conveyor 8 of the fuel supply device 4 without leakage. At the upper end of the screw conveyor 8, there are provided an input chute 11 for introducing the wood pellet a into the combustion chamber 2 and an air vent 12 for allowing outside air to pass through the input chute 11. It may be provided in the middle. The power of the screw conveyor 8 is obtained by the rotation of the motor 24.

  The rear wall 34 of the combustion chamber 2, the fuel tank 3, and the fuel supply device 4 are configured with a cooling space 17 therebetween, and outside air from the suction air passage 38 flows through the cooling space 17. The combustion heat in the combustion chamber 2 is not transferred to the fuel tank 3 and the fuel supply device 4.

  Below the combustion chamber 2, there is a combustion section 26, in which the wood pellets a that have fallen from the input chute 11 accumulate and burn, and a combustion dish 13 having a plurality of slits 14, and a combustion dish 13 The rear surface is provided with a heater 16 in a long thin tube, and the air passing through the long thin tube is heated to a high temperature (about 250 ° C. or higher) by the heater 16 and ignited by applying the high temperature air to the wood pellet a. An ignition device 15 having a structure is provided.

  On the front surface of the combustion chamber 2, there is provided a viewing window through which the flame of the wood pellets combusted in the combustion dish 13 can be confirmed from the outside in a range not reaching the heat exchange unit 5 from the combustion unit 26. The viewing window is composed of a transparent or semi-transparent heat-resistant glass 25, and the viewing window itself can be opened and closed so that the size of the viewing window can be cleaned.

  The slit 14 of the combustion dish 13 is formed in an elongated shape in either the front, rear, left, or right direction on the substantially entire surface of the combustion dish 13 while maintaining an opening width at which the input wood pellet a does not fall. A vertical slit on the side surface is connected to maintain the same opening width, and an ash collection container in which ash generated by combustion on the combustion dish 13 falls through the slit 14 and accumulates below the combustion dish 13. 29 is provided in a range covering the installation surface of the combustion dish 13. 28 is an ash removing means, and a plate-shaped uneven plate thinner than the width of the slit 14 is installed on the rotating shaft, and the uneven plate enters the slit 14 to force the fixed ash deposited on the slit 14. The ash collection container 29 is scraped off.

  The hot air exhaust port 7 at the upper end of the combustion chamber 2 is provided with an exhaust air section 6, which sucks the combustion air by the suction action of the suction fan 21 and exhausts the combustion air from the exhaust duct 22 to the outside of the machine. The exhaust duct 22 has an exhaust duct 22 on the inner side and a double cylinder of the suction air passage 38 on the outer side. When the outer wall 33 of the building is penetrated, a single through hole can be formed. In addition, the outside air flowing into the suction air passage 38 is warmed by exchanging heat with the exhaust of the exhaust duct 22, thereby increasing the combustion efficiency of the suction air whose temperature has increased.

The heat exchanging section 5 that longitudinally cuts the main body of the wood pellet stove 1 from the middle to the top of the combustion chamber 2 is composed of a heat radiating pipe 18 and a pressure feed fan 19, and from an opening 27 that takes in air around the wood pellet stove 1 Air is forcibly pumped into the plurality of heat radiating pipes 18 by a pressure feeding fan 19, and hot air or hot air heat-exchanged by the heat radiating pipes 18 is blown out from the hot air outlet 20 around the wood pellet stove 1. . In addition, in order to adjust the air pressure in the room in which the wood pellet stove 1 is installed, the air pressure in the room is provided if a vent hole 35 is provided to connect any location of the heat exchanging unit 5 and the suction air passage 38. Can be made equivalent to outdoor air pressure.

The at least one or several hot-air discharge ports 32 of the heat radiating pipe 18 are joined to a blowing portion 30 provided adjacent to the vicinity of the upper end of the heat-resistant glass 25 in the combustion chamber 2. As shown in FIG. 2, the blow-out portion 30 has a width over substantially the entire width of the heat-resistant glass 25, and a plurality of holes are provided in parallel to the glass surface on the bottom surface, and blown out from the holes. The air is blown onto the inner surface of the heat-resistant glass 25 at an oblique angle. If the hot air outlet 32 is provided on the lower end of the heat radiating pipe 18 provided in the combustion chamber 2, the distance to the heat-resistant glass 25 is short and can be easily connected to the outlet 30. good at.

  23 is a temperature sensor, which is provided at either the exhaust duct 22 or the inlet / outlet of the suction fan 21, and the motor 24, heater 16, pumping fan 19, suction fan 21, and ash removal means 28 are connected to the control unit 31. Each is controlled.

  As a result of the operation of the suction fan 21, the outside air flows directly from the suction air passage 38 or directly through the cooling space 17 into the slit 14 of the combustion unit 26 and the elongated cylinder of the ignition device 15, and a part of the outside air enters the charging chute 11. It reaches the combustion chamber 2 while cooling. The wood pellet a is introduced from the fuel tank 3 into the combustion section 26 of the combustion chamber 2 via the screw conveyor 8 and ignited by the ignition device 15, and is blown from the slit 14 by the suction action of the suction fan 21. Continue to burn stably. Thereafter, the combustion air is heat-exchanged in the heat exchanging section 5, passes through the suction fan 21 from the combustion air exhaust port 7, and is discharged out of the machine from the exhaust duct 22.

  At the start of operation, the heater 16 is energized, and after energization is determined to have completed the preheating, the motor 24 is energized and the fuel supply means 4 is operated for a certain period of time, so that the wood pellet a is moved from the fuel tank 3 into the screw conveyor 8. Is raised and supplied to the combustion dish 13. After the set time has elapsed, the suction fan 21 is started, and the wood pellets a are intermittently supplied onto the combustion dish 13 within the set time. When the temperature exhausted by the temperature sensor 23 reaches the set temperature (45 ° C.), it is regarded as combustion. Then, while operating the pressure feed fan 19, the normal combustion state is judged and the temperature control operation is started, and the motor 24 is energized within the set interval and the set time range, and the combustion fuel corresponding to the set combustion amount is set. Supply is intermittently performed, and thereafter, if the temperature of the temperature sensor 23 does not fall below the set temperature, stable combustion is determined and the energization of the heater 16 is stopped.

  As temperature adjustment for heating during stable combustion, the fuel supply can be adjusted in three stages, and the air volume of the suction fan 21 is controlled in three stages in accordance with the adjustment of the supply amount. In the case of fuel supply “large”, the wind speed rising up the slit 14 is about 2 to 3 m / s, the wind speed at “medium” is about 80% of the wind speed of “large”, and the wind speed at “small” is the wind speed of “large”. About 70%.

  By operating the suction fan 21, the combustion section 26 sucks outside air from the outside wall 33 of the building, that is, outside from the outside through the suction air passage 38, and enables stable combustion in the combustion section 26 of the wood pellet a. When the wind passes through the heat exchanging unit 5, the heat radiating pipe 18 is heated. The heat radiating pipe 18 heated by the combustion air heats the air in contact with the periphery of the wood pellet stove 1 fed from the pressure feeding fan 19, that is, the indoor air inside the outer wall 33 of the building to heat the air from the hot air outlet A20. The room is opened again, and the room is heated by repeating the circulation.

  As described above, the blowing portion 30 is provided near the upper end of the heat-resistant glass 25 and its width is connected to each hot air blowing port B32 over substantially the entire width of the heat-resistant glass 25. A plurality of holes 36 are provided at equal intervals from the heat-resistant glass 25 at the same distance. The indoor air that has passed through the heat radiating pipe 18 having one or a plurality of hot air outlets 32 spreads evenly into the outlet 30 when entering the outlet 30 and is located on the bottom surface of the outlet 30. The air is blown downward from the plurality of holes 36. The air blown out from the hole 36 is blown downward from the upper end of the heat-resistant glass 25, and the entire surface of the heat-resistant glass 25 is uniformly blown through the entire surface over the entire width and length. Since ash and soot generated in the combustion unit 26 are dropped toward the bottom surface of the combustion unit and do not adhere to the heat-resistant glass 25, and the air supplied to the surface of the heat-resistant glass 25 is heated air after heat exchange. Favorable combustion is possible without causing a temperature drop in the combustion chamber 2.

  Then, by creating a flow of air that descends from the upper side of the inner surface of the heat-resistant glass 25, a distance from the heat-resistant glass 25 is placed above the combustion part 26 that is disposed at the approximate center or rear of the combustion chamber. A rising air flow is formed and the upward flow of the combustion air is assisted to spread the flame to the side, and in particular, the flame burning phenomenon in the direction of the heat-resistant glass 25 is suppressed, and the flame stands in the vertical direction and has a good appearance. It is possible to produce a flame.

  The air blown out from the blow-out unit 30 is indoor air that has passed through the heat exchanging unit 5, and the air is discharged from the combustion air exhaust port 7 through the exhaust air unit 6 to the outside through the exhaust duct. When the degree of airtightness in the room where the pellet stove 1 is installed is high, the air pressure in the room decreases and the suction action of the suction fan 21 is reduced, so that good combustion may not be possible. Even if the wood pellet stove 1 is operated by allowing a part of the outdoor air to flow into the heat exchanging part 5 through the vent hole 35 provided in a part of the air, the outdoor and indoor air pressure is the same. Combustion is possible.

1 is a schematic side sectional view of a wood pellet stove showing an embodiment of the present invention. It is a perspective view of the wood pellet stove which shows embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Wood pellet stove 2 Combustion chamber 3 Fuel tank 4 Fuel supply means 5 Heat exchange part 6 Exhaust part 7 Combustion wind exhaust port 8 Screw conveyor 9 Input port 10 Bottom plate 11 Input chute 12 Ventilation port 13 Combustion dish 14 Slit 15 Ignition device DESCRIPTION OF SYMBOLS 16 Heater 17 Cooling space 18 Radiation pipe 19 Pressure feed fan 20 Hot air blowing outlet 21 Suction fan 22 Exhaust duct 23 Temperature sensor 24 Motor 25 Heat resistant glass 26 Combustion part 27 Opening part 28 Ash removal means 29 Ash collection container 30 Outlet part 31 Control part 32 Hot air outlet 33 Outer wall 34 Rear wall 35 Vent 36 hole 38 Suction air path a Wood pellet

Claims (1)

Combustion tank for storing wood pellets, combustion chamber with combustion section and heat exchange section, fuel supply device for supplying wood pellets from the fuel tank to the combustion section of the combustion chamber, and combustion burned in the combustion section of the combustion chamber A wood pellet fuel combustion apparatus comprising an exhaust for exhausting wind;
A transparent or translucent heat-resistant glass disposed at least on the front side of the combustion chamber, and is provided over the entire width of the heat-resistant glass adjacent to the vicinity of the upper end of the heat-resistant glass in the combustion chamber and faces the combustion portion of the heat-resistant glass. from substantially the upper end over the entire surface obliquely downward provided with a blowing unit that only blowing air of the interior surface,
We communicate with distance blowing a short heat radiating pipe section to heat the glass of several of the heat dissipation tubes of the heat exchange unit,
The sprayed blown along the inner surface of the heat-resistant glass Kudaro Succoth obliquely downward from the upper end toward the force supplied inside surface of the heat-resistant glass from the blowing unit of the warm air of the outside air heated by the combustion air to the heat exchange section A wood pellet fuel combustion device.

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