JP2007040542A - Woody pellet combustion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woody pellet combustion apparatus capable of finely controlling a combustion amount by providing a shutter composition in a fuel supply means for supplying woody pellet fuel and positively supplying the woody pellet fuel filled at a fixed quantity in a storage space to a combustion part, and excelling even in an aspect of safety by cutting off communication of the combustion part with the fuel supplying means in an emergency stop. <P>SOLUTION: The fuel supplying means of the woody pellet combustion apparatus is provided with the shutter composition preventing communication with the combustion part to block supply of the woody pellet fuel, and the storage space to be filled with woody pellets by the shutter composition. It is composed to arrange a supply start attitude of the woody pellet fuel by an accumulated amount detecting means provided in the storage space, and to quantitatively supply the woody pellet fuel with opening action of the shutter composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel supply of a wood pellet combustion apparatus using wood pellets formed by compressing and processing driftwood, crushed material of thinned wood, wood building materials, large sawdust and the like.

  Conventionally, fossil fuel oil, which has been used as a fuel for combustion devices and heaters, generates carbon dioxide, which becomes a greenhouse gas, by burning, causing global warming. There is an urgent need to switch to fuel resources that can be recycled and reused as soon as possible.

  Therefore, in recent years, attempts have been made to establish a recycling-oriented society by using organic resources (biomass) that can be recycled and reused as fuel. In particular, large sawdust, thinned wood, and wooden construction waste that have been incinerated until now. Or driftwood as a combustion fuel is compressed and molded into a shape of a certain particle size, and is beginning to be used as a fuel for combustion devices, heaters, and the like. For example, a solid fuel stove described in Japanese Utility Model Laid-Open No. 58-190301 (Patent Document 1) is known.

  Wood pellets that are formed into granules by compressing thinned wood, construction-generated timber, timber from thinned wood and driftwood, and large sawdust, etc., are usually in the shape of a cylinder with a diameter of 6 to 8 mm and a length of about 10 to 25 mm. It is assumed that there are considerable differences in the dimensions themselves. In addition, the shape and length of the wood pellets are slightly different depending on the wood to be pelletized. In particular, wood that has a low lignin content, such as cedar wood, is not easy to pelletize, and the shape and length of the molded pellets are easy to shred. It is hard to be constant.

  Fossil fuel oil, which has been regarded as a conventional combustion fuel, has the advantage of being able to obtain stable combustion by finely controlling the amount of combustion because it is in a liquid state and continuously. . Even when using wood pellets as combustion fuel, it is important to supply a constant amount of fuel uniformly and continuously to the combustion section. However, it is stable because of the difference in fuel shape and length. It was difficult to burn.

  Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2004-191011 (Patent Publication 2), the pitch of the blades at the screw conveyor outlet of the conveying means for conveying the pellet fuel from the fuel tank to the combustion section is made shorter than the pitch of the other blades. A configuration in which a delayed fuel is filled in the conveyor and the fuel supply amount is made constant is known.

  In addition, a pellet fuel combustion apparatus that has a structure in which the inclination of the blades is reversed to the other blades at the outlet upper part of the screw conveyor and can stably supply the fuel without reaching the motor unit on the upper part is also known. ing.

Japanese Utility Model Publication No. 58-190301 JP 2004-191011 A

  In the above-mentioned Patent Document 2, the dispersion of pellet fuel that is lifted and conveyed by the screw conveyor is filled with pellet fuel that is delayed at a place where the pitch of the blades in the outlet direction of the screw conveyor is short. Although it is possible, even if the pitch is shortened near the discharge part in the screw conveyor, the blades of the carrier itself exist, so it is impossible to efficiently store the pellet fuel in the entire cross section in the screw conveyor. However, many voids are generated between the blades and the pellet fuel, which hinders an increase in the filling rate of the pellet fuel.

  Also, wood pellet fuel has different lengths, so when long pellet fuel is thrown into the inlet of the screw conveyor, the gap between the pellet fuel is large, so the pellets thrown from the inlet The total amount of fuel is reduced, and no matter how much the blade pitch near the discharge port of the screw conveyor is shortened to pack the fuel, a large space is generated depending on the arrangement of pellet fuels. Since the gap is introduced into the combustor without narrowing, there may be a case where the pellet fuel cannot be stably supplied quantitatively.

  Therefore, in the present invention, the fuel supply means for supplying the wood pellet fuel to the combustion section has a shutter configuration for preventing communication with the combustion section and blocking the supply of the wood pellet fuel, and a storage space for depositing the wood pellets by the shutter configuration. A wood pellet combustion device that can finely control the amount of combustion is provided by reliably supplying the wood pellet fuel that has been filled in a fixed amount by operating the shutter configuration to the combustion section. Another object of the present invention is to provide a wood pellet combustion apparatus excellent in safety by blocking communication between the combustion section and the fuel supply means.

  In order to achieve the above object, the present invention proposes a wood pellet combustion apparatus according to claims 1 to 5.

  That is, in the wood pellet combustion apparatus using wood pellets as fuel according to claim 1, the fuel supply means for supplying the fuel from the fuel tank to the combustion section is prevented from communicating with the combustion section, thereby blocking the supply of the wood pellet fuel. A shutter configuration for stopping and a storage space for depositing wood pellets by the shutter configuration are provided.

  The wood pellet combustion apparatus according to claim 2 is the wood pellet combustion apparatus according to claim 1, wherein the fuel supply means is a screw conveyor that ascends and conveys the wood pellet fuel from below the fuel tank and supplies it to the combustion section. The space from the upper end of the conveying blade inside the screw conveyor to the substantially upper surface of the internal space of the screw conveyor is a storage space closed by a shutter configuration.

  The wood pellet combustion apparatus according to claim 3 is the wood pellet combustion apparatus according to claim 1, wherein the fuel supply means is a screw conveyor that ascends and conveys the wood pellet fuel from below the fuel tank and supplies it to the combustion section. The storage space is provided with a shutter structure below and adjacent to the discharge port of the screw conveyor.

  The wood pellet combustion apparatus according to claim 4 is the wood pellet combustion apparatus according to claim 1, 2 or 3, wherein the fuel supply means prepares the supply start state of the wood pellet fuel in the storage space, and the shutter configuration is A proper amount of wood pellet fuel can be appropriately supplied to the combustion section by operation.

  The wood pellet combustor according to claim 5, wherein the wood pellet combustor according to claim 1, 2, 3 or 4 senses that the supply start posture of the wood pellet fuel in the storage space cannot be prepared, It is characterized by being configured to issue an alarm.

  According to the wood pellet combustion apparatus according to the present invention, the shutter configuration that prevents the fuel supply means from communicating with the combustion unit and blocks the supply of the wood pellet fuel, and the storage space filled with the wood pellet fuel by the shutter configuration, It becomes possible to deposit a certain amount of wood pellet fuel in the storage space, and by operating the shutter configuration, the wood pellet fuel stored in a fixed amount is reliably supplied to the combustion portion, so that the combustion amount of the combustion portion is finely and reliably ensured. It can be controlled.

  In addition, since the storage space is provided with detection means for sensing a fixed amount of filling, even if the fuel supply means is operating, even if fuel cannot be supplied, detection of the amount of accumulation provided in the storage space is detected. Since it is possible to quickly detect a state in which the supply start posture of the wood pellet fuel cannot be adjusted by means, and an alarm or a stop operation can be taken, safety is also provided. Furthermore, since the shutter configuration is always in a closed state unexpectedly when the operation of supplying wood pellet fuel during normal operation is performed, the storage space for storing the wood pellet fuel for the flame or the combustion wind from the combustion section in the case of an emergency stop is provided. Since it is cut off, safety is also taken into consideration.

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

  FIG. 1 is a schematic sectional view of a pellet stove illustrating a wood pellet combustion apparatus according to the present invention. FIG. 2 is a cross-sectional view of the fuel supply means showing the first embodiment of the present invention, and FIG. 3 is a cross-sectional view of the fuel supply means showing the second embodiment of the present invention. FIG. 4 is a sectional view showing another example of the second embodiment shown in FIG. FIG. 5 is a time chart of the embodiment of the present invention.

  In FIG. 1, 1 is a pellet stove. a is a wood pellet, and inside the pellet stove 1 is provided a combustion chamber 2 provided with a combustion portion 25 in which the wood pellet a burns, and a heat exchanging portion 5 extending from an intermediate portion of the combustion chamber 2 upward. ing. A combustion wind exhaust port 7 is provided at the upper end of the combustion chamber 2 to circulate the combustion wind C to the exhaust section 6. The combustion chamber 2 is provided with a fuel tank 3 across the rear wall 34 and the cooling space 17, and fuel supply means 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. . The fuel tank 3 shown in FIG. 1 has a space up to the upper end of the pellet stove 1, and the upper surface of the pellet stove 1 serves as a door so that the wood pellet a can be put into the fuel tank 3 (see FIG. 1). Not shown).

  A bottom plate 10 constituting the lower end of the fuel tank 3 is inclined toward the fuel supply means 4 so that the wood pellets a can be introduced into the insertion port 9 of the screw conveyor 8 of the fuel supply means 4 without leakage. At the upper end of the screw conveyor 8, a charging chute 11 for charging the wood pellets a onto the combustion dish 13 of the combustion unit 25 is disposed, and this charging chute 11 has an operation that prevents communication between the fuel supply means 4 and the combustion unit 25. A possible shutter configuration 36 is provided. The power of the screw conveyor 8 is obtained by the rotation of the motor 24.

  Outside air circulates in the cooling space 17 between the rear wall 34 of the combustion chamber 2 and the fuel tank 3 and the fuel supply means 4, and the combustion heat of the combustion chamber 2 is transferred to the fuel tank 3 and the fuel supply means 4. It is designed not to transfer heat.

  In the combustion section 25 below the combustion chamber 2, the wood pellets a flowing down from the input chute 11 are accumulated and burned in the combustion dish 13 and continuously burned by the air passing through the plurality of slit parts 14 of the combustion dish 13. . Further, a heater 16 is provided in a long thin tube behind the combustion dish 13, 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 the high-temperature air is converted into the wood pellet a. An ignition device 15 having a structure that ignites when applied is provided.

  The slit portion 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 that does not cause the dropped wood pellet a to fall. The ash after combustion of the wood pellet falls from the slit portion 14. An ash collection container 29 for depositing ash falling from the slit portion 14 is provided in a range that covers the installation surface of the combustion dish 13.

  Although not shown in the figure, a rotating body passes through the opening of the slit portion 14 and forcibly passes below the opening of the slit portion 14 in order to remove the solid ash that floats or adheres to the combustion plate 13 and is solidified. Ash removing means for dropping the ash downward may be provided.

  The heat exchanging section 5 that longitudinally cuts the combustion chamber 2 back and forth from the middle to the upper part of the combustion chamber 2 is composed of a plurality of heat radiating pipes 18. Then, warm air is supplied from the warm air outlet 20 to the outside of the apparatus.

  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 C by the suction action of the suction fan 21 and exhausts the combustion air C from the exhaust duct 22 to the outside of the machine. . In addition, in order to prevent the light ash that reaches the exhaust section 6 from riding on the combustion air C, the exhaust section 6 is provided with a dust collector such as a cyclone to collect and collect the dust. The configuration may be such that the combustion air C that has passed through the dust device is discharged from the suction fan 21 to the outside of the machine (not shown).

  Reference numeral 23 in FIG. 1 denotes a temperature sensor, which is provided at either the exhaust duct 22 or the inlet / outlet of the suction fan 21. The temperature sensor 23, the motor 24, the heater 16, the pressure feed fan 19, the suction fan 21 and the shutter configuration 36 are controlled. It is connected to the unit 31 and controlled.

  By the operation of the suction fan 21, the outside air reaches the combustion chamber 2 directly or via the cooling space 17 and the slit portion 14 of the combustion portion 25 and the elongated cylinder of the ignition device 15. Wood pellet a is put into the combustion chamber 2 from the fuel tank 3 via the screw conveyor 8 and ignited by the igniter 15, receives ventilation from the slit portion 14, and the wood pellet a burns. Thereafter, the combustion air C 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.

  The screw conveyor 8 of the fuel supply means 4 shown in FIG. 2 is provided with a screw shaft 27 substantially at the center of the conveyor case 26, and the screw shaft 27 is moved in the vertical and horizontal directions by the bearings 32 of the bottom plate 28 and the upper plate 30. And is easily rotatable around the axis of the screw shaft 27, and a motor 24 is provided at the lower end thereof.

  The screw shaft 27 is provided with a spiral conveying blade 33 having a starting end below the inlet 9 and a slight distance from the bottom plate 28, and the upper end of the conveying blade 33 is equal to the lower surface of the discharge port 35. It is provided slightly lower than the surface.

  In the vicinity of the discharge port 35, a shutter structure 36 that prevents communication between the inside of the screw conveyor 8 of the fuel supply means 4 and the combustion unit 25 is provided. In the closed state, the upper plate 30 extends from the lower surface of the discharge port 35 in the screw conveyor 8. A storage space 37 is formed, and the wood pellet a is gradually deposited and filled in the storage space 37 by the rotation of the screw shaft 27 and the action of the conveying blade 33, and a full sensor 38 serving as a filling amount detection means. In response to this, the motor 24 is stopped to prepare the supply start posture of the wood pellet a. The wood pellet a is configured not to interfere with the good supply from the charging chute 11 to the combustion unit 25 when the shutter structure 36 is opened, that is, when the wood pellet a is started to be supplied. In addition, since the volume of the wood pellet a filled in the storage space 37 can be changed by the attachment position of the full sensor 38 on the upper plate 30, the upper and lower parts of the full sensor 38 can be adjusted so that the amount charged into the combustion dish 13 can be adjusted. It is assumed that the left and right can be easily changed. Further, since the vent 12 is provided in a part of the upper plate 30, when the shutter structure 36 is in the open state, outside air is taken in from the vent 12 by the suction action of the suction fan, and passes through the storage space 37. Since the flow of the wind leading to the combustion chamber 2 through the chute 11 can be formed, the wood pellet a filling the storage space 37 can be more efficiently guided to the charging chute 11 by using the flow. In addition, it is possible to prevent the generation of dust.

  The screw conveyor 8 of the fuel supply means 4 shown in FIG. 3 is similar to the screw conveyor 8 of the first embodiment in that the screw shaft 27 and the bearing 32 for fixing the screw shaft 27 are provided on the bottom plate 28 and the upper plate 30 at the center. The movement of the shaft 27 in the vertical and horizontal directions can be fixed and easily rotated, and a motor 24 is provided at the lower end.

  A scraping blade 39 is provided at the upper end of the screw shaft 27, and the starting end is provided below the insertion port 9 and at a slight distance from the bottom plate 28 so that the spiral conveying blade 33 does not contact the lower end of the scraping blade 39. A discharge chute 11 is provided adjacent to the discharge port 35 of the screw conveyor 8, and a shutter configuration 36 is provided in the middle of the input chute 11. When the shutter configuration 36 is in a closed state, the screw conveyor of the fuel supply means 4 is provided. 8 is provided so as to prevent communication between the inside and the combustion part 25 and in an open state so as not to prevent good supply of the wood pellets a to the combustion part 25. The upper plate 30 above the charging chute 11 is provided with a full sensor 41, and the motor 24 is stopped by the operation of the full sensor 41.

  In the closed state of the shutter structure 36, that is, in the state where the communication between the start end of the charging chute 11 and the combustor 25 is hindered, the storage space 40 includes the space of the rotating portion of the scraping blade 39, the start end of the charging chute 11 and the space above it. The wood pellet a is raised in the conveyor case 26 by the conveying blade 33 until the full sensor 41 is operated, and is accumulated on the starting end side of the charging chute 11 by the scraping blade 39 to fill the storage space 40 with the wooden pellet a. To prepare the supply start posture of the wood pellet a fuel. When the shutter structure 36 is in the open state, that is, when the start end of the charging chute 11 and the combustion part 25 are in communication, the wood pellet a in the storage space 40 flows down from the charging chute 11 to the combustion part 25.

  In addition, since the volume of the wood pellet a with which the storage space 40 is filled can be changed according to the attachment position of the full sensor 41 of the upper plate 30 as in the first embodiment, the full sensor 41 can be adjusted so that the input amount can be adjusted. The full sensor 41 may be provided on the starting end wall surface of the charging chute 11 or provided on the starting end wall surface of the charging chute 11 as shown in FIG. Thus, a small amount of wood pellet a can be introduced quantitatively. Further, since the vent hole 12 is provided in a part of the upper plate 30, when the shutter structure 36 is in the open state, outside air is taken in from the vent hole 12 by the suction action of the suction fan and passed through the storage space 40. Since the wind flow to the combustion chamber 2 through the chute 11 can be formed, the wood pellet a filling the storage space 40 can be more efficiently flowed down to the charging chute 11 using the flow. In addition, it is possible to prevent the generation of dust.

  FIG. 5 shows a time chart of the pellet stove 1 provided with the fuel supply means 4 of the first and second embodiments.

  The shutter structure 36 is in a closed state when the power to the pellet stove 1 is not turned on, and is kept closed when the shutter structure 36 at the time of emergency stop due to a power failure or the like is not energized. .

  When the operation is started, the heater 16 is energized, and it is determined that the preheating is completed after the specified time has elapsed. The motor 24 is operated, and the conveying blades 33 rotate the wood pellets a in the fuel tank 3 to raise the screw conveyor 8. Since the shutter structure 36 is in the closed state, the wood pellets a raised by the conveying blades 33 start to accumulate in the storage spaces 37 and 40 formed above the screw conveyor 8 or at the start end of the charging chute 11. When the accumulated amount reaches the range in which the full sensors 38 and 41 are operated, it is determined that the storage spaces 37 and 40 have been filled with the wood pellet a, and the motor 24 is stopped to start the supply of wood pellet fuel. Prepare and wait.

  Then, after the set time, the shutter structure 36 is opened, and the wood pellets a filled in the storage spaces 37 and 40 are caused to flow from the charging chute 11 to the combustion unit 25. The shutter structure 36 is maintained in the open state for a set time, and then closed to confirm that the shutter has been completely closed, and then the motor 24 is operated again to rotate the screw shaft 27 and the conveying blade 33 to store the storage spaces 37 and 40. The filling operation of the wood pellet a is performed, and this series of operations is repeated.

  Thereafter, the suction fan 21 is started after a set time, and the above-described series of fuel supply operations are repeated on the combustion dish 13, and the temperature sensor 23 provided in the exhaust duct 22 passes through the exhaust duct 22. It is determined that the combustion has been detected by confirming that the temperature has reached 45 ° C., the pressure feeding fan 21 is operated, and if the temperature of the temperature sensor 23 does not fall below the set temperature, it is determined that stable combustion has occurred. Then, the energization to the heater 16 is stopped.

  By stopping the energization of the heater 16 and maintaining a state in which the temperature sensor 23 does not cause a temperature drop, it is determined as a normal combustion state, and the fuel is supplied from the storage spaces 37 and 40, which are a series of fuel supply operations, onto the combustion dish 13. The combustion amount is adjusted and the hot air temperature is adjusted by adjusting the supply interval of the supplied wood pellet a. According to the apparatus of the embodiment of the present invention, the fuel supply interval can be adjusted in three stages, and the air volume of the suction fan 21 is controlled in three stages as the supply amount is adjusted. In the case of fuel supply “large”, the wind speed rising up the combustion dish vent 14 is about 2 to 3 m / s, the wind speed in “medium” is about 80% of the wind speed in “large”, and the wind speed in “small” is “large”. It is about 70% of the wind speed.

  In the stop operation, when the operation is turned off, the motor 24 is stopped, the shutter configuration 36 is kept closed, and when the temperature sensor 23 becomes 35 ° C. or less, it is determined that digestion is performed, and after the set time The suction fan 21 is stopped to enter a standby state.

  Since the storage spaces 37 and 40 do not have any obstacles inside, the wood pellets a having a large particle size can be filled without any gaps. A substantially fixed amount can be supplied to the combustion section 25. Moreover, by providing the full sensors 38 and 41 on the upper plate 30 of the fuel supply means 4, the volume of the storage spaces 37 and 40 can be filled to at least the range detected by the sensor, so that the quantitative determination can be made. It is possible to take the supply start posture efficiently.

  When the motor 24 is in an operating state and the wood pellet a is being filled into the storage space by the conveying blade 33, the wood pellet fuel is supplied in a state where the full sensor is not detected even after the set time has elapsed. It is determined that the start posture cannot be prepared, and an alarm is given for fuel shortage or supply start operation insufficiency, and the operation proceeds to supply of wood pellet fuel and stop operation of the pellet stove 1 itself. .

  Furthermore, when the pellet stove 1 itself stops in an emergency for some reason during combustion, the suction action of the combustion air C by the suction fan 21 is lost, so the flame of the wood pellet a burning on the combustion dish 13 and the combustion air C However, according to the embodiment of the present invention, the combustion chamber 25, the conveyor case 26, and the storage spaces 37 and 40 are blocked by the shutter structure 36 without communication. It is also excellent in safety in case of emergency.

The schematic sectional drawing of the pellet stove which illustrates the wood pellet combustion apparatus which concerns on this invention. Sectional drawing of the fuel supply means which shows the 1st Embodiment of this invention. Sectional drawing of the fuel supply means which shows the 2nd Embodiment of this invention. Sectional drawing which shows the other example of 2nd Embodiment shown in FIG. The time chart figure of implementation of the form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pellet stove 2 Combustion chamber 3 Fuel tank 4 Fuel supply means 5 Heat exchange part 6 Exhaust part 7 Combustion air exhaust port 8 Screw conveyor 9 Input port 10 Bottom plate 11 Input chute 12 Ventilation port 13 Combustion dish 14 Slit unit 15 Ignition device DESCRIPTION OF SYMBOLS 16 Heater 17 Cooling space 18 Radiation pipe 19 Pressure feed fan 20 Warm air blow-out port 21 Suction fan 22 Exhaust duct 23 Temperature sensor 24 Motor 25 Combustion part 26 Conveyor case 27 Screw shaft 28 Bottom plate 29 Ash collection container 30 Top plate 31 Control part 32 Bearing 33 Conveying blade 34 Rear wall 35 Discharge port 36 Shutter configuration 37 Storage space 38 Full sensor 39 Scraping blade 40 Storage space 41 Full sensor a Wood pellet c Combustion air

Claims (5)

  In a wood pellet combustion apparatus using wood pellets as fuel, a shutter configuration for blocking the supply of wood pellet fuel to a fuel supply means for supplying fuel from a fuel tank to a combustion portion and preventing communication with the combustion portion, and the shutter A wood pellet combustion apparatus comprising a storage space for depositing wood pellets according to a configuration. The fuel supply means is a screw conveyor that ascends and conveys the wood pellet fuel from below the fuel tank and supplies it to the combustion section,
The wood pellet combustion apparatus according to claim 1, wherein a space from the upper end of the conveying blade inside the screw conveyor to a substantially upper surface of the internal space of the screw conveyor is a storage space closed by a shutter configuration. The fuel supply means is a screw conveyor that ascends and conveys the wood pellet fuel from below the fuel tank and supplies it to the combustion section,
The wood pellet combustion apparatus according to claim 1, further comprising a storage space having a shutter structure below the screw conveyor outlet.   The wood pellet fuel is supplied to the storage space by the fuel supply means, and a set amount of the wood pellet fuel can be appropriately supplied to the combustion unit by operating the shutter configuration. The wood pellet combustion apparatus of Claim 2 or Claim 3. The wood pellet combustion apparatus according to claim 1, 2, 3 or 4, characterized in that an alarm is issued upon sensing that the supply start system of wood pellet fuel in the storage space cannot be prepared. .

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