JP2011185569A - Woody pellet burning hot air heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress scattering of combustion ash around a hot air heater during ash removal operation of the combustion ash. <P>SOLUTION: This woody pallet burning hot air heater includes: a combustor 9 fitted to one end of a lateral flue 11 and burning woody pellet fuel; a plurality of flue tubes 25 having one end side connected to the other end of the flue 11 and extended on the outer side of the flue 11 along the axial direction; a cyclone dust collector 31 communicated with the other end side of the flue tubes 25; an induced air blower 33 connected to the discharge side of the dust collector 31 and discharging combustion exhaust gas; a container 37 forming a space in which air is made to flow on the outer peripheral side of the flue 11 and the flue tubes 25; an ash taking-out port 45 connected to the bottom of the flue 11 to take out combustion ash; and an air quantity controller controlling exhaust air quantity of the induced air blower 33. The air quantity controller controls the exhaust air quantity when the combustion ash is taken out from the combustion ash taking-out port during stop of combustion operation to set air quantity smaller than the exhaust air quantity during the combustion operation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wood pellet fired hot air blower, and more particularly to a hot air blower that generates warm air by burning pelletized woody biomass fuel (hereinafter referred to as wood pellets).

  2. Description of the Related Art Conventionally, warm air machines that generate warm air by burning fuel such as oil or gas have been widely used in horticultural houses or farmers that grow in greenhouses. However, fuels such as oil and gas have a great influence on management when the fuel cost increases, and generate a large amount of carbon dioxide that causes global warming. Therefore, in recent years, attention has been focused on biomass fuel in which carbon dioxide generated during combustion and carbon dioxide absorbed by photosynthesis in the process of plant growth are approximately the same amount. Among them, wood pellets are compression-molded by crushing waste materials and forest land residue, etc. generated from main and thinned timber, etc., and can be obtained at a relatively low cost with stable quality such as shape and moisture content. be able to.

  As a warm air machine which burns a wood pellet, there exist some which are indicated by patent documents 1, for example. This type of hot air machine includes a combustion furnace that burns wood pellets, a heat exchanger that is in communication with the combustion furnace and through which combustion exhaust gas flows, a cyclone dust collector that is connected to the downstream side of the heat exchanger, And an induction blower connected to the discharge side of the cyclone dust collector. The warm air machine having such a configuration heats the air taken into the container in which the heat exchanger or the like is stored by exchanging heat with the heat exchanger or the like, and releases the heated warm air into the greenhouse. The greenhouse is heated to an appropriate temperature.

JP 2008-82567 A

  By the way, when wood pellets burn, a relatively large amount of combustion ash is generated. Most of the combustion ash is deposited at the bottom of the combustion furnace, and part of it is entrained by the flow of combustion exhaust gas and is drawn into the multiple smoke tubes that make up the heat exchanger, and then introduced into the cyclone dust collector. The collected combustion ash accumulates at the bottom of the cyclone dust collector. If combustion ash accumulates on the bottom of the combustion furnace in this way, the inside of the furnace is filled with ash, resulting in poor combustion, or the combustion residue and air may react, causing flaming combustion. It is necessary to periodically remove the combustion ash from the furnace. The ash removal operation of the combustion ash varies depending on the operation time, the combustion amount, etc., but is performed, for example, every day to once a week.

  To remove the ash from the combustion ash, stop the operation of the hot air blower, and with the inside of the furnace cooled, open the lid of the ash removal outlet provided at the bottom of the furnace and insert the ash scraper into the furnace. The ash is scraped out, or the ash in the furnace is crushed by ash soaking it out of the furnace and collected in an ash box or can.

  Here, in the conventional hot air blower, when the operation of the hot air blower stops, the rotation of the fan of the induction blower also stops, so that the combustion ash is scraped out in a state where the inside of the combustion furnace is at atmospheric pressure. As a result, burning ash is scraped off, so that the ash that has risen in the furnace is scattered outside the furnace from the ash removal outlet, and in some cases, the ash may adhere to nearby plants and reduce the commercial value. is there. In addition, if the burned ash scattered outside the furnace is sucked into the worker, there is a risk of damaging health.

  This invention is made | formed in view of such a problem, and makes it a subject to suppress that combustion ash disperses around a warm air machine at the time of ash extraction operation | work of combustion ash.

  In order to solve the above problems, a wood pellet fired hot air machine of the present invention includes a horizontal furnace tube, a combustor for burning wood pellet fuel attached to one end of the furnace tube, and one end at the other end of the furnace tube. A plurality of smoke pipes connected to the other side of the furnace tube along the axial direction, a dust collector provided in communication with the other end of the smoke pipe, and a exhaust gas connected to the discharge side of the dust collector. An induction blower for exhausting, a container that forms a space for air to flow around the outer periphery of the furnace tube and the smoke tube, a combustion ash outlet for connecting to the bottom of the furnace tube to take out the combustion ash, and an exhaust of the induction blower Air volume control means for controlling the air volume, and the air volume control means controls the exhaust air volume when taking out the combustion ash from the combustion ash outlet when the combustion operation is stopped to a set air volume smaller than the exhaust air volume during the combustion operation. It is a feature.

  According to such a configuration, even when the combustion operation is stopped, the induction blower can operate to make the inside of the furnace tube have a negative pressure, so that the combustion ash that has risen in the furnace tube at the time of ash removal is discharged from the ash removal outlet. It is possible to prevent scattering around the outside of the furnace. Then, by installing an ash box or the like in the vicinity of the ash removal outlet, the ash taken out from the ash removal outlet can be collected without being scattered. On the other hand, the combustion ash scattered in the furnace tube is attracted to the smoke pipe by being entrained in the air and then collected by the dust collector, so that the ash is not scattered in the surrounding environment.

  By the way, if the fan rotation speed of the induction blower when the combustion operation is stopped, that is, the amount of exhausted air is large, the amount of air sucked into the smoke pipe in the furnace tube increases, so not only the combustion ash scattered in the furnace tube The combustion ash that accumulates at the bottom of the furnace also rises, reducing the work efficiency of the ash extraction work. In addition, when a large amount of combustion ash is sucked into the smoke pipe in a short time, not only the suction force is reduced, but also maintenance inside the smoke pipe is required. On the other hand, in the present invention, at the time of ash extraction work, the exhaust air amount of the induction fan can be controlled to a set air amount smaller than the exhaust air amount during the combustion operation, that is, the exhaust air amount so that the combustion ash accumulated in the furnace does not rise. Therefore, the inside of the furnace can be maintained at a negative pressure with the combustion ash deposited in the furnace tube being deposited, and as a result, the ash extraction operation can be performed efficiently in a short time.

  In this case, as the air volume control means, for example, a well-known flow rate adjustment valve or the like may be provided in the exit side or entry side flue of the induction blower so that the valve opening degree can be adjusted. The rotational speed of the fan may be variably controlled.

It is an external appearance perspective view which shows the state which removed the partial cover of the container in the wood pellet fired warm air machine to which this invention is applied. 1 is an external perspective view of a wood pellet fired hot air machine to which the present invention is applied. It is a perspective view which shows the state which connected the wood pellet burning warm air machine to which this invention is applied, and the storage tank which stores a wood pellet. It is a figure explaining operation | movement of the wood pellet fired warm air machine to which this invention is applied. It is a figure explaining the flow of air when the wood pellet fired hot air machine to which this invention is applied is installed in a greenhouse.

  Hereinafter, an embodiment of a wood pellet fired hot air machine (hereinafter abbreviated as a hot air machine) to which the present invention is applied will be described with reference to FIGS.

  First, with reference to FIG. 3, FIG. 5, the whole system | strain structure using the warm air machine of this embodiment is demonstrated. The wood pellet fuel in which woody biomass fuel is formed into pellets is stored in a wood pellet tank 3 installed outside the greenhouse 1. The wood pellet fuel is cut out from the bottom of the wood pellet tank 3 and is transported by a transport device 5 to a warm air machine 7 installed in the greenhouse 1. The wood pellet fuel is introduced into the combustor 9 in the warm air machine 7 and burned together with combustion air supplied from a blower (not shown) attached to the warm air machine 7.

  Combustion exhaust gas generated by burning wood pellets in the combustor 9 is discharged from the chimney 13 to the outside of the greenhouse 1 through the furnace tube 11 in the hot air blower 7, a smoke pipe and a dust collector which will be described later. ing. The air in the greenhouse 1 is taken into the hot air blower 7 from the two air intakes 19 provided with the blower 17 at the upper part of the hot air blower 7, as indicated by an arrow 15, and each of the furnace tube 11 and the smoke pipe After being heated by heat exchange, the air is exhausted in the direction of the arrow 23 into the greenhouse 1 from the air outlet 21 formed on the opposite side surface of the warm air fan 7 to heat the greenhouse 1.

  Next, a specific embodiment of the warm air machine 7 will be described. As shown in FIGS. 1 and 4, the hot air blower 7 according to the present embodiment is disposed along the horizontal direction of the furnace tube 11 and the upper and lower sides of the outer peripheral surface of the furnace tube 11 along the axial direction of the furnace tube 11. A plurality of extending fire tubes 25, a cylindrical combustor 9 attached to one end of the furnace tube 11, and the other end of the furnace tube 11 and one end of the plurality of smoke tubes 25 a disposed above the furnace tube 11 The rear smoke chamber 27 to be communicated with the other end of the plurality of smoke tubes 25a disposed above the furnace tube 11 on one end side of the furnace tube 11 and the one of the plurality of smoke tubes 25b disposed below are communicated. 29. The other ends of the plurality of smoke tubes 25b arranged below the furnace tube 11 are connected to an inlet portion of a vertical cyclone dust collector 31 arranged on the other end side of the furnace tube 11, and an outlet of the cyclone dust collector 31 is The suction blower 33 is connected to the suction port. The outlet of the induction blower 33 is connected to the chimney 35 (FIG. 5). Further, the furnace tube 11 and the plurality of smoke tubes 25 arranged above and below it are accommodated in a container 37 formed in a rectangular parallelepiped shape, and the periphery of the furnace tube 11 and the plurality of smoke tubes 25 in the container 37. A space 39 through which air flows is formed. Further, an operation panel 41 for performing various operations of the warm air fan 7 is attached to the outer wall surface on the front side of the container 37 (FIG. 2).

  An opening (not shown) is formed at the bottom of the furnace tube 11 at a substantially central position in the longitudinal direction of the furnace tube 11, and one end of an L-shaped rectangular tube frame 43 is connected to the periphery of the opening. Has been. The other end of the cylindrical frame 43 passes through the front side wall of the container 37 and extends outward, and the opening at the other end is an ash removal outlet 45 provided with an openable / closable lid. ing. An ash removal pail can 47 is detachably attached to the outer wall surface below the outer wall surface of the container 37 provided with the ash removal outlet 45 (FIG. 2). Note that the ash removal pail 47 may be simply installed below the ash removal outlet 45 without being attached to the outer wall surface of the container 37.

  In the vicinity of the inlet part (rear smoke chamber) 49 of the cyclone dust collector 31, an ash accumulation part 51 is provided below the position of the furnace tube 11 (FIG. 1). An opening is formed in the ash accumulation portion 51, and one end of a cylindrical frame having a rectangular cross section is connected to the periphery of the opening, and the other end of the cylindrical frame extends through the side wall of the container to the outside. The opened opening at the other end is an ash removal outlet 53 provided with a lid that can be opened and closed. Although not shown, an ash accumulation portion is also provided at the bottoms of the front smoke chamber 29 and the rear smoke chamber 49, and an ash removal outlet is provided on the side wall of the container 37 in the vicinity thereof.

  Two blowers 17 are attached to the upper surface of the container 37, and each blower 17 is partitioned from each other by a frame body 55 having a rectangular section that protrudes upward from the upper surface of the container 37. Air intakes 19 for taking air into the warm air blower 7 are formed on the inner sides partitioned by the frame body 55. Air discharge ports 21 are respectively formed below the opposite side surfaces of the container 37 so as to open.

  The combustor 9 is mounted so that the front smoke chamber 29 and one end surface of the furnace tube 11 pass through, and the space between the front smoke chamber 29 and the furnace tube 11 is airtight. In this combustor 9, an inner cylinder 57 is coaxially accommodated inside an outer cylinder (not shown) arranged in a horizontal shape, and a combustion chamber 59 communicating with the inside of the furnace tube 11 is formed inside the inner cylinder 57. A flat combustion bed 61 having a large number of air holes is provided at the bottom of the combustion chamber 59. That is, the combustion chamber 59 has a cross-sectional structure surrounded by the inner cylinder 57 and the flat combustion bed 61. An air flow path for supplying primary air to the lower surface side of the combustion bed 61 is provided below the combustion bed 61, that is, in a gap between the combustion bed 61 and the outer cylinder. The air flow path is connected to the wind box 63 on the upstream side, and a blower (not shown) is connected to the wind box 63. The air supplied from the blower through the wind box passes through the gap between the combustion bed 61 and the outer cylinder and the gap between the outer cylinder and the inner cylinder 57 and is supplied into the furnace tube 11.

  A pellet supply port (not shown) for supplying wood pellets to the combustion bed 61 is provided in the upper part on the upstream side of the combustion chamber 59. The wood pellets supplied from the conveying device 5 are dropped and supplied to the pellet supply port in the direction of the arrow 65. Further, a burner storage box 67 is provided below the pellet supply port, and a start ignition heater 69 and an ignition blower 71 are accommodated therein.

  With this configuration, when the wood pellets are combusted in the combustion chamber 59, the combustion exhaust gas is disposed from the inside of the furnace tube 11 to the upper side of the furnace tube 11 through the rear smoke chamber 27 by the attractive force of the induction blower 33. The air is drawn into the plurality of smoke pipes 25a, flows in the direction of the arrow 73, flows through the front smoke chamber 29 in the plurality of smoke pipes 25b arranged below the furnace tube 11 in the direction of the arrow 75, and the cyclone dust collector 31 Led to. Here, the combustion ash contained in the combustion exhaust gas is separated from the gas, collected, and collected in the lower ash accumulation part 51. The combustion exhaust gas from which the combustion ash is separated is released from the chimney 13 into the atmosphere via the induction blower 33. On the other hand, the air taken into the container 37 in the direction of the arrow 15 from the air intake port 19 at the upper part of the warm air machine 7 flows in the container 37 and flows into the furnace cylinder 11 and a plurality of smoke pipes 25 a disposed above and below the furnace tube 11. After being heated by exchanging heat with 25b, the air is exhausted from the lower air outlet 21 in the direction of the arrow 23.

  By the way, when wood pellets burn, a relatively large amount of combustion ash is generated. Most of the combustion ash is accumulated at the bottom of the furnace tube 11, and part of the combustion ash is accompanied by the flow of the combustion exhaust gas, passes through the smoke pipe 25, is introduced into the cyclone dust collector 31, is removed, and is collected in the ash accumulation unit 51. When combustion ash accumulates at the bottom of the furnace tube 11 in this way, the inside of the furnace is filled with ash, resulting in poor combustion, or the combustion residue and air react to cause fire combustion in the furnace. Therefore, combustion ash is periodically taken out from the furnace. At the time of taking out the combustion ash, the operation of the hot air blower 7 is stopped, the lid of the ash outlet 45 at the bottom of the furnace is opened with the inside of the furnace cooled, and an ash scraper is inserted into the furnace to scrape out the ash. Alternatively, the combustion ash is collected in the ash removal pail can 47 by ashing the ash in the furnace with ash. Here, when the induction blower 33 is stopped, the inside of the furnace tube 11 is at atmospheric pressure, so the ash is scraped out in the furnace, and the ash that has risen in the furnace is scattered from the ash removal outlet 45 to the outside of the furnace. Sometimes.

  Next, the structure which controls operation | movement of the induction fan used as the characteristic part of this embodiment is demonstrated. The hot air blower 7 of this embodiment can rotate only the fan of the induction blower 33 at a predetermined rotational speed by an external input even when the hot air blower 7 is stopped, that is, when the combustion operation is stopped. Yes. Inside the operation panel 41, there is provided a control unit in which a circuit for controlling the fan speed of the induction blower 33 is controlled by an inverter. As a result, when a command for driving the induction blower 33 is input to the control unit by an input from the operation panel 41, for example, an input from the operation switch of the induction blower 33, when the combustion operation is stopped, the control unit An operation command is issued to the motor that rotates the 33 fans, and the motor that has received this operation command rotates the fan at a preset rotation speed.

  With this configuration, when taking out the combustion ash while the combustion operation is stopped, the induction blower 33 can be driven by an operation from the operation panel 41 to keep the inside of the furnace tube 11 at a negative pressure. Thereby, when the ash is scraped out in the furnace tube 11, it is possible to prevent the combustion ash that has risen in the furnace tube 11 from being scattered from the ash outlet 45 to the outside of the furnace. Moreover, the combustion ash scraped out from the ash removal outlet 45 can be recovered in the ash removal pail 47 installed below the ash removal outlet 45 without being scattered outside the furnace. On the other hand, the combustion ash scattered in the furnace tube 11 is automatically entrained by the cyclone dust collector 31 after being attracted to the smoke tube 25 by being entrained in the air, so that the ash does not scatter in the surrounding environment. .

  In addition, the hot air blower 7 of the present embodiment is configured so that the operation panel 41 can variably set the fan rotation speed of the induction blower 33 when the combustion operation is stopped. Specifically, the fan rotation speed can be adjusted in a predetermined range in which the exhaust air amount of the induced blower 33 when the combustion operation is stopped is smaller than the exhaust air amount of the induced blower 33 during the combustion operation.

  For example, if the amount of exhausted air from the induction blower 33 when the combustion operation is stopped is the same as the amount of exhausted air during the combustion operation, the air suction force in the furnace tube 11 is too strong at the time of taking out the combustion ash. The combustion ash that accumulates at the bottom is also attracted and rolled up with the air flow. For this reason, in the present embodiment, the inside of the furnace tube 11 is maintained at a moderate negative pressure that sucks only the combustion ash that has risen when scraped out in the furnace without rolling up the combustion ash accumulated in the furnace tube 11. The fan rotation speed of the induction blower 33 can be set so that the exhausted air amount is within a possible range. Thereby, at the time of ash extraction work, the fan blower 33 is controlled so as to be driven at a predetermined rotation speed lower than the fan rotation speed during the combustion operation, and as a result, is controlled to a desired exhaust air amount. Therefore, it is possible to prevent the combustion ash from rising due to attraction in the furnace tube 11. As a result, the ash removal operation can be performed efficiently in a short time, and the attraction force can be prevented from being lowered due to the large amount of combustion ash being sucked into the smoke pipe 25.

  As a method of inputting the fan rotation speed, for example, the operation panel 41 may be configured so that the rotation speed can be selected stepwise by a dial switching type, or the rotation speed can be selected continuously by a rotary knob, or a numerical value can be selected. You may enable it to input suitably by input. Further, when only the induction blower 33 is driven after the operation of the warm air fan 7 is stopped, the rotation speed during the combustion operation may be automatically switched to an arbitrary rotation speed set in advance. In this way, it is possible to prevent troubles caused by mistakes in inputting the number of rotations or forgetting to input them.

  In the above embodiment, the exhaust air amount of the induction blower 33 is controlled by the number of rotations of the fan. However, the present invention is not limited to this. For example, a well-known flow control valve is provided in the flue downstream or upstream of the induction blower 33. The valve opening may be adjusted. By adjusting the valve opening as described above, the exhaust air amount of the induction blower 33 can be controlled, so that the same effect as the above embodiment can be obtained.

  In the above-described embodiment, the case where the combustion ash deposited on the bottom portion in the furnace tube 11 is taken out from the ash removal outlet 45 is described as an example. However, the present invention is not limited to this, and, for example, the ash accumulation portion 51 below the cyclone dust collector 31. Needless to say, the same effect as that of the above embodiment can be obtained when the ash is taken out from the ash, so that the scattering of the combustion ash around the ash can be suppressed.

DESCRIPTION OF SYMBOLS 3 Wood pellet tank 5 Conveyance apparatus 7 Hot air machine 9 Combustor 11 Furnace cylinder 17 Blower 25 Smoke pipe 31 Cyclone dust collector 33 Induction fan 37 Container 39 Space 41 Operation panel 45,53 Ash removal outlet 59 Combustion chamber

Claims (2)

A horizontal furnace tube, a combustor for burning wood pellet fuel attached to one end of the furnace tube, and one end side connected to the other end portion of the furnace tube so that the outside of the furnace tube extends along the axial direction. A plurality of existing smoke tubes, a dust collector provided in communication with the other end of the smoke tube, an induction blower connected to the discharge side of the dust collector and exhausting combustion exhaust gas, and the outer periphery of the furnace tube and the smoke tube A container that forms a space through which air flows, a combustion ash outlet that is connected to the bottom of the furnace tube to take out the combustion ash, and an air volume control means that controls the exhaust air volume of the induction blower,
The said air volume control means is a wood pellet fired hot air machine which controls the exhaust air volume at the time of taking out combustion ash from the said combustion ash extraction outlet at the time of a combustion operation stop to the setting air volume smaller than the exhaust air volume in the said combustion operation.   2. The wood pellet fired hot air fan according to claim 1, wherein the air volume control means performs inverter control of a fan of the induction blower to variably control the rotation speed of the fan. 3.

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