JP2016000781A - Carbonization apparatus of wood fuel pellets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce maintenance work in an apparatus for carbonizing wood fuel pellets formed by compression molding or heat compression molding of a plant-derived powdery raw material such as sawdust powder and wood flour.SOLUTION: The powdery raw material has dust coal mixed as a heat-generating material. A microwave generator 2 of the carbonization apparatus irradiates the heat-generating material with a microwave from a microwave source 21 to generate heat. This enables wood fuel pellets 8 to be obtained in an uncarbonized state, which can further be red-heated to provide from black charcoal to, at a higher temperature, white charcoal. Further, the wood fuel pellets 8 are not stored in an electromagnetically shielded housing 22 as is but in a guide pipe 23 such as a glass pipe or a ceramic pipe, and are transported by a screw 61. Therefore, a high temperature gas such as tar generated from the wood fuel pellets 8 does not contact with and adhere to an inside surface of the housing 22 whose temperature is close to room temperature. Thus, maintenance work such as cleaning is reduced and productivity can be improved.

Description

  The present invention relates to an apparatus for carbonizing wood fuel pellets formed by compression molding or heat compression molding a plant-derived powdery raw material.

As the wood fuel pellets, those obtained by heat compression molding or compression molding of sawdust or wood powder obtained by pulverizing natural wood such as building waste and thinned wood are widely used. In such wood fuel pellets, oga powder and wood powder are plant-derived powdery raw materials, and the raw wood grows by photosynthesis using CO ₂ as a raw material, so even if burned as fuel, zero emission Is preferable from the environmental viewpoint.

  Now, in the world, a heat treatment technique called torrefaction is drawing attention. Treffection is defined by the International Energy Agency (IEA) as “heat treatment performed at 200 to 300 ° C. in an oxygen-free atmosphere”. Treffection originally means “roasting” such as coffee and tea. In Japan, there are cases in which this trough is translated into semi-carbonization or low-temperature carbonization.

At present, in Europe and other countries, the treffection treatment is performed from the research and development of facilities to the actual production in order to improve the performance of wood fuel pellets. The above-mentioned high performance means that the wood fuel pellets have drawbacks such as a low calorific value and weak water resistance, and it is possible to overcome the disadvantages. By applying this treatment, co-firing with coal becomes possible, and it is possible to reduce the use of coal and reduce CO ₂ generation only by using the wood fuel pellets that are the above-mentioned zero emission. Become.

  Therefore, the applicant of the present invention is a currently unrealized trefflection for ogarite, which is a rod-shaped artificial log formed by compression molding or heat compression molding of plant-derived powdery raw materials such as sawdust and wood flour. In order to realize the processing, Patent Document 1 has been proposed previously. In this prior art, the bar-shaped ogalite obtained by mixing pulverized coal as a heat-generating material that generates heat when irradiated with microwaves due to being electrically conductive is added to the ogal powder as a raw material of the ogalite. It is heated by being housed in a microwave generator and irradiated with microwaves.

  In this way, the prior art is very easy to obtain the uncarburized material of ogarite (Traffic processed product) which is a rod-shaped artificial log, and not only that, but also by adjusting the microwave output and the production (input) speed of ogarite It is possible to produce black charcoal or even reddish charcoal.

Japanese Patent No. 5474236

  The above-mentioned patent document 1 is an excellent technique that can produce not only uncarburized materials but also charcoal more than black charcoal at low cost. However, high-temperature gas such as tar generated from ogarite (artificial wood) touches and adheres to the inner wall surface of the microwave generator case close to room temperature, and maintenance such as cleaning is necessary accordingly. This leaves room for improvement in productivity (throughput). Further, since the above-mentioned Patent Document 1 is intended for large chunks of ogarite (artificial raw wood), it is difficult to handle a large number of granular wood fuel pellets having a diameter of 8 mm and a length of 20 mm. There is.

  An object of the present invention is to provide a carbonization device for wood fuel pellets which can easily handle wood fuel pellets and improve the productivity thereof.

  The carbonization device for woody fuel pellets of the present invention is a device for carbonizing woody fuel pellets formed by compression-molding or heat-compressing plant-derived powdery raw materials, and the plant-derived powdery materials include microwaves. Is mixed with pulverized coal as a heat generating material that generates heat by being irradiated, and the heat generating material is heated by irradiating the wooden fuel pellet with microwaves in an electromagnetically shielded casing, and the wooden fuel pellet The microwave generator is formed of a non-magnetic and heat-resistant material extending from an inlet / outlet through which the wood fuel pellets are taken into and out of the casing. A guide tube that hermetically shields the space between the interior space and the space inside the housing, and the wood fuel pellets that are laid in the guide tube and are disposed from the inlet side of the guide tube Characterized in that it comprises a conveying means for conveying the mouth side.

  According to the above configuration, when carbonizing a woody fuel pellet formed by compression molding or heat compression molding a plant-derived powdered raw material such as sawdust or wood powder, the plant-derived powdered raw material is electrically conductive. In addition, pulverized coal as a heat-generating material that generates heat when irradiated with microwaves is mixed, and the heat-generating material is irradiated with microwaves from a microwave generator so that the heat-generating material is Heat is generated and the wood fuel pellets are carbonized. As a result, the wood fuel pellets can be obtained in an uncarbonized state, and further reddish from the uncarbonized state to produce from black coal to higher temperature white coal.

  In the microwave irradiation, the wood fuel pellets are not housed in the electromagnetically shielded housing of the microwave generator. Instead, the wood fuel pellets are housed inside and outside the housing. It is housed in a guide tube that is airtightly shielded. The guide tube is made of a nonmagnetic and heat resistant tube. In addition, the entrance and exit of the wood fuel pellets that are the openings provided in the housing are provided separately, that is, the wood fuel pellets accommodated in the guide tube are discharged from the insertion in one way from the entrance side to the exit side. Or may be shared and taken in and out from the same doorway.

  Therefore, the wood fuel pellets that are heated by the microwave are surrounded by the guide tube and hermetically shielded from the inside of the housing, so that high-temperature gas such as tar generated from the wood fuel pellets is microwaved near normal temperature. The inner wall surface of the housing of the generator is not touched and adhered, and gas adhesion to the inner wall surface can be prevented. Thereby, maintenance work such as cleaning can be reduced, and productivity (throughput) can be improved. Since the guide tube also becomes hot, even if the high-temperature gas touches the guide tube, it hardly adheres.

  Furthermore, since the wood fuel pellets are a large number of grains, handling them in a tray or the like and putting them in and out of the microwave generator is difficult to handle and has low productivity (throughput). Therefore, by providing a conveying means that is laid in the guide tube and is realized by a belt, a screw, or the like and conveys the wood fuel pellets, handling becomes easy and productivity (throughput) can be further improved. .

  In the wood fuel pellet carbonization device of the present invention, the guide pipe is a straight pipe communicating between the entrance and the exit of the wood fuel pellet formed in the casing of the microwave generator, and the transport means Is a screw for extruding the wood fuel pellets introduced from the inlet side of the guide tube to the outlet side.

  According to the above configuration, when the guide pipe is a straight pipe and the wood fuel pellets are introduced from the inlet of the guide pipe and discharged from the outlet in one way, the conveying means can be realized by a belt or the like. it can. However, in that case, the wood fuel pellets are placed on the belt, and the belt itself also moves, so it is necessary to lay it in a reciprocating path, which requires space for the transport means and spills from the belt. The pellet stays at the same place in the guide tube, and continues to be irradiated with microwaves, so that carbonization proceeds excessively, absorbs microwaves to be irradiated to other pellets, and generates microwave loss.

  On the other hand, when the conveying means is a screw, the screw is stationary at the same place, and the rotor blades extrude the pellet, so that the conveying means can be made compact, and the guide tube is a cylinder and its inner periphery. By narrowing the space between the surface and the rotary blade of the screw, it is also possible to eliminate pellet conveyance leakage.

  Furthermore, in the wood fuel pellet carbonization device of the present invention, the screw is provided with a stirring blade at a predetermined pitch in the vicinity of the tip of the rotor blade.

  According to said structure, when using a screw as a conveyance means, especially when the particle | grains of a wood fuel pellet are small or it contains moisture, the movement (flow) of this wood fuel pellet with respect to rotation of a screw is bad, and a rotary blade It becomes easy to clog (bump) in between. Thus, by providing an agitating blade with a predetermined pitch, it is possible to eliminate such clogging (coagulation) and improve the movement (flow) of the wood fuel pellets.

  Thus, the degree of carbonization can be adjusted easily and with high accuracy by the power of the microwave and the conveyance speed of the conveyance means.

  Moreover, in the wood fuel pellet carbonization apparatus of the present invention, the stirring blade is formed of a plate-like body connecting adjacent rotary blades in the vicinity of the tip.

  According to the above configuration, the plate-like body is half-rotated with the rotation of the screw, and enters the lower side of the accumulated wood fuel pellets from the downstream side surface in the rotation direction, and scoops up and drops in the next half-rotation. .

  Therefore, clogging (coagulation) between the rotor blades can be prevented. In addition, the plate-like body can ensure strength compared to a pin or the like.

  Furthermore, in the wood fuel pellet carbonization device of the present invention, the predetermined pitch is two and a half rotations of the screw, and the stirring blades are arranged in a staggered manner in a side view of the screw. To do.

  According to the above configuration, the pitch of the stirring blades is two and a half rotations of the screw, and the stirring blades are arranged in a staggered manner in a side view, so that one of the stirring blades is woody between the adjacent stirring blades. If the process of raising the fuel pellets is performed, the other stirring blade performs the process of dropping the wood fuel pellets, and the same process is not performed at the same time, thus further preventing clogging of the stirring blades. be able to.

  In the wood fuel pellet carbonization device of the present invention, an end of the guide pipe on the upstream side in the conveying direction of the screw is connected to the bottom of the first hopper into which the wood fuel pellet is introduced. And

  According to the above configuration, the wood fuel pellets are simply fed into the first hopper, and the pellets are transported in a fixed amount (at a constant transport speed) as the screw rotates. Therefore, it is easy to supply the wood fuel pellets to the carbonizer, and the degree of carbonization can be finished uniformly.

  Moreover, the leakage of the microwave from the inlet side of the guide tube can be suppressed by depositing the wood fuel pellet mixed with the pulverized coal on the bottom of the first hopper. Furthermore, the first hopper is made of a metal material, so that the microwave can be shielded even if there is little accumulation of the wood fuel pellets.

  Furthermore, in the wood fuel pellet carbonization apparatus of the present invention, a stirring screw for preventing the bridge (crosslinking) from being formed by the wood fuel pellets is provided on the screw at the bottom of the first hopper. It is characterized by that.

  According to the above configuration, when the wood fuel pellets are particularly small or contain moisture, the pellets on the bottom side are easily compressed and set after being put into the first hopper. Therefore, by providing a stirring screw on the screw, formation of a bridge (crosslinking) by the pellet can be prevented.

  In the wood fuel pellet carbonization device of the present invention, the carbonized wood fuel pellets are accumulated at the downstream end of the guide pipe in the conveying direction of the screw, and discharged from the bottom at an appropriate timing. 2 hoppers are provided.

  According to said structure, the leakage of the microwave from the exit side of the said guide pipe | tube can be suppressed by depositing the said wood fuel pellet to the upper part of the screw above a 2nd hopper. Furthermore, by making the second hopper from a metal material, it is possible to reliably shield the microwave leaking from the outlet of the guide tube.

  Furthermore, in the wood fuel pellet carbonization apparatus of the present invention, in the screw, at least one rotation blade facing the inlet and the outlet of the microwave generator is made of an electromagnetic shielding material.

  According to said structure, the leakage of the microwave from the inlet_port | entrance and exit of a microwave generator can be prevented with the rotary blade for at least 1 rotation of the said screw.

  In the wood fuel pellet carbonization apparatus of the present invention, the first and / or second hopper is provided with a detection switch for detecting whether or not the wood fuel pellet is deposited in the vicinity of the hopper. The microwave generator is characterized in that the microwave irradiation is performed in a state where the accumulation of the wood fuel pellets is detected by the detection switch.

  According to the above configuration, as described above, it is possible to suppress microwave leakage from the entrance and exit of the guide tube by depositing the wood fuel pellet mixed with pulverized coal. While the non-deposited state is detected, the microwave generator is interlocked.

  Therefore, safety can be improved.

  Furthermore, in the carbonization apparatus for wood fuel pellets of the present invention, a high-temperature gas containing tar generated from the wood fuel pellets by microwave heating is sucked between the outlet of the guide tube and the second hopper, A detoxifying device that discharges after decomposing and burning is provided.

  According to said structure, adhesion of tar can further be suppressed by attracting | sucking high temperature gas with a fan etc. from a guide tube. Further, by burning the tar, it can be rendered harmless and discharged to the outside.

  Moreover, in the carbonization apparatus for wood fuel pellets of the present invention, the wood fuel pellets are wood biomass pellets formed by heat compression molding oga powder or wood powder as the plant-derived powdery raw material. And

According to the above configuration, the wood that is the raw material for sawdust and wood flour is produced by photosynthesis using CO ₂ as a raw material, so that zero emission can be achieved even if carbonized wood fuel pellets are burned as fuel. Can do.

  Furthermore, in the wood fuel pellet carbonization apparatus of the present invention, the guide tube is a glass tube or a ceramic tube.

  According to said structure, a glass tube or a ceramic tube has a high heat resistance while having nonmagnetism, and is suitable.

  Moreover, in the carbonization apparatus of the wood fuel pellet of this invention, the said pulverized coal is mixed 5 to 10weight%, It is characterized by the above-mentioned.

  According to said structure, a wooden fuel pellet can be heated in a comparatively short time.

  As described above, the carbonization apparatus for wood fuel pellets of the present invention is derived from the plant when carbonizing wood fuel pellets formed by compression molding or heat compression molding plant-derived powdery raw materials such as sawdust and wood flour. Pulverized coal as a heat generating material is mixed in the powdery raw material, and the heat generating material is heated by irradiating the heat generating material with microwaves, and the wood fuel pellets are obtained in an uncarbonized state. Furthermore, it can be made red from its uncarbonized state, and can be made from black charcoal to higher temperature white charcoal. In the electromagnetically shielded casing of the microwave generator, the wood fuel pellets are not accommodated as they are, but are accommodated in a nonmagnetic and heat resistant tube such as a glass tube or a ceramic tube.

  Therefore, a high-temperature gas such as tar generated from the wood fuel pellets does not touch and adhere to the inner wall surface of the case of the microwave generator close to room temperature. Gas adhesion can be prevented, maintenance work such as cleaning can be reduced, and productivity (throughput) can be improved.

  Furthermore, since the wood fuel pellets are a large number of grains, handling inside the guide tube by means of transport realized by belts or screws facilitates handling and further improves productivity (throughput). can do.

It is a longitudinal section showing the structure of the carbonization device concerning one embodiment of the present invention.

  FIG. 1 is a longitudinal sectional view showing a structure of a carbonizing apparatus 1 according to an embodiment of the present invention. This carbonization apparatus 1 is an apparatus for carbonizing wood fuel pellets 8 formed by compression molding or heat compression molding a plant-derived powdery raw material. Specifically, the wood fuel pellets 8 are formed in advance by mixing the plant-derived powdery raw material with a heat generating material that generates heat when irradiated with microwaves. When the microwave generator 2 irradiates the pellet 8 with microwaves, the exothermic material is heated, and the plant-derived powdery raw material is carbonized. In FIG. 1, the wood fuel pellets 8 that are filled or deposited are schematically shown in part for easy understanding of the drawing, and others are omitted.

  Regarding the degree and use of carbonization, Patent Document 1 is detailed, but roughly, when the microwave heating temperature is 200 to 250 ° C, it becomes uncarburized, and when it is 300 to 500 ° C, it becomes carbide, and at 800 ° C or more. It becomes high-temperature treated charcoal. The carbonization apparatus 1 of the present embodiment can obtain an arbitrary carbonization degree by microwave power and heating (conveyance described later) time, and has a small amount of ash such as white charcoal, and is made up to high-temperature treated charcoal that is a substitute for coke. This is possible even if only a large amount of the above-mentioned refracted uncarburized material that can be used as a substitute for bio-coke or co-fired with coal without being treated at such a high temperature. The carbonization apparatus 1 in the form is extremely effective.

  Here, in the following embodiment, the material carbonized by microwaves is described for the wood fuel pellet 8, but a material derived from a plant such as sawdust is directly mixed with pulverized coal. That is, pulverized coal may be produced by using a powdery material smaller than the level of pellets as it is. The activated carbon can be produced from the pulverized coal thus obtained, for example, by activation with steam at about 800 ° C., and the present invention is extremely effective for producing activated carbon. Further, the pellet is not limited to a cylindrical shape, and may be a spherical shape.

The wood fuel pellets 8 are wood biomass pellets 8 formed by heat compression molding or compression molding of sawdust or wood powder as the plant-derived powdery raw material. The plant-derived powdery raw material is also described in detail in Patent Document 1, but is not limited to woody materials such as wood powder, bamboo powder, and a mixture of wood powder and bamboo powder. , Fruit cores, fruit residues, coffee cakes, palm cocoons, peanut shells, etc. can be used. Therefore, since these raw materials are produced by plants using CO ₂ as a raw material, zero emission can be realized even if the carbonized wood fuel pellets 8 are burned as fuel. Note that an adhesive or a binder may be mixed when the wood fuel pellet 8 is molded. Examples of the adhesive include phenolic resins and creosote that are thermosetting resins.

  For example, the wood fuel pellet 8 can be prepared as follows. First, the exothermic material is mixed with 5 to 10% by weight of the raw material that has been sieved. The exothermic material is a powdered coal that has electrical conductivity and generates heat when irradiated with the microwave, and is a powder of high-temperature coal. For example, using a raw material of 100% wood powder, adjusting to a grain size wood powder that can be formed by sieving, the moisture content is dried to about 5%, and the moisture content is about 5%. The dried pulverized coal is mixed and put into a pellet molding machine to form the wood fuel pellets. In the case of pulverized coal, heat is sufficiently generated at about 5% by weight, so the mixing ratio is preferably about 5% by weight.

  As the pulverized coal, for example, crushed coal of about 60 mesh is used, cut into a thickness of about 3 mm in the state of the ogah, and measured between 1 cm with a milliohm meter and clipped. Then, around 20 mΩ, the electric resistance value in the state of pulverized coal is 1Ω or less. And since this pulverized coal is the high temperature coal (white coal) created at 800-1000 degreeC, it does not change up to that temperature, but can generate heat | fever by microwave irradiation. The finer the pulverized coal, the higher the cost. Therefore, it may be applied to a coarser screen.

  Returning to FIG. 1, the carbonization apparatus 1 of the present embodiment generally includes a microwave generation apparatus 2, a first hopper 3 provided in the preceding stage, a second hopper 4 provided in the subsequent stage, A detoxification device 5 provided between the wave generator 2 and the hopper 4 and a transport mechanism 6 are provided. And the carbonization apparatus 1 of this embodiment conveys the wood fuel pellet 8 thrown in from the hopper 3 to the microwave generator 2 continuously by the conveyance mechanism 6, performs microwave irradiation, and is harmless. In FIG. 5, the wood fuel pellets 8 are carbonized by burning the tar content, stored in the hopper 4 and appropriately taken out.

  The microwave generator 2 includes a microwave source 21, a casing 22 that electromagnetically shields microwaves from the microwave source 21, and a guide tube 23. The casing 22 is formed by lining a microwave shielding seal material 25 on an outer casing 24 formed in a box shape from an iron plate or the like, and the microwave source 21 is arranged at a substantially central portion of the top surface. Established. The microwave source 21 composed of a magnetron or the like may be installed at an appropriate location, and microwaves may be introduced into the housing 22 by a waveguide or the like.

  It should be noted that in the carbonization apparatus 1 of the present embodiment, a guide pipe 23 that guides the wood fuel pellets 8 communicates between an inlet 26 and an outlet 27 formed in the housing 22. Is open to the outside air, and the inside of the housing 22 is blocked from the outside air. In the present invention, the guide tube 23 only needs to communicate with one entrance / exit formed in the housing 22, that is, the guide tube 23 may be formed in a bottomed cylindrical shape, but the entrance 26 and the exit 27. By using a simple straight pipe that is divided into two, the transport mechanism 6 can continuously guide the wood fuel pellets 8 in one direction (from right to left in the example of FIG. 1). ) Can be improved.

  Therefore, with this configuration, the wood fuel pellets 8 that are heated by the microwave are surrounded by the guide tube 23 and are hermetically shielded from the inside of the housing 22, and thus are generated from the wood fuel pellets 8. High-temperature gas such as tar does not touch and adhere to the inner wall surface of the casing 22 of the microwave generator 2 close to room temperature, and can prevent gas from adhering to the inner wall surface. it can. Thereby, maintenance work such as cleaning can be reduced, and productivity (throughput) can be improved. In addition, since the guide tube 23 also becomes high temperature, even if the high temperature gas touches the guide tube 23, it hardly adheres. In the present embodiment, the inside of the casing 22 is not contaminated with tar as described above, but a ventilation means may be provided as appropriate for exhausting hot air or the like.

  The guide tube 23 is made of a material having nonmagnetic properties and high heat resistance, such as a glass tube or a ceramic tube. The guide tube 23 includes a tube main body 231 for guiding the wood fuel pellet 8 and flange plates 232 and 233 extending from the vicinity of the end of the tube main body 231 in the longitudinal direction. The flange plates 232 and 233 are formed to extend outward in the radial direction so that they are not pulled by the wood fuel pellets 8 flowing inside, and the axial displacement is not caused. The guide tube 23 is held at a position suitable for microwave irradiation in the housing 22 by being fixed to the wall surface 22 by the bolts 28 and 29.

  On the other hand, on the inlet 26 side of the housing 22, an introduction pipe 31 is connected by the bolt 28 via a packing 234 that ensures airtightness. A hopper 3 is provided above the introduction pipe 31. It has been. The flange 32 at the lower end of the hopper 3 is attached to the periphery of an opening 311 formed in the upper portion of the introduction pipe 31 by a bolt 313 with a packing 36 for ensuring airtightness interposed therebetween. A cleaning opening 314 is formed in the lower portion of the introduction pipe 31, and this opening 314 is closed by a swingable lid 316 by a hinge 315, and between the periphery of the opening 314 and the lid 316, A packing 37 for ensuring airtightness is interposed.

  The hopper 3 is formed by extending a frustum portion 34 from below a circular or rectangular tube portion 33, and an opening 341 formed at the lower end of the frustum portion 34 is an opening above the introduction pipe 31. Further, the flange 32 is formed by connecting the lower end of the frustum portion 34 outwardly. An opening 331 at the upper portion of the cylindrical portion 33 is closed by a swingable lid 35 by a hinge 332, and a packing 38 that ensures airtightness is interposed between the periphery of the opening 331 and the lid 35. The end portion of the introduction pipe 31 is closed by an end plate 317 folded inward.

  On the other hand, a discharge pipe 51 is connected to the outlet 27 side of the housing 22 by the bolt 29 via a packing 235 that ensures airtightness. A conversion device 5 is provided. The hopper 4 is connected to the rear stage of the discharge pipe 51 by a bolt 512 with a packing 511 for ensuring airtightness.

  The hopper 4 includes an upper part 41 that is continuous with the discharge pipe 51 and a lower frustum part 42. An opening 411 for cleaning / inspection is formed on the top surface of the upper portion 41, and the opening 411 is closed by a swingable lid 44 by a hinge 43, and between the periphery of the opening 411 and the lid 44. Is provided with a packing 45 for ensuring airtightness. The frustum portion 42 is formed in a truncated cone shape or a quadrangular frustum shape, and an intermittent valve 46 that is appropriately opened and closed with a predetermined duty is provided on the bottom thereof. FIG. 1 shows a state in which the intermittent valve 46 is open. The end of the hopper 4 opposite to the discharge pipe 51 is closed by an end plate 47 folded inward.

  The detoxification device 5 sucks high temperature gas such as tar generated from the wood fuel pellets 8 by microwave heating, burns it, detoxifies it, and discharges it to the dryer. The detoxification device 5 includes a chimney 52 and a processing unit 53. The chimney 52 rises from the discharge pipe 51, and is connected to the chimney 52, and an upper processing unit 53 is provided. From the inner periphery of the chimney 52, a wire mesh 54 is lined on the upper opening end to prevent microwave leakage. The wire mesh 54 is preferably a stainless steel wire mesh to suppress gas corrosion.

  The processing part 53 burns high-temperature gas such as tar and renders it harmless, and a caster 532 is lined on the outer wall 531 for fireproofing. A suction fan 55 is provided at the top of the processing unit 53. In the vicinity of the lower end of the processing unit 53, an ignition plug 56 and a gas supply port 57 are provided, and an air intake port 58 is formed. Then, a spark 59 is generated from the spark plug 56 while gas is supplied from the gas supply port 57, thereby forming a seed flame 60 at the gas supply port 57, and the gas generated from the wood fuel pellets 8 is aired. It can be burned with oxygen from the intake 58 and treated. In addition, when combustion of the gas generated from the wood fuel pellet 8 starts, this is detected by a flame detector or the like, the supply of gas to the gas supply port 57 is stopped, and the seed flame 60 is turned off. Also good.

  In this way, when the wood fuel pellets 8 pass through the discharge pipe 51 in a state where the wood fuel pellets 8 are irradiated with sufficient microwaves and are red hot, they self-combust and create higher temperature coal from the black coal. You can also. A scouring apparatus that performs scouring by burning the gas generated by the self-combustion to raise the temperature in the furnace may be provided in the subsequent stage of the detoxifying device 5.

  In the carbonization apparatus 1 configured as described above, since carbonized pellets 8 are a large number of particles of the wood fuel pellets 8, it is difficult to handle if stored in a tray or the like and put in and out of the microwave generator 2. In addition, productivity (throughput) is low. On the other hand, the guide tube 23 is a straight tube that communicates from the inlet 26 to the outlet 27 of the microwave generator 2. Therefore, it should be noted that in the present embodiment, a conveying device 6 is provided which is laid in the guide tube 23 and conveys the wood fuel pellets 8 in one direction. The conveying device 6 can be realized by a belt or a screw that can convey in the one direction (screw 61 in the example of FIG. 1), and by laying the conveying device 6 in the guide tube 23, The handling of the wood fuel pellets 8 is facilitated, and the productivity (throughput) can be further improved.

  The transport device 6 for transporting the wood fuel pellets 8 in the guide tube 23 can also be realized by the belt described above, but in the case of a belt, the wood fuel pellets 8 are placed on the belt and the belt itself is also moved. I will do it. Therefore, in the case of a belt, it is necessary to lay it in a reciprocating path in the guide tube 23, and space for the conveying device 6 is required, and pellets 8 that have fallen from the belt stay in the same place in the guide tube 23, Microwave continues to be irradiated and carbonization proceeds excessively, and microwaves to be irradiated to other pellets 8 are absorbed, and microwave loss is also generated.

  On the other hand, by realizing the conveying device 6 with the screw 61 as in the example of FIG. 1, the screw 61 stops at the same place, and the rotating blade 612 extrudes the pellet 8. In addition to being compact, the guide tube 23 can be a cylinder, and the gap between the inner peripheral surface (particularly the inner peripheral surface on the lower side) and the rotary blade 612 of the screw 61 can be reduced, thereby eliminating the conveyance leakage of the pellet 8. it can.

  The conveying device 6 includes a power transmission mechanism including a pulley 62 and a power source (not shown) in addition to the screw 61. The power source includes a motor, a drive circuit and a control circuit thereof, and the like. The power transmission mechanism includes a pulley 62 as a final stage, and includes a belt and a pulley that transmit power from the motor and an appropriate speed reduction mechanism in front of the pulley 62. The control circuit may perform not only control of the motor but also control of the microwave power from the microwave source 21, the intermittent valve 46, and the like. The pulley 62 may be driven by a rack belt having an anti-slip effect, and the power transmission mechanism may be realized by a gear or the like.

  The screw 61 is configured by fixing the spiral rotating blade 612 around a rotating shaft 611. The screw 61 does not absorb or reflect microwaves, for example, can be realized with glass or ceramic, or stainless steel can be used. In the case of stainless steel, SUS310S having high heat resistance is preferable. In that case, the screw 61 may be appropriately grounded.

  In the present embodiment, the screw 61 is disposed not only in the guide pipe 23 of the microwave generator 2 but also from the introduction pipe 31 below the hopper 3 beyond the guide pipe 23 and below the detoxification apparatus 5. 51 and the hopper 4 are formed. Therefore, bearings 63 and 64 that pivotally support both ends of the rotating shaft 611 are provided at the end portions of the introduction pipe 31 and the hopper 4. Further, both ends of the rotating shaft 611 are hermetically sealed by packings 65 and 66. The bearings 63 and 64 and the packings 65 and 66 are fixed to the end plates 317 and 47 by screws 67 and 68, respectively. The pulley 62 is fixed to one end of the rotating shaft 611 protruding from the end plate 317.

  As the screw 61 deepens the valley, that is, the rotation shaft 611 is narrowed and the width of the rotary blade 612 is increased, the conveyance amount per unit rotation can be increased, but the conveyance tends to be sparse. Specifically, especially when the pellets 8 are small or contain moisture, the movement (flow) of the wood fuel pellets 8 with respect to the rotation of the screw 61 is poor, and the conveyance direction (in FIG. 1, from right to left toward the paper surface). F), the pellets 8 are coarsely and densely formed and become a lump in a dense portion and clogged between the rotor blades 612.

  Therefore, the screw 61 of the present embodiment is provided with a stirring blade 613 at a predetermined pitch in the vicinity of the tip of the rotary blade 612. Therefore, such clogging (coagulation) can be eliminated and the movement (flow) of the wood fuel pellets 8 can be improved. Thereby, the above-mentioned control device (not shown) adjusts the degree of carbonization easily and with high accuracy by controlling the power of the microwave from the microwave source 21 and the conveyance (rotation) speed of the screw 61. be able to.

  Here, the stirring blade 613 can also be realized by a pin or the like that connects between the tips of the rotating blades 612. However, if the pin enters the hardened wood fuel pellet, there is a possibility of breakage. Therefore, in the screw 61 of the present embodiment, the stirring blade 613 is made of a plate-like body that can ensure strength compared to a pin or the like, and connects between adjacent rotating blades 613 in the vicinity of the tip. . Therefore, as the screw 61 rotates, the plate-like body sinks below the accumulated wood fuel pellets 8, drops the scooped wood fuel pellets 8 and performs stirring. Thus, the stirring blade 613 can prevent clogging (coagulation) of the pellet 8 between the rotating blades 612.

  Further, in the present embodiment, the pitch at which the stirring blades 613 are provided is half of the rotation of the screw 61. Therefore, the stirring blades 613 are arranged in a staggered manner as shown in FIG. 1 in a side view of the screw 61. Thus, if one stirring blade performs the step of scooping up the wood fuel pellets 8 between the stirring blades adjacent to each other, the other stirring blade performs the step of dropping the wooden fuel pellets 8 and at the same time Since the same process is not performed, clogging of the stirring blade 613 can be further prevented.

  The rotary blades 612 themselves may be made difficult to adhere to the wood fuel pellets 8 by roughening the surface or performing a treatment that makes tar difficult to adhere. Such treatment is particularly effective when the wood flour is directly conveyed. As shown in FIG. 1, the stirring blade 613 is provided at a portion of the rotating blade 612, particularly in the guide tube 23, so that microwave irradiation can be performed uniformly by stirring.

  By configuring in this way, for example, when the microwave power of the microwave generator 2 is 700 W, the guide tube 23 is 50 mm in diameter, and the length in the furnace is 40 to 50 cm, the wood fuel pellet 8 is about 1 minute. The mixture can be heated to 200 ° C. or higher to be in an uncarbonized state, and further heating can be continued from the uncarbonized state to produce red-hot and higher-temperature white coal. The relationship between the microwave power, the heating time, and the temperature is merely an example.

  And in the carbonization apparatus 1 of this embodiment, in the guide tube 23, the end 234 on the upstream side in the conveying direction of the screw 61 is connected to the bottom of the hopper 3 into which the wood fuel pellets 8 are charged. The wood pellet 8 is simply put into the pellet 8 and is transported in a fixed amount (at a constant transport speed) as the screw 61 rotates. Therefore, it is easy to supply the wood fuel pellets 8 to the carbonization apparatus 1, and the degree of carbonization can be uniformly finished.

  In order to adjust the degree of carbonization, the microwave generator 2 is provided with an infrared sensor for measuring the temperature of the internal wood fuel pellet 8 through the guide tube 23 made of the glass tube, or the combustion temperature is measured in the exhaust pipe 51. It is preferable that the control device (not shown) senses the rotational speed of the screw 61 and the microwave power from the microwave source 21 in response to the detection results of these sensors.

  Further, when the hopper 3 is connected to the guide pipe 23, as shown by reference numeral 81, the wood fuel pellets 8 mixed with the pulverized coal are deposited on the hopper 3, thereby the guide pipe 23. Leakage of microwaves from the inlet 26 side can be suppressed. Furthermore, by making the introduction pipe 31 and the hopper 3 with a metal material, the microwave can be shielded even if the wood fuel pellet 8 is little deposited.

  In order to prevent further leakage of the microwave, a sensor 91 for detecting the accumulation of the wood fuel pellets 8 is provided at the bottom of the hopper 3 or the opening of the lids 35 and 316 of the hopper 3 and the introduction pipe 31 is detected. Sensors 92 and 93 may be provided, and the control device (not shown) may interlock the microwave source 21 in response to the detection results of the sensors 91 to 93. Thereby, safety can be improved.

  On the other hand, when the hopper 3 is provided, if the amount of the wood fuel pellets 8 is large, the particles of the wood fuel pellets 8 are small, or contain moisture, the pellets 8 on the bottom side after being put into the hopper 3 Compressed and easily solidified, there is a possibility that a bridge (bridge) by the wood fuel pellets 8 is formed on the screw 61. Therefore, in this embodiment, a stirring screw 94 is provided at the bottom of the hopper 3. The stirring screw 94 is driven by a motor 95 continuously or intermittently at a predetermined cycle. In this way, the formation of bridges (crosslinks) by the pellets 8 can be prevented.

  Further, the carbonization apparatus 1 of the present embodiment includes the hopper 4 that accumulates the carbonized wood fuel pellets 8 on the downstream side in the conveying direction of the screw 61 and discharges the pellets from the intermittent valve 46 at the bottom at an appropriate timing. Therefore, as indicated by reference numeral 82, the wood fuel pellets 8 are deposited up to the upper part of the screw 61 above the hopper 4, so that microwave leakage from the outlet 27 side of the guide tube 23 can be prevented. Can be suppressed. Furthermore, the microwave leaking from the outlet 27 of the guide tube 23 can be reliably shielded by making the hopper 4 and the discharge tube 51 with a metal material.

  Accordingly, the hopper 4 is also provided with a sensor 96 for detecting the accumulation of the wood fuel pellets 8 and a sensor 97 for detecting the opening of the lid 44, as in the hopper 3 described above. , 97, the control device (not shown) may interlock the microwave source 21.

  In the case where the operation of the carbonization apparatus 1 is started in a state where all the wood fuel pellets 8 in the hopper 4 have been discharged, such as after the carbonization apparatus 1 has been stopped for a long time or cleaned, the hopper 4 It is preferable to start the operation after depositing the dummy wood fuel pellets 8 in order to prevent microwave leakage.

  In order to prevent the microwave leakage, at least one rotation facing the inlet 26 and the outlet 27 of the microwave generator 2 in the rotor blade 612 of the screw 61 may be configured by an electromagnetic shielding material.

  In the example of FIG. 1, the inner diameters of the guide tube 23 and the discharge tube 51 are slightly larger than the inner diameter of the introduction tube 31. For example, the inner diameter of the guide tube 23 and the discharge tube 51 is 50 mm, and the inner diameter of the introduction tube 31 is 2 mm smaller than them. At the joint between the guide tube 23 and the introduction tube 31 at the inlet 26, the center axis of the guide tube 23 and the center axis of the introduction tube 31 are eccentric. Specifically, the guide tube 23 having an inner diameter of 50 mm is used. The central axis of the introduction pipe 31 having an inner diameter of 48 mm is decentered by 1 mm from the central axis so that the inner peripheral bottom surfaces of the guide pipe 23 and the introduction pipe 31 are flush with each other so that the wood fuel pellets 8 are smoothly guided. It has become. Therefore, a step is formed between the top surface of the guide tube 23 and the introduction tube 31.

  With this configuration, when the pellets 8 that have been compressed and conveyed from the hopper 3 enter the guide tube 23, the compressed state is relaxed, and the pellets 8 are less likely to be solidified. The removal of tar generated by microwave irradiation is improved.

  Moreover, it is preferable to provide a device for producing the wood fuel pellets 8 in the front stage of the hopper 3. Since the pellet production apparatus heats and compresses the input raw material such as wood powder to produce the wood fuel pellet 8, the molded pellet 8 has a temperature of 200 ° C. or more, for example. Therefore, by putting the pellets 8 at the high temperature into the microwave generator 2 and continuously processing them, the microwave generator 2 can increase the temperature of the pellets 8 by about 100 ° C. Carbonized wood pellets 8 can be prepared in a short time, or even with the same production time, the microwave power can be reduced compared to the case of heating from the cold wood fuel pellets 8. Can be very efficient.

  Furthermore, when the pellets are continuously fed into the hopper 3 from the device for producing the woody fuel pellets 8 or the like, the microwaves are shielded by the pellets as described above. It may remain open.

DESCRIPTION OF SYMBOLS 1 Carbonization apparatus 2 Microwave generator 21 Microwave source 22 Case 23 Guide pipe 24 Outer case 25 Sealing material 26 Inlet 27 Outlet 3 First hopper 31 Introduction pipe 33 Cylindrical part 34 Frustum part 4 Second hopper 41 Upper part 42 Frustum part 46 Intermittent valve 5 Detoxification device 51 Drain pipe 52 Chimney 53 Processing part 54 Wire net 55 Fan 56 Spark plug 57 Gas supply port 6 Transport mechanism 61 Screw 611 Rotating shaft 612 Rotating blade 613 Stirring blade 63, 64 Bearing 8 Wood Fuel pellets 91-93, 96, 97 Sensor 94 Stir screw 95 Motor

Claims (14)

An apparatus for carbonizing a wood fuel pellet formed by compression molding or heat compression molding a plant-derived powdery raw material,
The plant-derived powdery raw material is mixed with pulverized coal as a heat-generating material that generates heat when irradiated with microwaves, and the microwave pellets are irradiated with microwaves in an electromagnetically shielded casing. And a microwave generator for heating the heat-generating material and carbonizing the wood fuel pellets,
The microwave generator is
A guide that extends from the entrance and exit through which the wood fuel pellets are taken into and out of the housing into the housing and is made of a non-magnetic and heat-resistant material and hermetically shields the space inside the housing and the space in the housing. Tube,
An apparatus for carbonizing wood fuel pellets, comprising: conveying means that is laid in the guide pipe and transports the wood fuel pellets from an inlet side to an outlet side of the guide pipe. The guide pipe is a straight pipe communicating between the inlet and the outlet of the wood fuel pellet formed in the casing of the microwave generator,
2. The wood fuel pellet carbonizing apparatus according to claim 1, wherein the conveying means is a screw for extruding the wood fuel pellet introduced from the inlet side of the guide tube to the outlet side.   3. The wood fuel pellet carbonization apparatus according to claim 2, wherein the screw is provided with a stirring blade at a predetermined pitch in the vicinity of the tip of the rotor blade.   4. The wood fuel pellet carbonization apparatus according to claim 3, wherein the stirring blade is formed of a plate-like body connecting adjacent rotary blades in the vicinity of the tip.   The wood fuel pellet carbonization apparatus according to claim 3 or 4, wherein the predetermined pitch is two and a half rotations of the screw, and the stirring blades are arranged in a staggered manner in a side view of the screw. .   3. The wood fuel pellet carbonization device according to claim 2, wherein an end of the guide pipe upstream in the conveying direction is connected to a bottom portion of a first hopper into which the wood fuel pellet is introduced. .   7. The wood fuel pellet carbonizing apparatus according to claim 6, wherein a stirring screw for preventing bridge formation by the wood fuel pellet is provided on the screw at the bottom of the first hopper.   The guide pipe is provided with a second hopper that accumulates carbonized wood fuel pellets and discharges them from the bottom at an appropriate timing at the downstream end of the screw in the conveying direction. Item 8. A carbonization apparatus for wood fuel pellets according to any one of Items 2 to 7.   The wood fuel pellet according to any one of claims 2 to 8, wherein in the screw, at least one rotation blade facing the inlet and the outlet of the microwave generator is made of an electromagnetic shielding material. Carbonization equipment.   The hopper is provided with a detection switch for detecting whether or not the wood fuel pellets are accumulated in the vicinity of the hopper, and the microwave generator detects the accumulation of wood fuel pellets with the detection switch. The wood fuel pellet carbonization apparatus according to any one of claims 6 to 8, wherein microwave irradiation is performed in a state where the fuel is pelletized.   A detoxification device is provided between the outlet of the guide tube and the second hopper for sucking high-temperature gas containing tar generated from the wood fuel pellets by microwave heating, burning it, detoxifying it, and discharging it. The carbonization apparatus for woody fuel pellets according to claim 8, wherein   The wood fuel pellet is a woody biomass pellet formed by heat compression molding oga powder or wood powder as the plant-derived powdery raw material according to any one of claims 1 to 11. Carbonization equipment for wood fuel pellets as described.   The carbonized apparatus for woody fuel pellets according to any one of claims 1 to 12, wherein the guide tube is a glass tube or a ceramic tube.   The apparatus for carbonizing woody fuel pellets according to any one of claims 1 to 13, wherein the pulverized coal is mixed in an amount of 5 to 10% by weight.

Images