JP2008208360A - Solid fuel and method for preparing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid fuel and a method for preparing the same that can be burned in a good state while being prepared with an improved crushing efficiency. <P>SOLUTION: The solid fuel is prepared by supplying a vertical-type roller mill 30 of an apparatus 100 for preparation and burning with a mixture of rice hulls and saw dust, and the mixture is crushed and introduced into a combustion boiler 25 as a solid fuel. The solid fuel is prepared by mixing 5-15 wt.% rice hulls with a 100 wt.% biomass other than the rice hulls. The solid fuel can be dried sufficiently in the course of crushing the mixture of rice hulls and saw dust because the inside of the vertical-type roller mill 30 is provided by a hot blast P taken out of an exhaust gas S of the combustion boiler 25 via a pressurizing fan 27. Crushing efficiency of the solid fuel can be improved because the amount of supply of saw dust can be increased while suppressing vibration by decreasing grinding resistance at the time of operating the vertical-type roller mill 30. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a solid fuel for combustion in which biomass is finely pulverized and dried to a fine powder, and a method for producing the same, and more specifically, a solid fuel that can be combusted satisfactorily while improving the pulverization efficiency during production, and the production thereof Regarding the method.

  In response to the increasing demand for energy in recent years, pulverized coal produced by crushing and drying coal containing a lot of moisture and volatiles such as brown coal instead of high-grade coal such as bituminous coal Further, development of a combustion apparatus for use in an industrial furnace such as a boiler or a kiln that uses a solid fuel such as a pulverized biomass fuel obtained by pulverizing and drying biomass such as wood into a powder form is underway.

  As what discloses such a combustion apparatus, what was described in patent document 1, for example is known. In the combustion apparatus described in Patent Document 1, first, wood is pulverized by a mill and dried by an air flow for drying to generate wood powder, which is discharged together with exhaust gas A to the outside. The dust collector collects the wood powder conveyed by the exhaust gas A, removes the wood powder from the exhaust gas A, and discharges the exhaust gas B. The boiler burns the wood powder as fuel and exhausts the exhaust gas C. To do.

Further, the control unit mixes a part of the exhaust gas B and a part of the exhaust gas C at an appropriate mixing ratio based on a detection signal of a temperature sensor installed near the outlet of the exhaust gas A of the mill. The temperature of A is controlled to be 95 ° C to 130 ° C. As a result, even when wood powder is used as a fuel, this combustion device can sufficiently pulverize and dry the wood powder while preventing ignition in the wood mill and condensation of sulfur components. It has a configuration that can.
JP 2005-48967 A

  However, in the combustion apparatus described in Patent Document 1 described above, when the particle size distribution of the wood thrown into the mill is biased toward the coarse grain side or the fine grain side, mechanical vibration is generated during the grinding of the wood in the mill. Therefore, there is a problem that the amount of wood input to the mill must be reduced, and the mill cannot be operated satisfactorily.

  Also, increasing the amount of wood input to the mill in order to increase the amount of solid fuel discharged from the mill increases the crushing resistance, and depending on the performance of the mill, crushing and drying of the wood may be insufficient. Therefore, there is a problem that it may become impossible to produce a solid fuel having good combustibility.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a solid fuel that can be combusted satisfactorily while improving the pulverization efficiency during production, and a method for producing the same.

  In order to achieve the above object, the solid fuel according to the present invention is characterized in that rice husk and biomass other than the rice husk are mixed and pulverized.

  The solid fuel according to the present invention is configured by mixing and pulverizing rice husk and biomass other than the rice husk as described above, so that the pulverization resistance in the mill is smaller than that of the conventional solid fuel and mechanical at the time of pulverization. Since vibration is suppressed, the pulverization efficiency during production can be improved. Further, since the pulverization resistance is reduced, it can be sufficiently pulverized to have good combustibility.

  Moreover, you may be set as the structure formed by mixing and grind | pulverizing rice husk and 5-15 weight% rice husk with respect to 100 weight% of biomass other than this rice husk.

  The biomass may be woody biomass composed of building waste, felled trees, and the like.

  The method for producing a solid fuel according to the present invention is characterized in that a rice husk and biomass other than the rice husk are mixed to form a mixture, and the mixture is pulverized by a vertical roller mill.

  In the method for producing a solid fuel according to the present invention, a rice husk and biomass other than this rice husk are mixed to produce a mixture, and the mixture is pulverized by a vertical roller mill, as compared with the conventional production method. In addition, since the pulverization resistance in the mill can be reduced to suppress mechanical vibration during pulverization, the pulverization efficiency during production can be improved and the mill can be operated well. In addition, since the pulverization resistance can be reduced, the mixture can be sufficiently pulverized to produce a solid fuel having good combustibility.

  Alternatively, the mixture may be pulverized while supplying hot air to the vertical roller mill.

  The biomass may be woody biomass composed of building waste, felled trees, and the like.

  According to the present invention, there is an effect that it is possible to provide a solid fuel that can be combusted satisfactorily while improving the pulverization efficiency during production, and a method for producing the same.

  Hereinafter, a solid fuel and a manufacturing method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an explanatory diagram for explaining an example of the entire configuration of a solid fuel production combustion facility according to an embodiment of the present invention. As shown in FIG. 1, in the production combustion facility 100, first, for example, a mixture that is a material of solid fuel obtained by mixing biomass other than the rice husk into the rice husk is input from the truck 11 to the receiving hopper 12. Note that dust in the air in the receiving hopper 12 accompanying the introduction of the mixture is collected by a dust collector (not shown).

  The mixture to be added is a mixture of rice husk and 5 to 15% by weight of rice husk with respect to 100% by weight of biomass other than the rice husk. Here, the biomass constituting the mixture may be wood waste, which is woody biomass such as building waste and felled wood, and the rice husk may be a grain-based rice husk such as rice, wheat, straw, and straw.

  Then, the mixture charged into the receiving hopper 12 is stirred and conveyed by the screw feeder 13 at a predetermined conveying speed, and impurities in the mixture are removed via the disk screen 14, and then the belt conveyor 16 and the screw feeder. 17 is fed into the supply hopper 18 through the storage 17 and stored. The magnetic material such as iron pieces is removed from the mixture discharged from the disk screen 14 by the magnetic separator 15 during conveyance by the belt conveyor 16.

  The mixture stored in the supply hopper 18 is discharged to the weighing belt conveyor 20 by a predetermined amount via the supply feeder 19, and after a fixed amount is measured by the weighing belt conveyor 20, the vertical shape is passed through the double flap gate 21. Supplied to the roller mill 30.

  In the vertical roller mill 30, the charged mixture is finely pulverized. In the vertical roller mill 30, among the pulverized mixture, the pulverized lightweight powder is pneumatically conveyed upward by the hot air P supplied by the pressure fan 27 into the vertical roller mill 30, and is a rotary classifier. 31 is distinguished based on particle diameter, density, shape, etc., and supplied to the cyclone 22 as a powder separator as a solid fuel according to the present embodiment.

  In the cyclone 22, the solid fuel transported by air is separated from the air, and the separated air is supplied to the bag filter 29 by the mill fan 28 and is sent to an environmental facility (not shown) after dust is removed. A part is sent to the pressure fan 27.

  A part of the separated air can be sent to the outlet of the combustion hot gas cyclone 26 or the inlet of the pressurized fan 27 as shown in FIG. Further, a part of the separated air can be sent to the exhaust side of the pressure fan 27.

  On the other hand, the solid fuel separated from the air in the cyclone 22 falls downward and is sent to the distributor 24 by the transport blower 23 and then distributed according to the number of combustion burners (not shown) provided in the combustion boiler 25. And used as fuel in the combustion boiler 25.

  The dust removed by the bag filter 29 is sent to the distributor 24 together with the solid fuel from the cyclone 22 by the feeder 29a and used as the above-described solid fuel. Further, in the production combustion facility 100 of this example, pulverized coal is further mixed with the solid fuel distributed via the distributor 24 and used as fuel in the combustion boiler 25.

  The exhaust gas S in the combustion boiler 25 is discharged from the combustion boiler 25 and supplied to the combustion hot gas cyclone 26, where it is separated into hot air P and soot dust, and the separated soot dust is not shown. While being sent to the environmental equipment, the hot air P is sent to the pressure fan 27 and supplied to the vertical roller mill 30.

  Therefore, in the production combustion facility 100 of this example, in the vertical roller mill 30, the mixture of rice husk and wood chips is not only finely pulverized but also sufficiently dried by the hot air P from the pressure fan 27 (pulverization). Dry).

  FIG. 2 is a diagram showing various operation data during operation of the vertical roller mill 30 in the manufacturing combustion facility 100 described above. 2A shows the change in the amount of wood waste (the unit of the vertical axis is t / h), and FIG. 2B shows the change of the differential pressure of the mill (the unit of the vertical axis is kPa). c) shows the transition of the vibration of the mill (the unit of the vertical axis is μm). In the vertical roller mill 30 of the present example, as shown in FIG. 3A, the supply amount of wood chips that can be supplied through the double flap gate 21 is more than that before the rice husks are added to the wood chips. The latter increases. That is, it is shown that the supply amount can be increased as a whole when the rice husk and the wood waste are mixed, compared with the case of the wood waste alone.

  Further, as shown in FIG. 5B, the pressure difference (differential pressure) between the exhaust gas supply side and the solid fuel discharge side to the vertical roller mill 30 is greater than that before the rice husks are added to the wood chips. The latter will decrease. This indicates that the wood crushing efficiency is improved in the vertical roller mill 30 when the rice husk and the wood waste are mixed, and the amount of pulverized material circulated within the roller mill 30 is reduced. Show.

  Furthermore, as shown in FIG. 3C, the mechanical vibration in the vertical roller mill 30 is reduced after the rice husks are added to the wood chips than before the rice husks are added. This means that the mixture of rice husk and wood waste improves the biting of the pulverized material into the grinding roller in the vertical roller mill 30 compared to the case of wood waste alone, reduces the pulverization resistance, and reduces the mechanical load. It is shown that.

  The composition of each of the rice husks, wood chips, and the mixture of the rice husks and the wood chips (solid fuel) used in the production combustion facility 100 of this example is as shown in Table 1 below. Rice husks were made from rice husks, and wood chips were made from construction waste. 10% by weight of rice husk was mixed with 100% by weight of the total weight of building waste and rice husk.

また、本例の製造燃焼設備１００の燃焼ボイラ２５における固体燃料として、木屑のみを用いた場合と籾殻と木屑の混合物を用いた場合の各種運用データは、次の表２に示すようなものとなった。表２によれば、籾殻を混合した場合とそうでない場合を比べると、発電量等のボイラ性能や、排ガス濃度は同程度であった。

In addition, as shown in Table 2 below, various operation data when using only wood waste and a mixture of rice husk and wood waste as solid fuel in the combustion boiler 25 of the production combustion facility 100 of this example are as follows. became. According to Table 2, when the case where the rice husk was mixed was compared with the case where the rice husk was not mixed, the boiler performance such as the amount of power generation and the exhaust gas concentration were comparable.

このように、図２、表１および表２からも明らかなように、籾殻と木屑を混合して粉砕した本実施形態に係る固体燃料は、木屑のみからなる固体燃料と比較しても、同等あるいはそれ以上の燃焼性を備えつつ竪型ローラミル３０の運用を良好にすることが可能であるといえる。したがって、この固体燃料によれば、製造時における粉砕効率を向上させつつ良好に燃焼させることが可能となる。

Thus, as is clear from FIG. 2, Table 1 and Table 2, the solid fuel according to the present embodiment obtained by mixing and pulverizing rice husk and wood waste is equivalent even when compared with the solid fuel consisting only of wood waste. Alternatively, it can be said that it is possible to improve the operation of the vertical roller mill 30 while having more combustibility. Therefore, according to this solid fuel, it becomes possible to burn well while improving the pulverization efficiency at the time of manufacture.

  In the above-described production combustion facility 100, the material of the solid fuel input from the truck 11 to the receiving hopper 12 is a mixture obtained by mixing rice husks and wood chips. It is possible to adopt such a method.

  FIG. 3 is a diagram for explaining a method of mixing rice husks and wood chips in the production combustion facility 100. For example, as shown in FIG. 3 (a), the rice husk is first stored in advance in the rice husk receiving hopper 42 of the mixing yard 50 by the shovel loader 41. When the sensor 47 (not shown) detects the entry of the truck 47 into the vicinity of the receiving hopper 45, the rice husk cutting conveyor 43 and the rice husk charging conveyor 44 are activated to start feeding the rice husk into the receiving hopper 45, and the truck 47 The wood chips loaded on the hopper 45 are put into the receiving hopper 45.

  At this time, the amount of rice husk transported and fed by the rice husk cutting conveyor 43 and the rice husk feeding conveyor 44 may be adjusted in advance so as to obtain an optimum mixing ratio based on the cutting ability of the screw feeder 46. In the receiving hopper 45, the rice husks and wood chips that are respectively charged are mixed while being agitated by the screw feeder 46, and are discharged and supplied to the vertical roller mill 30 side. Therefore, according to such a mixing method, the screw feeder 46 can be used not only as a dispenser to the vertical roller mill 30 but also as a mixer of rice husk and wood waste, and the rice husk and wood waste can be used. It can be easily mixed.

  Further, for example, as shown in FIG. 3B, the mixing of rice husks and wood chips is performed so that the loading amounts of the truck 48 loaded with rice husks and the truck 49 loaded with wood chips become optimum mixing ratios in advance. Set it. Then, the trucks 48 and 49 are made to enter the mixing yard 50, and the rice husks and wood chips are put into the receiving hopper 45, stirred and mixed by the screw feeder 46, and discharged to the vertical roller mill 30 side. In this case, when the entry of the trucks 48 and 49 to the vicinity of the receiving hopper 45 is detected by a sensor (not shown), the screw feeder 46 is activated and the rice husk and the wood waste can be mixed via the receiving hopper 45. Even in this case, rice husk and wood chips can be easily mixed as described above. The receiving hopper 45 and the screw feeder 46 shown in FIG. 3 can be used as the receiving hopper 12 and the screw feeder 13 shown in FIG.

  Further, the mixing of wood chips and rice husks can also be carried out by the following method. First, wood chips and rice husks are alternately stacked by using a shovel car or the like (not shown) to form a layer. In this case, for example, the thickness of the wood chip and rice husk layer is about 20 to 50 centimeters. In addition, the number of layers is 1 to 5 when wood chips and rice husks are one layer. The layered material thus formed is cut in a cross section from the end by a shovel car or the like and loaded on a track (not shown). The wood chips and rice husks are cut and mixed when loaded. Thereby, wood chips and rice husk can be mixed by a simple method. Finally, the mixed wood chips and rice husks are fed from the truck into the receiving hopper 12 shown in FIG.

  As described above, according to the solid fuel and the manufacturing method thereof according to the present embodiment, the pulverization efficiency in the vertical roller mill 30 at the time of manufacturing the solid fuel can be improved. In addition, a solid fuel that is sufficiently finely pulverized and burns well with little difference in performance from the conventional solid fuel can be easily manufactured.

It is explanatory drawing for demonstrating an example of the whole structure of the manufacture combustion equipment of the solid fuel which concerns on one Embodiment of this invention. It is a figure which shows the various operation data at the time of the driving | operation of the vertical roller mill in the manufacturing combustion equipment. It is a figure for demonstrating the mixing method of the chaff and the wood chip in the manufacturing combustion equipment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Truck, 12 ... Receiving hopper, 13 ... Screw feeder, 14 ... Disc screen, 15 ... Magnetic separator, 16 ... Belt conveyor, 17 ... Screw feeder, 18 ... Feeding hopper, 19 ... Feeding feeder, 20 ... Belt conveyor, DESCRIPTION OF SYMBOLS 21 ... Double flap gate, 22 ... Cyclone, 23 ... Conveyance blower, 24 ... Distributor, 25 ... Combustion boiler, 26 ... Combustion hot gas cyclone, 27 ... Pressurization fan, 28 ... Mill fan, 29 ... Bag filter, 30 ... Vertical roller mill, 31 ... Rotary classifier.

Claims (6)

  A solid fuel comprising a rice husk and a biomass other than the rice husk mixed and pulverized.   2. The solid fuel according to claim 1, wherein 5-15% by weight of the rice husk is mixed and pulverized with respect to 100% by weight of rice husk and biomass other than the rice husk.   3. The solid fuel according to claim 1, wherein the biomass is a woody biomass composed of building waste, felled trees, or the like.   A method for producing a solid fuel, characterized in that rice husk and biomass other than the rice husk are mixed to form a mixture, and the mixture is pulverized by a vertical roller mill.   The method for producing a solid fuel according to claim 4, wherein the mixture is pulverized while supplying hot air to the vertical roller mill.   6. The method for producing a solid fuel according to claim 4, wherein the biomass is a woody biomass composed of building waste, felled trees, and the like.

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