Biomass Gasifier

Abstract

To provide a biomass gasification device capable of efficiently and sufficiently producing a combustible gas from a biomass raw material.SOLUTION: A biomass gasification device 1 comprises: a furnace body 3 capable of heating the inside; an inner cylinder 5 in which a biomass raw material is supplied into an inner space 5a; an outer cylinder 6 disposed on an outer side thereof and having an outer space 6a between itself and the inner cylinder 5; a communication part 9 formed below the inner cylinder 5 and the outer cylinder 6 and communicating the inner space 5a and the outer space 6a; a stirring device 11 for stirring the biomass raw material; and a discharge pipe for discharging the biomass raw material. The stirring device 11 comprises: a partition wall 15 that vertically partitions the communication part 9 and has an opening part 15a; a first stirring mechanism 17 that is provided in an upper space 9a of the partition wall 15 and stirs the biomass raw material; a second stirring mechanism 19 that is provided in a lower space 9b of the partition wall 15 and stirred by the first stirring mechanism 17 to stir the biomass raw material flowing through the opening part 15a; and a driving source 21.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a biomass gasifier. [Background technology]

[0002] When producing combustible gas from biomass materials, a gasification device is used, which supplies the biomass materials and heats them to generate combustible gas. Methods for obtaining combustible gas include directly burning the biomass materials to generate combustible gas, and sealing the biomass materials and heating them from the outside to generate combustible gas. In either method, it is necessary to generate gas from the biomass materials efficiently and sufficiently.

[0003] Patent Document 1 discloses a gasification furnace in which ignited biomass raw materials are fed into the furnace body to generate combustible gas inside the furnace. This document describes how an oxidant supply pipe and a lower scraper are rotated inside the furnace, an oxidant is supplied to the biomass raw materials by the oxidant supply pipe to cause a reaction over a wide horizontal range, the biomass raw materials are stirred by the lower scraper, and the carbonized biomass raw materials are discharged below a punching plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-119771 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above Patent Document 1, the height of the charged biomass raw material is made uniform by the upper scraper, and stirring is performed by the lower scraper. In this invention, the uniformity of the reaction of the biomass raw material is considered, but there is a demand for more efficient and sufficient generation of combustible gas from biomass fuel, while ensuring the processing amount of the biomass raw material and the hourly production amount of combustible gas.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and the problem that the present invention aims to solve is to provide a biomass gasification apparatus that can efficiently and sufficiently generate combustible gas from biomass raw materials and ensure the production volume of the combustible gas. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following means. That is, the biomass gasification apparatus of the present invention comprises a furnace body capable of heating the inside, an inner cylinder extending vertically inside the furnace body and into which biomass raw materials are supplied, an outer cylinder arranged outside the inner cylinder and having an outer space between the inner cylinder and the outer cylinder, a communication section formed below the inner cylinder and the outer cylinder and connecting the inner space to the outer space, a stirring device provided in the communication section and stirring the biomass raw materials, and a discharge pipe provided below the stirring device and discharging the biomass raw materials, the stirring device comprising: a partition wall dividing the communication section in the vertical direction and having an opening; a first stirring mechanism provided in the upper space of the partition wall and stirring the biomass raw materials; a second stirring mechanism provided in the lower space of the partition wall and stirring the biomass raw materials that are stirred by the first stirring mechanism and flow through the opening; and a drive source that drives the first stirring mechanism and the second stirring mechanism.

[0008] According to this invention, since the first stirring mechanism provided in the upper space of the partition for stirring the biomass raw material and the second stirring mechanism provided in the lower space of the partition for stirring the biomass raw material that has passed through the opening are provided, the biomass raw material can be sufficiently heated and stirred on the path from the first stirring mechanism to the second stirring mechanism. Therefore, the combustible gas can be efficiently and sufficiently generated from the biomass raw material, and the biomass raw material can be heated and stirred without stagnation, and the production amount of the combustible gas can be guaranteed.

[0009] In one aspect of the present invention, an intermediate tube is provided in the communication portion and is heated by the furnace body. In this embodiment, since the intermediate tube is heated by the furnace body, heat is stored in the intermediate tube and the biomass raw material can be sufficiently heated by the radiant heat to generate combustion gas.

[0010] In one aspect of the present invention, the intermediate cylinder is fixed to an upper portion of a blade of the first stirring mechanism. In this embodiment, since the intermediate cylinder is fixed to the upper part of the blades, the intermediate cylinder that rotates together with the blades can be installed with a simple structure, and the heating of the biomass raw material can be made uniform.

[0011] In one aspect of the present invention, the first stirring mechanism and the second stirring mechanism are each arranged to extend in the vertical direction and are configured to include a rotating shaft that is rotated by the driving source and a plurality of blades extending laterally from the rotating shaft. In this embodiment, the first and second agitation mechanisms are each composed of a plurality of blades extending laterally from the rotation shaft, so that the agitation mechanisms can be easily produced with a simple structure.

[0012] In one aspect of the present invention, the exhaust pipe is provided at a tip of a rotational path of the blade. In this embodiment, the exhaust pipe is provided at the tip of the blade rotation path, ensuring a sufficient path for heating the biomass feedstock. Effect of the Invention

[0013] According to the present invention, it is possible to provide a biomass gasification apparatus that can efficiently and sufficiently generate combustible gas from biomass raw materials and ensure the production amount of the combustible gas. [Brief description of the drawings]

[0014] [Figure 1] 1 is a vertical cross-sectional view showing a schematic configuration of a biomass gasification apparatus according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged vertical cross-sectional view of a main portion as seen from the direction of arrow P in FIG. 1. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2. [Diagram 5] FIG. 2 is an enlarged vertical cross-sectional view of a main portion of a biomass gasification apparatus according to an embodiment of the present invention. [Figure 6] 6 is a cross-sectional view taken along the line CC in FIG. 5. [Figure 7] FIG. 1 is a vertical cross-sectional view of a biomass gasification apparatus according to a prerequisite technology of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along the line DD in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] First, a technology on which the present invention is based (prerequisite technology) will be described. (Prerequisite technology) 7 is a vertical cross-sectional view of a biomass gasification apparatus 100 according to the prerequisite technology of the present invention. Here, the main parts for generating combustible gas from biomass raw materials will be described, and a detailed description of the entire apparatus will be given later in the embodiments. The biomass gasification apparatus 100 comprises a furnace body 3 capable of heating the inside, an inner tube 5 extending vertically inside the furnace body 3 and into which biomass raw material is supplied (arrow M) into the inner space 5a, an outer tube 6 arranged outside the inner tube 5 and having an outer space 6a between it and the inner tube 5, a communication section 9 formed below the inner tube 5 and the outer tube 6 and connecting the inner space 5a to the outer space 6a, an agitator 11 provided within the communication section 9 for agitating the biomass raw material, and a discharge pipe 13 provided below the agitator 11 for discharging the biomass raw material.

[0016] The biomass gasification apparatus 100 is equipped with a heat insulating material 3a inside the furnace body 3, and the space inside the heat insulating material 3a is a heating space 3b, into which combustion gas is introduced to heat the outer cylinder 6 together with the biomass material placed below it, generating combustion gas. The generated combustion gas is collected via the external space 6a (arrow G).

[0017] Fig. 8 is a cross-sectional view taken along the line DD in Fig. 7. The agitator 11 is a scraper equipped with a plurality of blades 27 extending laterally from a rotating shaft 25, and rotates in the direction of the arrow R to discharge from an exhaust pipe 13 the carbonized biomass material (biomass material that has finished generating combustion gas) after the production of the combustion gas.

[0018] In this base technology, it is required to prevent the ungasified biomass raw material from being discharged and to further extend the residence time of the biomass raw material to improve gasification efficiency, and the present invention has been made to solve these problems.

[0019] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a vertical cross-sectional view that shows a schematic configuration of a biomass gasification apparatus according to an embodiment of the present invention. Fig. 2 is an enlarged vertical cross-sectional view of a main part as seen from the direction of arrow P in Fig. 1. Fig. 3 is a cross-sectional view taken along the line AA in Fig. 2. Fig. 4 is a cross-sectional view taken along the line BB in Fig. 2.

[0020] The biomass gasification apparatus 1 includes a furnace body 3 capable of heating the inside, an inner cylinder 5 extending vertically inside the furnace body 3 and into which biomass raw materials are supplied (arrow M), an outer cylinder 6 arranged outside the inner cylinder 5 and having an outer space 6a between the inner cylinder 5 and the outer cylinder 6, a communication part 9 formed below the inner cylinder 5 and the outer cylinder 6 and communicating the inner space 5a with the outer space 6a, an agitator 11 provided in the communication part 9 for agitating the biomass raw materials, and a discharge pipe 13 provided below the agitator 11 for discharging the biomass raw materials. As shown in FIG. 4, the discharge pipe 13 is provided at the tip of the rotation locus of the blade 27b.

[0021] As shown in Figures 1 and 2, the furnace body 3 is provided with a heat insulating material 3a inside, and the space between the outer cylinder 6 and the heat insulating material 3a is a heating space 3b where combustion gas is introduced from a combustion gas inlet 3d shown in Figure 2, the introduced combustion gas heats the outer cylinder 6, and the combustion gas is then discharged from a combustion gas outlet 3e. Also, as shown in Figure 1, an inspection port 3c for inspection is provided at the lower part of the furnace body 3.

[0022] The stirring device 11 comprises a partition 15 which divides the communicating portion 9 in the vertical direction and has an opening 15a, a first stirring mechanism 17 which is provided in the upper space 9a of the partition 15 and stirs the biomass raw material, a second stirring mechanism 19 which is provided in the lower space 9b of the partition 15 and stirs the biomass raw material which is stirred by the first stirring mechanism 17 and flows through the opening 15a, and a drive source 21 which drives the first stirring mechanism 17 and the second stirring mechanism 19.

[0023] As shown in Fig. 2, the first stirring mechanism 17 and the second stirring mechanism 19 are each disposed to extend in the vertical direction, and include a rotating shaft 25 that is rotated by a driving source 21, and a plurality of blades 27a, 27b extending laterally from the rotating shaft 25. As shown in Figs. 2 to 4, the first stirring mechanism 17 and the second stirring mechanism 19 are scrapers that include blades 27a, 27b extending laterally from the rotating shaft 25. The driving source 21 includes a motor 21a and a transmission unit 21b that includes gears or the like that transmit the rotation of the motor 21a to the rotating shaft 25.

[0024] As shown in Fig. 1, the biomass gasifier 1 is provided with a raw material hopper 29 for storing biomass raw material, a flight conveyor 31 for transporting the biomass raw material to the upper part of the biomass gasifier 1, a supply pipe 33 for feeding the biomass raw material from the flight conveyor 31, and a screw conveyor 39 for feeding the biomass raw material from the supply pipe 33 to the internal space 5a of the inner cylinder 5. A gate valve 41 is provided between the screw conveyor 39 and the inner cylinder 5, and is opened and closed by a drive piston 41a that controls the start and stop of feeding the biomass raw material. The raw material hopper 29 is held by a support leg 29a, and a load cell 29b for measuring the weight of the biomass raw material stored in the raw material hopper is provided at the end of the support leg 29a that supports the raw material hopper 29.

[0025] The flight conveyor 31 is structured so that multiple flights (flat plates) with both ends connected to chain conveyors are arranged inside a casing 31b, and the chain conveyor is rotated by a motor 31a to transport the biomass raw material on the flat plates within the casing 31b.

[0026] Next, the operation of the biomass gasifier 1 configured as described above will be described. The biomass gasifier 1 feeds the biomass raw material stored in the raw material hopper 29 into the flight conveyor 31. The flight conveyor 31 transfers the fed biomass raw material to a supply pipe 33 provided at the top of the biomass gasifier 1. The biomass raw material dropped into the supply pipe 33 is supplied to the top of the inner cylinder 5 by the screw conveyor 39. A gate valve 41 provided between the screw conveyor 39 and the inner cylinder 5 controls the feeding of the biomass raw material into the internal space 5a. The biomass raw material fed into the inner cylinder 5 falls into the agitator 11 provided in the communication part 9 that communicates between the internal space 5a and the external space 6a.

[0027] As shown in FIG. 2, the agitator 11 is provided with a partition wall 15 having an opening 5a that divides the communication section 9 into an upper space 9a and a lower space 9b. A first scraper (first agitation mechanism) 17 is disposed in the upper space 9a, and as shown in FIG. 3, a blade 27a rotates counterclockwise as shown by an arrow R to guide the charged biomass raw material to the opening 15a of the partition wall 15. The biomass raw material guided to the opening 5a falls into the lower space 9b. A second scraper (second agitation mechanism) 19 is disposed in the lower space 9b, and as shown in FIG. 4, a blade 27b rotates counterclockwise as shown by an arrow R to guide the charged biomass raw material to the discharge pipe 13. The biomass raw material guided to the discharge pipe 13 is discharged to the outside of the outer cylinder 6 via the discharge pipe 13.

[0028] While the biomass raw material is being stirred by the first scraper 17 and the second scraper 19 of the stirring device 11 described above, combustion gas is introduced from the combustion gas inlet 3d shown in Fig. 2, filling the heating space 3b with combustion gas and heating the entire outer cylinder 6. Combustible gas is generated from the stirred and heated biomass raw material and is collected via the path indicated by arrow G shown in Fig. 1. The combustion gas introduced into the heating space 3b is discharged to the outside from the combustion gas outlet 3e shown in Fig. 2.

[0029] As described above, in this embodiment, the communication section 9 below the outer cylinder 6 is divided into an upper space 9a and a lower space 9b by a partition wall 15 having an opening 5a. In each of the divided upper space 9a and lower space 9b, the biomass material is heated and stirred by a first scraper 17 and a second scraper 19 having blades 27a and 27b. The biomass material flows from the upper space 9a to the lower space 9b through the opening 5a while being stirred. Here, the discharge pipe 13 is provided at the tip of the rotation trajectory of the blade 27b in the lower space 9b, so that a sufficient path is secured for discharging the biomass material that has passed through the opening 5a. Therefore, the biomass material can be sufficiently heated and stirred in the path from the first scraper to the second scraper.

[0030] In this way, the residence time for heating the biomass raw materials to generate combustible gas can be extended, so combustible gas can be generated efficiently and sufficiently from the biomass raw materials without increasing the thermal energy required for gasification. The first scraper 17 and the second scraper 19 are arranged in series and both scrapers are used for stirring simultaneously, so the two-stage stirring improves the stirring efficiency, increasing the gasification efficiency, and the flow rate of the biomass raw materials can be set to the same as that of the prerequisite technology with only one scraper. Therefore, the biomass raw materials can be heated and stirred without stagnation, and the production volume of combustible gas can be guaranteed.

[0031] Second embodiment Fig. 5 is an enlarged vertical cross-sectional view of the main part according to the second embodiment of the present invention. Fig. 6 is a cross-sectional view taken along the CC arrow in Fig. 5. This embodiment differs from the first embodiment in that an intermediate tube 23 heated by the furnace body 3 is provided in the communication part 9. Other parts having the same configuration and function are given the same reference numerals as in the first embodiment, and their description will be omitted. In this embodiment, a series of steps from feeding the biomass raw material into the inner tube 5 to generating flammable gas by heating and stirring with the first scraper 17 and the second scraper 19, and discharging the biomass raw material from the discharge pipe 13 are the same as those in the first embodiment.

[0032] In this embodiment, the intermediate cylinder 23 is fixed to the upper part of the blade 27a of the first scraper 17, and rotates counterclockwise together with the blade 27a as indicated by the arrow R, as shown in Fig. 6. The intermediate cylinder 23 is heated together with the outer cylinder 6 by the combustion gas introduced into the heating space 3b. The heated intermediate cylinder accumulates heat, and heats the biomass raw material introduced into the outer cylinder 6 by radiant heat.

[0033] In this embodiment, in addition to the same effects as those of the first embodiment, the intermediate cylinder 23 heated by the furnace body 3 is provided in the communication part 9, so that the temperature of the communication part 9 at the bottom of the outer cylinder 6, which is an important part where gasification takes place, can be increased by radiant heat from the intermediate cylinder 23. Therefore, the amount of heat applied to the biomass raw material can be increased, and the efficiency of gasification can be improved. The intermediate cylinder 23 is fixed to the upper part of the blade 27a and rotates inside the outer cylinder 6 together with the blade 27a, so that the uniformity of the heat distribution in the communication part 9 can be ensured.

[0034] In the above embodiment, the agitator 11 has one partition wall 15, but the present invention is not limited to this and multiple partition walls 15 may be provided. A scraper for agitating the biomass raw material may be provided between each partition wall 15. The opening 5a of each partition wall 15 is the central opening 5a through which the rotating shaft 25 passes, but the present invention is not limited to this and the opening 5a may be provided at an appropriate portion in consideration of a path in which the biomass raw material is sufficiently retained. For example, the opening 5a may be provided at the tip of the rotation trajectory of the blade 27b, similar to the discharge pipe 13.

[0035] In the second embodiment, the intermediate cylinder 23 is fixed to the blades 27a, but the present invention is not limited to this and may be fixed to the lower part of the inner cylinder 6. Alternatively, the intermediate cylinder 23 may be supported from the outer cylinder 5 by a support mechanism. [Explanation of symbols]

[0036] 1, 10, 100 Biomass Gasifier 3. Furnace body 5 Inner cylinder 5a Inner space 6 Outer cylinder 6a Outside space 9 Communication section 9a Upper space 9b Lower space 11 Mixing device 13 Discharge pipe 15 Bulkhead 15a opening 17 First stirring mechanism (first scraper) 19 Second stirring mechanism (second scraper) 21 Power Source 23 Intermediate tube 25 Rotational Axis 27, 27a, 27b Feather

Claims

1. 1. A biomass gasification apparatus comprising: A furnace body capable of heating the inside; An inner cylinder that is provided inside the furnace body so as to extend in the vertical direction and into which the biomass raw material is supplied; an outer cylinder disposed outside the inner cylinder and defining an outer space between the outer cylinder and the inner cylinder; a communication portion formed below the inner cylinder and the outer cylinder, which communicates the inner space with the outer space; A stirring device provided in the communication portion and configured to stir the biomass raw material; A discharge pipe is provided below the stirring device and discharges the biomass material, The stirring device is A partition wall that divides the communication portion in the vertical direction and has an opening; a first stirring mechanism provided in an upper space of the partition wall and configured to stir the biomass material; A second stirring mechanism provided in a lower space of the partition wall and configured to stir the biomass material stirred by the first stirring mechanism and flowing through the opening; A biomass gasification apparatus comprising: a drive source that drives the first stirring mechanism and the second stirring mechanism.

2. The biomass gasification apparatus according to claim 1 , further comprising an intermediate cylinder provided in the communication portion and heated by the furnace body.

3. The biomass gasification apparatus according to claim 2 , wherein the intermediate cylinder is fixed to an upper portion of a blade of the first stirring mechanism.

4. The biomass gasification apparatus according to any one of claims 1 to 3, wherein the first stirring mechanism and the second stirring mechanism are each arranged to extend in the vertical direction and are configured to include a rotating shaft that is rotated by the driving source and a plurality of blades extending laterally from the rotating shaft.

5. The biomass gasification apparatus according to claim 2 , wherein the exhaust pipe is provided at a tip of a rotational locus of the blades.

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