Carbonization furnace and control method thereof

Abstract

To provide a carbonization furnace which can produce a carbide whose carbonization state is as uniform as possible.SOLUTION: A carbonization furnace 1A includes: a container 5 in which a matter to be carbonized W is accommodated; and air supply parts 7 which are provided at a plurality of positions in the container 5 and which supply an oxidant to the interior of the container 5. The air supply part 7 at a position where the carbonization progression of the matter to be carbonized W is low gives a larger air supply amount than the air supply part 7 at a position where the carbonization progression of the matter to be carbonized W is high. The carbonization furnace further includes a control part which controls a flow rate of air supplied from each of the air supply parts 7. The control part causes the air supply amount to increase in order of going from the lower side of the container 5 to the upper side according to the degree of carbonization progression of the matter to be carbonized W stacked in the container 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a carbonization furnace and a control method thereof. [Background technology]

[0002] A carbonization furnace is known that obtains a carbonized material by dry distilling a material to be carbonized, such as woody biomass (Patent Document 1). Patent Document 1 discloses that a combustion gas is caused to flow around the outside of a carbonization chamber, and the woody biomass raw material stored in a carbonization tray inside the carbonization chamber is heated by radiant heat and carbonized. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-21173 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 states that the wood biomass raw materials stored in the carbonization tray are heated uniformly by radiant heat, but in reality, there may be areas in the carbonization tray where the degree of carbonization differs depending on the storage state of the wood biomass raw materials and the structure of the carbonization device, etc. This may result in areas where carbonization is excessive or insufficient, resulting in the production of a carbonized product that is not uniformly carbonized.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a carbonization furnace and a control method thereof capable of producing carbonized material with a carbonized state that is as uniform as possible. [Means for solving the problem]

[0006] A carbonization furnace (1A, 1B) according to one embodiment of the present disclosure comprises a container (5) in which a material to be carbonized (W) is accommodated, and oxidizer supply units (7) provided at multiple positions in the container (5) for supplying an oxidizer to the inside of the container (5), and the oxidizer supply unit (7) supplies a greater amount of oxidizer at positions where the material to be carbonized (W) is less advanced than at positions where the material to be carbonized (W) is more advanced.

[0007] A control method for a carbonization furnace (1A, 1B) according to one embodiment of the present disclosure is a control method for a carbonization furnace (1A, 1B) comprising a container (5) in which a material to be carbonized (W) is accommodated, and oxidizer supply units (7) provided at multiple positions in the container (5) for supplying an oxidizer to the inside of the container (5), wherein the amount of oxidizer supplied by the oxidizer supply unit (7) at a position where the degree of carbonization of the material to be carbonized (W) is less is greater than the amount of oxidizer supplied by the oxidizer supply unit (7) at a position where the degree of carbonization of the material to be carbonized (W) is greater. Effect of the Invention

[0008] It is possible to produce a carbonized product with a carbonized state as uniform as possible. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram showing a carbonization furnace according to a first embodiment of the present disclosure. [Diagram 2] 11 is a graph showing a change in the amount of air supplied from an air supply unit. [Diagram 3] FIG. 4 is a schematic configuration diagram showing a carbonization furnace according to a second embodiment of the present disclosure. [Figure 4] 10 is a graph showing the amount of air supplied from each air supply unit. [Diagram 5] 1 is a graph showing an example of feedback control. [Figure 6] FIG. 11 is a perspective view showing a modified example of the second embodiment. [Figure 7] FIG. 11 is a perspective view showing another modified example of the second embodiment. [Figure 8]FIG. 8 is a side view taken along the line AA in FIG. [Figure 9] FIG. 11 is a perspective view showing another modified example of the second embodiment. [Figure 10] FIG. 10 is a perspective view showing a modified example of FIG. 9.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [First embodiment] The first embodiment of the present disclosure will be described below. A carbonization furnace 1A of the present embodiment is shown in Fig. 1. The carbonization furnace of the present disclosure includes not only a carbonization furnace that produces biochar from a biomass raw material, but also a reactor that produces a biofuel from a biomass raw material that has been carbonized to a lesser extent than biochar.

[0011] The carbonization furnace 1A is fixed to a loading platform 3a of the vehicle 3. The carbonization furnace 1A may be detachable from the loading platform 3a.

[0012] The carbonization furnace 1A includes a container 5 capable of forming an enclosed space, and a feeding hopper 6 provided on the upper portion of the container 5 and feeding a material to be carbonized W, which is a biomass raw material. For example, wood-based material is used as the biomass raw material.

[0013] The container 5 is capable of housing the material to be carbonized W, and includes a drying chamber 5a and a carbonization chamber 5b.

[0014] The drying chamber 5a is provided above the container 5. In the drying chamber 5a, the material W to be carbonized is dried by heat transferred from below. A partition wall 5c is provided between the drying chamber 5a and the carbonization chamber 5b, and the material W to be carbonized is dried while being temporarily stored on the partition wall 5c. A transfer device (not shown) is provided on the partition wall 5c, and the material W to be carbonized after drying is transferred to the carbonization chamber 5b below. In addition, an opening (not shown) may be provided in a part of the partition wall 5c to allow the material W to be carbonized after drying to fall into the carbonization chamber 5b below.

[0015] The carbonization chamber 5b is provided below the drying chamber 5a. In the carbonization chamber 5b, the material W to be carbonized is stacked from the bottom up. An ignition unit (not shown) is provided at the bottom of the carbonization chamber 5b, and carbonization proceeds from the bottom up of the material W to be carbonized stacked in the carbonization chamber 5b.

[0016] The carbonization chamber 5b is kept in an oxygen-deficient state with an air ratio of, for example, about 0.6 to 0.7, whereby partial combustion of the material to be carbonized W is carried out and carbonization progresses.

[0017] The container 5 (carbonization chamber 5b and drying chamber 5a) is provided with a plurality of air supply units (oxidizer supply units) 7. Note that other oxidizers such as water vapor may be used instead of air. A plurality of air supply units 7 are provided at positions in the longitudinal direction x (longitudinal direction of the vehicle 3), width direction y (width direction of the vehicle 3), and height direction z of the container 5. Air is supplied from each of the air supply units 7 to the inside of the container 5. In FIG. 1, the air supply unit 7 at the bottom is indicated by the reference number 7-1, and is distinguished by adding branch numbers such as 7-2 and 7-3 to the upper part. The air supply unit 7 provided in the drying chamber 5a is indicated by the reference number 7-n. Here, n means the nth stage from the bottom. Note that the branch numbering method is the same for the branch pipe 9, the branch adjustment valve 9a, the collecting pipe 11, and the collecting adjustment valve 11a described later.

[0018] The air supply unit 7 is not particularly limited as long as it is configured to supply air into the container 5, but for example, a pipe extending in the y direction (perpendicular to the paper surface) with multiple nozzles formed around it, or a porous pipe made of sintered metal or the like can be used.

[0019] Each air supply unit 7 is connected to a branch pipe 9. Each branch pipe 9 is connected to a collector pipe 11 provided at a respective position in the height direction z. Each collector pipe 11 is connected to a main pipe 13. An air supply source such as a blower (not shown) is provided upstream of the main pipe 13.

[0020] Each branch pipe 9 is provided with a branch adjustment valve 9a that adjusts the air flow rate flowing through the branch pipe 9. Each collecting pipe 11 is provided with a collecting adjustment valve 11a that adjusts the air flow rate flowing through the collecting pipe 11. The main pipe 13 is provided with a main adjustment valve 13a that adjusts the air flow rate supplied to the entire container 5. Note that while Fig. 1 only shows the branch pipe 9 (9-1) and branch adjustment valve 9a (9a-1) connected to the lowest collecting pipe 11 (11-1), the other collecting pipes 11 are also provided with branch pipes 9 and branch adjustment valves 9a.

[0021] The opening degrees of the branch regulating valve 9a, the collective regulating valve 11a, and the main regulating valve 13a are each controlled by a control unit (not shown).

[0022] A temperature sensor (measurement unit) TX and an analysis unit (measurement unit) AT are provided at each position inside the container 5 (carbonization chamber 5b and drying chamber 5a). A plurality of temperature sensors TX and analysis units AT are provided at each position in the longitudinal direction x, width direction y, and height direction z of the container 5. The analysis units AT perform solid component analysis and / or gas component analysis of the carbonized material W. The outputs of the temperature sensor TX and analysis unit AT are transmitted to the control unit, and the control amount is calculated by the calculation unit FX.

[0023] In the analysis section AT, in the case of solid component analysis, the moisture content, carbon, volatile components, etc. of the carbonized material W are analyzed. In the case of gas component analysis, water vapor, carbon monoxide, hydrogen, carbon dioxide, hydrocarbons such as methane, etc. are analyzed.

[0024] The feeding hopper 6 is provided with an analysis section (pre-analysis section) AT that analyzes the solid components of the carbonized material W fed into the feeding hopper 6. The output of the analysis section AT is sent to the control section, and the control amount is calculated in the calculation section FX. The analysis section AT analyzes the moisture content, carbon content, volatile component content, etc. of the carbonized material W.

[0025] A product coal removal section 15 is provided for removing and storing product coal that has been carbonized in the carbonization chamber 5b. The product coal removal section 15 is provided with an analysis section AT that performs solid component analysis of the product coal (carbonized material) W1. The analysis section AT analyzes the carbon content of the product coal W1, etc. The output of the analysis section AT is sent to the control section, and the control amount is calculated in the calculation section FX.

[0026] The control unit is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads this program into the RAM or the like and executes information processing and arithmetic processing to realize various functions. The program may be installed in a ROM or other storage medium in advance, may be provided in a state stored in a computer-readable storage medium, or may be distributed via a wired or wireless communication means. The computer-readable storage medium may be a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

[0027] <Control method of carbonization furnace 1A> Next, a method for controlling the carbonization furnace 1A having the above configuration will be described. First, the material W to be carbonized is charged into the container 5 from the charging hopper 6. At this time, the analysis unit AT provided in the charging hopper 6 performs solid component analysis of the material W to be carbonized, and the calculation unit FX of the control unit calculates the control amount. The calculated control amount is given to the main adjustment valve 13a and / or the collective adjustment valves 11a-n connected to the drying chamber 5a, and feedforward controls FF1 and FF2 are performed. For example, when the moisture content detected by the analysis unit AT provided in the charging hopper 6 is larger than expected, the openings of the main adjustment valve 13a and the collective adjustment valve 11a are controlled to be increased. Alternatively, when the moisture content detected by the analysis unit AT provided in the charging hopper 6 is smaller than expected, the openings of the main adjustment valve 13a and the collective adjustment valve 11a are controlled to be decreased.

[0028] The carbonized material W fed from the feeding hopper 6 into the container 5 is stacked from the bottom of the carbonization chamber 5b of the container 5. When a predetermined amount of carbonized material W is stacked, the carbonized material W located at the bottom of the carbonization chamber 5b is ignited using an ignition unit not shown. At this time, the air ratio in the container 5 is set to an oxygen-deficient state of, for example, about 0.6 to 0.7. As a result, the ignited carbonized material W undergoes partial combustion, and carbonization progresses from the bottom. The combustion heat of the carbonized material W at the bottom is transferred to the carbonized material W above, and carbonization progresses sequentially from the bottom to the top. At this time, each air supply unit 7 increases the amount of air from the lower air supply unit 7-1, then increases the amount of air from the upper air supply unit 7-2, and further increases the amount of air from the upper air supply units 7-3, 7-4, and 7-5 in that order. The amount of air is adjusted by controlling the collective adjustment valve 11a and / or the branch adjustment valve 9a by the control unit. These control valves 11a and 9a are feedback-controlled FB1 based on the control amount calculated by the calculation unit FX of the control unit using the output of the temperature sensor TX and the analysis unit AT provided at each position in the container 5. Specifically, the collective control valve 11a and / or the branch control valve 9a that supplies air to a nearby position are controlled based on the output of the temperature sensor TX and the analysis unit AT provided in the container 5. For example, when the temperature detected by the temperature sensor TX provided in the container 5 is higher than a preset temperature, the opening degree of the collective control valve 11a and / or the branch control valve 9a in the vicinity (for example, below) is controlled to be reduced. Alternatively, when the progress of carbonization calculated based on the analysis unit AT provided in the container 5 reaches a desired value, the opening degree of the collective control valve 11a and / or the branch control valve 9a is controlled to be reduced.

[0029] FIG. 2 shows an example of air volume control. In the figure, the horizontal axis indicates time and the vertical axis indicates air volume. The amount of air supplied from the lower part of the container 5 (solid line) is initially large and then gradually decreased. This is because ignition occurs from the bottom, so carbonization proceeds first from the lower carbonized material W. The timing to decrease the air volume is determined by the degree of carbonization obtained based on the measurement values ​​of the temperature sensor TX and / or the analysis unit AT provided at each position in the container 5 as described above. In other words, when it is determined that the desired carbonization degree is approaching, the air volume is decreased. The dashed lines shown above and below the solid line indicate the control width when feedback control is performed on the set value (solid line).

[0030] The degree of carbonization is determined, for example, based on the change in the degree of carbonization of the carbonized material W. Here, the degree of carbonization means the proportion of fixed carbon in the remaining components, expressed as a weight percentage, after removing moisture and ash from the carbonized material W. Here, the index for determining the degree of carbonization is not limited to the degree of carbonization, and the amount of carbon contained in the carbonized material W may also be used.

[0031] The amount of air (dashed line) supplied from the middle of the container 5 is initially small, and is increased when the amount of air in the lower part decreases, and then is decreased. This means that carbonization of the material W in the middle part proceeds following the lower part.

[0032] The amount of air (two-dot chain line) supplied from the upper stage of the container 5 is initially small, and is increased when the amount of air in the middle stage decreases, and then is decreased. This means that carbonization of the material W to be carbonized in the middle stage proceeds following the middle stage.

[0033] In addition, in the product coal removal section 15, comprehensive feedback controls FB2, FB3 of the main regulating valve 13a and the lowest stage collective regulating valve 11a-1 of the carbonization furnace 1A are performed according to the degree of carbonization obtained from the solid components of the product coal W1 measured in the analysis section AT.

[0034] As carbonization progresses, the combustion heat is transmitted to the drying chamber 5a, and drying in the drying chamber 5a progresses. At this time, feedback control FB4 is performed on the collective control valve 11a-n and the branch control valve 9a-n (not shown) that supply air to the drying chamber 5a based on the output of the temperature sensor TX and / or the analysis unit AT provided near the partition wall 5c. This adjusts the moisture content of the carbonized material W to a desired value before it is supplied to the carbonization chamber 5b.

[0035] Carbonization proceeds through the above steps, and when all of the material W to be carbonized placed in the container 5 finally reaches the desired carbonization degree, the carbonization process ends. After that, the material W to be carbonized is cooled to a temperature at which it will not spontaneously combust even when exposed to air, and then the material W to be carbonized inside the container 5 is taken out as product charcoal W1. In this way, the carbonization furnace 1A performs carbonization as a so-called batch type.

[0036] The effects of the present embodiment described above are as follows. Carbonization proceeds by partially burning the material W to be carbonized with air supplied from the air supply unit 7. By supplying more air to positions where the carbonization degree is low than to positions where the carbonization degree is high, carbonization is carried out as uniformly as possible regardless of position. This allows the production of product charcoal W1 with a uniform carbonization state.

[0037] Carbonization of the material W stacked inside the container 5 progresses from the bottom to the top because the heat of combustion due to partial combustion is transferred from the bottom to the top by natural convection, etc. For this reason, the amount of air supplied to the container 5 is gradually increased from the bottom to the top according to the progress of carbonization of the material W. This allows carbonization to progress uniformly from the bottom to the top.

[0038] When the progress of carbonization reaches a predetermined value, the supply of oxygen is reduced, which prevents the proportion of fixed carbon in the material W to be carbonized from decreasing due to the progress of combustion.

[0039] The degree of carbonization of the material to be carbonized W can be obtained by the analysis part AT and / or the temperature sensor TX provided at each position. Based on this, the air supply part 7 at each position is feedback controlled FB1, FB2, FB3, FB4, so that the degree of carbonization of the material to be carbonized W can be made as uniform as possible.

[0040] Based on the component analysis of the carbonized material W before carbonization, the main regulating valve 13a and the collective regulating valve 11a are subjected to feedforward control FF1, FF2. This allows stable control by setting an appropriate air supply amount.

[0041] In the above-described embodiment, a temperature sensor TX and an analysis unit AT are used, but it is also possible to use only the temperature sensor TX, or only the analysis unit AT that analyzes solid components, or only the analysis unit AT that analyzes gas components, or to use an appropriate combination of these.

[0042] Further, although the drying chamber 5a is provided in the container 5, the drying chamber 5a may be omitted and the material to be carbonized W may be dried in the carbonization chamber 5b.

[0043] [Second embodiment] Next, a second embodiment of the present disclosure will be described. Fig. 3 shows a carbonization furnace 1B according to this embodiment. The carbonization furnace 1A of the first embodiment performs the carbonization process as a batch type, but the carbonization furnace 1B of this embodiment is different in that it performs the carbonization process as a continuous type. Therefore, in the following description, differences from the first embodiment will be mainly described, and the same components will be denoted by the same reference numerals and their description will be omitted.

[0044] As shown in Fig. 3, the carbonization furnace 1B includes a drying chamber 5a and a carbonization chamber 5b as a container 5. The drying chamber 5a and the carbonization chamber 5b are arranged adjacent to each other in the longitudinal direction x. An input hopper 6 is provided at the upper part of the drying chamber 5a.

[0045] A belt conveyor (transport section) 20 is provided extending in the longitudinal direction x between the drying chamber 5a and the carbonization chamber 5b. The belt conveyor 20 includes an endless belt 20a and a plurality of rollers 20b around which the belt 20a is wound. The belt 20a is capable of holding the material to be carbonized W, and is made of a mesh that allows air to flow when it is desired to further promote air flow, for example, a wire mesh. The rollers 20b are rotated by a drive section (not shown), and the rotation speed is controlled by a control section. The belt conveyor 20 is not limited to one as shown in FIG. 3, and a plurality of belt conveyors may be combined in series as long as the material to be carbonized W can be transported from the drying chamber 5a to the carbonization chamber 5b.

[0046] Air is supplied into the container 5 from air supply units 7 (7-1, 7-2, 7-3) provided at multiple positions in the longitudinal direction x. As shown in FIG. 3, air is supplied, for example, from below the belt conveyor 20. Each air supply unit 7 is connected to a branch pipe 9 (9-1, 9-2, 9-3), and each branch pipe 9 is connected to one main pipe 13. Each branch pipe 9 is provided with a branch adjustment valve 9a (9a-1, 9a-2, 9a-3), and the main pipe 13 is provided with a main adjustment valve 13a. The opening degree of the branch adjustment valve 9a and the main adjustment valve 13a is controlled by the control unit.

[0047] 3, multiple air supply units 7 are provided in the longitudinal direction x, but multiple air supply units 7 are also provided in the width direction y. An adjustment valve may be provided so that the amount of air can be adjusted at each position in the width direction y, or a configuration may be adopted in which holes are simply formed in a supply pipe so that the same amount of air flows at each position in the width direction y.

[0048] A temperature sensor TX and an analysis part AT are provided at each position inside the container 5 (the carbonization chamber 5b and the drying chamber 5a). The temperature sensor TX and the analysis part AT may be provided not only in the longitudinal direction x of the container 5 but also in the width direction y and the height direction z.

[0049] In the analysis section AT, in the case of solid component analysis, the moisture content, carbon, volatile components, etc. of the carbonized material W are quantitatively analyzed. In the case of gas component analysis, water vapor, carbon monoxide, hydrogen, carbon dioxide, hydrocarbons such as methane, etc. are quantitatively analyzed.

[0050] The feeding hopper 6 is provided with an analysis section (pre-analysis section) AT that analyzes the solid components of the material to be carbonized W fed into the feeding hopper 6.

[0051] There is provided a product coal removal section 15 which removes and stores the carbonized product coal from the carbonization chamber 5b. The product coal removal section 15 is provided with an analysis section AT which performs solid component analysis of the product coal (carbonized material) W1.

[0052] <Control method of carbonization furnace 1B> Next, a method for controlling the carbonization furnace 1B having the above-mentioned configuration will be described. First, the material W to be carbonized before drying is charged from the charging hopper 6 into the drying chamber 5a of the container 5. At this time, the analysis unit AT provided in the charging hopper 6 performs solid component analysis of the material W to be carbonized, and the calculation unit FX of the control unit calculates the control amount. The calculated control amount is given to the main adjustment valve 13a and / or the branch adjustment valve 9a-1 connected to the drying chamber 5a, and feedforward controls FF1 and FF2 are performed. For example, when the moisture content detected by the analysis unit AT provided in the charging hopper 6 is larger than expected, the openings of the main adjustment valve 13a and the branch adjustment valve 9a-1 are controlled to be increased. Alternatively, when the moisture content detected by the analysis unit AT provided in the charging hopper 6 is smaller than expected, the openings of the main adjustment valve 13a and the branch adjustment valve 9a-1 are controlled to be decreased.

[0053] Feedback control FB1 is performed on the branch adjustment valve 9a-1 based on the analysis unit AT and the temperature sensor TX located between the outlet of the drying chamber 5a and the inlet of the carbonization chamber 5b. This is to feed back the dryness state at the outlet of the drying chamber 5a to the branch adjustment valve 9a-1.

[0054] The material W to be carbonized fed from the feeding hopper 6 into the drying chamber 5a is transported to the carbonization chamber 5b in a stacked state on the belt conveyor 20. In the drying chamber 5a, drying is performed by air supplied from the air supply unit 7-1 and heat generated by an oxidation reaction of the material W by the air during transport. In addition, when the drying chamber 5a and the carbonization chamber 5b are not thermally insulated from each other, drying is performed by heat transferred from the carbonization chamber 5b.

[0055] When the material W to be carbonized is introduced into the carbonization chamber 5b, the material W is ignited and partial combustion is performed under oxygen deficiency. Ignition is performed using an ignition unit (not shown) at the beginning of startup, but after startup, ignition is performed without using an ignition unit depending on the temperature in the carbonization chamber 5b that has reached the ignition temperature. The air ratio in the carbonization chamber 5b is set to, for example, about 0.6 to 0.7. The material W to be carbonized progresses as it is transported by the belt conveyor 20. At this time, air amounts according to the progress of carbonization are supplied from the air supply units 7-2 and 7-3. The air amount is adjusted by controlling the branch adjustment valves 9a-2 and 9a-3 by the control unit.

[0056] The branch adjustment valve 9a-2 provided on the upstream side of the carbonization chamber 5b is feedback controlled FB2 based on a control amount calculated by the calculation unit FX of the control unit based on the output of the temperature sensor TX and the analysis unit AT provided immediately downstream (on the right side in FIG. 3) of the branch adjustment valve 9a-2. For example, when the temperature detected by the temperature sensor TX is higher than a preset temperature (set value), the opening of the branch adjustment valve 9a-2 on the upstream side is controlled to decrease. Alternatively, when the degree of carbonization calculated based on the analysis unit AT reaches a desired value (set value), the opening of the branch adjustment valve 9a-2 is controlled to decrease.

[0057] The branch adjustment valve 9a-3 provided downstream of the carbonization chamber 5b performs feedback control FB3 according to the carbonization degree obtained from the solid components of the product coal W1 measured by the analysis part AT in the product coal unloading part 15. The carbonization degree obtained from the solid components of the product coal W1 measured by the analysis part AT in the product coal unloading part 15 is also used for feedback control FB4 of the main adjustment valve 13a.

[0058] In addition, one or more air supply units 7 (branch adjustment valve 9a) may be provided between the air supply unit 7-2 (branch adjustment valve 9a-2) and the air supply unit 7-3 (branch adjustment valve 9a-3). This makes it possible to more accurately control the degree of carbonization of the material W to be carbonized while it is being transported by the belt conveyor 20.

[0059] An example of air volume control is shown in FIG. 4. In the figure, the horizontal axis indicates the position in the longitudinal direction x, and the vertical axis indicates the air volume. The air volume (solid line) is increased on the upstream side of the container 5, and the air volume is gradually decreased toward the downstream side. This is because carbonization is less advanced on the upstream side. The position at which the air volume is decreased is determined by the progress of carbonization obtained based on the measurement values ​​of the temperature sensor TX and / or the analysis unit AT, as described above. In other words, when it is determined that the desired carbonization degree is approached, the air volume on the upstream side of the temperature sensor TX and / or the analysis unit AT is decreased.

[0060] The dashed lines shown above and below the solid line, which is the set value, indicate the control width when feedback control is performed. For example, as shown in Fig. 5, when the measured value (marked with an x) of O2 (oxygen) deviates from the control target value (set value: solid line), a correction amount corresponding to the deviation is instructed to the branch adjustment valve 9a immediately upstream to perform feedback control. Note that, although Fig. 5 shows O2 as an example of the measurement target, feedback control is performed in the same way even for other measurement targets.

[0061] Carbonization proceeds through the above steps, and the product coal W1 is taken out from the most downstream position of the belt conveyor 20. When taking out the product coal W1, the product coal W1 is cooled to a temperature at which it will not spontaneously combust even when exposed to air. In this way, carbonization is performed continuously in the carbonization furnace 1B of this embodiment.

[0062] The above-described operational effects of this embodiment are as follows in addition to the operational effects of the first embodiment. Inside the container 5, the material W to be carbonized is transported from the upstream side to the downstream side by the belt conveyor 20. Air is supplied to the material W to be carbonized while it is being transported, and the material W is partially burned and carbonized. The amount of air supplied is gradually reduced from the upstream side to the downstream side of the belt conveyor depending on the degree of carbonization of the material W to be carbonized. This allows the carbonization of the material W to be transported to proceed uniformly.

[0063] The degree of carbonization of the material W to be carbonized can be obtained by the analysis unit AT or the temperature sensor TX provided at each position in the traveling direction of the belt conveyor 20. Based on this, the branch adjustment valve 9a immediately upstream of each position is feedback controlled, so that the degree of carbonization of the material W to be carbonized can be made as uniform as possible.

[0064] <Variation 2-1> In this embodiment, the material W to be carbonized is transported by the belt conveyor 20, but as shown in FIG. 6, a screw feeder (transport unit) 22 may be used. The screw feeder 22 includes a rotating shaft 22a having an axis extending in the longitudinal direction x, and a spiral blade 22b attached to the rotating shaft 22a. The rotating shaft 22a is rotated by a drive unit (not shown). The rotation speed of the rotating shaft 22a may be variable and is controlled by a control unit.

[0065] The material to be carbonized W before drying is input from an input hopper 6 and is transported from the upstream side to the downstream side by a screw feeder 22. When the material to be carbonized W is transported by the screw feeder 22, the control unit controls the branch adjustment valve 9a based on the measurement value of the analysis unit AT and / or the temperature sensor TX to adjust the amount of air from the air supply unit 7 in the same manner as in the second embodiment described above.

[0066] <Variation 2-2> In the above-described second embodiment, the air supply unit 7 is configured to blow air from the bottom of the container 5, but the following modifications can be made. As shown in Fig. 7 and Fig. 8, an air supply unit 27 may be employed. The air supply unit 27 is box-shaped, erected in the height direction z, and extending in the longitudinal direction x. In this modification, the air supply units 27 are arranged in parallel at a predetermined interval in the width direction y. The length of the air supply unit 27 in the longitudinal direction x is from a position corresponding to the input hopper 6 to a midway position of the belt conveyor 20. The position of the downstream end of the air supply unit 27 is determined according to the expected degree of progress of carbonization.

[0067] The air supply section 27 is trapezoidal when viewed from the side as shown in Fig. 8, and the upper end 27a, the lower end 27b, and the inclined end 27c are closed. The inclination angle α (see Fig. 8) of the inclined end 27c is set to an angle equivalent to, for example, the angle of repose of the material to be carbonized W. The angle of repose is determined according to the physical properties of the material to be carbonized W, such as viscosity and grain size.

[0068] 7, the left upstream end 27d is opened and serves as an air inlet port 27e through which air is supplied from the air supply chamber 29. A plurality of discharge holes 27g are formed in the side surfaces 27f on both sides of the air supply section 27. Air to be supplied into the container 5 is discharged from the air supply chamber 29 through the air inlet port 27e and each discharge hole 27g.

[0069] Each discharge hole 27g is provided so that the total opening area at each position in the longitudinal direction x becomes gradually smaller from the upstream side (left side) to the downstream side (right side), that is, the total opening area at each position in the longitudinal direction x becomes gradually larger from the downstream side to the upstream side. The total opening area is adjusted by the number of each discharge hole 27g, the area of ​​each discharge hole 27g, the arrangement density of the discharge holes 27g, etc. As a result, the amount of air supplied into the container 5 becomes gradually smaller from the upstream side to the downstream side. For example, the set value (solid line) of the amount of air shown in FIG. 4 is obtained in advance, and the total opening area of ​​the discharge holes 27g at each position in the longitudinal direction x is set to correspond to this amount of air.

[0070] According to this modified example, the following advantageous effects are achieved. By making the total opening area of ​​the outlet holes 27g of the air supply section 27 provided on the upstream side larger than the total opening area of ​​the outlet holes 27g on the downstream side, more air can be supplied to the upstream side, where carbonization has progressed less than on the downstream side, thereby making it possible to make the carbonization progress uniform.

[0071] By setting in advance the total opening area of ​​the discharge holes 27g at each position in the longitudinal direction x to correspond to the amount of air required for carbonization, carbonization can be performed without using the control by the branch adjustment valve 9a described in embodiment 2.

[0072] When the material W to be carbonized is supplied from the input hopper 6 to the belt conveyor 20, it is transported toward the downstream side of the belt conveyor 20 at a height corresponding to the angle of repose of the material W to be carbonized. Therefore, the angle α of the inclined end 27c is set according to the angle of repose of the material W to be carbonized, and the height at which air is supplied from the discharge hole 27g is set according to the angle of repose. This makes it possible to uniformly supply air to the material W to be carbonized stacked on the belt conveyor 20.

[0073] <Modification 2-3> Moreover, the above-mentioned modified example 2-2 can be modified as follows. As shown in Fig. 9, a plurality of air discharge pipes 38 are used as the air supply unit 37. The air discharge pipes 38 are, for example, metal pipes having a circular cross section, and have a plurality of discharge holes 38a formed on the outer periphery. Note that the air discharge pipes 38 may be formed using porous ceramic or porous sintered metal instead of providing the discharge holes 38a.

[0074] Each air discharge pipe 38 is provided with an axis in the width direction y. Both ends of each air discharge pipe 38 are open, and each is connected to an air supply chamber 39. The air supply chambers 39 are provided on both sides of the container 5 in the width direction y.

[0075] The air discharge pipes 38 are provided at a predetermined interval in the longitudinal direction x, and at each longitudinal direction x, a plurality of air discharge pipes 38 are provided at a predetermined interval in the height direction z. The uppermost air discharge pipe 38 at each position in the longitudinal direction x is positioned lower toward the downstream side, and the inclination angle is set to be, for example, the angle of repose of the material W to be carbonized.

[0076] The amount of air supplied from the air discharge pipe 38 at each position in the longitudinal direction x is set to gradually decrease from the upstream side to the downstream side. For example, the set value of the air amount (solid line) shown in Fig. 4 is obtained in advance, and the total opening area of ​​the air discharge pipe 38 at each position in the longitudinal direction x is set to correspond to this air amount. This makes it possible to perform carbonization without using the control by the branch adjustment valve 9a described in the second embodiment.

[0077] 10, the air discharge pipes 38 at each position in the longitudinal direction x may be connected to branch pipes 9, and the amount of air may be individually controlled by branch adjustment valves 9a provided in each branch pipe 9. This makes it possible to individually control the amount of air by combining feedforward and feedback from the temperature sensor TX and analysis unit AT shown in FIG.

[0078] The carbonization furnace and the control method thereof described in each of the above-described embodiments can be understood, for example, as follows.

[0079] The carbonization furnace (1A, 1B) according to the first aspect of the present disclosure comprises a container (5) in which a material to be carbonized (W) is accommodated, and oxidizer supply units (7) provided at multiple positions in the container (5) for supplying an oxidizer to the inside of the container (5), and the oxidizer supply unit (7) supplies a greater amount of oxidizer at positions where the carbonization of the material to be carbonized (W) is less advanced than at positions where the carbonization of the material to be carbonized (W) is more advanced.

[0080] Carbonization proceeds by partially burning the material to be carbonized with the oxidizing agent supplied from the oxidizing agent supply unit. By supplying more oxidizing agent to positions where the carbonization progresses less than positions where the carbonization progresses more, carbonization is carried out as uniformly as possible regardless of position. This allows the production of carbonized material with a uniform carbonization state. As the oxidizing agent, air is typically used, but water vapor can also be used.

[0081] The carbonization furnace (1A) according to the second aspect of the present disclosure, in the first aspect, is provided with a control unit that controls the flow rate of the oxidizer supplied from each of the oxidizer supply units (7), and the control unit sequentially increases the supply amount of the oxidizer from the bottom to the top of the container (W) depending on the degree of carbonization of the material to be carbonized (W) stacked inside the container (5).

[0082] The carbonization of the materials stacked inside the container progresses from bottom to top because the heat of partial combustion is transferred from bottom to top by natural convection, etc. For this reason, the supply amount of oxidizing agent is gradually increased from bottom to top of the container according to the progress of carbonization of the materials. This allows the carbonization to progress uniformly from bottom to top.

[0083] In the carbonization furnace (1A) according to a third aspect of the present disclosure, in the second aspect, the control unit reduces the supply amount of the oxidizing agent after the degree of progress of carbonization reaches a predetermined value.

[0084] When the carbonization progresses to a predetermined value, the supply amount of the oxidizing agent is reduced, which makes it possible to prevent a decrease in the fixed carbon ratio of the carbonized material due to the progress of combustion.

[0085] The carbonization furnace (1B) according to the fourth aspect of the present disclosure, in the first aspect, includes a conveying section (20) that conveys the material to be carbonized (W) inside the container (5) from the inlet side to the outlet side of the container (5), and a control section that controls the flow rate of the oxidizer supplied from each of the oxidizer supply sections (7), and the control section sequentially reduces the amount of oxidizer supplied from the inlet side to the outlet side of the conveying section (20) depending on the degree of carbonization of the material to be carbonized (W) conveyed by the conveying section (20).

[0086] Inside the container, the material to be carbonized is transported from the inlet side to the outlet side by a transport section. An oxidizing agent is supplied to the material to be carbonized while it is being transported, causing partial combustion and carbonization. The amount of oxidizing agent supplied is gradually reduced from the inlet side to the outlet side of the transport section depending on the degree of carbonization of the material to be carbonized. This allows the carbonization of the material to be transported to proceed uniformly.

[0087] The carbonization furnace (1B) according to the fifth aspect of the present disclosure, in the first aspect, is provided with a transport section (20) that transports the material to be carbonized (W) inside the container (5) from the inlet side to the outlet side of the container (5), and the oxidizer supply section (7) is provided at a plurality of positions between the inlet side and the outlet side, and the opening area through which the oxidizer is supplied from the oxidizer supply section (7) provided on the inlet side is larger than the opening area through which the oxidizer is supplied from the oxidizer supply section (7) provided on the outlet side.

[0088] By making the opening area of ​​the oxidant supply section provided on the inlet side larger than the opening area of ​​the oxidant supply section on the outlet side, more oxidant can be supplied to the inlet side, where carbonization has progressed less than the outlet side, thereby allowing carbonization to proceed uniformly. When a plurality of openings are formed, the area of ​​the openings through which the oxidant is supplied can be adjusted by the size of each opening or the number of openings.

[0089] In the carbonization furnace (1B) of the sixth aspect of the present disclosure, in the fifth aspect, the oxidizer supply section (7) has a height at which the oxidizer is supplied set according to a predetermined angle represented by the angle of repose of the material to be carbonized (W) formed from the supply position of the material to be carbonized (W) toward the outlet side.

[0090] When the material to be carbonized is supplied from the supply position to the conveying section, it is conveyed toward the outlet side of the conveying section at a height according to a predetermined angle represented by the angle of repose of the material to be carbonized. Therefore, the height at which the oxidizer is supplied is set according to the predetermined angle represented by the angle of repose of the material to be carbonized. This makes it possible to uniformly supply the oxidizer to the material to be carbonized stacked on the conveying path.

[0091] The carbonization furnace (1A, 1B) according to the seventh aspect of the present disclosure, in any one of the first to sixth aspects, is provided with a control unit that controls the flow rate of the oxidizer supplied from each of the oxidizer supply units (7), and at multiple positions of the container (5), measurement units such as a solid analysis unit (AT) that performs component analysis of the carbonized material and / or a gas analysis unit (AT) that performs component analysis of the gas and / or a temperature sensor (TX) that measures temperature are provided, and the control unit controls the oxidizer supply unit (7) at each position based on the results of the measurement units.

[0092] The degree of carbonization of the material to be carbonized can be obtained by the measuring unit provided at each position. Based on this, the oxidizer supply unit at each position is feedback controlled, so that the degree of carbonization of the material to be carbonized can be made as uniform as possible.

[0093] The carbonization furnace (1A, 1B) according to an eighth aspect of the present disclosure, in any one of the first to seventh aspects, includes a control unit that controls the flow rate of the oxidant supplied from each of the oxidant supply units (7) and a pre-analysis unit (AT) that performs a component analysis of the material to be carbonized before carbonization, and the control unit controls the oxidant supply unit (7) based on the results of the pre-analysis unit (AT).

[0094] The oxidizer supply unit is feed-forward controlled based on the composition analysis of the material to be carbonized before carbonization. This allows stable control by setting the appropriate amount of oxidizer to be supplied.

[0095] The carbonization furnace (1A, 1B) according to a ninth aspect of the present disclosure in any one of the first to eighth aspects can be attached to a vehicle.

[0096] A control method for a carbonization furnace (1A, 1B) according to a first aspect of the present disclosure is a control method for a carbonization furnace (1A, 1B) comprising a container (5) in which a material to be carbonized (W) is accommodated, and oxidizer supply units (7) provided at multiple positions in the container (5) and supplying an oxidizer to the inside of the container (5), wherein the amount of oxidizer supplied by the oxidizer supply unit (7) at a position where the carbonization of the material to be carbonized (W) is less advanced is greater than the amount of oxidizer supplied by the oxidizer supply unit (7) at a position where the carbonization of the material to be carbonized (W) is more advanced. [Explanation of symbols]

[0097] 1A,1B Carbonization furnace 3. Vehicle 3a Cargo bed 5 containers 5a Drying room 5b Carbonization chamber 5c Partition wall 6 Input hopper 7 Air supply section 9 Branch Pipe 9a Branch control valve 11 Collecting pipe 11a Collective adjustment valve 13 Master 13a Main regulating valve 15 Product charcoal removal section 20 Belt conveyor (transport section) 20a Belt 20b Lola 22 Screw feeder (conveying section) 22a Rotation axis 22b Feather 27 Air supply section 27a top end 27b Bottom end 27c sloped end 27d Upstream end 27e Air inlet 27f side 27g discharge hole 37 Air supply section 38 Air discharge pipe 38a Discharge hole 39 Air Supply Room AT Analysis Section (Measurement Section, Solid Analysis Section, Gas Analysis Section, Pre-Analysis Section) FX calculation section TX Temperature sensor (measurement part) W Carbide W1 Product carbon (carbide)

Claims

1. A container for accommodating the material to be carbonized; an oxidant supply unit provided at a plurality of positions in the container and supplying an oxidant to the inside of the container; Equipped with A carbonization furnace in which the oxidizer supplying portion at a position where the carbonization of the material to be carbonized is less supplies a larger amount of oxidizer than the oxidizer supplying portion at a position where the carbonization of the material to be carbonized is more advanced.

2. a control unit for controlling a flow rate of the oxidant supplied from each of the oxidant supply units, The carbonization furnace according to claim 1 , wherein the control unit gradually increases the amount of oxidizing agent supplied from the bottom to the top of the container depending on the degree of carbonization of the material to be carbonized stacked inside the container.

3. The carbonization furnace according to claim 2 , wherein the control unit reduces the amount of oxidizing agent supplied after the degree of carbonization reaches a predetermined value.

4. a conveying section that conveys the material to be carbonized from an inlet side to an outlet side of the container inside the container; A control unit for controlling a flow rate of the oxidant supplied from each of the oxidant supply units; Equipped with The carbonization furnace according to claim 1 , wherein the control unit gradually reduces the amount of oxidant supplied from the inlet side to the outlet side of the transporting section depending on the degree of carbonization of the carbonized material transported by the transporting section.

5. a conveying unit that conveys the material to be carbonized from an inlet side to an outlet side of the container inside the container, The oxidant supply unit is provided at a plurality of positions between the inlet side and the outlet side, The carbonization furnace according to claim 1 , wherein an opening area through which the oxidant is supplied from the oxidant supply section provided on the inlet side is larger than an opening area through which the oxidant is supplied from the oxidant supply section provided on the outlet side.

6. A carbonization furnace as described in claim 5, wherein the oxidizer supply section has a height at which the oxidizer is supplied set according to a predetermined angle represented by the angle of repose of the material to be carbonized formed from the supply position of the material to be carbonized toward the outlet side.

7. a control unit for controlling a flow rate of the oxidant supplied from each of the oxidant supply units, At a plurality of positions of the container, a solid analysis unit that performs component analysis of the carbonized material, and / or a gas analysis unit that performs component analysis of the gas, and / or a temperature sensor that performs temperature measurement are provided as measurement units, The carbonization furnace according to claim 1 , wherein the control unit controls the oxidizing agent supply unit at each position based on the result of the measurement unit.

8. A control unit for controlling a flow rate of the oxidant supplied from each of the oxidant supply units; a pre-analysis section for performing a component analysis of the material to be carbonized before carbonization; Equipped with The carbonization furnace according to claim 1 , wherein the control unit controls the oxidizing agent supply unit based on a result of the pre-analysis unit.

9. 2. The carbonization furnace according to claim 1, which is mountable on a vehicle.

10. A container for accommodating the material to be carbonized; an oxidant supply unit provided at a plurality of positions in the container and supplying an oxidant to the inside of the container; A method for controlling a carbonization furnace comprising: A method for controlling a carbonization furnace, in which the oxidizer supplying section at a position where the carbonization of the material to be carbonized is less supplies a larger amount of oxidizer than the oxidizer supplying section at a position where the carbonization of the material to be carbonized is more advanced.

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