JP7496341B2 - Carbide processing device and carbide processing method - Google Patents

Description

The present invention relates to a carbide processing device and a carbide processing method.

Organic waste such as sewage sludge is carbonized, for example by heating, and reused as fuel. The carbonized organic waste obtained in this way has highly active surface functional groups on its particle surface immediately after carbonization, and is known to have self-heating properties (see, for example, Patent Document 1). Therefore, in order to ensure safety during storage, a process is carried out to reduce the self-heating properties (so-called aging process, hereinafter sometimes simply referred to as "carbonization process") (see, for example, Patent Documents 1 and 2).

Patent Document 1 describes a method for treating charcoal obtained by carbonizing organic matter-containing sludge generated during wastewater treatment in a carbonization furnace. In this treatment method, the charcoal obtained by carbonization is oxidized in a low-temperature oxidizing atmosphere, thereby converging the surface oxidation reaction of the charcoal in advance. This prevents the stored charcoal from inducing combustion due to self-heating caused by the low-temperature oxidation reaction.

Patent Document 2 describes a carbonization furnace that carbonizes woody biomass under oxygen deficiency, a storage hopper that stores the carbonized material produced in the carbonization furnace, and a carbonized material transport system having a cooling means that transports the carbonized material discharged from the carbonization furnace to the storage hopper while cooling it under oxygen deficiency. The carbonized material storage and transport device is provided for the purpose of enabling the carbonized material to be transported without igniting in carbonization processing and utilizing the carbonized material as pulverized coal. In this carbonized material storage and transport device, as an example of a usable storage hopper, one that is configured to include a partition wall provided inside the storage tank of the storage hopper, two partition spaces formed by the partition wall, a discharge conveyor that discharges the carbonized material in each partition space in a forward and reverse direction, a flow path switching means that switches the flow path of the carbonized material provided in the space formed on the partition wall, and an inert gas injection means that is configured to be able to inject an inert gas is given as an example of a storage hopper that can be used.

JP 2004-267950 A JP 2009-079118 A

As such, even in conventional technology, there have been efforts to improve the safety of carbide through carbide processing, and to improve safety during carbide processing. However, there is still a demand for improved safety when processing carbide.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a carbide processing device and a carbide processing method that improve the safety of carbide processing.

A characteristic configuration of a carbide treatment apparatus according to the present invention for achieving the above object includes a storage unit for storing self-heating carbide by depositing it in layers, an aeration unit for supplying a curing gas containing oxygen to the storage unit, and a control unit for controlling the aeration amount of the curing gas, wherein the storage unit has a first storage tank for storing the carbide and a second storage tank for storing the carbide discharged from the first storage tank, the aeration unit supplies gas exhausted from the first storage tank to the second storage tank , and the control unit controls the aeration amount of the gas supplied to the second storage tank based on the oxygen consumption characteristic of the carbide discharged from the first storage tank .

According to the above configuration, in the storage section, for example, particulate carbide is deposited in layers to form a deposition layer, and the ventilation section supplies a curing gas, which is a gas containing oxygen, to the storage section, thereby allowing the curing gas to be ventilated into the deposition layer. This allows for a carbide treatment that oxidizes highly active surface functional groups on the surfaces of the carbide particles and reduces self-heating properties. During the carbide treatment, the carbide generates heat due to oxidation, but is cooled by the ventilation of the curing gas.

According to the above configuration, the storage section has a first storage tank and a second storage tank, and the second storage tank is connected in series downstream of the first storage tank to store the carbonized material discharged from the first storage tank in the second storage tank. This makes it possible to reduce the amount of storage (retention) per storage tank when performing carbonized material processing for a specified period of time. In addition, the carbonized material stored in the second storage tank can be made safer with reduced self-heating tendency than the carbonized material stored in the first storage tank. As a result, it becomes possible to perform more careful safety management of the first storage tank, thereby achieving both a reduction in the burden on safety management of the entire carbonized material processing apparatus and an improvement in safety.

According to the above configuration, the carbide treatment in the second storage tank can be promoted. The carbide stored in the second storage tank has a lower self-heating tendency than the carbide stored in the first storage tank. Therefore, there are cases where the temperature of the carbide in the second storage tank cannot be maintained at a sufficiently high temperature to properly proceed with the carbide treatment. On the other hand, the carbide stored in the first storage tank has a high self-heating tendency, so the temperature of the exhaust gas from the first storage tank becomes high. Therefore, by supplying the exhaust gas whose temperature has increased by passing through the first storage tank to the second storage tank by mixing it with the curing gas supplied to the second storage tank, the temperature of the carbide in the second storage tank can be maintained at a temperature appropriate for promoting the carbide treatment, and the carbide treatment in the second storage tank can be promoted to improve the treatment efficiency of the carbide treatment.
According to the above configuration, the control unit controls the amount of gas supplied to the second storage tank based on the oxygen consumption characteristic of the carbonized material discharged from the first storage tank. As a result, for example, when the self-heating property of the carbonized material discharged from the first storage tank is still high (high oxygen consumption characteristic), increasing the amount of gas supplied to the second storage tank increases the amount of heat carried away by the gas, so that the carbonized material can be prevented from igniting while promoting the carbonized material treatment in the second storage tank. On the other hand, even when the self-heating property of the carbonized material discharged from the first storage tank is low (low oxygen consumption characteristic) and the carbonized material supplied to the second storage tank is cooled too much, decreasing the amount of gas supplied to the second storage tank reduces the amount of heat carried away by the gas, so that the temperature of the carbonized material in the second storage tank can be maintained at a temperature appropriate for promoting the carbonized material treatment, and the carbonized material treatment in the second storage tank can be promoted to improve the treatment efficiency.

A further characteristic feature of the carbonized material treatment device according to the present invention is that it further includes a cooling section between the first storage tank and the second storage tank, capable of cooling the carbonized material discharged from the first storage tank.

According to the above configuration, even if the self-heating tendency of the charcoal discharged from the first storage tank is still high, by feeding the charcoal cooled in the cooling section into the second storage tank, the charcoal stored in the second storage tank can be made safer with reduced self-heating tendency than the charcoal stored in the first storage tank.

A further characteristic configuration of the carbide treatment device according to the present invention is that it comprises a storage section that accumulates and stores carbide having self-heating properties in layers, and an aeration section that supplies a curing gas containing oxygen to the storage section, wherein the storage section has a first storage tank that stores the carbide and a second storage tank that stores the carbide discharged from the first storage tank, the first storage tank has a first main body section that accommodates the carbide and a first outlet that discharges the carbide from the first main body section, the second storage tank has a second main body section that accommodates the carbide and a second outlet that discharges the carbide from the second main body section, a flow path cross-sectional area of the first outlet is larger than a flow path cross-sectional area of the second outlet, and the aeration section supplies gas exhausted from the first storage tank to the second storage tank .

According to the above configuration, by making the flow cross-sectional area of the first outlet larger than the flow cross-sectional area of the second outlet, the flow of carbide passing through the first main body part of the first storage tank can be made relatively more homogeneous than the flow of carbide passing through the second main body part of the second storage tank. Here, homogeneous means that the residence time distribution is small. In other words, homogeneous means that the flow is closer to a plug flow. On the other hand, for the second storage tank, it is possible to miniaturize the discharge device such as a rotary valve provided at the second outlet with a small flow cross-sectional area, and it can be made less expensive than the first storage tank.

As mentioned above, the charcoal stored in the first storage tank has a greater tendency to self-heat than the charcoal stored in the second storage tank. Therefore, if a short path occurs in the first main body and charcoal that has not been subjected to the expected degree of charcoal processing in the first storage tank is supplied to the second storage tank, this can cause problems such as unintended localized heat generation in the second storage tank or charcoal with insufficiently reduced self-heating being discharged from the second storage tank. However, this problem can be avoided by making the flow of charcoal passing through the first main body uniform.

Conversely, since the carbonized material stored in the second storage tank has a low self-heating property, even if some short path occurs, it will not cause heat generation in the equipment downstream of the second storage tank. Therefore, the flow path cross-sectional area of the second discharge outlet for the second storage tank can be made small, thereby reducing the cost of the equipment. In this way, the cross-sectional area of each discharge outlet can be adjusted according to the self-heating property of the carbonized material stored in each storage tank, and an appropriate balance can be achieved between the quality (reliability) of the carbonized material processing and the cost of the equipment.

The carbide processing method of the present invention for achieving the above-mentioned object includes a storage step in which carbide having self-heating properties is deposited in layers and stored, and an aeration step in which a curing gas containing oxygen is passed through the carbide deposition layer during the storage step, the storage step including a first storage step in which the carbide is stored for a first predetermined period, and a second storage step in which the carbide that has been through the first storage step is stored for a second predetermined period, and the aeration step is characterized in that the gas discharged through the first storage step, and the gas whose aeration amount is controlled based on the oxygen consumption characteristics of the carbide that has been through the first storage step, is used in the second storage step.
Furthermore, a further characteristic configuration of the carbide processing method according to the present invention includes a storage step of depositing and storing carbide having self-heating properties in layers, and an aeration step of passing a curing gas containing oxygen through the carbide deposition layer during the storage step, the storage step including a first storage step of storing the carbide in a first storage tank for a first predetermined period, and a second storage step of storing the carbide discharged from a first outlet of the first storage tank after the first storage step in a second storage tank for a second predetermined period, the first outlet having a flow path cross-sectional area larger than the flow path cross-sectional area of a second outlet from which the carbide is discharged in the second storage tank, and the aeration step uses the gas discharged after the first storage step in the second storage step.

The above method can achieve the same effects as the above-mentioned carbide treatment device.

It is possible to provide a carbide processing device and method that performs processing to reduce the self-heating properties of carbides while appropriately controlling the self-heating during processing.

Diagram of the organic sludge recycling system Illustrative diagram of the first storage tank Illustrative diagram of the second storage tank FIG. 1 is an explanatory diagram showing a modified example of an organic sludge recycling system.

The following describes a carbide processing device and a carbide processing method according to an embodiment of the present invention, based on the drawings.

[Explanation of overall configuration]
1 shows an organic sludge recycling system 200 including a carbonized material treatment apparatus 100 according to this embodiment. The organic sludge recycling system 200 realizes recycling of organic sludge, such as sewage sludge, as fuel.

The organic sludge recycling system 200 includes a carbonization furnace 10 that carbonizes dried sludge L, which is made by drying and granulating sewage sludge in advance, a cooling device 11 that cools the carbonized material M carbonized in the carbonization furnace 10, a secondary combustion furnace 12 that burns the combustible gas generated in the carbonization furnace 10, an exhaust gas treatment facility 13 that purifies the exhaust gas generated in the secondary combustion furnace 12 by deodorizing and collecting dust, a carbonized material treatment device 100 that performs a process to reduce the self-heating property of the carbonized material M (so-called aging process or low-temperature oxidation process, hereinafter referred to as "carbonized material treatment") to obtain recycled fuel F, and a stock tank 19 that stores the recycled fuel F in preparation for shipment.

The dried sludge L is granulated into cylindrical pellets, for example by extrusion granulation, in order to obtain the desired particle properties, such as particle shape and bulk density, of the recycled fuel F, and to improve handling during carbonization processing, etc.

The transportation of the carbide M between each device (e.g., from the cooling device 11 to the carbide processing device 100) can be performed using an appropriate transport mechanism, such as a flight conveyor or a transport mechanism that uses gravity.

The carbonized material M or recycled fuel F is transported in the following order: carbonization furnace 10, cooling device 11, carbonized material processing device 100, and stock tank 19. Hereinafter, the upstream and downstream sides of the transport path of the carbonized material M or recycled fuel F will be referred to simply as "upstream" or "upstream side" and "downstream" or "downstream side", respectively.

The carbonization furnace 10 is a device that heats the dried sludge L in a low-oxygen atmosphere to obtain the carbonized material M. The carbonization furnace 10 is, for example, a rotary kiln, a fluidized bed type, or a screw type heating device. The carbonization furnace 10 heats the dried sludge L at a temperature of about 250°C to 600°C to carbonize it. After being discharged from the carbonization furnace 10, the carbonized material M is transported to the downstream cooling device 11 via a transport mechanism such as a chute and cooled. In the cooling device 11, the carbonized material M is cooled by spraying and supplying cooling water. An inert gas such as nitrogen is supplied to the chute and the cooling device 11 from downstream to upstream to prevent the carbonized material M from igniting. The carbonized material M cooled in the cooling device 11 is transported to the downstream carbonized material processing device 100 by a flight conveyor or the like. The carbonized material M is carbonized in the carbonized material processing device 100 and transported to the downstream stock tank 19 by a flight conveyor or the like as recycled fuel F. The recycled fuel F is stored in a stock tank 19 in preparation for shipment.

[Explanation of Carbide Treatment Apparatus]
[Overall configuration of carbide treatment device]
The following is a detailed description of the carbide processing device 100. The carbide processing device 100 is a device that processes the carbide M to obtain recycled fuel F, as described above.

The carbonized material processing apparatus 100 will now be described in detail. As shown in FIG. 1, the carbonized material processing apparatus 100 includes a storage section H for storing carbonized material M and performing carbonization processing, a ventilation section K for supplying oxygen-containing curing gases G1 and G2 to the storage section H, sensors S11, S12, S21, and S22 constituting an oxygen concentration measuring section for measuring the oxygen consumption of the storage section H, and air flow meters U1 and U2 for detecting the ventilation rates of the curing gases G1 and G2, and a control section 9 having a CPU for controlling the operation of the storage section H and the ventilation section K, and a storage device for storing programs and parameters for implementing the control of the CPU.

The storage section H includes a first storage tank 4 that stores the charcoal M supplied from the upstream side (cooling device 11) of the charcoal processing device 100 and performs charcoal processing, and a second storage tank 6 that stores the charcoal M discharged from the first storage tank 4 and subsequently performs charcoal processing to obtain recycled fuel F. Details of the first storage tank 4 and the second storage tank 6 will be described later.

[Control Unit]
The control unit 9 includes an aeration control unit 91 that controls the aeration unit K, and a retention time control unit 92 that controls the retention time of the carbide M in the first storage tank 4 and the second storage tank 6. The operation of the aeration control unit 91 and the retention time control unit 92 will be described together with the explanation of the aeration unit K, the first storage tank 4, and the second storage tank 6.

[Ventilation section]
The ventilation section K includes a first blower 31 such as a fan or a blower for ventilating (for example, blowing) the curing gas G1 into the first storage tank 4, a second blower 32 such as a fan or a blower for ventilating (for example, blowing) the curing gas G2 into the second storage tank 6, and valves 51 to 56 provided on piping such as an air pipe connected to the first blower 31, the first storage tank 4, the second blower 32, and the second storage tank 6. The valves 51 to 56 are adjustable aperture valves such as butterfly valves. The first blower 31, the second blower 32, and the valves 51 to 56 have their rotation speeds and apertures adjusted based on, for example, an operation command from an aeration control section 91 of the control section 9, thereby adjusting the ventilation amounts of the curing gases G1, G2 in the first storage tank 4 and the second storage tank 6. Hereinafter, the curing gas G1 exhausted from the first storage tank 4 will be referred to as exhaust gas E1, and the curing gas G2 exhausted from the second storage tank 6 will be referred to as exhaust gas E2.

The curing gases G1 and G2 are gases containing oxygen for carbonizing the carbide M. The curing gases G1 and G2 also contribute to cooling the carbide M heated by the reaction heat generated by the carbonizing process. The oxygen concentration of the curing gases G1 and G2 is adjusted to be lower than the oxygen concentration in air in order to slow down the rate of the oxidation reaction of the carbide M in the first storage tank 4 and the second storage tank 6 and to avoid ignition. The curing gases G1 and G2 are adjusted to have a lower oxygen concentration than air by mixing air with a low-oxygen gas (for example, nitrogen gas or exhaust gas E1 or exhaust gas E2, exhaust gas E1 in this embodiment).

The exhaust gases E1 and E2 are exhaust gases from the first storage tank 4 and the second storage tank 6. In the first storage tank 4 and the second storage tank 6, the oxygen contained in the curing gases G1 and G2 is consumed by the carbonization process. Therefore, the oxygen concentration of the exhaust gas E1 is less than the oxygen concentration of the curing gas G1. Also, the oxygen concentration of the exhaust gas E2 is less than the oxygen concentration of the curing gas G2.

As described below, the first blower 31 draws in outside air A and exhaust gas E2, mixes them, and blows them to the first storage tank 4 as curing gas G1. The amount of outside air A drawn in by the first blower 31 is controlled by adjusting the opening of a valve 55 provided on an intake pipe whose one end is connected to the first blower 31 and whose other end is open to the outside. The outside air A and exhaust gas E2 drawn in by the first blower 31 are cooled or humidified with water (atomized water) or the like as necessary. In this embodiment, the curing gas G1, or the outside air A and exhaust gas E2 drawn in by the first blower 31 may be cooled so that the temperature of the curing gas G1 is 40°C or less. The outside air A and exhaust gas E2 drawn in by the first blower 31 may be humidified with water (atomized water) or the like as necessary.

The valve 51 is provided in the blower pipe between the first blower 31 and the first storage tank 4, and the flow rate of the curing gas G1 blown from the first blower 31 to the first storage tank 4 is controlled by adjusting the opening degree of the valve 51.

The valve 53 is provided in an exhaust pipe that exhausts the exhaust gas E1 from the first storage tank 4, and the internal pressure of the first storage tank 4 is controlled to a positive pressure by adjusting the opening degree of the valve 53. The exhaust pipe downstream of the valve 53 is connected to the outside, and the exhaust gas E1 can be released to the outside.

As described below, the second blower 32 draws in outside air A and, if necessary, exhaust gas E1, mixes them, and blows them to the second storage tank 6 as the curing gas G2. The amount of exhaust gas E1 drawn in by the second blower 32 is controlled by adjusting the opening of a valve 56 provided in a bypass pipe whose one end is connected to an intake pipe through which the second blower 32 draws in outside air A and whose other end is connected downstream of a valve 53. In this embodiment, the curing gas G2, or the outside air A or exhaust gas E1 drawn in by the second blower 32 may be cooled so that the temperature of the curing gas G2 is 40°C or less. In addition, the outside air A or exhaust gas E1 drawn in by the second blower 32 may be humidified with water (atomized water) or the like, if necessary. An opening adjustment valve may be provided in the intake pipe, one end of which is connected between the valve 56 and the second blower 32 and the other end of which is open to the outside, to control the amount of outside air A taken in by the second blower 32. Also, in the exhaust pipe that exhausts the exhaust gas E1 from the first storage tank 4, an opening adjustment valve may be provided in the exhaust line that exhausts the exhaust gas E1 to the outside of the system after branching into a bypass pipe connected downstream of the valve 53.

The valve 52 is provided in the blower pipe between the second blower 32 and the second storage tank 6, and the flow rate of the curing gas G2 ventilated from the second blower 32 to the second storage tank 6 is controlled by adjusting the opening degree of the valve 52.

The valve 54 is provided in an exhaust pipe that exhausts the exhaust gas E2 from the second storage tank 6, and the internal pressure of the second storage tank 6 is controlled to a positive pressure by adjusting the opening degree. The exhaust pipe downstream of the valve 54 is connected to the outside, and the exhaust gas E2 can be discharged to the outside. The above-mentioned first blower 31 draws in the exhaust gas E2 from the downstream side of the valve 54, but a bypass pipe whose one end is connected to the intake pipe through which the first blower 31 draws in the outside air A and whose other end is connected to the downstream side of the valve 54 may be provided with an opening degree adjustment valve that controls the intake amount of the exhaust gas E2 by the first blower 31. In addition, in the exhaust pipe that exhausts the exhaust gas E2 from the second storage tank 6, after branching into the bypass pipe connected to the downstream side of the valve 54, an opening degree adjustment valve may be provided in the exhaust line that discharges the exhaust gas E2 outside the system.

[Oxygen concentration measurement section]
The sensor S11 is provided in a blower pipe between the valve 51 and the first storage tank 4 and detects the oxygen concentration of the curing gas G1. The sensor S12 is provided in an exhaust pipe between the first storage tank 4 and the valve 53 and detects the oxygen concentration of the exhaust gas E1. The ventilation control unit 91 controls the ventilation amount of the curing gas G2 supplied to the second storage tank 6, as described below, based on the oxygen concentrations (concentration difference in this embodiment) detected by the sensors S11 and S12 or the oxygen consumption characteristic of the intermediate N discharged from the first storage tank 4, which is calculated or measured by sampling the intermediate N.

Sensor S21 is provided in the air supply pipe between valve 52 and second storage tank 6, and detects the oxygen concentration of curing gas G2. Sensor S22 is provided in the exhaust pipe between second storage tank 6 and valve 54, and detects the oxygen concentration of exhaust gas E2. Based on the oxygen concentrations (concentration difference in this embodiment) detected by sensors S21 and S22, the residence time control unit 92 may determine a target residence time for second storage tank 6, as described below.

[Air volume meter]
The airflow meters U1 and U2 are devices for measuring the amount of ventilation, including a pitot tube (total static pressure tube) and a hot wire anemometer. The airflow meter U1 is provided in the airflow pipe between the valve 51 and the first storage tank 4, and detects the amount of ventilation of the curing gas G1. The airflow meter U2 is provided in the airflow pipe between the valve 52 and the second storage tank 6, and detects the amount of ventilation of the curing gas G2.

[Storage section]
[First storage tank]
2, the first storage tank 4 is a storage vessel that stores the carbide M by stacking it in layers (an example of a storage step, an example of a first storage step). "Stacked in layers" refers to a state in which the carbide M supplied from the upstream side is sequentially deposited in the first storage tank 4, and the carbide M is stored as a stationary layer.

The first storage tank 4 is a metal (e.g., iron alloy such as stainless steel) container with a tank body 40 (an example of a first main body portion) having a circular cross section, and comprising an upper container 41 with a top plate at its upper end and a cylindrical body portion, and a lower container 42 that is connected to the lower part of the upper container 41 and has a mortar shape that narrows slightly towards the lower end. The first storage tank 4 also includes a supply unit 43 that introduces (supplies) the carbide M into the tank from the top of the upper container 41 while the atmosphere inside the tank body 40 is separated from the outside atmosphere, a discharge unit 44 that discharges (supplies to the downstream side) the carbide M from the lower part (lower end in this embodiment) of the upper container 41 while the atmosphere inside the tank body 40 is separated from the outside atmosphere, an air supply unit 48 that is connected to the valve 51 and introduces the curing gas G1 into the tank body 40 from the lower end (an example of a first exhaust port) of the lower container 42 (an example of an aeration step), and an exhaust unit 49 that is connected to the valve 53 and has an opening that exhausts the exhaust gas E1 inside the tank body 40 from the upper part (top plate in this embodiment) of the upper container 41. Hereinafter, the carbide M stored in layers in the tank body 40 of the first storage tank 4 may be simply referred to as a sedimentary layer B1.

In FIG. 2, the diameter of the horizontal cross section of the upper container 41 is indicated as diameter D11, and the diameter of the horizontal cross section of the lower end of the lower container 42 is indicated as diameter D12. It is preferable that the diameter D12 is 40% or more and less than 100% of the diameter D11.

The supply unit 43 is a powder supply device that is a fixed quantity supply mechanism for powder, such as a rotary valve, and has a function of isolating the atmosphere before and after. The supply unit 43 is provided on the top plate of the upper container 41, and supplies the carbonized material M supplied from the upstream side into the tank from the top of the tank body 40. As a result, the carbonized material M is stacked in layers inside the tank body 40. The supply unit 43 may be provided with a buffer tank upstream of the rotary valve for temporarily storing the carbonized material M supplied from the upstream side of the first storage tank 4.

The discharge section 44 is a powder discharge (supply) device such as a rotary valve or table feeder having a larger diameter in horizontal cross section than that of the supply section 43. The discharge section 44 cuts out the carbide M from the lower part of the sedimentary layer B1 while maintaining the layer state of the sedimentary layer B1 as much as possible, discharges it from the tank body 40, and supplies it to the downstream side. In this embodiment, the casing 44a of the discharge section 44 is cylindrical and has the same diameter D12 overall. In order for the discharge section 44 to cut out the carbide M from the lower part of the sedimentary layer B1 while maintaining the layer state of the sedimentary layer B1 as much as possible and discharge it from the tank body 40, it is preferable that the diameter D12 is set as large as possible. Hereinafter, the carbide M discharged from the tank body 40 is particularly referred to as the intermediate body N. The intermediate body N is transported to the second storage tank 6 (see Figures 1 and 3) by, for example, gravity drop or transport by a flight conveyor.

The gas supply section 48 has, for example, a short pipe that connects from the lower end of the lower container 42 to the inside of the tank body 40, and supplies the curing gas G1 to the lower end of the sedimentary layer B1 by introducing the curing gas G1 into the tank body 40. The curing gas G1 passes through the sedimentary layer B1 and is released from the upper end of the sedimentary layer B1 into the upper space in the tank body 40. As the curing gas G1 passes through the sedimentary layer B1, it comes into solid-gas contact with the carbide M and oxidizes surface functional groups on the particle surface. The curing gas G1 released into the upper space in the tank body 40 is exhausted from the exhaust section 49 to the outside of the tank body 40 as exhaust gas E1.

In this embodiment, a temperature sensor T1 that measures the temperature of the sedimentary layer B1 is provided on the side of the tank body 40. The temperature sensor T1 is installed so that it is at least possible to detect the temperature of the hottest location (the temperature of the carbonized material M) inside the tank body 40 (sedimentary layer B1).

In this embodiment, the ventilation control unit 91 adjusts the oxygen concentration (oxygen concentration detected by sensor S11) and supply amount of the curing gas G1 based on the oxygen concentration detected by sensor S12 so that the oxygen contained in the curing gas G1 is within a predetermined range (e.g., 17% by volume to 19% by volume). This predetermined range is set so that oxygen remains in the exhaust gas E1 so that the oxidation reaction proceeds slowly even in the upper part of the sedimentary layer B1.

The carbide M stored in the first storage tank 4 is flammable and has a higher self-heating tendency than the carbide M stored in the second storage tank 6 (see FIG. 1) described later, so it is important to manage the temperature of the carbide M and the oxygen concentration of the curing gas G1. If the temperature of the sedimentary layer B1 (carbide M) becomes too high, the risk of ignition increases. Even if the oxygen concentration of the curing gas G1 becomes high, the amount of heat generated by the carbide treatment increases, and as a result, the temperature of the carbide M may rise and cause a risk of ignition. On the other hand, if the temperature of the sedimentary layer B1 becomes low, the reaction rate of the carbide treatment decreases, which is uneconomical. Therefore, the ventilation control unit 91 appropriately adjusts the oxygen concentration, temperature, and supply amount of the curing gas G1 as described later.

[Second storage tank]
As shown in FIG. 3, the second storage tank 6 is a storage container that stores the carbonized material M in layers (an example of a storage step, an example of a second storage step), similar to the first storage tank 4.

The second storage tank 6 is a container made of metal (e.g., an iron alloy such as stainless steel) with a tank body 60 (an example of a second main body portion) having a circular cross section, and comprising an upper container 61 with a top plate at its upper end and a cylindrical body portion, and a lower container 62 that is connected to the lower part of the upper container 61 and has a cone-shaped configuration that narrows towards the lower end. The second storage tank 6 also includes a supply section 63 that introduces (supplies) the carbide M as the intermediate N into the tank from the top of the upper container 61 while the atmosphere inside the tank body 60 is separated from the outside atmosphere, a discharge section 64 that discharges (supplies to the downstream side) the carbide M that has become the recycled fuel F from the lower part (the lower end in this embodiment) of the upper container 61 while the atmosphere inside the tank body 60 is separated from the outside atmosphere, an air supply section 68 that is connected to the valve 52 and introduces the curing gas G2 into the tank body 60 from the lower end (an example of a second exhaust port) of the lower container 62 (an example of an aeration step), and an exhaust section 69 that is connected to the valve 54 and has an opening that exhausts the exhaust gas E1 inside the tank body 60 from the upper part (the top plate in this embodiment) of the upper container 61. Hereinafter, the carbide M stored in layers in the tank body 60 of the second storage tank 6 may be simply referred to as the sedimentary layer B2.

In FIG. 3, the diameter of the horizontal cross section of the upper container 61 is indicated as diameter D21, and the diameter of the horizontal cross section of the lower end of the lower container 62 is indicated as diameter D22. Diameter D22 should be 20% or more and less than 40% of diameter D21. In this way, the initial cost of the second storage tank 6 can be reduced. In this embodiment, diameter D22 may be smaller than diameter D12. In other words, the flow path cross-sectional area (horizontal cross-sectional area) of the lower end of the lower container 42 is larger than the flow path cross-sectional area (horizontal cross-sectional area) of the lower end of the lower container 62. In this way, the initial cost of the second storage tank 6 can be reduced compared to that of the first storage tank 4.

In this embodiment, the tank height of the tank body 60 of the second storage tank 6 is equal to the tank height of the tank body 40 of the first storage tank 4 (see FIG. 2). In this embodiment, the diameter D21 of the upper container 61 of the second storage tank 6 is equal to the diameter D11 of the upper container 41 of the first storage tank 4. In this way, the device design can be standardized and the manufacturing cost of the tank bodies 40, 60 can be reduced. The diameter D21 of the upper container 61 of the second storage tank 6 and the diameter D11 of the upper container 41 of the first storage tank 4 may be different. In this case, by making D12/D11>D22/D21, the flow of the carbonized material M passing through the first storage tank 4 can be made relatively more homogeneous than the flow of the intermediate N (carbonized material M) passing through the second storage tank 6.

The supply unit 63 is, for example, a powder supply device having a rotary valve. The supply unit 63 is provided on the top plate of the upper container 61, and supplies the intermediate body N supplied from the upstream side into the tank from the top of the tank body 60. As a result, the intermediate body N is stacked in layers inside the tank body 40. The supply unit 63 may be provided with a buffer tank upstream of the rotary valve for temporarily storing the carbonized material M supplied from the upstream side of the second storage tank 6. Also, the supply unit 63 may be omitted, and the discharge unit 44 of the first storage tank 4 may also serve as the supply unit 63 for the second storage tank 6.

The discharge section 64 is a powder discharge (supply) device, such as a rotary valve with a horizontal cross-sectional diameter slightly larger than that of the supply section 63, or a table feeder smaller than that suitable for the supply section 43. The discharge section 64 cuts out recycled fuel F from the lower part of the sedimentary layer B2 while maintaining the layer state of the sedimentary layer B2 to some extent, discharges it from the tank body 60, and supplies it to the downstream side. In this embodiment, the casing 64a of the discharge section 64 is cylindrical and has the same overall diameter D22. The recycled fuel F falls freely onto the conveyor of, for example, a flight conveyor, and is transported by the flight conveyor to the stock tank 19 (see FIG. 1) and stored therein.

The gas supply section 68 has, for example, a short pipe that connects from the lower end portion of the lower container 62 to the inside of the tank body 60, and supplies the curing gas G2 to the lower end of the sedimentary layer B2 by introducing the curing gas G2 into the tank body 60. The curing gas G2 passes through the sedimentary layer B2 and is released from the upper end of the sedimentary layer B2 into the upper space in the tank body 60. As the curing gas G2 passes through the sedimentary layer B2, it comes into solid-gas contact with the intermediate N and oxidizes surface functional groups on the particle surface. The curing gas G2 released into the upper space in the tank body 60 is exhausted from the exhaust section 69 to the outside of the tank body 60 as exhaust gas E2.

In this embodiment, a temperature sensor T2 that measures the temperature of the deposition layer B2 is provided on the side of the tank body 60. The temperature sensor T2 is installed so that it is at least possible to detect the temperature of the hottest location (the temperature of the intermediate body N) inside the tank body 60 (the deposition layer B2).

In this embodiment, the ventilation control unit 91 adjusts the oxygen concentration (oxygen concentration detected by sensor S21) and supply amount of the curing gas G2 based on the oxygen concentration detected by sensor S22 so that the oxygen contained in the curing gas G2 is not consumed completely in the deposition layer B2. Here, the condition that oxygen is not consumed completely in the deposition layer B2 means that the oxygen concentration detected by sensor S22 is 1 volume % or more, and refers to leaving a certain amount of oxygen in the exhaust gas E so that the oxidation reaction proceeds even in the upper part of the deposition layer B2. As a result, the exhaust gas E2 has a relatively high proportion of nitrogen and carbon dioxide compared to air, and is a gas with reduced activity against the oxidation reaction.

The intermediate N (carbonized material M) stored in the second storage tank 6 is ignitable and still has a higher self-heating property than the recycled fuel F, so as in the case of the first storage tank 4, it is important to manage the temperature of the carbonized material M and the oxygen concentration of the curing gas G2. However, the intermediate N has a lower self-heating property than the carbonized material M stored in the first storage tank 4. Therefore, compared to the case of the first storage tank 4, the risk of the temperature of the sedimentary layer B2 becoming high and causing the risk of ignition is reduced. Therefore, in the case of the second storage tank 6, even if the oxygen concentration of the curing gas G2 becomes high (for example, due to insufficient cooling action by the curing gas G2 described later), the temperature of the carbonized material M does not usually become high and cause the risk of ignition, and rather, it is important to control the temperature of the sedimentary layer B2 so that it does not become too low in order to avoid a decrease in the reaction rate of the carbonized material treatment. Therefore, the ventilation control unit 91 appropriately adjusts the oxygen concentration, temperature, and supply amount of the curing gas G2 as described later.

[Control Unit]
[Ventilation control section]
As shown in FIG. 1, the ventilation control unit 91 is a functional unit that controls the ventilation unit K to control the oxygen concentration, temperature, and supply amount of the curing gases G1, G2 based on the oxygen concentration detected by the sensors S12, S22 and the temperatures of the deposition layers B1, B2 detected by the temperature sensors T1, T2.

The ventilation control unit 91 controls the oxygen concentration of the curing gas G1 so that the oxygen concentration of the exhaust gas E1, i.e., the oxygen concentration detected by the sensor S12, is between 1% and 3% by volume.

When the oxygen concentration detected by the sensor S12 decreases and approaches 1 volume % and it becomes necessary to increase the oxygen concentration of the curing gas G1, the ventilation control unit 91 increases the opening of the valve 55 and increases the mixing ratio of outside air A to the exhaust gas E2. When the oxygen concentration detected by the sensor S12 increases and approaches 3 volume % and it becomes necessary to decrease the oxygen concentration of the curing gas G1, the ventilation control unit 91 decreases the opening of the valve 55 and decreases the mixing ratio of outside air A to the exhaust gas E2.

The ventilation control unit 91 controls the supply amount and temperature of the curing gas G1 so that the temperature of the deposition layer B1, i.e., the temperature detected by the temperature sensor T1, is greater than or equal to 40°C and less than 60°C.

When the temperature detected by the temperature sensor T1 rises and approaches 60°C, the ventilation control unit 91 increases the opening of the valve 51 to increase the supply of the curing gas G1 and cool the sedimentary layer B1. This prevents ignition of the carbide M. When the temperature detected by the temperature sensor T1 falls and approaches 40°C, the ventilation control unit 91 decreases the opening of the valve 51 to reduce the supply of the curing gas G1 and prevent cooling of the sedimentary layer B1. This prevents a decrease in the reaction rate of the carbide treatment.

The ventilation control unit 91 controls the oxygen concentration of the curing gas G2 so that the oxygen concentration of the exhaust gas E2, i.e., the oxygen concentration detected by the sensor S22, is 1% by volume or more.

When the oxygen concentration detected by the sensor S22 decreases to below a predetermined range (e.g., below 17% by volume) and the oxygen concentration of the curing gas G2 is increased, the ventilation control unit 91 reduces the opening of the valve 56 and increases the mixing ratio of outside air A to the exhaust gas E1.

The ventilation control unit 91 controls the supply amount and temperature of the curing gas G2 so that the temperature detected by the temperature sensor T2 is 40°C or higher and less than 60°C. In order to prevent the intermediate body N being carbonized in the second storage tank 6 from being cooled too much, it is preferable that the ventilation amount of the curing gas G2 supplied to the second storage tank 6 is less than the ventilation amount of the curing gas G1 supplied to the first storage tank 4.

When the temperature detected by the temperature sensor T2 rises and approaches 60°C, the ventilation control unit 91 reduces the opening of the valve 56 and increases the mixing ratio of outside air A to the exhaust gas E1, thereby lowering the temperature of the curing gas G2 and increasing the oxygen concentration, thereby preventing/promoting a decrease in the reaction rate of the carbonization treatment while cooling the sedimentary layer B2. When the valve 56 is fully closed, the opening of the valve 52 is increased to increase the supply of the curing gas G2 and cool the sedimentary layer B2.

When the temperature detected by the temperature sensor T2 drops away from 60°C and approaches 40°C, the ventilation control unit 91 reduces the opening of the valve 52 to reduce the supply of the curing gas G2, thereby preventing the sediment layer B2 from cooling. This prevents a decrease in the reaction rate of the carbide treatment.

Here, the oxygen consumption characteristic will be described. The oxygen consumption characteristic is the mass of oxygen consumed per unit time by the carbide M (intermediate N) per unit mass. The oxygen consumption characteristic means the degree of activity (activity of oxidation by oxygen) of the intermediate N cured in the first storage tank 4 and discharged in the second storage tank 6. The higher the oxygen consumption characteristic, the more the intermediate N generates heat in an oxygen-containing atmosphere, and the greater the risk of fire. Therefore, in order to use the intermediate N as the recycled fuel F, it is required to reduce the oxygen consumption characteristic to a specified value (e.g., 5 mgO ₂ /g/day) or less. The oxygen consumption characteristic can be obtained from the mass of the carbide M (intermediate N), the amount of oxygen supplied to the first storage tank 4, and the amount of oxygen discharged from the first storage tank 4. Alternatively, the intermediate N discharged from the first storage tank 4 can be sampled and directly measured. In this embodiment, the oxygen consumption characteristic can be calculated as a value proportional to a value obtained by multiplying the difference in concentration, obtained by subtracting the oxygen concentration contained in the exhaust gas E1 discharged from the first storage tank 4, from the oxygen concentration contained in the curing gas G1 supplied to the first storage tank 4, by the ventilation speed, which is the ventilation volume of the curing gas G1 per unit time. The oxygen concentrations measured by the sensors S12 and S22 may be used as the oxygen concentrations contained in the curing gas G1 supplied to the first storage tank 4 and the oxygen concentrations contained in the exhaust gas E1 discharged from the first storage tank 4. For example, the oxygen consumption characteristic of the intermediate N cured in the first storage tank 4 and discharged can be calculated as a value proportional to a value obtained by multiplying the difference between the oxygen concentration measured by the sensor S11 and the oxygen concentration measured by the sensor S12 by the ventilation volume (ventilation speed) of the curing gas G1 detected by the air flow meter U1. In addition, in this embodiment, the intermediate N discharged from the first storage tank 4 can be sampled and stored in a sealed container for a predetermined time (e.g., one hour), and the oxygen consumption characteristic of the intermediate N can be measured after the predetermined time has elapsed. Hereinafter, the oxygen consumption characteristic and a value proportional to the oxygen consumption characteristic may be collectively referred to simply as the "oxygen characteristic value".

The ventilation control unit 91 in this embodiment controls the ventilation amount of the curing gas G2 supplied to the second storage tank 6 based on the oxygen consumption characteristics of the intermediate body N (an example of a carbonized material) discharged from the first storage tank 4. When the oxygen characteristic value of the intermediate body N is greater than a predetermined value or the reduction amount of the oxygen characteristic value of the intermediate body N is less than a predetermined reduction threshold (a target reduction amount of the oxygen characteristic value in the carbonized material M cured in the first storage tank 4), the ventilation control unit 91 increases the opening of the valve 52 for the curing gas G2 and/or increases the driving force of the second blower 32 to increase the supply amount of the curing gas G2, increase the amount of heat carried away by the curing gas G2, and prevent ignition of the sedimentary layer B2 while promoting the carbonized material treatment in the second storage tank 6. On the other hand, when the oxygen characteristic value of the intermediate N is equal to or lower than a predetermined value or when the reduction amount of the oxygen characteristic value of the intermediate N is greater than a predetermined reduction threshold, the ventilation control unit 91 maintains or reduces the opening degree of the valve 52 for the curing gas G2 and/or the driving force of the second blower 32, thereby performing the carbonization treatment of the sedimentary layer B2 in the second storage tank 6. As a result, even if the intermediate N supplied to the second storage tank 6 is cooled too much, the amount of heat carried away by the curing gas G2 is reduced by reducing the ventilation rate of the curing gas G2 supplied to the second storage tank 6, so that the temperature of the sedimentary layer B2 in the second storage tank 6 can be maintained at a temperature appropriate for promoting the carbonization treatment, and the carbonization treatment in the second storage tank 6 can be promoted to improve the treatment efficiency. In addition, it is difficult to set the oxygen characteristic value of the recycled fuel F to a specified value suitable for shipment using a curing process in one storage tank, but by obtaining an intermediate N through the curing process in the first storage tank 4 and controlling the curing process in the second storage tank 6 based on the oxygen characteristic value (or the amount of reduction in the oxygen characteristic value) of the intermediate N, the oxygen characteristic value of the recycled fuel F can be set to a specified value suitable for shipment. Note that the predetermined value or reduction threshold value that serves as the judgment threshold is set in advance taking into account the specifications of the second storage tank 6 so that the oxygen characteristic value of the recycled fuel F produced by curing the intermediate N in the second storage tank 6 is set to a specified value suitable for shipment.

As shown in FIG. 4, when the oxygen characteristic value of the intermediate N is greater than a predetermined value or when the reduction amount of the oxygen characteristic value of the intermediate N is less than a predetermined reduction threshold, a cooling section 20 capable of cooling the intermediate N (an example of a carbide) discharged from the first storage tank 4 may be provided between the first storage tank 4 and the second storage tank 6 in order to prevent ignition of the intermediate N discharged from the first storage tank 4. In this cooling section 20, the intermediate N is cooled by spraying and supplying cooling water, for example. In the figure, the cooling section 20 is provided in the path connecting the first storage tank 4 and the second storage tank 6, but "between the first storage tank 4 and the second storage tank 6" includes providing the cooling section 20 in the first storage tank 4 and/or the second storage tank 6. If the cooling section 20 is provided in the first storage tank 4 and the second storage tank 6, even if there is a risk of ignition in either the first storage tank 4 or the second storage tank 6 and the moisture content of the carbide M (intermediate N) increases in the cooling section 20, making it unshippable, recycled fuel F can be produced using the carbide M (intermediate N) cured in the other of the first storage tank 4 and the second storage tank 6. In addition, by referring to the operating conditions when there is a risk of ignition in either the first storage tank 4 or the second storage tank 6, the operating conditions of the other of the first storage tank 4 and the second storage tank 6 can be changed to produce good recycled fuel F.

As shown in FIG. 4, by providing a cooling section 20 between the first storage tank 4 and the second storage tank 6 that can cool the carbide M (intermediate N) discharged from the first storage tank 4, even if the self-heating tendency of the intermediate N discharged from the first storage tank 4 is still high, the intermediate N cooled in the cooling section 20 can be introduced into the second storage tank 6, making the intermediate N stored in the second storage tank 6 safer and with a lower self-heating tendency than the carbide M stored in the first storage tank 4.

[Residence Time Control Unit]
The residence time control unit 92 is a functional unit that controls the supply or discharge speeds of the supply unit 43, the discharge unit 44, the supply unit 63, and the discharge unit 64, thereby controlling the residence time of the carbonized material M in the first storage tank 4 and the second storage tank 6.

The residence time control unit 92 normally operates the supply unit 43 and the supply unit 63 at a predetermined supply speed. When the amount of carbonized material M retained in the first storage tank 4 or the second storage tank 6 exceeds a predetermined value (e.g., 90% of the tank capacity), the residence time control unit 92 slows down the supply speed of the supply unit 43 or the supply unit 63 or stops the supply.

The retention time control unit 92 typically operates the discharge unit 44 at a predetermined discharge speed so that the retention time of the carbonized material M in the first storage tank 4 is maintained at a predetermined value (e.g., 1.5 days). The retention time control unit 92 may increase or decrease the discharge speed of the discharge unit 44 so that the retention amount in the first storage tank 4 is maintained at a predetermined value (e.g., 70% to 80% of the tank capacity).

The residence time control unit 92 first operates the discharge unit 64 at a predetermined discharge speed so that the residence time of the carbonized material M in the second storage tank 6 is maintained at a specified value (e.g., 1.5 days, hereinafter sometimes referred to as the "default residence time").

The residence time control unit 92 controls the discharge speed of the discharge unit 64 based on the oxygen concentrations of the curing gas G1 and the exhaust gas E1 detected by the sensors S11 and S12, and the ventilation volume of the curing gas G1 detected by the air flow meter U1.

The retention time control unit 92 performs the following control when the physical properties of the carbonized material M supplied from the cooling device 11 to the carbonized material processing device 100 are constant (for example, when the dried sludge L used as the raw material is from the same lot).

If the oxygen characteristic value of the intermediate N discharged from the first storage tank 4 is equal to or less than a predetermined value, the residence time control unit 92 determines that the carbonization process in the first storage tank 4 has progressed beyond a predetermined target value. Based on the determination result, the residence time control unit 92 increases the discharge speed of the discharge unit 64 so that the residence time of the carbonization M in the second storage tank 6 is shorter than the default residence time. This is because if the carbonization process in the first storage tank 4 has progressed sufficiently, it is possible to obtain recycled fuel F with reduced self-heating properties to a desired degree even if the residence time in the second storage tank 6 is shortened. This is also to reduce the amount of carbonization in the second storage tank 6 in preparation for the case in which the residence time of the carbonization M in the second storage tank 6 is extended as described below.

As a result, in this embodiment, the residence time control unit 92 increases the discharge rate of the discharge unit 64 when the oxygen consumption characteristics of the intermediate N discharged from the first storage tank 4 become smaller.

If the oxygen characteristic value of the intermediate N discharged from the first storage tank 4 is greater than a predetermined value, the residence time control unit 92 determines that the carbonization process in the first storage tank 4 has not progressed beyond a predetermined target value. Then, the discharge speed of the discharge unit 64 is reduced so that the residence time of the carbonization material M in the second storage tank 6 becomes longer than the default residence time. If the carbonization process in the first storage tank 4 has not progressed sufficiently, the residence time in the second storage tank 6 can be lengthened to advance the carbonization process, thereby obtaining recycled fuel F with reduced self-heating properties to the desired degree.

As a result, in this embodiment, the residence time control unit 92 reduces the discharge rate of the discharge unit 64 more when the oxygen consumption characteristics of the intermediate N discharged from the first storage tank 4 become greater.

As in the case of the first storage tank 4, the retention time control unit 92 may increase or decrease the discharge speed of the discharge unit 64 so that the retention volume of the second storage tank 6 is maintained at a predetermined value (for example, 70% to 80% of the tank capacity).

In this way, it is possible to provide a carbide processing device and a carbide processing method that improve the safety of carbide processing.

[Another embodiment]
(1) In the above embodiment, the first blower 31 draws in the outside air A and the exhaust gas E2 and blows the intake air as the curing gas G1 to the first storage tank 4. However, there are cases where the first blower 31 does not draw in the exhaust gas E2. In these cases, the exhaust gas E2 may not be mixed with the curing gas G1, or the first blower 31 may draw in the exhaust gas E1 or draw in an inert gas such as nitrogen instead of the exhaust gas E2.

(2) In the above embodiment, the second blower 32 draws in outside air A and exhaust gas E1, and blows it to the second storage tank 6 as the curing gas G2. However, there are cases where the second blower 32 does not draw in the exhaust gas E1. In this case, the exhaust gas E1 may not be mixed with the curing gas G2, or the second blower 32 may draw in the exhaust gas E2 or an inert gas such as nitrogen instead of the exhaust gas E1.

(3) In the above embodiment, the residence time control unit 92 controls the discharge speed of the discharge unit 64 based on the oxygen concentrations of the curing gas G1 and the exhaust gas E1 detected by the sensors S11 and S12 and the ventilation volume of the curing gas G1 detected by the air flow meter U1. However, such control of the discharge speed of the discharge unit 64 is not essential.

(4) In the above embodiment, the residence time control unit 92 controls the discharge speed of the discharge unit 64 based on the oxygen consumption characteristics of the intermediate N discharged from the first storage tank 4, and the discharge unit 44 is operated at a predetermined supply speed. However, in addition to controlling the discharge speed of the discharge unit 64 of the second storage tank 6, the discharge speed of the discharge unit 44 of the first storage tank 4 may also be controlled. The residence time control unit 92 may also control the discharge speed of the discharge unit 44 in the first storage tank 4 based on the oxygen consumption characteristics of the intermediate N.

For example, the residence time control unit 92 may increase the discharge speed of the discharge unit 44 of the first storage tank 4 if the oxygen characteristic value of the intermediate N is equal to or less than a predetermined value, and may decrease the discharge speed of the discharge unit 44 of the first storage tank 4 if the oxygen characteristic value of the intermediate N is greater than the predetermined value. In this way, the overall processing efficiency (processing capacity) of the carbonization processing device 100 can be improved.

(5) In the above embodiment, when the physical properties of the carbonized material M supplied from the cooling device 11 to the carbonized material processing device 100 are constant (for example, the dried sludge L used as the raw material is the same lot), the retention time control unit 92 increases the discharge rate of the discharge section 64 of the second storage tank 6 if the oxygen consumption characteristics of the intermediate N become smaller, and decreases the discharge rate of the discharge section 64 if the oxygen consumption characteristics of the intermediate N become larger.

In contrast, when the physical properties of the carbonized material M supplied from the cooling device 11 to the carbonized material processing device 100 are not constant (for example, when the physical properties of the dried sludge L used as the raw material are unknown or it is known in advance that there is a large variation in the physical properties), the retention time control unit 92 may control the discharge speed of the discharge section 64 of the second storage tank 6 as follows to ensure that the self-heating amount of the recycled fuel F is the desired value.

If the oxygen characteristic value of the intermediate N is greater than or equal to a predetermined value, the residence time control unit 92 may further reduce the discharge rate of the discharge unit 64 of the second storage tank 6 in order to lengthen the residence time in the second storage tank 6. If the oxygen consumption characteristic of the intermediate N is large, it is also assumed that the initial self-heating amount of the charcoal M supplied from the cooling device 11 to the charcoal processing device 100 is large. In this case, the residence time in the second storage tank 6 is lengthened to sufficiently perform charcoal processing and sufficiently reduce the self-heating amount of the recycled fuel F. This ensures the safety of the recycled fuel F.

(6) In the above embodiment, the amount of outside air A taken in by the first blower 31 is controlled by adjusting the opening of a valve 55 provided in an intake pipe having one end connected to the first blower 31 and the other end open to the outside. However, the valve 55 may be omitted, and the amount of outside air A taken in by the first blower 31 may be adjusted by adjusting the opening of valves 51 and 54.

The configurations disclosed in the above embodiment (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, so long as no contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. They can be modified as appropriate within the scope of the purpose of the present invention.

The present invention can be applied to a carbide processing device and a carbide processing method.

4: First storage tank 6: Second storage tank 9: Control unit 20: Cooling unit 31: First blower 32: Second blower 40: Tank body (first main body)
41: Upper container 42: Lower container 60: Tank body (second body portion)
61: Upper vessel 62: Lower vessel 91: Ventilation control unit 92: Residence time control unit 100: Carbonized material treatment device 200: Organic sludge recycle system A: Outside air B1: Sediment layer B2: Sediment layer E1: Exhaust gas (curing gas)
E2: Exhaust gas (curing gas)
F: Recycled fuel G1: Curing gas G2: Curing gas H: Storage section K: Ventilation section L: Dried sludge M: Carbonized material N: Intermediate body (Carbonized material discharged from the first storage tank)
S11: Sensor (oxygen concentration measuring unit)
S12: Sensor (oxygen concentration measuring unit)
S21: Sensor (oxygen concentration measuring unit)
S22: Sensor (oxygen concentration measuring unit)
U1: Air flow meter U2: Air flow meter

Claims (5)

a storage section for storing the self-heating carbide by depositing it in layers;
a vent for supplying an oxygen-containing curing gas to the storage;
A control unit for controlling the amount of the curing gas passed through the curing gas ;
The storage section includes:
A first storage tank for storing the carbonized material;
a second storage tank for storing the carbonized material discharged from the first storage tank,
The ventilation section supplies the gas exhausted from the first storage tank to the second storage tank ,
The control unit controls the amount of gas supplied to the second storage tank based on the oxygen consumption characteristics of the carbonized material discharged from the first storage tank . a storage section for storing the self-heating carbide by depositing it in layers;
and a ventilation section for supplying an oxygen-containing curing gas to the storage section,
The storage section includes:
A first storage tank for storing the carbonized material;
a second storage tank for storing the carbonized material discharged from the first storage tank,
the first storage tank has a first main body portion that accommodates the carbide and a first discharge port that discharges the carbide from the first main body portion,
the second storage tank has a second main body portion that accommodates the carbide and a second discharge port that discharges the carbide from the second main body portion,
A flow path cross-sectional area of the first outlet is larger than a flow path cross-sectional area of the second outlet,
The ventilation section supplies the gas exhausted from the first storage tank to the second storage tank. The carbonized material treatment apparatus according to claim 1 or 2 , further comprising a cooling section between the first storage tank and the second storage tank, the cooling section being capable of cooling the carbonized material discharged from the first storage tank. a storing step of depositing and storing the self-heating carbide in layers;
and aeration step of aerating the carbonized material deposit layer with a curing gas containing oxygen during the storage step,
The storage step includes:
a first storage step of storing the carbide for a first predetermined period of time;
A second storage step of storing the carbide that has undergone the first storage step for a second predetermined period of time,
The aeration step is a carbonized material processing method in which the gas discharged after the first storage step is used in the second storage step, and the aeration rate of the gas is controlled based on the oxygen consumption characteristics of the carbonized material that has undergone the first storage step . a storing step of depositing and storing the self-heating carbide in layers;
and aeration step of aerating the carbonized material deposit layer with a curing gas containing oxygen during the storage step,
The storage step includes:
a first storage step of storing the carbonized material in a first storage tank for a first predetermined period of time;
a second storage step of storing the charcoal discharged from the first discharge port of the first storage tank in a second storage tank for a second predetermined period of time, wherein a flow path cross-sectional area of the first discharge port is configured to be larger than a flow path cross-sectional area of a second discharge port that discharges the charcoal in the second storage tank,
The carbonized material processing method, in which the ventilation step uses gas exhausted through the first storage step in the second storage step.

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