Operating method for melting device and melting device

Abstract

To enable stable waste treatment.SOLUTION: An operating method for a melting device is an operating method for a melting device 1 including: a melting furnace 10 for melting waste W; a charge section 20 that can sequentially charge the waste W into the melting furnace 10; and an oxygen supply section 30 that supplies oxygen into the melting furnace 10. The operating method includes: a charge step of charging the waste W into the melting furnace 10 by using the charge section 20; an acquisition step of acquiring a total oxygen flow rate indicating a flow rate of oxygen to be supplied from the oxygen supply section 30 into the melting furnace 10; and a calculation step of calculating a charge time until the waste W is charged from the charge section 20 into the melting furnace 10 next or a fluctuation value indicating fluctuation in amount of the waste W within the melting furnace 10, on the basis of the total oxygen flow rate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method of operating a melting device and to a melting device. [Background technology]

[0002] BACKGROUND ART In the treatment of waste using a melting furnace, a technique for determining the timing of charging waste is known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-196897 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a method for operating a melting device that enables stable waste treatment, and the melting device. [Means for solving the problem]

[0005] [1] A method for operating a melting apparatus comprising a melting furnace for melting waste, a loading section capable of sequentially loading waste into the melting furnace, and an oxygen supply section for supplying oxygen into the melting furnace, the method comprising: a loading step for loading waste into the melting furnace by the loading section; an acquisition step for acquiring a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply section to the melting furnace; and a calculation step for calculating, based on the total oxygen flow rate, the loading time until the next waste is loaded from the loading section into the melting furnace, or a fluctuation value indicating the fluctuation in the amount of waste in the melting furnace.

[0006] From the perspective of stable waste treatment, it is preferable to charge waste at an appropriate time in accordance with fluctuations in the amount of waste in the melting furnace. The inventors focused on the correlation between the flow rate of oxygen supplied to the melting furnace and a fluctuation value indicating fluctuations in the amount of waste in the melting furnace, and as a result, they empirically confirmed that there is a good correlation in the operation of actual melting equipment. Therefore, as in the melting equipment operating method described in [1] above, by calculating the charging time until the next waste is charged into the melting furnace or a fluctuation value indicating fluctuations in the amount of waste in the melting furnace based on the total oxygen flow rate indicating the flow rate of oxygen supplied to the melting furnace, waste can be charged at an appropriate time. This enables stable waste treatment.

[0007] [2] The method for operating a melting apparatus described in [1] above further includes a control step of calculating the charging time based on the total oxygen flow rate in the calculation step, and controlling the charging unit so that the waste is charged from the charging unit into the melting furnace based on the charging time calculated in the calculation step.

[0008] According to this method of operating the melting apparatus, waste is automatically charged at an appropriate timing based on the total oxygen flow rate, making it possible to treat waste more stably.

[0009] [3] The method for operating a melting apparatus according to the above item [1], further comprising: a display step of calculating the charging time based on the total oxygen flow rate in the calculation step; and displaying the charging time calculated in the calculation step on a monitor.

[0010] According to this method of operating a melting device, the operator can easily know when the next waste should be charged, so that the waste can be charged at the appropriate timing more reliably, thereby enabling stable waste treatment.

[0011] [4] The method for operating a melting apparatus according to any one of [1] to [3] above, wherein in the calculation step, the charging time is calculated so that the larger the total oxygen flow rate, the smaller the value.

[0012] It is estimated that the greater the total oxygen flow rate, the more advanced both the gasification reaction and the melting reaction of the waste in the melting furnace are, and the greater the fluctuation in the amount of waste. According to this melting device operating method, the greater the fluctuation in the amount of waste, the earlier the charging time is calculated. Therefore, waste can be charged at a more appropriate time, enabling more stable waste treatment.

[0013] [5] A method for operating a melting apparatus according to any one of [1] to [4] above, wherein in the calculation step, the charging time is calculated further based on the temperature of a location located above the waste in the melting furnace.

[0014] If waste is unevenly distributed in the melting furnace, creating cavities in the piled waste, high-temperature gas that should be at a lower position in the melting furnace will flow up to the upper part of the melting furnace due to the cavities. As a result, the temperature of the area above the waste in the melting furnace (the furnace top) may become high. In such cases, it is preferable to calculate the charging time taking into account the uneven distribution of waste in the melting furnace. On the other hand, if the temperature at the furnace top is low, it is inferred that waste is present at a relatively high position in the melting furnace. In this case, it is often not an appropriate time to charge waste, so it is preferable to wait for the waste at a relatively high position to melt before charging the waste. According to the above operating method, the charging time is calculated based on the furnace top temperature, which can reflect the state of the waste in the melting furnace, enabling more appropriate timing for charging the waste.

[0015] [6] A method for operating a melting apparatus as described in [1] above, wherein in the calculation step, the fluctuation value is calculated based on the total oxygen flow rate, and in the calculation step, the fluctuation value is calculated using a prediction model that has been constructed in advance to show the relationship between the total oxygen flow rate and the fluctuation value.

[0016] According to this method of operating a melting apparatus, the fluctuation value is calculated based on a pre-constructed prediction model, so that it is highly likely that a more appropriate value can be obtained.

[0017] [7] A method for operating a melting apparatus according to any one of [1] to [6] above, wherein the oxygen supply unit includes an air supply unit that supplies air into the melting furnace from a first supply port of the melting furnace, and an oxygen-enriched fluid supply unit that supplies a fluid containing oxygen generated by an oxygen generator into the melting furnace from a second supply port located below the first supply port of the melting furnace, and in the acquisition step, the sum of the flow rate of oxygen contained in the air from the air supply unit and the flow rate of oxygen contained in the fluid from the oxygen-enriched fluid supply unit is acquired as the total oxygen flow rate.

[0018] According to this melting method, oxygen can be supplied into the melting furnace from multiple supply ports at different heights, with the oxygen concentration in the fluid being changed for each height, making it possible to treat waste more efficiently.

[0019] [8] A melting device comprising: a melting furnace for melting waste; a loading section capable of loading waste sequentially into the melting furnace; an oxygen supply section for supplying oxygen into the melting furnace; a flow rate acquisition section for acquiring a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply section into the melting furnace; and a calculation section for calculating, based on the total oxygen flow rate, the loading time until the next waste is loaded into the melting furnace, or a fluctuation value indicating the fluctuation in the amount of waste in the melting furnace.

[0020] The melting device described in [8] above can be operated in the manner described in [1] above. This achieves the same effects as the melting device operation method described in [1] above. In other words, stable waste treatment becomes possible. [Effects of the Invention]

[0021] According to the present disclosure, a method for operating a melting device that enables stable waste treatment and a melting device are provided. [Brief explanation of the drawings]

[0022] [Figure 1]FIG. 1 is a schematic diagram showing an example of a melting device. [Figure 2] FIG. 2 is a scatter diagram showing an example of the relationship between fluctuations in the height of the waste material and the total oxygen flow rate. [Figure 3] FIG. 3 is a schematic diagram illustrating an example of a functional configuration of the control device. [Figure 4] FIG. 4 is a diagram illustrating an example of a hardware configuration of the control device. [Figure 5] FIG. 5 is a flowchart showing an example of a control process executed in a method for operating a melting device. [Figure 6] FIG. 6 is a flowchart showing an example of a control process executed in a method for operating a melting device. DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment will be described below with reference to the drawings. In the description, the same elements or elements having the same functions are designated by the same reference numerals, and redundant description will be omitted.

[0024] [Melting equipment] FIG. 1 schematically shows an example of the system configuration of a melting device according to one embodiment. The melting device 1 shown in FIG. 1 is a gasification melting device that melts waste W by pyrolyzing and gasifying it at high temperatures. The melting device 1 converts the waste W into residue (slag) or gas, for example, by melting solid waste W. The waste W may be household waste or industrial waste. The thermal energy generated during the melting process of the waste W may be reused by a power generation device including a turbine or the like.

[0025] The melting apparatus 1 includes a melting furnace 10, a charging section 20, an oxygen supply section 30, a flow rate measuring device 40, and a control device 50.

[0026] The melting furnace 10 is a furnace for melting waste W. The melting furnace 10 may be of any type, for example, a shaft furnace-type gasification melting furnace. The waste W is charged into the melting furnace 10 from a charging section 20 together with, for example, coke and limestone. The waste W charged into the melting furnace 10 from the charging section 20 is melted at high temperature inside the melting furnace 10. The melting furnace 10 includes, for example, a melting section 11, a furnace top section 12, a slag discharge port 13, and an exhaust port 14.

[0027] The melting section 11 is a section in which the waste W charged into the melting furnace 10 from the charging section 20 is melted at high temperatures. Inside the melting section 11, a temperature gradient is generated by the combustion of coke and the like. For example, the inside of the melting section 11 is divided into a drying / preheating zone 101 (approximately 300°C to 400°C), a pyrolysis gasification zone 102 (approximately 600°C to 800°C), a combustion zone 103 (approximately 1000°C to 1700°C), and a melting zone 104 (approximately 1700°C to 1800°C) from top to bottom depending on the temperature. The waste W introduced into the melting section 11 passes through the drying / preheating zone 101, the pyrolysis gasification zone 102, the combustion zone 103, and the melting zone 104 in that order.

[0028] Inside the melting section 11, waste W is piled up while undergoing melting treatment. In FIG. 1, the pile height of the waste W inside the melting section 11 is indicated by "H". The pile height H varies depending on the introduction of new waste W into the melting section 11 and the progress of the melting treatment of the waste W that has already been introduced. Therefore, the pile height H can represent the amount of waste W inside the melting section 11 (inside the melting furnace 10).

[0029] The furnace top 12 is connected to the melting section 11 and is located above the melting section 11. The furnace top 12 is located above the waste W in the melting furnace 10. The furnace top 12 is located above the pile height H of the waste W, even if the amount of waste W fluctuates depending on, for example, the progress of the melting process. The temperature range of the furnace top 12 may be the drying / preparation zone 101. The melting apparatus 1 is equipped with a temperature sensor 121, and the temperature sensor 121 may be provided in the furnace top 12. The temperature sensor 121 is a sensor for measuring the temperature of the furnace top 12. The temperature sensor 121 is provided, for example, on the outer surface 12a of the furnace top 12 of the melting furnace 10 and is connected to the control device 50. Information indicating the measurement results by the temperature sensor 121 is sent to the control device 50.

[0030] Waste W charged into the melting furnace 10 first passes through the drying / preheating zone 101, is deposited in the pyrolysis gasification zone 102, and moves downward within the melting section 11. The waste W is melted as it moves gradually through the pyrolysis gasification zone 102, combustion zone 103, and melting zone 104 in this order, and is decomposed into high-temperature pyrolysis gas and residue (slag). The pyrolysis gas is discharged from the exhaust port 14, and the residue is discharged from the slag discharge port 13.

[0031] The loading section 20 is capable of sequentially loading the waste material W into the melting furnace 10. "Sequential loading" means loading the waste material W (e.g., a predetermined amount of waste material W) sequentially at time intervals. As an example, the loading section 20 includes an inlet 21 and a flap 22. The inlet 21 is an entrance through which the waste material W is loaded. The inlet 21 may be provided with a sealing member 21a that separates the inside of the melting furnace 10 from the outside. The flap 22 is a member that can be opened and closed vertically, and is connected to the control device 50. The flap 22 opens and closes in response to a signal transmitted from the control device 50. The waste material W is loaded into the melting furnace 10 by opening the flap 22. In the example shown in FIG. 1, the flap 22 is in a closed state.

[0032] Waste W fed into the charging section 20 from the feed opening 21 is placed on the closed flap 22. The charging section 20 opens the flap 22 upon receiving a signal from the control device 50. As a result, the waste W is charged into the melting furnace 10. The control device 50 repeats this control process at time intervals, so that the waste W is sequentially charged from the charging section 20 into the melting furnace 10.

[0033] The oxygen supply unit 30 supplies oxygen into the melting furnace 10. The oxygen supply unit 30 includes an air supply unit 31 and an oxygen-enriched fluid supply unit 32. The air supply unit 31 supplies air into the melting furnace 10. The air supply unit 31 includes, for example, a combustion auxiliary unit blower 301, a forced draft blower 302, a first supply port 33, an upper air duct 351, a middle air duct 352, a first valve 361, and a second valve 362. The first supply port 33 includes an upper supply port 331 and a middle supply port 332. The upper supply port 331 and the middle supply port 332 are provided in portions of the melting zone 11 corresponding to the combustion zone 103.

[0034] The auxiliary combustion unit blower 301 and the forced draft blower 302 supply air into the melting furnace 10. The air sent from the auxiliary combustion unit blower 301 passes through an upper air duct 351 and is supplied to the melting zone 11 (combustion zone 103) from an upper supply port 331. A portion of the air sent from the forced draft blower 302 passes through a middle air duct 352 and is supplied to the melting zone 11 (combustion zone 103) from a middle supply port 332. The remaining air sent from the forced draft blower 302 is sent to a second middle air duct 353 (described below). A first valve 361 is located in the upper air duct 351 and adjusts the amount of air sent to the upper supply port 331. A second valve 362 is located in the middle air duct 352 and adjusts the amount of air sent to the middle supply port 332.

[0035] The oxygen-enriched fluid supply unit 32 includes an oxygen generator 303 and supplies an oxygen-containing fluid generated by the oxygen generator 303 into the melting furnace 10. In addition to the oxygen generator 303, the oxygen-enriched fluid supply unit 32 also includes a second supply port 34, a second middle-stage air duct 353, an oxygen flow path 354, a lower-stage air duct 355, a third valve 363, and a fourth valve 364. The oxygen generated by the oxygen generator 303 passes through the oxygen flow path 354 and merges with air passing through the second middle-stage air duct 353 at a junction 37. The oxygen and air merged at the junction 37 pass through the lower-stage air duct 355 as an oxygen-enriched fluid and are supplied from the second supply port 34 to the melting zone 11 (melting zone 104). The third valve 363 is located midway along the second middle-stage air duct 353 and adjusts the flow rate of air sent to the second supply port 34. The fourth valve 364 is located in the oxygen flow path 354 and adjusts the flow rate of oxygen sent to the second supply port 34 .

[0036] The flow rate measuring device 40 measures the flow rate of the fluid supplied from the oxygen supply section 30 into the melting furnace 10. The flow rate measuring device 40 includes a first flow rate measuring device 41, a second flow rate measuring device 42, a third flow rate measuring device 43, and a fourth flow rate measuring device 44. The first flow rate measuring device 41 measures the flow rate of air passing through the upper-stage air duct 351. The second flow rate measuring device 42 measures the flow rate of air passing through the middle-stage air duct 352. The third flow rate measuring device 43 measures the flow rate of air passing through the second middle-stage air duct 353. The fourth flow rate measuring device 44 measures the flow rate of the oxygen-enriched fluid passing through the oxygen flow path 354.

[0037] The flow rate of various fluids measured by the flow rate measuring device 40 may be the volume of the fluid passing through the flow path per unit time converted to standard conditions, the product of the volume of the fluid passing through the flow path per unit time and the pressure, or the amount of substance of the fluid passing through the flow path per unit time, or the average value of these within a specified time.

[0038] The flow rate measuring device 40 transmits information indicating the measurement results of each of the first flow rate measuring device 41, the second flow rate measuring device 42, the third flow rate measuring device 43, and the fourth flow rate measuring device 44 to the control device 50. From the measurement results of the first flow rate measuring device 41, the second flow rate measuring device 42, the third flow rate measuring device 43, and the fourth flow rate measuring device 44 and the oxygen concentration in each fluid, a flow rate acquiring unit 51 (described later) calculates the flow rate of oxygen contained in each fluid. In the present disclosure, the flow rate of all oxygen contained in the fluid supplied from the oxygen supply unit 30 is referred to as the "total oxygen flow rate." The total oxygen flow rate may be the flow rate per unit time, a moving average value of the flow rate per unit time, or the sum of the flow rates over a certain time range (accumulated flow rate).

[0039] The control device 50 is a computer that performs predetermined calculations and controls. The control device 50 calculates the time until the next waste material W is charged into the melting furnace 10 from the charging unit 20 (hereinafter referred to as the "charging time") based on the total amount of oxygen supplied from the oxygen supply unit 30 into the melting furnace 10 (the total oxygen flow rate). The control device 50 may control the charging unit 20 based on the calculated charging time.

[0040] In order to efficiently melt the waste W in the melting device 1, it is desirable to charge the waste W at an appropriate timing according to fluctuations in the pile height H of the waste W. In the melting device 1 (controller 50), the "total oxygen flow rate" is measured in order to charge the waste W at an appropriate timing. FIG. 2 is a scatter diagram showing actual measurement data of the pile height H and the total oxygen flow rate. In the scatter diagram of FIG. 2, the horizontal axis represents the fluctuation value of the pile height H, and the values ​​on the horizontal axis are shown as a ratio to a fluctuation value (mm) arbitrarily selected as a reference value. The vertical axis represents the total oxygen flow rate, and the values ​​on the vertical axis represent the total oxygen flow rate (m 3 It is expressed as a ratio to N.

[0041] Each plotted point in the scatter diagram of Figure 2 represents the actual measured value of the total oxygen flow rate (cumulative flow rate) within a certain period of time and the measurement result of the fluctuation value, which indicates the degree to which the pile height H fluctuated during that period. The measurement result of the fluctuation value was obtained by measuring the pile height H at multiple locations using a level meter that can measure the distance to an object by irradiating it with a laser, calculating the average value, and then calculating the difference between these average values ​​at different times. The line L is an approximation line calculated from the multiple plotted points using the least squares method. As shown in the scatter diagram of Figure 2, a positive correlation was observed between the fluctuation value of the pile height H and the total oxygen flow rate. Therefore, the value of the total oxygen flow rate itself can indicate the degree to which the pile height H fluctuated.

[0042] 3 shows an example of the functional configuration of the control device 50. The control device 50 includes, as functional components (hereinafter referred to as "functional blocks"), for example, a flow rate acquisition unit 51, a temperature acquisition unit 52, a calculation unit 53, and a charging control unit 55. The processes executed by these functional blocks correspond to the processes executed by the control device 50. Hereinafter, the processes executed by the control device 50 will be referred to as "control processes" to distinguish them from the melting process in the melting device 1.

[0043] The flow rate acquiring unit 51 acquires information indicating the measurement results of the flow rate measuring device 40. The flow rate acquiring unit 51 receives, for example, information indicating the measurement results of the first flow rate measuring device 41, the second flow rate measuring device 42, the third flow rate measuring device 43, and the fourth flow rate measuring device 44 of the flow rate measuring device 40. The flow rate acquiring unit 51 multiplies the measurement result of the first flow rate measuring device 41 by the oxygen concentration (%) in the air to obtain a first flow rate, multiplies the measurement result of the second flow rate measuring device 42 by the oxygen concentration (%) in the air to obtain a second flow rate, and multiplies the measurement result of the third flow rate measuring device 43 by the oxygen concentration (%) in the air to obtain a third flow rate. The flow rate acquiring unit 51 then calculates the sum of the first flow rate, the second flow rate, the third flow rate, and the measurement results of the fourth flow rate measuring device 44.

[0044] The flow rate acquiring unit 51 may calculate the above sum as the total oxygen flow rate at a predetermined cycle (at every predetermined cycle). In one example, the flow rate acquiring unit 51 may calculate the above sum as the total oxygen flow rate every 1 to 60 seconds. Alternatively, the flow rate acquiring unit 51 may calculate the above sum as the total oxygen flow rate at the timing when control using the total oxygen flow rate is performed. The flow rate acquiring unit 51 may calculate a moving average of the above sum as the total oxygen flow rate. The moving average may be an average value every 1 to 15 minutes.

[0045] The temperature acquisition unit 52 acquires information indicating the temperature measurement results by the temperature sensor 121. The temperature acquisition unit 52 may acquire information indicating the temperature measurement results by the temperature sensor 121 at a predetermined cycle (at every predetermined cycle) as the temperature of the furnace top section 12. In one example, the temperature acquisition unit 52 acquires information indicating the temperature measurement results by the temperature sensor 121 every 1 to 60 seconds. The temperature acquisition unit 52 may calculate a time average value of the measurement results by the temperature sensor 121 as the temperature of the furnace top section 12.

[0046] The calculation unit 53 calculates the charging time, which is the time until the next waste material W is charged into the melting furnace 10, based on the total oxygen flow rate acquired by the flow rate acquisition unit 51. The calculation unit 53 may calculate the charging time as the time from a reference time point until the next waste material W is charged. The reference time point may be the time point at which the charging time is calculated, or the time point at which the most recent waste material W is charged. The calculation unit 53 calculates the charging time based on the total oxygen flow rate obtained at the time of calculating the charging time. Since the fluctuation in the pile height H is larger (presumably larger) as the total oxygen flow rate increases, it is preferable to charge the next waste material W at an earlier timing. Therefore, the calculation unit 53 may calculate the charging time so that the value decreases as the total oxygen flow rate increases. The calculation unit 53 may also calculate the charging time based on the temperature of the furnace top 12 acquired by the temperature acquisition unit 52.

[0047] In one example, the calculation unit 53 calculates the charging time using the following formula (1). The constants in formula (1) are determined in advance by an operator or the like. The constants may be determined based on various theoretical values ​​related to the treatment of the waste W. Instead of or in addition to the various theoretical values ​​related to the treatment of the waste W, the constants may be determined based on various past measured data indicating the status inside the melting furnace 10, or based on measured data indicating the relationship between the total oxygen flow rate and the fluctuation value of the pile height H. The correction coefficient is determined based on the temperature of the furnace top 12, and the relationship between the correction coefficient and the temperature of the furnace top 12 is determined in advance by an operator or the like. The correction coefficient may be determined based on various past measured data indicating the status inside the melting furnace 10. The calculation unit 53 may set the correction coefficient to 1 when the temperature of the furnace top 12 is within a predetermined reference range, and may set the correction coefficient to a value smaller than 1 when the temperature of the furnace top 12 is outside the reference range. Charge time = (constant / total oxygen flow rate) × correction factor (1)

[0048] The charging control unit 55 controls the charging unit 20 to charge the waste material W from the charging unit 20 into the melting furnace 10 based on the charging time calculated by the calculation unit 53. The charging control unit 55 controls the charging unit 20, for example, to open the flap 22 on which the waste material W is placed. In one example, the charging control unit 55 controls the charging unit 20 to open the flap 22 when the charging time calculated by the calculation unit 53 has elapsed from the reference time point. The charging control unit 55 may also control the charging unit 20 to open the flap 22 when a time determined by the reference time point and the charging time calculated by the calculation unit 53 arrives.

[0049] 4 shows an example of the hardware configuration of the control device 50. The control device 50 includes a circuit 70. The circuit 70 includes a processor 71, a memory 72, a storage 73, a timer 74, and an input / output port 75. The storage 73 is configured with one or more non-volatile memory devices such as a flash memory or a hard disk. For example, the storage 73 stores a program for causing the control device 50 to configure the above-mentioned functional blocks.

[0050] The memory 72 is composed of one or more volatile memory devices such as a random access memory. The memory 72 temporarily stores programs loaded from the storage 73. The processor 71 is composed of one or more arithmetic devices such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The processor 71 executes the programs loaded in the memory 72, causing the control device 50 to configure each of the above-mentioned functional blocks. The results of calculations by the processor 71 are temporarily stored in the memory 72.

[0051] The timer 74 measures the elapsed time, for example, by counting a reference pulse at a fixed interval. The input / output port 75 inputs and outputs information between the flow rate measuring device 40, the temperature sensor 121, the loading section 20, etc., in accordance with instructions from the processor 71. Note that the circuit 70 is not necessarily limited to one in which each function is configured by a program. For example, the circuit 70 may have at least some of its functions configured by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates such a logic circuit.

[0052] Next, a method of operating the melting device 1 (method of operating the melting device 1) will be described as an example of a method of operating a melting device. Fig. 5 shows a flow S1 of a series of control processes executed by the control device 50 in the method of operating the melting device 1. The method of operating the melting device 1 includes at least step S13 of charging waste material W into the melting furnace 10 by the charging unit 20, step S10 of acquiring a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit 30 into the melting furnace 10, and step S11 of calculating a charging time until the next waste material is charged from the charging unit 20 into the melting furnace 10 based on the total oxygen flow rate.

[0053] At the start of flow S1, the melting furnace 10 begins operation, and the waste material W is piled up to a certain height in the melting furnace 10. After the melting furnace 10 begins operation (while flow S1 is being executed), oxygen is continuously supplied into the melting furnace 10 from the oxygen supply unit 30, and the waste material W is melted. After the melting furnace 10 begins operation (while flow S1 is being executed), measurements by the flow rate measuring device 40 and the temperature sensor 121 are continuously performed. The measurement results by the flow rate measuring device 40 are acquired at predetermined time intervals by the flow rate acquiring unit 51. The measurement results by the temperature sensor 121 are acquired at predetermined time intervals by the temperature acquiring unit 52. After the melting furnace 10 begins operation (while flow S1 is being executed), the control device 50 may adjust the amounts of various fluids supplied from the oxygen supply unit 30 based on information indicating the status inside the melting furnace 10.

[0054] The control device 50 may start flow S1 when a certain condition is met after the melting furnace 10 starts operating (for example, when a control mode in which the loading unit 20 automatically loads the waste material W) is selected. In flow S1, the control device 50 first executes step S10. In step S10, for example, the flow rate acquisition unit 51 acquires a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit 30 into the melting furnace 10. The flow rate acquisition unit 51 may calculate the total oxygen flow rate from the measurement result by the flow rate measurement device 40 obtained at the time of execution of step S10.

[0055] Next, the control device 50 executes step S11. In step S11, for example, the calculation unit 53 calculates a charging time from the charging unit 20 until the next waste material W is charged into the melting furnace 10 based on the total oxygen flow rate. The calculation unit 53 may calculate the charging time using the above-mentioned formula (1). The calculation unit 53 may calculate the remaining time from the execution of step S11 until the next waste material W is charged as the charging time.

[0056] Next, the control device 50 executes step S12. In step S12, for example, the charging control unit 55 determines whether the elapsed time from the execution of step S11 has reached the charging time calculated in step S11. If it is determined that the elapsed time has not reached the charging time (NO in step S12), the control process executed by the control device 50 returns to step S12. If it is determined that the elapsed time has reached the charging time (YES in step S12), the control process executed by the control device 50 proceeds to step S13.

[0057] In step S13, for example, the charging control unit 55 controls the charging unit 20 to charge new waste material W into the melting furnace 10. The charging control unit 55 may also control the charging unit 20 to open the flap 22 on which the waste material W is placed. As described above, the charging unit 20 may be controlled to charge the waste material W from the charging unit 20 into the melting furnace 10 based on the charging time calculated in step S11. A step of waiting for a predetermined time may be performed between steps S12 and S13. In this case, the waste material W is charged after an arbitrary time interval has elapsed after the elapsed time reaches the charging time.

[0058] Next, the control device 50 executes step S14. In step S14, for example, the control device 50 determines whether the operation of the melting furnace 10 has been stopped. If it is determined that the operation of the melting furnace 10 has not been stopped (NO in step S14), the control process executed by the control device 50 returns to step S10, and the control device 50 repeats steps S10 to S14. Before executing step S10 again, a step of waiting for a predetermined time may be executed.

[0059] On the other hand, if it is determined that the operation of the melting furnace 10 has been stopped (YES in step S14), flow S1 ends. Note that, if flow S1 is executed by selecting a control mode for automatic charging, the control device 50 may end flow S1 when the selection of that control mode is canceled.

[0060] [Variations] Instead of automatically charging the waste material W based on the calculated charging time, the melting device 1 may charge the waste material W from the charging unit 20 based on instructions from a worker, such as an operator of the melting device 1. As shown in FIG. 3, the control device 50 may include a display control unit 54. An input / output device 60 may be connected to the control device 50. The display control unit 54 displays the charging time calculated by the calculation unit 53 on a monitor 61. By displaying the charging time on the monitor 61, the worker can grasp the charging time.

[0061] The input / output device 60 is a device for inputting information indicating input from a worker to the control device 50 and outputting information from the control device 50 to the worker. The input / output device 60 may include a keyboard, an operation panel, or a mouse as an input device, and may include a monitor 61 (e.g., a liquid crystal display) as an output device. The input / output device 60 may be a touch panel in which an input device and an output device are integrated. The control device 50 and the input / output device 60 may be integrated.

[0062] The worker who has grasped the charging time may input a charging instruction to charge the waste material W according to the charging time into the control device 50. The control device 50 may control the charging unit 20 so that the waste material W is newly charged into the melting furnace 10 in response to the charging instruction from the worker.

[0063] As another variation, the calculation unit 53 may calculate a fluctuation value (hereinafter simply referred to as "fluctuation value") representing fluctuations in the amount of waste W in the melting furnace 10 based on the total oxygen flow rate acquired by the flow rate acquisition unit 51 instead of the charging time. The fluctuation value may be a value representing fluctuations in the amount of waste W in the melting furnace 10 per unit time, or may be a value representing fluctuations in the amount of waste W in the melting furnace 10 over a predetermined time period. As an example, the fluctuation value is a value representing fluctuations in the pile height H of the waste W from the time when the waste W was last charged.

[0064] The calculation unit 53 may calculate the fluctuation value using a prediction model previously constructed to show the relationship between the total oxygen flow rate and the fluctuation value. The prediction model may be constructed from actual measurement data of the total oxygen flow rate and the fluctuation value. The actual measurement data used to construct the prediction model includes multiple data sets, and in one data set, the total oxygen flow rate (actual measurement value) is associated with the fluctuation value (actual measurement value). The prediction model may be, for example, a linear function showing the relationship between the total oxygen flow rate and the fluctuation value, such as the line L shown in FIG. 2. Instead of a linear function, the prediction model may be a quadratic or higher order function showing the relationship between the total oxygen flow rate and the fluctuation value. The prediction model may be updated using data (actual measurement data of the total oxygen flow rate and the fluctuation value) obtained while the melting furnace 10 is operating.

[0065] FIG. 6 shows a series of control processes executed by the control device 50 in the method of operating the melting apparatus 1 as flow S2. At the start of flow S2, the melting furnace 10 starts operating, and the waste material W is piled up to a certain height in the melting furnace 10. After the melting furnace 10 starts operating (while flow S2 is being executed), oxygen is continuously supplied from the oxygen supply unit 30 into the melting furnace 10, and the waste material W is melted. After the melting furnace 10 starts operating (while flow S2 is being executed), the flow rate measuring device 40 continues to measure. The measurement results from the flow rate measuring device 40 are acquired by the flow rate acquiring unit 51 at predetermined time intervals. After the melting furnace 10 starts operating (while flow S2 is being executed), the control device 50 may adjust the amounts of various fluids supplied from the oxygen supply unit 30 based on information indicating the status inside the melting furnace 10.

[0066] The control device 50 may start flow S2 when a certain condition is met after the start of operation of the melting furnace 10 (for example, when a predetermined time has passed since the start of operation of the melting furnace 10). In flow S2, the control device 50 first executes step S20. In step S20, for example, the flow rate acquisition unit 51 acquires a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit 30 into the melting furnace 10. The flow rate acquisition unit 51 may calculate the total oxygen flow rate from the measurement result by the flow rate measurement device 40 obtained at the time of execution of step S20.

[0067] Next, the control device 50 executes step S21. In step S21, for example, the calculation unit 53 calculates a fluctuation value representing a fluctuation in the amount of waste W based on the total oxygen flow rate. The calculation unit 53 may calculate, as the fluctuation value, a value representing a fluctuation in the pile height H from the point in time when the waste W was most recently charged. The calculation unit 53 may acquire, as the fluctuation value, an output from the prediction model obtained when the total oxygen flow rate obtained at the time of execution of step S21 is input to the above-mentioned prediction model.

[0068] Next, the control device 50 executes step S22. In step S22, for example, the display control unit 54 displays the fluctuation value calculated in step S21 on the monitor 61. This allows the operator to check the fluctuation value (for example, a value representing the fluctuation in the pile height H from the previous loading of the waste W).

[0069] Next, the control device 50 executes step S23. In step S23, for example, the charging control unit 55 determines whether or not a charging instruction is given. The charging instruction may be given by an operator checking the variable values ​​displayed on the monitor 61. If it is determined that there is no charging instruction (NO in step S23), the control process executed by the control device 50 returns to step S20, and the control device 50 repeats steps S20 to S23.

[0070] On the other hand, if it is determined that a charging instruction has been issued (YES in step S23), the process executed by the control device 50 proceeds to steps S24 and S25. The control device 50 executes steps S24 and S25 in the same manner as steps S13 and S14 in flow S1. If it is determined in step S25 that the operation of the melting furnace 10 has not been stopped (NO in step S25), the control process executed by the control device 50 returns to step S20, and the control device 50 repeats steps S20 to S25. If it is determined that the operation of the melting furnace 10 has been stopped (YES in step S25), flow S2 ends.

[0071] Instead of displaying the fluctuation value on the monitor 61, the charging control unit 55 may control the charging unit 20 so that new waste W is charged when the fluctuation value from the time of the most recent charging of waste W reaches a predetermined threshold. As described above, the calculation unit 53 calculates the charging time or the fluctuation value based on the total oxygen flow rate. Calculating the charging time or the fluctuation value also includes calculating both the charging time and the fluctuation value. When the charging unit 20 is not controlled based on the charging time or the fluctuation value, a computer (computing device) that does not control the charging unit 20 may have the flow rate acquisition unit 51, the temperature acquisition unit 52, the calculation unit 53, and the display control unit 54 as functional blocks.

[0072] The flow rate obtaining unit 51 may calculate the total oxygen flow rate based on a command value used by the control device 50 to adjust the amount of each fluid supplied from the oxygen supply unit 30, instead of the measurement result by the flow rate measuring device 40. The air supply unit 31 may not include the auxiliary burner blower 301, the upper-stage air passage 351, and the first valve 361. In this case, the first supply port 33 may be configured by only the middle-stage supply port 332 (upper-stage supply port). In one example of the various examples described above, at least some of the features described in the other examples may be combined.

[0073] Summary of this disclosure The operating method of the melting device 1 described above is a method for operating a melting device 1 that includes a melting device 1 that melts waste W, a charging section 20 that can sequentially charge the waste W into the melting device 1, and an oxygen supply section 30 that supplies oxygen into the melting furnace 10. This operating method includes a charging step (S13, S24) in which the waste W is charged into the melting furnace 10 by the charging section 20, an acquisition step (S10, S20) in which a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply section 30 into the melting furnace 10 is acquired, and a calculation step (S11, S21) in which, based on the total oxygen flow rate, a charging time until the next waste W is charged into the melting furnace 10 from the charging section 20, or a fluctuation value indicating a fluctuation in the amount of waste W in the melting furnace 10, is calculated.

[0074] From the viewpoint of stable waste W treatment, it is preferable to charge waste W at an appropriate timing in accordance with fluctuations in the amount of waste W in the melting furnace 10. The inventors focused on the correlation between the flow rate of oxygen supplied to the melting furnace 10 and a fluctuation value indicating fluctuations in the amount of waste W in the melting furnace 10, and as a result, it was confirmed through actual experience that there is a good correlation in the operation of the melting apparatus 1. Therefore, as in this operating method of the melting apparatus 1, by calculating the charging time until the next time waste W is charged into the melting furnace 10 or a fluctuation value indicating fluctuations in the amount of waste W in the melting furnace 10 based on the total oxygen flow rate indicating the flow rate of oxygen supplied into the melting furnace 10, waste W can be charged at an appropriate timing. This enables stable waste W treatment.

[0075] In the operation method of the melting apparatus 1 described above, the calculation step (S11) may calculate the charging time based on the total oxygen flow rate. The operation method may further include control steps (S12, S13) of controlling the charging section 20 so that the waste material W is charged from the charging section 20 into the melting furnace 10 based on the charging time calculated in the calculation step (S11). In this case, the waste material W is automatically charged at an appropriate timing based on the total oxygen flow rate, enabling more stable treatment of the waste material W.

[0076] In the operation method of the melting apparatus 1 described above, the calculation step (S11) may calculate the charging time based on the total oxygen flow rate. The operation method may further include a display step of displaying the charging time calculated in the calculation step (S11) on the monitor 61. In this case, the operator can easily know the next charging time, so that the waste W can be charged at a more appropriate timing with more certainty. This allows for stable processing of the waste W.

[0077] In the operation method of the melting apparatus 1 described above, in the calculation step (S11), the charging time may be calculated so that the larger the total oxygen flow rate, the smaller the value. It is presumed that the larger the total oxygen flow rate, the more advanced the melting in the melting furnace 10 is, and the greater the fluctuation in the amount of waste W. According to the above operation method, the greater the fluctuation in the amount of waste W, the earlier the charging time is calculated. Therefore, the waste W can be charged at a more appropriate timing, and more stable waste W treatment is possible.

[0078] In the above-described method for operating the melting apparatus 1, the calculation step (S11) may further calculate the charging time based on the temperature of a location located above the waste W in the melting furnace 10. If the waste W is unevenly distributed in the melting furnace 10 and cavities are formed in the piled waste W, the cavities may cause high-temperature gas that should be at a lower position in the melting furnace 10 to flow to the vicinity of the upper part of the melting furnace 10. As a result, the temperature of a location located above the waste W in the melting furnace 10 (the furnace top 12) may become high. In such a case, it is preferable to calculate the charging time taking into account the uneven distribution of the waste W in the melting furnace 10. On the other hand, if the temperature of the furnace top 12 is low, it is estimated that the waste W is present at a relatively high position in the melting furnace 10. In this case, it is often not an appropriate time to charge the waste W, so it is preferable to wait until the waste W present at a relatively high position has melted before charging the waste W. According to the above-described operating method, the charging time is calculated based on the temperature of the furnace top 12, which can reflect the state of the waste W in the melting furnace 10, so that the waste W can be charged at a more appropriate timing.

[0079] In the above-described method for operating the melting apparatus 1, the calculation step (S21) may calculate the fluctuation value based on the total oxygen flow rate. In the calculation step (S21), the fluctuation value may be calculated using a prediction model that is pre-constructed to show the relationship between the total oxygen flow rate and the fluctuation value. In this case, since the fluctuation value is calculated based on the pre-constructed prediction model, it is highly likely that a more appropriate value will be obtained.

[0080] In the method of operating the melting apparatus 1 described above, the oxygen supply unit 30 may include an air supply unit 31 that supplies air into the melting furnace 10 through a first supply port 33 of the melting furnace 10, and an oxygen-enriched fluid supply unit 32 that supplies a fluid containing oxygen generated by the oxygen generator 303 into the melting furnace 10 through a second supply port 34 located below the first supply port 33 of the melting furnace 10. In the obtaining step, the total oxygen flow rate may be obtained as the sum of the flow rate of oxygen contained in the air from the air supply unit 31 and the flow rate of oxygen contained in the fluid from the oxygen-enriched fluid supply unit 32. In this case, oxygen can be supplied into the melting furnace from multiple supply ports at different heights, with the oxygen concentration in the fluid being changed for each height, thereby enabling more efficient treatment of the waste W.

[0081] The melting apparatus 1 described above includes a melting furnace 10 for melting waste W, a charging unit 20 capable of sequentially charging the waste W into the melting furnace 10, an oxygen supply unit 30 for supplying oxygen into the melting furnace 10, a flow rate acquisition unit 51 for acquiring a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit 30 into the melting furnace 10, and a calculation unit 53 for calculating, based on the total oxygen flow rate, the charging time until the next waste W is charged into the melting furnace 10 or a fluctuation value indicating the fluctuation in the amount of waste W in the melting furnace 10. This melting apparatus 1 can perform the operating method of the melting apparatus 1 described above. This achieves the same effects as the operating method of the melting apparatus 1 described above. That is, stable waste W processing is possible. [Explanation of symbols]

[0082] 1...melting device, 10...melting furnace, 12...furnace top, 20...charging section, 30...oxygen supply section, 31...air supply section, 32...oxygen-enriched fluid supply section, 33...first supply port, 34...second supply port, 51...flow rate acquisition section, 53...calculation section, 61...monitor, W...waste.

Claims

1. A method for operating a melting apparatus including a melting furnace for melting waste, a charging section capable of sequentially charging waste into the melting furnace, and an oxygen supply section for supplying oxygen into the melting furnace, comprising: a charging step of charging waste into the melting furnace by the charging unit; an acquisition step of acquiring a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit into the melting furnace; a calculation step of calculating a charging time until the next waste is charged into the melting furnace from the charging section based on the total oxygen flow rate, or a fluctuation value representing a fluctuation in the amount of waste in the melting furnace; A method for operating a melting device, comprising:

2. In the calculation step, the charging time is calculated based on the total oxygen flow rate, 2. The method for operating a melting apparatus according to claim 1, further comprising a control step of controlling the charging section so as to charge the waste from the charging section into the melting furnace based on the charging time calculated in the calculation step.

3. In the calculation step, the charging time is calculated based on the total oxygen flow rate, 2. The method for operating a melting device according to claim 1, further comprising a display step of displaying the charging time calculated in the calculation step on a monitor.

4. 4. The method for operating a melting apparatus according to claim 2, wherein in the calculating step, the charging time is calculated so that the charging time decreases as the total oxygen flow rate increases.

5. 4. The method for operating a melting apparatus according to claim 2, wherein the calculation step further calculates the charging time based on a temperature of a location located above the waste in the melting furnace.

6. In the calculation step, the fluctuation value is calculated based on the total oxygen flow rate; The method for operating a melting apparatus according to claim 1 , wherein the calculation step calculates the fluctuation value using a prediction model that is pre-constructed to indicate a relationship between the total oxygen flow rate and the fluctuation value.

7. The oxygen supply unit includes an air supply unit that supplies air into the melting furnace from a first supply port of the melting furnace, and an oxygen-enriched fluid supply unit that supplies a fluid containing oxygen generated by an oxygen generator into the melting furnace from a second supply port located below the first supply port of the melting furnace, The method for operating a melting apparatus according to any one of claims 1 to 3, wherein in the acquisition step, the sum of the flow rate of oxygen contained in the air from the air supply unit and the flow rate of oxygen contained in the fluid from the oxygen-enriched fluid supply unit is acquired as the total oxygen flow rate.

8. a melting furnace for melting the waste; a charging section capable of sequentially charging waste into the melting furnace; an oxygen supply unit that supplies oxygen into the melting furnace; a flow rate acquiring unit that acquires a total oxygen flow rate indicating the flow rate of oxygen supplied from the oxygen supply unit into the melting furnace; a calculation unit that calculates a charging time until the next waste is charged into the melting furnace or a fluctuation value that represents a fluctuation in the amount of waste in the melting furnace based on the total oxygen flow rate; a melting device comprising:

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