Odor treatment equipment

Abstract

To provide an odor treatment device for suppressing the discharge of an odor compound to an atmosphere.SOLUTION: In an odor compound treatment device having a preheating chamber 12 for discharging a gas containing an odor compound, a combustion chamber 20 connected to the preheating chamber 12, being a combustion chamber 20 for combusting the odor compound which is discharged from the preheating chamber 12, and a treatment part connected to the combustion chamber 20, being a treatment part for cooling the gas which is discharged from a combustion part and discharging it to an atmosphere, the odor treatment device comprises: an odor measurement part S3 for measuring an odor level of the gas which is not discharged yet in the treatment part; and a control part for controlling an oxygen burner in the combustion chamber 20 so as to reduce a calorie which is supplied to the odor compound by the combustion chamber 20 as a measurement result of the odor measurement part S3 is at a low level.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an odor treatment device for treating odor compounds generated from iron scrap.

Background Art

[0002] The melting facility for iron scrap preheats the iron scrap with the exhaust gas from the melting chamber, thereby suppressing the power consumption for melting. In addition, since the organic substances mixed in the iron scrap are decomposed by the preheating to generate odor compounds, a technique for suppressing the atmospheric emission of odor compounds is essential for a melting facility having a preheating function for iron scrap.

[0003] The first example of emission suppression is to blow oxygen from the side wall of the preheating chamber into the inside of the preheating chamber. The oxygen blown into the melting chamber burns part of the carbon monoxide generated in the melting chamber in the preheating chamber. The combustion of carbon monoxide suppresses the decrease in the exhaust temperature in the preheating chamber, thereby promoting the decomposition of plastics without requiring a thermal decomposition burner (see, for example, Patent Document 1).

[0004] The second example of emission suppression is to use at least one of a burner and oxygen supply at the joint between the preheating chamber and the duct to almost completely burn the combustible components of the exhaust gas. The combustion of the combustible components suppresses abnormal combustion in the latter stage of the duct and also suppresses the emission of odor compounds (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As mentioned above, oxygen supply to the preheating chamber promotes carbon monoxide combustion and suppresses the drop in exhaust gas temperature. Oxygen supply to the joints adjusts the degree of carbon monoxide oxidation and suppresses abnormal combustion. On the other hand, oxygen supply solely for the purpose of carbon monoxide combustion can suppress the drop in exhaust gas temperature and abnormal combustion, but there is still room for improvement in suppressing the release of odor compounds that proceed through pathways different from carbon monoxide combustion. [Means for solving the problem]

[0007] An odor treatment device for solving the above problems comprises: an exhaust unit for discharging a gas containing organic matter; a combustion unit connected to the exhaust unit for burning the organic matter discharged from the exhaust unit; and a processing unit connected to the combustion unit for cooling the gas discharged from the combustion unit and releasing it into the atmosphere. The processing unit further comprises: an odor measuring unit for measuring the odor level of the gas before discharge; and a control unit for controlling the combustion unit so as the measurement result from the odor measuring unit is at a lower level, the amount of heat supplied by the combustion unit to the odor compounds generated from the organic matter is reduced.

[0008] The combustion of organic matter involves the thermal decomposition of organic matter and the oxidation of odor compounds. When the odor level before release to the atmosphere is below a predetermined permissible value, it is presumed that the thermal decomposition of organic matter and the oxidation of odor compounds have progressed sufficiently. With the above configuration, the odor level before release to the atmosphere is measured, and the lower the odor level, the lower the heat output of the combustion section, thereby suppressing the release of odor compounds into the atmosphere and reducing the excess heat output for odor treatment.

[0009] In the odor treatment apparatus described above, the combustion unit may be equipped with a plurality of oxygen burners for heating the odor compound. The control unit may reduce the heat output by stopping the fuel supply to at least some of the plurality of oxygen burners and supplying only oxygen.

[0010] With the above configuration, the cessation of fuel supply and the supply of oxygen proceed simultaneously, which makes it possible to improve the responsiveness of heat in the combustion section. This increases the effectiveness of reducing excess heat in odor treatment.

[0011] The odor treatment device described above may have a control unit that changes the change in heat quantity by changing the number of oxygen burners that switch to oxygen supply. The odor treatment device may also further include a storage unit that stores mode information that associates different drive patterns with a plurality of different odor levels. The drive pattern is information that associates each oxygen burner with one of two modes: an oxygen supply mode that only supplies oxygen, or an oxidation combustion mode that produces a flame. The mode information associates the drive pattern with the odor level such that the lower the odor level, the greater the number of oxygen burners associated with the oxygen supply mode. The control unit may then drive the plurality of oxygen burners according to the drive pattern that corresponds to the odor level that matches the measurement result of the odor measuring unit.

[0012] According to the above configuration, the lower the odor level, the greater the number of burners in oxygen supply mode, and since the number of burners is preset according to the odor level, the effectiveness of suppressing excess heat is further enhanced, and the range of excess heat suppression is also easily expanded.

[0013] The odor treatment device described above may further include a temperature measuring unit for measuring the temperature of the gas discharged from the combustion unit. The control unit may reversibly switch between a first process, in which the amount of heat supplied by the combustion unit to the odor compound is reduced as the measurement result from the odor measuring unit becomes lower, and a second process, in which the amount of heat supplied by the combustion unit to the odor compound is reduced as the measurement result from the temperature measuring unit becomes higher.

[0014] As described above, the combustion of organic matter involves the thermal decomposition of organic matter and the oxidation of odor compounds. It is presumed that the higher the temperature of the gas emitted from the combustion section, the more the thermal decomposition of organic matter is progressing. With the above configuration, the first treatment switches to the second treatment, so even in the event of a malfunction in the odor measurement unit, the excess heat amount for odor treatment is suppressed. Also, since the second treatment switches to the first treatment, the excess heat amount for odor treatment is suppressed even in the event of a malfunction in the temperature measurement unit.

[0015] The odor treatment device described above may further include an oxygen supply unit that supplies oxygen to the combustion unit, and a CO measuring unit that measures the amount of carbon monoxide discharged together with the odor compound. The control unit may set the amount of oxygen to be supplied to the combustion unit to increase as the measurement result from the CO measuring unit reaches a higher level.

[0016] According to the above configuration, in addition to suppressing the odor of the gas released from the processing unit, the amount of carbon monoxide in the gas released from the processing unit is also suppressed. In the odor treatment apparatus described above, the first and second processes are priority controls, and the control unit is configured to execute the priority controls when the measurement result of the odor measuring unit is above a predetermined level, and may execute a predetermined process other than the priority controls when the measurement result of the odor measuring unit is below a predetermined level.

[0017] With the above configuration, priority control is performed to suppress excess heat when the measurement result from the odor measurement unit is above a predetermined level, thus increasing the effectiveness of achieving the effect of suppressing excess heat. [Effects of the Invention]

[0018] According to the above configuration, the release of odor compounds into the atmosphere is suppressed. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 is a diagram showing the configuration of the odor treatment system. [Figure 2] Figure 2 is a diagram showing the configuration of the odor treatment device. [Figure 3] Figure 3 is a block diagram showing the configuration of the control unit. [Figure 4] Figure 4 is a screen diagram showing the odor treatment settings by the control unit. [Figure 5] Figure 5 is a flowchart showing the flow of the odor treatment method. [Figure 6] Figure 6 is a flowchart showing the flow of the odor treatment method.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, an embodiment of the odor treatment apparatus will be shown. First, an odor treatment system including the odor treatment apparatus will be described, then the odor treatment apparatus will be described, and then the odor treatment method executed by the odor treatment apparatus will be described.

[0021] (Odor Treatment System) As shown in FIG. 1, the odor treatment system includes a steelmaking chamber 10, a combustion chamber 20, a cooling chamber 32, an exhaust dust collection chamber 34, and a building dust collection chamber 43. The cooling chamber 32, the exhaust dust collection chamber 34, and the building dust collection chamber 43 are examples of the treatment unit.

[0022] The steelmaking chamber 10 houses an electric furnace having a melting chamber 11. The combustion chamber 20 is an example of a combustion unit and is disposed outside the steelmaking chamber 10. The combustion chamber 20 is connected to the exhaust port 12A (see FIG. 2) of the electric furnace via an intake duct 13 (see FIG. 2). The combustion chamber 20 burns the exhaust gas coming out of the electric furnace. The cooling chamber 32 is disposed outside the combustion chamber 20. The cooling chamber 32 is connected to the exhaust port 22 (see FIG. 2) of the combustion chamber 20 via an exhaust duct 31. The cooling chamber 32 cools the exhaust gas coming out of the combustion chamber 20. The exhaust dust collection chamber 34 is connected to the exhaust port of the cooling chamber 32 via a direct suction dust collection fan 33. The exhaust dust collection chamber 34 cleans the exhaust gas coming out of the cooling chamber 32 with a bag filter.

[0023] The building dust collection chamber 43 is connected to the exhaust port of the steelmaking room 10 via the building duct 41 and the building dust collection fan 42. The building dust collection chamber 43 is connected to the exhaust port of the exhaust dust collection chamber 34 via the building dust collection fan 42 and the direct-flow junction fan 35. The building dust collection chamber 43 cleans the air coming out of the steelmaking room 10 and the air coming out of the exhaust dust collection chamber 34 using a bag filter. The building dust collection chamber 43 releases the cleaned air into the atmosphere.

[0024] The building dust collection chamber 43 is equipped with an odor measuring unit S3. The odor measuring unit S3 uses air immediately before it is released into the atmosphere from the building dust collection chamber 43 and measures the odor level of the air. An example of the odor level is the concentration of odor compounds in the air immediately before it is released into the atmosphere from the building dust collection chamber 43. The odor measuring unit S3 inputs the measured odor level to the control device 51 (see Figure 3).

[0025] (Odor treatment device) As shown in Figure 2, the electric furnace comprises a melting chamber 11 and a preheating chamber 12. The melting chamber 11 supplies arc heat to the scrap iron, thereby generating molten metal from the scrap iron. The melting chamber 11 adds oxygen and carbon material to the molten metal, thereby utilizing the heat of combustion of the carbon material as a heat source. The melting chamber 11 includes the air that enters the melting chamber 11 and the carbon monoxide produced from the carbon material in its exhaust gas. The melting chamber 11 discharges the molten metal from its outlet.

[0026] The preheating chamber 12 is an example of a discharge section and extends upward from the melting chamber 11. Iron scrap is charged into the preheating chamber 12 from its upper end. The preheating chamber 12 allows the exhaust gas from the melting chamber 11 to flow upward from the melting chamber 11, thereby preheating the iron scrap inside the preheating chamber 12. The preheating chamber 12 supplies the preheated iron scrap to the melting chamber 11 from its lower end. The iron scrap supplied to the melting chamber 11 generates molten metal. The preheating chamber 12 further supplies preheated iron scrap to the melting chamber 11 to replenish the iron scrap that has been melted in the melting chamber 11. The preheating chamber 12 is further charged with iron scrap to replenish the iron scrap supplied to the melting chamber 11.

[0027] The side wall of the preheating chamber 12 is equipped with an exhaust port 12A. The exhaust port 12A of the preheating chamber 12 extends from the lower end of the preheating chamber 12 to above the center in the height direction of the preheating chamber 12. The exhaust port 12A of the preheating chamber 12 is connected to the intake duct 13. The high-temperature exhaust gas generated in the melting chamber 11 passes through the iron scrap in the preheating chamber 12 and then exits the preheating chamber 12 towards the intake duct 13. In this way, organic matter that requires a lot of heat to be discharged is continuously heated by the exhaust gas as it moves from the upper end to the lower end of the preheating chamber 12, and is thus included in the exhaust gas. Also, organic matter that does not require a lot of heat to be discharged is heated at the upper end of the preheating chamber 12 and is thus included in the exhaust gas. Finally, organic matter of various molecular weights contained in the iron scrap is included in the exhaust gas and enters the intake duct 13 from the preheating chamber 12.

[0028] The intake duct 13 is connected to the preheating chamber 12 and the combustion chamber 20. The intake duct 13 includes a CO measuring unit S1, an explosion-proof valve 14, and pyrolysis burners C1A and C1B. The CO measurement unit S1 is located on the side of the preheating chamber 12 rather than the middle of the intake duct 13 in the direction of exhaust gas flow. The CO measurement unit S1 is located in the upstream portion of the intake duct 13. The CO measurement unit S1 may also be located at the upstream end of the intake duct 13. The CO measurement unit S1 uses the exhaust gas coming out of the preheating chamber 12 to measure the concentration of carbon monoxide (CO) in the exhaust gas. The CO measurement unit S1 inputs the measured carbon monoxide concentration to the control device 51 (see Figure 3).

[0029] The explosion-proof valve 14 releases the intake duct 13 by operating pressure, thereby preventing the intake duct 13 from exceeding a predetermined pressure. The pyrolysis burners C1A and C1B are positioned closer to the combustion chamber 20 than the middle of the intake duct 13 in the direction of exhaust gas flow. The pyrolysis burners C1A and C1B are positioned in the downstream portion of the intake duct 13. Pyrolysis burner C1A is positioned closer to the preheating chamber 12 than pyrolysis burner C1B. Pyrolysis burner C1B is positioned closer to the combustion chamber 20 than pyrolysis burner C1A. The pyrolysis burners C1A and C1B are distributed upstream of the explosion-proof valve 14 and downstream of the explosion-proof valve 14.

[0030] However, the explosion-proof valve 14 may be located upstream of the pyrolysis burner C1A or downstream of the pyrolysis burner C1B. The pyrolysis burners C1A and C1B burn fuel by mixing it with air. Examples of fuels include LPG, kerosene, and heavy oil. The pyrolysis burners C1A and C1B raise the temperature of the exhaust gas flowing through the intake duct 13 with a flame. For example, the pyrolysis burners C1A and C1B raise the temperature of the exhaust gas to 750°C or higher. The pyrolysis burners C1A and C1B pyrolyze organic matter contained in the exhaust gas into highly volatile organic compounds (VVOCs) and odor compounds such as volatile organic compounds (VOCs) by raising the temperature. Hereafter, highly volatile organic compounds (VVOCs) and odor compounds such as volatile organic compounds (VOCs) will also be simply referred to as VOCs.

[0031] The combustion chamber 20 includes an air intake port 12B, an exhaust port 22, a dust discharge door 21, a temperature measuring unit S2, air combustion burners C1C, C1D, and oxygen burners E2A, E2B, E2C, E2D, E2E.

[0032] The intake port 12B of the combustion chamber 20 is located at the lower end of the combustion chamber 20 in the height direction. The exhaust port 22 of the combustion chamber 20 is located at the upper end of the combustion chamber 20 in the height direction. The combustion chamber 20 is connected to the intake duct 13 via the intake port 12B. The combustion chamber 20 is connected to the exhaust duct 31 (see Figure 1) via the exhaust port 22. The combustion chamber 20 allows exhaust gas from the intake duct 13 to flow from the intake port 12B to the exhaust port 22.

[0033] The dust discharge door 21 is located at the lower end of the combustion chamber 20. The dust discharge door 21 is used to discharge dust accumulated in the combustion chamber 20. The temperature measuring unit S2 is located downstream of the air combustion burners C1C, C1D and the oxygen burners E2A, E2B, E2C, E2D, E2E. The temperature measuring unit S2 may be located at the upper end of the combustion chamber 20 or immediately before the exhaust port 22 in the combustion chamber 20. The temperature measuring unit S2 measures the temperature of the exhaust gas immediately after it has been oxidized by the air combustion burners C1C, C1D and the oxygen burners E2A, E2B, E2C, E2D, E2E. The temperature measuring unit S2 inputs the measured temperature of the exhaust gas to the control device 51 (see Figure 3).

[0034] The air combustion burners C1C and C1D are located downstream of the intake port 12B of the combustion chamber 20, and are positioned between the intake port 12B and the temperature measuring unit S2. The air combustion burners C1C and C1D each burn fuel by mixing it with oxygen. Examples of fuels include LPG, kerosene, and heavy oil. The air combustion burners C1C and C1D raise the temperature of the exhaust gas flowing into the combustion chamber 20 with the flame and oxidize VOCs.

[0035] Oxygen burner E2A is located at the lower end of the combustion chamber 20. Four oxygen burners E2B, E2C, E2D, and E2E are located between the intake port 12B and the temperature measuring unit S2 in the direction of exhaust gas flow. Two oxygen burners E2B and E2E are located downstream of the intake port 12B of the combustion chamber 20 and between the air combustion burners C1C and C1D. Two oxygen burners E2C and E2D are located downstream of the air combustion burners C1C and C1D. Oxygen burners E2A, E2B, E2C, E2D, and E2E each burn fuel by mixing it with oxygen. Examples of fuels include LPG, kerosene, and heavy oil. Oxygen burners E2A, E2B, E2C, E2D, and E2E raise the temperature of the exhaust gas flowing into the combustion chamber 20 with their flames and oxidize VOCs.

[0036] Oxygen burners E2A, E2B, E2C, E2D, and E2E can reversibly switch between oxygen supply, which supplies only oxygen, and oxidative combustion, which involves the combustion of oxygen and fuel. The control device 51 (see Figure 3) reversibly switches the operation of oxygen burners E2A, E2B, E2C, E2D, and E2E between oxygen supply and oxidative combustion, respectively. Oxygen burners E2A, E2B, E2C, E2D, and E2E that perform oxygen supply are examples of oxygen supply units. Oxygen burners E2A, E2B, E2C, E2D, and E2E that perform oxidative combustion are examples of oxidative burners.

[0037] The organic matter discharged from the preheating chamber 12 is first heated by the pyrolysis burners C1A and C1B in the intake duct 13, which is not supplied with oxygen, and then converted into carbon dioxide and water in the combustion chamber 20, which is supplied with oxygen. In this way, the odor treatment device proceeds with (i) pyrolysis of organic matter and (ii) oxidation of odor compounds in the order of (i) and (ii).

[0038] (Control device) As shown in Figure 3, the odor treatment system comprises a control device 51, an input device 52, and an output device 53. The control device 51 comprises a control unit 51A and a storage unit 51B. The control device 51 reads the odor treatment program and various information used for odor treatment stored in the storage unit 51B, and executes the odor treatment method according to the odor treatment program.

[0039] The control device 51 controls all oxygen burners E2, namely oxygen burners E2A, E2B, E2C, E2D, and E2E. The control quantity of the control device 51 is the fuel amount for each oxygen burner E2. The fuel amount for each oxygen burner E2 may be the fuel supply amount for that oxygen burner E2, or the opening degree of the fuel supply valve.

[0040] The control variables of the control device 51 may include the amount of oxygen for each oxygen burner E2 and the corrected amount of oxygen for each oxygen burner E2. The amount of oxygen for each oxygen burner E2 is the amount of oxygen used for combustion in the oxygen burner E2. The corrected amount of oxygen for each oxygen burner E2 is the amount of oxygen used to suppress the carbon monoxide concentration. The amount of oxygen for each oxygen burner E2 and the corrected amount of oxygen for each oxygen burner E2 may be the oxygen supply amount of the oxygen burner E2 or the opening degree of the oxygen supply valve in the oxygen burner E2.

[0041] The odor treatment method includes returning the measurement result from the odor measurement unit S3, which is the output of the odor treatment, to the input, and correcting the estimated fuel amount and oxygen amount to target values ​​for the fuel amount and oxygen amount, respectively, that are appropriate for the measurement result. Correcting the target values ​​for the fuel amount and oxygen amount may include reversibly switching between oxidative combustion and oxygen supply in each oxygen burner E2.

[0042] The odor treatment method may include returning the measurement result from the temperature measuring unit S2, which is the output of the odor treatment, to the input, and correcting the estimated fuel amount and oxygen amount suitable for the measurement result to the target value of the fuel amount and the target value of the oxygen amount. The odor treatment method may also include returning the measurement result from the CO measuring unit S1, which is the output of the odor treatment, to the input, and correcting the estimated oxygen amount suitable for the measurement result to the target value of the oxygen amount.

[0043] The following example shows that the control variables of the control device 51 are the fuel amount for each oxygen burner E2, the oxygen amount for each oxygen burner E2, and the corrected oxygen amount for each oxygen burner E2. Furthermore, an example is shown in which the odor treatment method uses the measurement results of the odor measurement unit S3 and the temperature measurement unit S2 to correct the target values ​​of the fuel amount and oxygen amount, and uses the measurement results of the CO measurement unit S1 to correct the target value of the corrected oxygen amount.

[0044] The input device 52 inputs various information for odor treatment to the control device 51. The information for odor treatment includes presets to be applied to odor treatment. The presets include a manual preset, a low-odor preset, and a fuel preset. The manual preset is used for manual control. The low-odor preset and the fuel preset are used for automatic control.

[0045] The memory unit 51B stores various presets. [a] The manual preset includes a fixed fuel quantity and a fixed oxygen quantity for each oxygen burner E2. The control unit 51A uses the manual preset for manual control. Manual control does not use the measurement results of each measurement unit S1, S2, S3 to determine the target value of each control quantity. The control unit 51A executes manual control in the event of a failure of each measurement unit S1, S2, S3, etc. The control unit 51A sets the oxygen quantity and fuel quantity of the manual preset as the target values ​​of each control quantity in manual control.

[0046] [b] The low-odor preset associates one of the drive modes with each oxygen burner E2. The drive modes are an oxygen supply mode that only supplies oxygen and an oxidative combustion mode that emits a flame. The low-odor preset associates a fixed value for the corrected oxygen amount with the oxygen burner E2 in oxygen supply mode. The low-odor preset associates a fixed value for the fuel amount and a fixed value for the oxygen burner E2 in oxidative combustion mode.

[0047] The low-odor preset associates an oxygen supply mode with at least one oxygen burner E2. The low-odor preset may associate an oxygen supply mode with all oxygen burners E2. The low-odor preset may associate an oxidative combustion mode with at least one oxygen burner E2. In the low-odor preset, the total amount of fuel associated with all oxygen burners E2 is the total amount of fuel at low operating levels such that the odor level is sufficiently low.

[0048] [c] The fuel preset associates one of the drive modes with each oxygen burner E2. The low-odor preset associates the fuel amount with the oxygen burner E2 in oxidative combustion mode. The fuel preset associates an oxidation combustion mode with at least one oxygen burner E2. The fuel preset may also associate an oxygen supply mode with at least one oxygen burner E2. In the fuel preset, the total amount of fuel associated with all oxygen burners E2 is estimated to be the amount of fuel needed to suppress odor levels during steady operation, such as when iron scrap is regularly charged.

[0049] The input device 52 includes information for odor treatment, an odor threshold to be applied to the odor treatment, and a target air-fuel ratio. The odor threshold and target air-fuel ratio are used for automatic control. The memory unit 51B stores the odor threshold and the target air-fuel ratio.

[0050] [d] The odor threshold is an example of a predetermined level and is the concentration value of the odor compound. The concentration value that is the odor threshold is the measurement result of the odor measurement unit S3 obtained in advance when little or no organic matter is generated from the iron scrap charged into the preheating chamber 12, or when there is almost no iron scrap charged into the preheating chamber 12.

[0051] [e] The target air-fuel ratio is the target value of the air-fuel ratio in the oxygen burner E2. The target air-fuel ratio is the ratio of the amount of oxygen to the amount of fuel during oxidative combustion. The amount of oxygen may be the amount of pure oxygen that makes the combustion by the oxygen burner E2 pure oxygen combustion, or the amount of air with a higher oxygen concentration that makes the combustion by the oxygen burner E2 oxygen enriched combustion. The target air-fuel ratio is the air-fuel ratio that is estimated to promote the oxidation of odor compounds. The target air-fuel ratio is the air-fuel ratio that is estimated to stabilize the oxidation of odor compounds during steady operation, such as when iron scrap is regularly charged. In the combustion of the oxygen burner E2 in automatic control, the control unit 51A refers to the target air-fuel ratio to determine the target value of the amount of oxygen.

[0052] Furthermore, the input device 52 includes information for odor treatment, such as corrected oxygen information, fuel information, and mode information applicable to odor treatment. The corrected oxygen information, fuel information, and mode information are used for automatic control.

[0053] Furthermore, the input device 52 includes information for odor treatment indicating whether or not automatic control is specified. The input device 52 also includes information for odor treatment indicating the type of priority control to be applied to the odor treatment. The memory unit 51B stores corrected oxygen information, fuel information, mode information, whether or not automatic control is specified, and the type of priority control.

[0054] [f] The corrected oxygen information associates the corrected oxygen amount with the carbon monoxide amount 68A (see Figure 4). The carbon monoxide amount 68A is the concentration of carbon monoxide. The corrected oxygen amount is the amount of oxygen estimated to be required to oxidize the carbon monoxide associated with that corrected oxygen amount. The corrected oxygen amount in the corrected oxygen information is the total amount of oxygen supplied to all oxygen burners E2 associated with the oxygen supply mode. The corrected oxygen amount may be the amount of pure oxygen supplied or the amount of air with increased oxygen concentration supplied. If there is insufficient oxygen in the exhaust gas, the carbon monoxide amount 68A in the exhaust gas will increase, while if there is sufficient oxygen in the exhaust gas, the carbon monoxide amount 68A in the exhaust gas will decrease and the amount of carbon dioxide will increase. In diligent research into the correlation between carbon monoxide levels 68A and odor levels 69B, the inventors found a linear correlation: in the range of 0 to 800 ppm, higher carbon monoxide levels 68A corresponded to higher odor levels 69B. From this perspective, the corrected oxygen information is configured such that lower levels of carbon monoxide levels 68A correspond to lower amounts of corrected oxygen.

[0055] The control unit 51A returns the measurement result of the CO measurement unit S1, which is the output, to the input, and determines the corrected oxygen amount that corresponds to the measurement result of the CO measurement unit S1 within the corrected oxygen information as the target value of the corrected oxygen amount.

[0056] [g] The fuel information associates the fuel quantity 69C with the exhaust gas temperature 69A (see Figure 4). The exhaust gas temperature 69A is the temperature of the exhaust gas. The fuel quantity 69C in the fuel information is the total amount of fuel supplied to all oxygen burners E2 associated with the oxidative combustion mode. The fuel information associates the fuel quantity 69C with the exhaust gas temperature 69A in such a way that the lower the exhaust gas temperature 69A level, the higher the fuel quantity 69C associated with that level.

[0057] The control unit 51A returns the measurement result from the temperature measurement unit S2, which is the output, to the input, and determines the fuel amount corresponding to the measurement result from the temperature measurement unit S2 within the fuel information as the target value for the fuel amount. Furthermore, fuel information associates the amount of fuel with odor level 69B (see Figure 4). Odor level 69B is the concentration of odor compounds. Fuel information associates the amount of fuel with odor level 69B such that the higher the odor level 69B, the higher the amount of fuel associated with that level.

[0058] The control unit 51A returns the measurement result from the odor measurement unit S3, which is the output, to the input, and determines the fuel amount corresponding to the measurement result from the odor measurement unit S3 in the fuel information as the target value of the fuel amount. [h] Mode information associates the drive pattern with the exhaust gas temperature level of 69A. Each drive pattern is a set of drive modes, with one of the drive modes associated with each oxygen burner E2. The mode information associates the drive pattern with the exhaust gas temperature such that the higher the exhaust gas temperature, the greater the number of oxygen burners E2 associated with the oxygen supply mode.

[0059] The control unit 51A returns the measurement result of the temperature measurement unit S2, which is the output, to the input, and determines a new drive pattern that corresponds to the measurement result of the temperature measurement unit S2 in the mode information.

[0060] Furthermore, the mode information associates the drive pattern with the odor level 68B. The mode information associates the drive pattern with the odor level such that the lower the odor level, the greater the number of oxygen burners associated with the oxygen supply mode.

[0061] The control unit 51A returns the measurement result from the odor measurement unit S3, which is the output, to the input, and determines a new drive pattern that corresponds to the measurement result from the odor measurement unit S3 in the mode information.

[0062] (Automatic control) The control unit 51A determines the target values ​​for fuel quantity, oxygen quantity, and corrected oxygen quantity according to the odor treatment program. The target values ​​for fuel quantity, oxygen quantity, and corrected oxygen quantity are target values ​​for automatic control in odor treatment.

[0063] The control unit 51A reversibly switches the operation of each oxygen burner E2 between oxygen supply and oxidative combustion according to the odor treatment program. The control unit 51A uses at least one measurement result from the CO measurement unit S1, the temperature measurement unit S2, and the odor measurement unit S3 to switch between oxygen supply and oxidative combustion.

[0064] The control device 51 sets the output for each pyrolysis burner C1A, C1B and each air combustion burner C1, which are not subject to control, according to the odor treatment program. Specifically, the control device 51 sets the fuel amount and air amount for each pyrolysis burner C1A, C1B according to the odor treatment program. The fuel amount and air amount set for the pyrolysis burners C1A, C1B are set in advance so that organic matter contained in the exhaust gas is pyrolyzed into odor compounds. In addition, the control device 51 sets the fuel amount and air amount for the air combustion burners C1C, C1D according to the odor treatment program. The fuel amount and air amount set for the air combustion burners C1C, C1D are set in advance so as to assist in the oxidation of odor compounds.

[0065] The control unit 51A may include dedicated hardware such as an Application Specific Integrated Circuit (ASIC) that performs at least some of the various processes. The control unit 51A can also be configured as a circuit including one or more dedicated hardware circuits such as ASICs, one or more processors that operate according to a computer program, or a combination thereof. In the following, an example will be described in which the control unit 51A reads an odor treatment program stored on a readable medium and executes the read odor treatment program.

[0066] The control unit 51A performs the following automatic controls [1] to [5]. The automatic controls change the target value of each control variable based on the measurement results. Based on the availability status of each measurement unit S1, S2, S3, the control unit 51A selectively performs either [3] temperature priority control or [4] odor priority control. The control unit 51A selectively performs either [2] fixed fuel control or [5] corrected oxygen control. [1] Low odor control [2] Fixed fuel control [3] Temperature priority control [4] Odor priority control [5] Corrected oxygen control

[0067] Based on the fact that automatic control is specified, the control unit 51A executes [1] low-odor control. Low-odor control does not use the measurement results of each measurement unit S1, S2, S3 to determine the target value of each control quantity. Low-odor control is executed when the measurement result of the odor measurement unit S3 is [d] less than the odor threshold. Low-odor control uses [b] low-odor presets. In low-odor control, the control unit 51A refers to the correspondence of low-odor presets and sets the drive mode of each oxygen burner E2 to a drive mode that conforms to the correspondence of low-odor presets. The control unit 51A sets the target value of each control quantity to a value that conforms to the low-odor preset.

[0068] The control unit 51A executes [2] fixed fuel control based on the fact that automatic control is specified and each measurement unit S2, S3 is unavailable. Fixed fuel control does not use the measurement results of each measurement unit S1, S2, S3 to determine the target value of the fuel amount. Fixed fuel control is executed when each measurement unit S1, S2, S3 fails, etc. Fixed fuel control uses [c] fuel presets. In fixed fuel control, the control unit 51A refers to the fuel preset mapping and determines the drive mode of each oxygen burner E2 according to the fuel preset mapping. The control unit 51A determines the fixed value of the fuel preset as the target value of the fuel amount.

[0069] Based on the fact that the priority control type is temperature priority control, the control unit 51A executes temperature priority control. In temperature priority control, the measurement result of the temperature measurement unit S2 is used to determine the target value of the fuel amount, without using the measurement results of the individual measurement units S1 and S3. In temperature priority control, the measurement result of the temperature measurement unit S2 is used to switch between oxygen supply and oxidative combustion, without using the measurement results of the individual measurement units S1 and S3.

[0070] Temperature-priority control uses [g] fuel information and [h] mode information to switch between oxygen supply and oxidative combustion. In temperature-priority control, the control unit 51A identifies the supply amount corresponding to the measurement result of the temperature measuring unit S2 from the fuel information and determines the identified supply amount as the target value of the fuel amount. The control unit 51A refers to the mode information and identifies the drive pattern corresponding to the measurement result of the temperature measuring unit S2 and determines the identified drive pattern as the drive pattern for the oxygen burner E2.

[0071] Based on the fact that the priority control type is odor priority control, the control unit 51A executes [4] odor priority control. Odor priority control does not use the measurement results of each measurement unit S1 and S2, but uses the measurement results of the odor measurement unit S3 to determine the target value of the fuel amount. Odor priority control does not use the measurement results of each measurement unit S1 and S2, but uses the measurement results of the odor measurement unit S3 to switch between oxygen supply and oxidative combustion.

[0072] Odor-priority control uses [g] fuel information and [h] mode information to switch between oxygen supply and oxidative combustion. In odor-priority control, the control unit 51A identifies the supply amount corresponding to the measurement result of the odor measurement unit S3 from the fuel information and determines the identified supply amount as the target value of the fuel amount. The control unit 51A refers to the mode information and identifies the drive pattern corresponding to the measurement result of the odor measurement unit S3 and determines the identified drive pattern as the drive pattern for the oxygen burner E2.

[0073] As shown in Figure 4, the output device 53 displays various information for odor treatment on the processing status screen 60. Furthermore, the output device 53 displays the status of odor treatment by the control device 51 on the processing status screen 60. The output device 53 may also display the measurement results of the CO measurement unit S1, the temperature measurement unit S2, and the odor measurement unit S3 on the processing status screen 60.

[0074] The processing status screen 60 includes a control mode column 61, measurement unit status columns 62, 63, 64, priority mode column 65, odor threshold column 66, and air-fuel ratio column 67. The control mode column 61 indicates whether the control device 51 is performing automatic control or manual control. Whether to perform automatic or manual control is determined by the control device 51 based on whether automatic control is specified or not. The control mode column 61 displays "Automatic Mode" when automatic control is being performed. The control mode column 61 also displays "Manual Mode" when manual control is being performed. In this way, the odor treatment device that displays the type of control on the processing status screen 60 assists the user in determining the appropriateness of automatic control. Furthermore, the odor treatment device that displays the type of control on the processing status screen 60 assists the user in determining the appropriate timing for switching to automatic control.

[0075] The measurement unit status columns 62, 63, and 64 indicate whether each measurement unit S1, S2, and S3 is usable or not. For example, the odor measurement unit status column 62 lights up "Odor Measurement in Use" when the odor measurement unit S3 is usable and turns off "Odor Measurement in Use" when the odor measurement unit S3 is unusable, such as during maintenance or malfunction. The temperature measurement unit status column 63 lights up "Temperature Measurement in Use" when the temperature measurement unit S2 is usable and turns off "Temperature Measurement in Use" when the temperature measurement unit S2 is unusable, such as during maintenance or malfunction. The CO measurement unit status column 64 lights up "Gas Analysis in Use" when the CO measurement unit S1 is usable and turns off "Gas Analysis in Use" when the CO measurement unit S1 is unusable, such as during maintenance or malfunction. In this way, the odor treatment device, which displays the availability of each measurement unit S1, S2, and S3 on the processing status screen 60, helps users understand the reasons for selecting various controls.

[0076] The priority mode column 65 indicates whether the control device 51 is performing [3] temperature priority control or [4] odor priority control. For example, the priority mode column 65 displays "temperature priority mode" during automatic control execution based on the type of priority control input to the input device 52 being temperature priority control. The priority mode column 65 displays "odor priority mode" during automatic control execution based on the type of priority control input to the input device 52 being odor priority control. In this way, the odor control device that displays the type of priority control on the processing status screen 60 assists the user in determining the appropriateness of the type of priority control. Furthermore, the odor control device that displays the type of priority control on the processing status screen 60 assists the user in determining the appropriate timing for switching between priority controls.

[0077] The odor threshold column 66 displays the odor threshold stored in the memory unit 51B. The air-fuel ratio column 67 displays the target air-fuel ratio stored in the memory unit 51B. The corrected oxygen list 68 shows the correspondence of corrected oxygen information stored in the memory unit 51B. As shown in Figure 4, the corrected oxygen information associates, for example, the common corrected oxygen amount Qox0 with the amount of unused carbon monoxide 68A. When the control unit 51A does not use the CO measurement unit S1 to determine the target value of the corrected oxygen amount, it determines that the amount of carbon monoxide 68A is unused. When the control unit 51A determines the corrected oxygen amount regardless of the carbon monoxide concentration, it refers to the corrected oxygen information and sets the common corrected oxygen amount Qox0 as the target value of the corrected oxygen amount.

[0078] For example, the corrected oxygen information associates a second corrected oxygen amount Qox2 with a carbon monoxide amount 68A between 0.0 and less than 0.5. For example, the corrected oxygen information associates a third corrected oxygen amount Qox3 with a carbon monoxide amount 68A between 0.5 and less than 2.0.

[0079] When the control unit 51A uses the measurement results of the CO measurement unit S1 to determine the target value of the corrected oxygen amount, if the carbon monoxide amount 68A is 0.0 or more and less than 0.5, the control unit 51A sets the target value of the corrected oxygen amount to the second corrected oxygen amount Qox2. On the other hand, if the carbon monoxide amount 68A is 0.5 or more and less than 2.0, the control unit 51A sets the target value of the corrected oxygen amount to the third corrected oxygen amount Qox3.

[0080] The fuel list 69 shows the mapping of fuel information stored in the memory unit 51B. As shown in Figure 4, the fuel information maps, for example, the maximum fuel amount Qf0 to an exhaust gas temperature 69A between 0°C and 700°C. The fuel information maps, for example, the first fuel amount Qf1 to an exhaust gas temperature 69A between 700°C and 750°C. The fuel information maps, for example, the second fuel amount Qf2 to an exhaust gas temperature 69A between 750°C and 800°C.

[0081] When the control unit 51A uses the measurement result of the temperature measurement unit S2 to determine the target value of the fuel amount, that is, when performing temperature priority control, if the measurement result is 0°C or higher and less than 700°C, it sets the target value of the fuel amount to the maximum fuel amount Qf0. On the other hand, if the measurement result is 700°C or higher and less than 750°C, the control unit 51A sets the target value of the target fuel amount to the first fuel amount Qf1.

[0082] As shown in Figure 4, the fuel information associates, for example, the maximum fuel amount Qf0 with odor levels 69B of 400 or higher. The fuel information associates, for example, the first fuel amount Qf1 with odor levels 69B between 250 and 400. The fuel information associates, for example, the second fuel amount Qf2 with odor levels 69B between 150 and 250.

[0083] When the control unit 51A uses the measurement result of the odor measurement unit S3 to determine the target value of the fuel amount, that is, when executing odor priority control [4], if the measurement result is 400 or more, it sets the target value of the fuel amount to the maximum fuel amount Qf0. On the other hand, if the measurement result is 250 or more and less than 400, the control unit 51A sets the target value of the fuel amount to the second fuel amount Qf2.

[0084] The processing status screen 60 includes a mode list 70. The mode list 70 shows the correspondence of mode information stored in the storage unit 51B. The mode information associates, for example, one common drive pattern 70A with one level of exhaust gas temperature 69A and one level of odor level 69B. The mode information associates a separate drive pattern 70A with each level of exhaust gas temperature 69A, and a separate drive pattern 70A with each level of odor level 69B. Each drive pattern 70A associates one of two modes 70B, either oxygen supply mode or oxidation combustion mode, with each oxygen burner E2A, E2B, E2C, E2D, or E2E.

[0085] For example, the mode information associates one pattern P1 with exhaust gas temperatures 69A between 0°C and 700°C, and odor levels 69B above 400. The mode information associates one pattern P2 with exhaust gas temperatures 69A between 700°C and 750°C, and odor levels 69B between 250 and 400. The mode information associates one pattern P3 with exhaust gas temperatures 69A between 750°C and 800°C, and odor levels 69B between 150 and 250. The mode information associates one pattern P4 with exhaust gas temperatures 69A between 800°C and 900°C, and odor levels 69B between 100 and 150. The mode information associates one pattern P5 with exhaust gas temperatures 69A between 900°C and 1000°C, and odor levels 69B between 50 and 100.

[0086] Pattern P1 assigns the oxidative combustion mode to all oxygen burners E2A, E2B, E2C, E2D, and E2E. Pattern P1 assigns all oxygen burners E2A, E2B, E2C, E2D, and E2E the task of emitting a high-temperature flame using oxygen and oxidizing odor compounds.

[0087] Pattern P1 allocates a portion of the maximum fuel amount Qf0, which is the target value of the fuel amount, to the oxygen burners E2A, E2B, E2C, E2D, and E2E. The control device 51 controls the fuel supply so that each oxygen burner E2A, E2B, E2C, E2D, and E2E is supplied with fuel equivalent to the amount allocated to that burner.

[0088] For example, pattern P1 allocates 15% of the maximum fuel amount Qf0 to oxygen burner E2A. Pattern P1 allocates 21% of the maximum fuel amount Qf0 to oxygen burner E2B. Pattern P1 allocates 22% of the maximum fuel amount Qf0 to oxygen burners E2C and E2D, respectively. Pattern P1 allocates 20% of the maximum fuel amount Qf0 to oxygen burner E2E.

[0089] Pattern P2 assigns an oxidative combustion mode to all oxygen burners E2A, E2B, E2C, E2D, and E2E. Pattern P2 allocates a portion of the target fuel amount, the first fuel amount Qf1, to oxygen burners E2A, E2B, E2C, E2D, and E2E. Pattern P2 allocates the first fuel amount Qf1 to oxygen burners E2A, E2B, E2C, E2D, and E2E with a different value than Pattern P1.

[0090] For example, pattern P2 allocates 15% of the maximum fuel amount Qf0 to oxygen burner E2A. Pattern P1 allocates 20% of the maximum fuel amount Qf0 to oxygen burners E2B, E2C, and E2E. Pattern P1 allocates 25% of the maximum fuel amount Qf0 to oxygen burner E2D.

[0091] Pattern P3 associates the oxygen supply mode, indicated by "E", with the two oxygen burners E2A and E2E. Pattern P3 associates the oxidation combustion mode with the three oxygen burners E2B, E2C, and E2D. Pattern P3 allocates a portion of the second fuel amount Qf2, which is the target fuel amount, to the three oxygen burners E2B, E2C, and E2D. For example, Pattern P3 allocates 30% of the second fuel amount Qf2 to oxygen burners E2B and E2D. Pattern P3 allocates 40% of the second fuel amount Qf2 to oxygen burner E2C.

[0092] Pattern P4 associates the oxygen supply mode, indicated by "E", with the four oxygen burners E2A, E2B, E2D, and E2E. Pattern P4 associates the oxidation combustion mode with the single oxygen burner E2C. Pattern P4 distributes the entire target fuel amount to the single oxygen burner E2C. Pattern P5 associates the oxygen supply mode, indicated by "E", with all oxygen burners E2A, E2B, E2D, and E2E.

[0093] (Odor treatment method) The odor treatment method performed by the odor treatment device is described below. In the odor treatment method, the odor treatment device repeatedly determines the target value of the fuel amount, the target value of the oxygen amount, and the target value of the corrected oxygen amount at predetermined intervals.

[0094] [0] Manual control As shown in Figure 5, the control device 51 checks whether automatic control is specified and determines whether manual control is selected or automatic control is selected. If the control device 51 determines that manual control is selected for odor treatment (NO in step S11), it applies the [a] manual preset mapping to the drive mode of each oxygen burner E2. The control device 51 then applies the [a] manual preset values ​​to the target values ​​of the fuel amount and the oxygen amount, thereby completing the determination of each target value (step S31).

[0095] If the control device 51 determines that automatic control is specified for odor treatment (YES in step S11), it determines whether the odor measurement unit S3 is usable. If the control device 51 determines that the odor measurement unit S3 is unusable (NO in step S12), it determines whether the temperature measurement unit S2 is usable. If the control device 51 determines that both the odor measurement unit S3 and the temperature measurement unit S2 are unusable (NO in step S32), it determines whether the CO measurement unit S1 is usable. If the control device 51 determines that all measurement units S1, S2, and S3 are unusable (NO in step S33), it applies the [a] manual preset mapping to the drive mode of each oxygen burner E2. Then, the control device 51 applies the [a] manual preset values ​​to the target values ​​of the fuel amount and the target values ​​of the oxygen amount (step S31), thereby completing the determination of the target values.

[0096] On the other hand, if the control device 51 determines that the odor measuring unit S3 is unavailable and the temperature measuring unit S2 is available (YES in step S32), it proceeds to [3] temperature priority control (step S18).

[0097] [1] Low odor control If the control device 51 determines that automatic control is specified for odor treatment and that the odor measuring unit S3 is usable (YES in step S12), it executes low-odor control (steps S13 to S15).

[0098] In this process, the control device 51 refers to [a] the low odor preset and applies the correspondence of the low odor preset to the drive mode of each oxygen burner E2 until the measurement result of the odor measurement unit S3 is [d] equal to or greater than the odor threshold. The control device 51 also applies the fixed values ​​of the [b] low odor preset to the target value of the fuel amount, the target value of the oxygen amount, and the target value of the corrected oxygen amount until the measurement result of the odor measurement unit S3 is [d] equal to or greater than the odor threshold (step S14).

[0099] As a result, the control device 51 reduces fuel supply and suppresses the generation of excess heat when little odor compounds are generated or when little iron scrap is charged into the preheating chamber 12. Then, when the measurement result of the odor measurement unit S3 exceeds the odor threshold, the control device 51 switches to priority control (step S15).

[0100] [2] Fixed fuel control If the control device 51 determines that the odor measurement unit S3 is unavailable, the temperature measurement unit S2 is unavailable, and the CO measurement unit S1 is available (YES in step S33), it proceeds to [2] fixed fuel control.

[0101] In this step, the control device 51 refers to the fuel preset and determines the drive mode of the oxygen burner E2, which is associated with the oxidative combustion mode in the fuel preset, to be the oxidative combustion mode. The control device 51 also applies the fixed value of the fuel preset to the target value of the fuel amount (step S34). Then, the control device 51 proceeds to determine the target value of the oxygen amount and the target value of the corrected oxygen amount (step S22A).

[0102] [3] Temperature priority control The control device 51 determines whether the temperature measuring unit S2 is usable in priority control. When the control device 51 determines that the odor measuring unit S3 is usable and the temperature measuring unit S2 is usable (YES in step S16), it determines whether the type of priority control is temperature priority control or odor priority control. When the control device 51 determines that the type of priority control is temperature priority control (YES in step S17), it refers to the temperature level correspondence in the mode information (step S18) and switches to temperature priority control.

[0103] In this step, the control device 51 applies the measurement result of the temperature measuring unit S2 to the mode information and identifies a drive pattern 70A that corresponds to the level of the measurement result. The control device 51 refers to the identified drive pattern 70A and determines that the drive mode of the oxygen burner E2, which is associated with the oxidative combustion mode, is the oxidative combustion mode (step S19).

[0104] Furthermore, the control device 51 applies the measurement results from the temperature measurement unit S2 to the fuel information and determines the fuel amount corresponding to the level of the measurement result as the target value of the fuel amount. Then, the control device 51 allocates the determined target value of fuel amount to the oxygen burner E2 which has been determined to be in oxidative combustion mode (step S20).

[0105] [4] Odor priority control On the other hand, if the control device 51 determines that the odor measurement unit S3 is usable and the temperature measurement unit S2 is unavailable (NO in step S16), it refers to the odor level correspondence in the mode information (step S21) and switches to odor priority control.

[0106] Furthermore, if the control device 51 determines that the odor measurement unit S3 is usable, the temperature measurement unit S2 is usable, and the type of priority control is not temperature priority control (NO in step S17), it refers to the odor level correspondence in the mode information (step S21) and switches to odor priority control.

[0107] In this case, the control device 51 applies the measurement results of the odor measurement unit S3 to the mode information and extracts a drive pattern 70A that corresponds to the level of the measurement results. The control device 51 refers to the extracted drive pattern 70A and determines that the drive mode of the oxygen burner E2, which is associated with the oxidative combustion mode, is the oxidative combustion mode (step S22).

[0108] Furthermore, the control device 51 applies the measurement results from the odor measurement unit S3 to the fuel information and determines the fuel amount corresponding to the level of the measurement results as the target value for the fuel amount. Then, the control device 51 allocates the determined target value for the fuel amount to the oxygen burner E2, which has been determined to be in oxidative combustion mode (step S20).

[0109] [Corrective oxygen control] As shown in Figure 6, once the control device 51 has determined the target value for the fuel amount, it determines whether the CO measurement unit S1 is usable or not. If the control device 51 determines that the CO measurement unit S1 is usable (YES in step S21A), it refers to the identified drive pattern 70A and determines whether or not there is an oxygen supply mode. Alternatively, if the control device 51 determines that the odor measurement unit S3 is unavailable, the temperature measurement unit S2 is unavailable, and the CO measurement unit S1 is usable (YES in step S33), it refers to the [c] fuel preset and determines whether or not there is an oxygen supply mode.

[0110] If the control device 51 determines that there is an oxygen supply mode (YES in step S22A), it sets the drive mode of the oxygen burner E2 associated with the oxygen supply mode to the oxygen supply mode (step S23). The control device 51 also applies the measurement result of the CO measurement unit S1 to the corrected oxygen information (step S24), and sets the corrected oxygen amount associated with the level of the measurement result to the target value of the corrected oxygen amount for all oxygen burners E2 (step S25). Then, the control device 51 refers to the target air-fuel ratio (step S26) and determines whether or not it is referring to the [c] fuel preset (step S27).

[0111] When the control device 51 determines that it is referring to a fuel preset, it determines a target value for the amount of oxygen from the target value of the fuel amount, which is a fixed value of the combustion preset, so as to satisfy the target air-fuel ratio for the oxygen burner E2 which has been determined to be in oxidation combustion mode (step S27A). Also, when the control device 51 determines that it is referring to a fuel preset, it distributes the determined target value of the corrected oxygen amount to the oxygen burner E2 which has been determined to be in oxygen supply mode (step S27C).

[0112] If the control device 51 determines that the fuel preset is not being referenced, it determines a target value for the amount of oxygen from the target value of the allocated fuel to satisfy the target air-fuel ratio for the oxygen burner E2 which has been determined to be in oxidative combustion mode (step S27B). Also, if the control device 51 determines that the fuel preset is not being referenced, it distributes the determined target value of the corrected oxygen amount to the oxygen burner E2 which has been determined to be in oxygen supply mode (step S27C).

[0113] In response, if the control device 51 determines that at least one of the odor measuring unit S3 and the temperature measuring unit S2 is usable and the CO measuring unit S1 is unavailable (NO in step S21A), it refers to the identified drive pattern 70A and executes processing for each drive mode.

[0114] In this case, if the control device 51 finds that an oxygen supply mode exists in the identified drive pattern 70A (YES in step S41), it determines the drive mode of the oxygen burner E2 associated with the oxygen supply mode to be the oxygen supply mode. The control device 51 also refers to the corrected oxygen information and determines the common corrected oxygen amount Qox0 associated with non-use as the target value of the corrected oxygen amount for all oxygen burners E2 (step S42). Then, the control device 51 distributes the determined target value of the corrected oxygen amount equally among the oxygen burners E2 that have been determined to be in oxygen supply mode (step S43).

[0115] Furthermore, if an oxidative combustion mode exists in the identified drive pattern 70A (NO in step S22A, NO in step S41), the control device 51 refers to the target air-fuel ratio (step S44). Then, for the oxygen burner E2 determined to be in oxidative combustion mode, the control device 51 determines a target value for the oxygen amount from the target value of the fuel amount of the oxygen burner E2 so as to satisfy the target air-fuel ratio (step S45).

[0116] As a result, the control device 51 stops the fuel supply to some oxygen burners E2 to the extent that the odor level is suppressed, and supplies oxygen to other oxygen burners E2 to satisfy the target air-fuel ratio. Then, as the temperature level rises, the control device 51 increases the number of burners from which the fuel supply is stopped and reduces the heat generated by combustion to satisfy the target air-fuel ratio. Furthermore, as the temperature level falls, the control device 51 decreases the number of burners from which the fuel supply is stopped and increases the heat generated by combustion to satisfy the target air-fuel ratio. Furthermore, as the odor level rises, the control device 51 decreases the number of burners from which the fuel supply is stopped and increases the heat generated by combustion to satisfy the target air-fuel ratio. Furthermore, as the odor level falls, the control device 51 increases the number of burners from which the fuel supply is stopped and reduces the heat generated by combustion to satisfy the target air-fuel ratio.

[0117] Furthermore, according to the odor treatment method executed by the control device 51, a significant reduction in the emission of odor compounds such as acetaldehyde, isobutyraldehyde, toluene, xylene, formaldehyde, methanol, and propionaldehyde was observed compared to the case where the oxygen burner E2 is not installed in the combustion chamber 20. For example, acetaldehyde was reduced to less than 0.3% of the detected amount when the oxygen burner E2 is not installed in the combustion chamber 20, and isobutyraldehyde was reduced to less than 6% of the detected amount when the oxygen burner E2 is not installed in the combustion chamber 20. In addition, toluene was reduced to less than 5% of the detected amount when the oxygen burner E2 is not installed in the combustion chamber 20, and xylene was reduced to less than 28% of the detected amount when the oxygen burner E2 is not installed in the combustion chamber 20.

[0118] According to the above embodiment, the following effects can be obtained. (1) Because the thermal decomposition of organic matter and the oxidation of odor compounds proceed in this order, thermal decomposition in accordance with elementary reactions proceeds smoothly in the intake duct 13 where oxygen is not supplied. As a result, organic matter is easily thermally decomposed into odor compounds. Furthermore, by promoting the thermal decomposition of organic matter before oxidation, the oxidation of odor compounds is promoted, thereby suppressing odor release.

[0119] (2) If oxygen for oxidizing odor compounds were to be supplied to the preheating chamber 12, the oxidation of the iron scrap would be promoted, leading to a decrease in yield and an increase in the amount of slag. Also, if oxygen for oxidizing odor compounds were to be supplied to the preheating chamber 12, excessive melting of the iron scrap would occur in the preheating chamber 12, leading to welding of the iron scrap in the preheating chamber 12. In this respect, if the oxygen for oxidizing odor compounds is supplied to the combustion chamber 20, the decrease in yield and the increase in the amount of slag can be suppressed.

[0120] Furthermore, if oxygen to oxidize odor compounds were to be supplied to the preheating chamber 12, it would be necessary to install oxygen supply equipment inside the steelmaking room 10. Inside the steelmaking room 10, the electric furnace and the equipment that operates it are densely packed, making it usually difficult to install new oxygen supply equipment. In this respect, if the oxygen is supplied to the combustion chamber 20 located outside the steelmaking room 10, it becomes easier to secure space for installing oxygen supply equipment.

[0121] (3) Supplying oxygen to the combustion chamber 20 is easier to install the oxygen burner E2 compared to supplying oxygen to the joint between the preheating chamber 12 and the intake duct 13. If the temperature of the exhaust gas is raised to the temperature at which odor compounds oxidize, it is effective to reduce the flow velocity of the exhaust gas to ensure the residence time of the exhaust gas. It is usually impossible to secure such a large volume at the joint between the preheating chamber 12 and the intake duct 13, but it is possible with oxygen supply to the combustion chamber 20. Also, it is usually difficult to identify the range in which the oxidation reaction proceeds within the intake duct 13 where the exhaust gas flow velocity is relatively high, but it is possible with oxygen supply to the combustion chamber 20, which can reduce the flow velocity of the exhaust gas. Furthermore, compared to supplying oxygen to the joint between the preheating chamber 12 and the intake duct 13, supplying oxygen to the combustion chamber 20 makes it easier to identify the range in which the oxidation reaction proceeds in response to the rapid expansion of exhaust volume due to the progress of the oxidation reaction, thus increasing the structural and thermal load resistance.

[0122] (4) When supplying oxygen to the joint between the preheating chamber 12 and the intake duct 13, if the temperature of the exhaust gas is low at the joint, combustion of the exhaust gas will not proceed, and only the temperature of the exhaust gas will be lowered. In this respect, supplying oxygen to the combustion chamber 20 supplies oxygen to the combustion environment of the odor compounds, thus increasing the likelihood of deodorizing the odor compounds.

[0123] (5) When the oxygen burner E2 is driven by oxygen supply, the oxidation of odor compounds is promoted by the oxygen supply, and the fuel consumption of the oxygen burner E2 is reduced. (6) When the oxygen burner E2 is driven by oxidative combustion, the oxidation of odor compounds proceeds by oxidative combustion. Controlling the oxygen burner E2, which can reversibly switch between oxygen supply and oxidative combustion, not only suppresses odor emission but also allows for the reduction of excess heat in odor treatment.

[0124] Furthermore, while the thermal decomposition of organic matter requires temperatures between 300°C and 500°C, secondary combustion, such as the oxidation of odor compounds, may require temperatures above 750°C. If oxygen for oxidizing odor compounds were supplied to the preheating chamber 12, the oxidation of odor compounds would become difficult to promote if the exhaust gas temperature in the preheating chamber 12 decreased. In this respect, if oxygen is supplied to the combustion chamber 20 through the oxygen supply of the oxygen burner E2, the likelihood of secondary combustion, such as the oxidation of odor compounds, proceeding increases even if the exhaust gas temperature in the preheating chamber 12 decreases.

[0125] (7) Furthermore, since the oxygen burner E2, which is a single device, switches between oxygen supply and oxidative combustion, the cessation of oxidative combustion and the commencement of oxygen supply proceed simultaneously. This makes it possible to improve the responsiveness of the heat quantity in the combustion chamber 20 to changes in the measurement results of each measurement unit S2, S3. This increases the effectiveness of suppressing excess heat in odor treatment.

[0126] (8) The lower the measurement result from the odor measurement unit S3, the more the oxygen burner E2 switches from oxidative combustion to oxygen supply. Furthermore, the lower the odor level, the greater the number of burners in oxygen supply mode, and since the number of burners is preset according to the odor level, the effectiveness of suppressing excess heat is further enhanced.

[0127] (9) The higher the measurement result from the temperature measurement unit S2, the more the oxygen burner E2 switches from oxidative combustion to oxygen supply. As a result, unnecessary fuel consumption is suppressed, such as when odor emission is suppressed. Also, because the [3] temperature priority control switches to the [4] odor priority control, excess heat for odor treatment is suppressed even when the temperature measurement unit S2 malfunctions. Similarly, because the [4] odor priority control switches to the [3] temperature priority control, excess heat for odor treatment is suppressed even when the odor measurement unit S3 malfunctions.

[0128] (10) The higher the measurement result from the CO measurement unit S1, the more the amount of compensatory oxygen supplied to the combustion chamber 20 is increased. As a result, the emission of carbon monoxide is suppressed while obtaining the effects described in (1) to (6) above.

[0129] The above embodiment can also be implemented with the following modifications. [Automatic control] The control device 51 may receive instructions from the input device 52 to sequentially execute [4] odor priority control and [5] compensatory oxygen control, and execute [4] odor priority control and [5] compensatory oxygen control accordingly. In other words, the control device 51 may receive separate instructions for the execution of each of the controls [1] to [5] from the input device 52, and execute the controls specified in the execution instructions in the order specified. In this case, the control device 51 may omit controls that are not specified in the execution instructions, such as [1] low odor control or controls that are not specified.

[0130] [4] Odor priority control returns the measurement results from the odor measurement unit S3, which is the output, to the input, thereby changing the target values ​​of each control value, and thus improving the real-time capability of suppressing odor levels. [3] Temperature priority control also returns the measurement results from the temperature measurement unit S2, which is the output, to the input, thereby changing the target values ​​of each control value, and thus improving the real-time capability of suppressing odor levels. In other words, these priority controls [3] and [4] allow thermal decomposition and oxidation to smoothly follow steep changes in odor levels, sudden changes in odor levels, or transient changes in odor levels, thereby making the odor level suppression effect even more pronounced.

[0131] In this case, the control device 51 may monitor the degree of change in the measurement results of the odor measurement unit S3. When the degree of change in the measurement results is within a predetermined range, the control device 51 may perform [1] low odor control or [2] fixed fuel control. When the degree of change in the measurement results is outside the predetermined range, the control device 51 may perform [4] odor priority control.

[0132] Similarly, the control device 51 may monitor the degree of change in the measurement results of the temperature measuring unit S2. When the degree of change in the measurement results is within a predetermined range, the control device 51 may perform [1] low odor control or [2] fixed fuel control. When the degree of change in the measurement results is outside the predetermined range, the control device 51 may perform [3] temperature priority control.

[0133] The control device 51 may receive an execution instruction from the input device 52 to alternately repeat [4] odor priority control and [3] temperature priority control, thereby alternately executing [4] odor priority control and [3] temperature priority control. Alternatively, the control device 51 may receive an instruction from the input device 52 to alternately repeat [5] corrected oxygen control using the measurement results of the CO measurement unit S1 and [5] corrected oxygen control not using the measurement results of the CO measurement unit S1, thereby alternately changing the processing by [5] corrected oxygen control. In this way, the control device 51 may repeat separate controls using the measurement results of each measurement unit S1, S2, and S3 as a single set.

[0134] The control device 51 may obtain permission from the input device 52 to switch from one control to another when executing each of the controls [1] to [5]. This configuration improves the processing accuracy by switching between each control.

[0135] For example, if the control device 51 determines that the odor level is above the odor threshold, it may prompt the input device 52 to grant permission to switch from [1] low odor control to priority control via the display of the output device 53. Alternatively, if the control device 51 determines that the odor measurement unit S3 has become usable, it may prompt the input device 52 to grant permission to switch from [2] fixed fuel control to [4] odor priority control via the display of the output device 53. Or, if the control device 51 determines that the odor measurement unit S3 has become usable, it may prompt the input device 52 to grant permission to switch from [3] temperature priority control to [4] odor priority control via the display of the output device 53.

[0136] The control device 51 may determine whether or not to apply the measurement results of each measurement unit S1, S2, and S3 to odor treatment based solely on the type of priority control. For example, if the type of priority control is odor priority control, the control device 51 may refer to the type of priority control and omit the determination of whether or not to use the temperature measurement unit S2.

[0137] The control device 51 may perform priority control to identify pattern P1 as the drive pattern 70A, and in the next control cycle after the priority control, it may perform priority control to identify pattern P2 as the drive pattern 70A, or it may perform priority control to identify pattern P3. In other words, the control device 51 may change the change in oxygen supply by changing the number of oxygen burners E2 whose drive mode is switched. If the number of oxygen burners E2 to be switched is changed, it becomes easier to make the combustion changes in the combustion chamber 20 follow the changes in organic matter generation in order to suppress the odor level, whether the odor level rises sharply or the temperature level falls sharply.

[0138] Furthermore, the control device 51 may change the change in the corrected oxygen supply by changing the number of oxygen burners E2 whose drive mode is switched. If the number of oxygen burners E2 to be switched is changed, it becomes easier to make the combustion changes in the combustion chamber 20 follow the change in the amount of carbon monoxide so as to suppress the amount of carbon monoxide, whether the amount of carbon monoxide increases sharply or decreases sharply.

[0139] [Mode Information] The mode information may consist of two or more patterns in which the arrangement of oxygen burners E2 for each mode differs from one another. For example, the number of oxygen burners E2 corresponding to the oxygen supply mode may be the same in the two patterns, and the number of oxygen burners E2 corresponding to the oxidation combustion mode may be the same, and only the arrangement of oxygen burners E2 for each mode may differ. This configuration allows for detailed modification of the heat supply location within the combustion chamber 20.

[0140] The mode information may include patterns that associate either combustion or extinction with the pyrolysis burners C1A and C1B. The mode information may also include patterns that associate either combustion or extinction with the air combustion burners C1C and C1D. With these configurations, it becomes possible to control pyrolysis and oxidation in the exhaust system, including the intake duct 13, based on the measurement results of each measurement unit S2 and S3.

[0141] [Oxygen Supply Unit] The pyrolysis burners C1A and C1B can be replaced with oxygen burners that burn fuel using oxygen. The pyrolysis burners C1A and C1B may be omitted from the odor treatment system. In this case, the odor treatment system simultaneously carries out (i) the pyrolysis of organic matter and (ii) the oxidation of odor compounds in the combustion chamber 20.

[0142] The oxygen burner E2 can be changed to an air combustion burner that uses air for combustion. In this case, the control device 51 changes the controlled amount, which is the amount of oxygen and the corrected amount of oxygen, to the amount of air supplied to the air combustion burner and the corrected amount of air.

[0143] The oxygen supply unit that supplies oxygen to the combustion chamber 20 can be changed to a separate device from the oxygen burner E2, which is specialized for supplying oxygen and performs oxidative combustion, such as an oxygen supply nozzle. In this case, the oxygen burner E2 may be changed to an air combustion burner.

[0144] [Odor Treatment System] • Odor treatment systems are applicable not only to steelmaking but also to technologies that burn odor compounds, such as waste incineration. [Explanation of Symbols]

[0145] C1A, C1B... Pyrolysis burner C1, C1C, C1D... Air combustion burner E2, E2A, E2B, E2C, E2D, E2E... Oxygen burners Qf0…Maximum fuel amount Qf1…1st fuel amount Qf2…Second fuel amount Qox0…Common Corrected Oxygen Amount Qox2…Second Correction Oxygen Level Qox3…Third Correction Oxygen Level S1...CO measuring section S2…Temperature measurement section S3...Odor measurement unit 10…Steelmaking Room 11…Dissolution chamber 12… Preheating chamber 12A, 22... Exhaust port 12B... Air intake 13…Intake duct 14… Explosion-proof valve 20... Combustion chamber 21... Dust discharge door 32...Cooling room 33…Direct-draw dust collection fan 34… Exhaust dust collection room 35... Direct recruitment fan 41... Building ducts 42…Building dust collection fan 43…Building dust collection room 51...Control device 51A...Control Unit 51B…Storage section 52…Input device 53…Output device 60... Processing status screen 61...Control Mode Section 62, 63, 64... Measurement section status column 65…Priority Mode Section 66... ​​Odor threshold column 67…Air-fuel ratio column 68A...Carbon monoxide content 68B... Odor level 69A... Exhaust gas temperature 69B... Odor level

Claims

1. An exhaust section that discharges gas containing organic matter, A combustion unit connected to the discharge unit, the combustion unit burns the organic matter discharged from the discharge unit, A processing unit connected to the combustion unit, the processing unit cools the gas discharged from the combustion unit and releases it into the atmosphere, An odor treatment device comprising: The aforementioned processing unit includes an odor measuring unit that measures the odor level in the gas before release, The system includes a control unit that controls the combustion unit to reduce the amount of heat supplied by the combustion unit to the odor compounds generated from the organic matter, as the measurement result of the odor measuring unit is at a lower level. The aforementioned combustion section is The system includes multiple oxygen burners that heat the odor compounds by burning fuel using a gas with a higher oxygen concentration than air. The control unit, The lower the measurement result from the odor measuring unit, the more the combustion unit is controlled to reduce the heat output by stopping the fuel supply to at least some of the multiple oxygen burners and supplying only oxygen with gas that has a higher oxygen concentration than air. Odor treatment device.

2. The control unit, The change in heat quantity is altered by changing the number of oxygen burners that switch to the aforementioned oxygen supply. The odor treatment apparatus according to claim 1.

3. The system further includes a storage unit that stores mode information, which associates separate drive patterns with multiple odor levels that are different from each other. The aforementioned drive pattern is This information associates each oxygen burner with either an oxygen supply mode that only supplies oxygen, or an oxidative combustion mode that produces a flame. The aforementioned mode information is, The odor level is associated with the drive pattern such that the number of oxygen burners associated with the oxygen supply mode increases as the odor level decreases. The control unit, The plurality of oxygen burners are driven according to the drive pattern corresponding to the odor level that corresponds to the measurement result of the odor measuring unit. The odor treatment apparatus according to claim 1 or 2.

4. The system further includes a temperature measuring unit for measuring the temperature of the gas discharged from the combustion section. The control unit, The first treatment involves reducing the amount of heat supplied by the combustion unit to the odor compound as the measurement result from the odor measuring unit becomes lower. A second process is performed in which the amount of heat supplied by the combustion unit to the odor compound is reduced as the measurement result of the temperature measurement unit becomes higher, and this process is reversibly switched. The odor treatment apparatus according to claim 1 or 2.

5. The combustion section is supplied with an oxygen supply unit that supplies a gas with a higher oxygen concentration than air, The system further includes a CO measuring unit for measuring the amount of carbon monoxide emitted together with the odor compound, The control unit, The amount of oxygen supplied to the combustion section is set so that the higher the measurement result from the CO measurement unit, the greater the amount of oxygen supplied to the combustion section. The odor treatment apparatus according to claim 1 or 2.

6. The first process and the second process are priority control, The control unit, The system is configured to execute the priority control when the measurement result of the odor measuring unit is above a predetermined level, and to execute a predetermined process other than the priority control when the measurement result of the odor measuring unit is below the predetermined level. The odor treatment apparatus according to claim 4.

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