Extraction or dust removal system for metalworking industrial plants, method for operating the extraction or dust removal system and computer program

Description

[0001] Extraction or dust removal system for metallurgical industrial plants and a method for operating the extraction or dust removal system. Title of the invention field of technology

[0002] The present invention relates to the field of extraction or dust removal systems for metallurgical industrial plants.

[0003] On the one hand, the invention relates to a method for operating an extraction and / or dust removal system of a metallurgical industrial plant and to an extraction or dust removal system, wherein the extraction and / or dust removal system comprises at least the following components: a metallurgical unit, an extraction duct, an extraction device, an extraction control and / or extraction regulation of the extraction device based on at least one predefined value dependent on the operating state of the metallurgical unit, a camera system for detecting outflowing flue gas in the area of ​​the metallurgical unit, an outflow control for quantifying the outflowing flue gas detected by the camera system and for controlling the extraction device in the event of outflowing flue gas.

[0004] On the other hand, the invention relates to a computer program and a computer-readable medium. State of the art

[0005] Steel production processes are equipped with extraction and dust collection systems. For the most part, the required extraction volume remains relatively constant. This volume can be determined by the process conditions of the primary process, such as the oxygen bubble rate in a steelmaking converter and / or the current hood pressure. Typically, pressure control in the extraction duct influences the flow rate control of the extraction system. The flow rate control, in turn, influences the speed control. The interaction of these various control loops results in a certain inertia in the control function during normal operation. This inertia can also lead to a slow response to large flames and / or bursts of exhaust gases.In such steelmaking processes, for example, material additions or process fluctuations can lead to sudden pressure increases in the transition area between the primary unit and the extraction and dust removal system, which can subsequently result in flames or the release of emissions. These can lead to excessive emissions or the release of toxic gases within the production hall.

[0006] Document EP 3 748 267 A1 concerns industrial plants with different process phases. An automation unit controls an optical sensor system in such a way that, depending on the process phase, at least a predetermined area of ​​the industrial plant is monitored and flue gas emissions within that area are detected.

[0007] Document US 2010 / 208765 A1 shows a furnace damper control system. This includes a furnace with at least one opening through which electromagnetic radiation from the interior of the furnace can be detected, an exhaust duct that can receive an exhaust gas flow exiting the furnace, and a controllable damper that can regulate the pressure in the exhaust duct. Summary of the invention

[0008] The object of the invention is to provide a method which reacts very quickly to the occurrence of outbursts of flue gas in order to prevent outbursts of flue gas.

[0009] The task is solved by a surge control system, which determines the quantity of flue gas escaping as detected by the camera system and calculates the additional required surge extraction volume. This additional required surge extraction volume is used to set a new operating point for the extraction system from its current operating point. The surge control system transmits the new operating point directly to the extraction system, and from this point onward, the system takes over control of the extraction system exclusively until a predefined handover event defines the point at which the extraction system's control and / or regulation is once again used exclusively. A handover event could be, for example, that no more flue gas is escaping or that only 10% of the previously determined amount of flue gas remains.

[0010] By directly setting a new operating point via the exhaust control of the extraction system, a very rapid response is possible, and the escaping flue gas and flame formation can be suppressed very quickly. The exhaust control thus regulates the extraction system solely based on the current operating point and the amount of escaping flue gas, which is quantified by the camera system. However, the extraction control and / or regulation also operates based on predefined values, preferably dependent on the operating state of the metallurgical unit. For example, in the case of an LD converter, these predefined values ​​could depend on the current oxygen purge rate introduced through the oxygen nozzle. Predefined values ​​could include, for example, a volume flow rate or a pressure and / or pressure drop.

[0011] In a dust extraction system, at least one filter system - for cleaning extracted gas from the metallurgical industrial plant - is preferably arranged along the extraction duct.

[0012] In an advantageous embodiment, the quantity of the outgoing flue gas is determined by a method of optical flux and / or flame analysis.

[0013] The overflow control system determines the additional required overflow extraction volume using methods such as optical flow and / or flame analysis. The optical flow of an image sequence is a vector field representing a velocity projected onto an image plane. These velocity vectors are calculated and displayed for various pixels. Thus, the movement of characteristic patterns within image sequences can be used to determine, for example, the movement of characteristic smoke plumes. When a smoke plume moves, the characteristic pattern maintains its geometric shape, allowing the movement of this pattern to be detected within the image sequence. A velocity can then be determined. In flame analysis, the size of the flame is a criterion used to determine the additional extraction volume required.This results in a current flue gas volume in m³ / h from the flame size and flame / smoke velocity, which must be taken into account in the overburden control. Furthermore, the intensity of the overburden can be inferred from the size of the flames / smoke clouds. It is also conceivable that the scale-invariant feature transformation method (SIFT method) could be used.

[0014] In a suitable design, the exhaust system is an induced draft fan, a support fan, or a compressor.

[0015] A preferred embodiment provides that the handover event is a change in the process phase, the absence of any remaining flue gas, or a corresponding event defined by an operator. For example, an operator can specify that the flue gas control should only remain active until 90% of the flue gases have disappeared. The precise way in which the operator defines this event depends on the specific requirements of the extraction system and its regulations. For instance, the event could also stipulate that the handover should occur at least one minute after the flue gases have disappeared.

[0016] Another advantageous embodiment provides that the metallurgical unit is a converter, an electric arc furnace or a metallurgical melting device, for example an induction furnace.

[0017] The target values ​​for the suction control and / or regulation can, for example in an LD converter, depend on the current oxygen bubble rate introduced through the blow lance.

[0018] In an electric arc furnace (EAF), the carbon injection rate, the burner volume flow rate of a Refining Combined Burner (RCB), the current of the melting electrodes, the process progress and charged materials during the ongoing process can influence a setpoint value.

[0019] In a preferred embodiment, the new operating point is determined using a blower characteristic curve and a system characteristic curve of the extraction and / or dust removal system.

[0020] A new operating point can be determined using a blower characteristic curve and a system characteristic curve of the extraction or dust collection system. This new operating point is transmitted to the extraction unit and adjusted using setting parameters to achieve the new operating point. In a simple design, a relative increase in speed proportional to the current volume of exhausted flue gas is implemented. This speed increase is achieved using fixed values—based on experience gained from operating such systems—or is determined empirically.

[0021] One advantageous embodiment provides that the temperature of the exhaust flue gas is determined and used to calculate the required exhaust gas extraction rate. This temperature is determined, for example, by a calculation model. Based on the temperature of a product being manufactured by the metallurgical unit, the temperature of the flue gas can be calculated.

[0022] A particularly preferred embodiment provides that the camera system has a detectable wavelength range of 380 nm - 780 nm, 780 nm - 3000 nm, and / or 3 µm - 50 µm. Recordings are possible in both the visible and infrared ranges. The appropriate wavelength range must be selected depending on the recording situation and any interference. For consistently good lighting conditions in the metallurgical plant, a visible wavelength range of 400 nm - 780 nm is preferred. For poor and / or frequently changing lighting conditions, a near-infrared wavelength range of 780 nm - 3000 nm or a mid-infrared wavelength range of 3 µm - 50 µm is preferred. Such changing lighting conditions occur, for example, when the hall lighting is frequently switched on and off or when the sunlight intensity fluctuates.

[0023] The task is solved by an extraction system described below.

[0024] The extraction control and / or extraction regulation and the surge control are connected to the extraction system via a switch. The switch receives signals indicating whether the extraction control and / or extraction regulation is controlling the extraction system, or whether the surge control is controlling the extraction system. The surge control is configured to determine a new operating point for the extraction system based on the quantification of the surged flue gas detected by the camera system and the current operating point of the extraction system, in order to prevent surged flue gas. The switch can be a physical switch or part of program code. In any case, switching from the extraction control and / or extraction regulation to the surge control is necessary.The extraction system and / or dust removal system is always operated either by the extraction control or the discharge control. Therefore, switching between the extraction control and the discharge control is required.

[0025] An advantageous embodiment provides that the extraction device is an induced draft fan, a support fan or a compressor.

[0026] A suitable design provides that the metallurgical unit is a melting unit or a heating unit, for example an induction furnace.

[0027] One particularly advantageous embodiment provides that the metallurgical unit is a converter, an electric arc furnace, or a metallurgical melting device.

[0028] The task is further solved by a computer program comprising machine code that can be executed by a control device according to a previously described extraction or dust removal system, wherein the execution of the machine code by a control device causes the extraction or dust removal system to be operated according to a previously described method.

[0029] The task is also solved using a computer-readable medium on which the previously described computer program is stored. Brief description of the drawings

[0030] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of an exemplary embodiment, which is explained in more detail in conjunction with the drawings. These drawings show: Fig 1 und 2 A schematic representation of a control system for an extraction system for a metallurgical unit. Fig. 3 shows a schematic representation of a blower characteristic curve and a system characteristic curve. Description of the embodiments

[0031] In the Fig. 1 A schematic representation of an extraction or dust removal system 4 for a metallurgical unit 1 is shown; this could be, for example, an LD converter or an electric arc furnace. The extraction or dust removal system 4 has an extraction hood 2, an extraction duct 3, and an extraction device 9, which is, for example, designed as an induced draft fan. The extraction device 9 is connected via a switch 7. The switch 7 can toggle between an extraction control unit 6 and a discharge control unit 5. A preset value 6b is transmitted to the extraction control unit 6; this could be, for example, a volume flow rate, a pressure, or a desired pressure drop. The switch 7 can be a physical switch. However, it can also be implemented as program code, which, depending on the operating state, outputs a signal between the extraction control unit 6 and the discharge control unit 5 to a control line 9a. The switch is controlled via control signals 7a and 7b.These control signals 7a, 7b can be transmitted directly by the overflow control 5 and the extraction control 6, but it is also conceivable that these signals originate from a higher-level control system for the entire process of the extraction or dust removal system 4 and / or the metallurgical unit 1. The overflow control 5 is connected to a camera system 8, which can detect the overflowing flue gas 15. When overflowing flue gas 15 is detected, the overflow control 5 determines a volume flow rate of the overflowing flue gas 15.

[0032] Based on the volume flow rate of the outgoing flue gas 15, the outgoing gas control unit 5 determines a new operating point for the extraction unit 9, using the current operating point of the extraction unit 9, in order to eliminate the outgoing flue gas 15. This new operating point is transmitted to the extraction unit 9 via switch 7. If the camera system 8 does not detect any outgoing flue gas 15, a signal is sent to switch 7, for example via data line 7b, and the extraction control unit 5 resumes operation. It is also conceivable that a signal is sent from the extraction control unit 7 via data line 7a because, for example, a change has occurred due to altered process conditions of the metallurgical unit 1. An example of an altered process condition is an increase in the oxygen bubble rate in an LD converter.

[0033] In the Fig. 2 A schematic representation of an extraction or dust removal system for a metallurgical unit 1 is also shown. In contrast to Fig. 1 is in Fig. 2 An extraction control system is shown. This system consists of a volume flow control 6a and a hood pressure control 11. The hood pressure control 11 regulates the hood pressure so that the target pressure value 11a is reached. The hood pressure is measured by a pressure sensor 12. An output of the hood pressure control 11 is connected to an input of an adding element 10, whereby the hood pressure control output is added to a volume flow target value 10a and then transmitted as a target value 6b to the volume flow control 6a. In addition to the target value 6b, the volume flow control 6a also has a measured value for the volume flow, which is measured by the measuring device 13 in the extraction duct. The output of the volume flow control 6a is again connected to the switch 7.If outflowing flue gas 15 is detected by the camera system 4, then the switch is switched back to the outflow control 5 until no outflowing flue gas 15 is present or, for example, if the operating condition changes.

[0034] In the Fig. 3 The diagram shows a system characteristic curve 20 and fan characteristic curves 21. The pressure loss and the volume flow rate V are plotted on the two axes. Each fan characteristic curve 21 represents a constant speed n1 - n4 of the fan. The overflow control can, for example, determine a new operating point 23 based on the measured volume flow rate of the overflowing flue gas and an initial operating point 22. This new operating point 23 eliminates the overflowing flue gas. Reference symbol list

[0035] 1 Metallurgical unit 2 Extraction hood 3 Extraction duct 4 Extraction system or dust extraction system 5 Overflow control 6 Extraction control 6a Volume flow control 6b Setpoint 7 Switch 7a Data line 7b Data line 8 Camera system 9 Extraction device 9a Control line 10 Adder 10a Volume flow setpoint 11 Hood pressure control 11a Pressure setpoint 12 Pressure measurement 13 Measuring device 15 Overflowing flue gas 20 System characteristic curve 21 Blower characteristic curve 22 First operating point 23 New operating point n1 ... n4 Speed ​​V Volume flow

Claims

1. Method for operating an extraction or dust removal installation (4) of a metallurgical industrial plant, wherein the extraction or dust removal installation has at least the following components: - a metallurgical unit (1), - an extraction channel (3), - an extraction device (9), - an open-loop extraction control (6) and / or a closed-loop extraction control of the extraction device (9), preferably on the basis of at least one default value dependent on the operating state of the metallurgical unit, - a camera system (8) for detecting emitted flue gas (15) in the area of the metallurgical unit (1), - an open-loop emission control (5) for quantifying the emitted flue gas (15) detected by the camera system (8) and for controlling the extraction device (9) when there is emitted flue gas (15), wherein the open-loop emission control (5) determines the amount of emitted flue gas (15) detected by the camera system (8) and ascertains an additionally required emission extraction amount, wherein the additionally required emission extraction amount is used to set a new operating point of the extraction device from a current operating point of the extraction device, wherein the open-loop emission control (5) transmits the new operating point directly to the extraction device (9) and, as from the transmission, the control of the extraction device (9) is undertaken exclusively by the open-loop emission control (5) until a specified transfer event defines the point in time at which the open-loop extraction control (6) and / or closed-loop extraction control is again used exclusively for the open-loop and / or closed-loop control of the extraction device (9).

2. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the amount of emitted flue gas (15) is determined by an optical flow method and / or a flame analysis and / or a scale-invariant feature transform method.

3. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the extraction device (9) is an induced draught fan, a supporting fan or a compressor.

4. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the transfer event is a change in a process phase of the metallurgical unit, when there is no longer any emitted flue gas (15) and / or when an operator defines a corresponding event.

5. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the metallurgical unit (1) is a converter, an electric arc furnace or a metallurgical melting device, particularly preferably an induction furnace.

6. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the new operating point is ascertained on the basis of a fan characteristic (21) and an installation characteristic (20) of the extraction or dust removal installation (4).

7. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the temperature of the emitted flue gas (15) is determined and is used for the determination of the required emission extraction amount.

8. Method for operating an extraction or dust removal installation (4) of an industrial plant according to Claim 1, characterized in that the camera system (8) has a detectable wavelength range of 400 nm - 780 nm, 780 nm - 3000 nm and / or 3 µm - 50 µm.

9. Extraction installation or dust removal installation (4) for a metallurgical industrial plant comprising - an extraction channel (3), - an extraction device (9), - an open-loop extraction control (6) and / or a closed-loop extraction control of the extraction device (9), preferably on the basis of at least one default value dependent on the operating state of the metallurgical unit (1), - a camera system (8) for detecting emitted flue gas (15) in the area of the metallurgical unit (1), - an open-loop emission control (5) for quantifying the emitted flue gas (15) detected by the camera system (8) and for controlling the extraction device (9) when there is emitted flue gas (15), wherein the open-loop extraction control (6) and / or closed-loop extraction control and the open-loop emission control (5) are connected to the extraction device (9) by way of a switch (7) and the switch (7) is set up in such a way as to receive signals to connect the open-loop extraction control (6) and / or closed-loop extraction control to the extraction device (9) or to connect the open-loop emission control (5) to the extraction device (9), wherein the open-loop emission control (5) is set up in such a way that it can determine and transmit a new operating point of the extraction device (9) on the basis of the quantification of the emitted flue gas (15) detected by the camera system (8) and on the basis of a current operating point of the extraction device in order to avoid emitted flue gas (15) .

10. Extraction installation or dust removal installation (4) for a metallurgical industrial plant according to Claim 9, characterized in that the extraction device (9) is an induced draught fan, a supporting fan or a compressor.

11. Extraction installation or dust removal installation (4) for a metallurgical industrial plant according to Claim 9, characterized in that the metallurgical unit (1) is a melting unit or a heating unit, particularly preferably an induction furnace.

12. Extraction installation or dust removal installation for a metallurgical industrial plant according to Claim 9, characterized in that the camera system (8) has a detectable wavelength range of 400 nm - 780 nm, 780 nm - 3000 nm and / or 3 µm - 50 µm.

13. Extraction installation or dust removal installation (4) for a metallurgical industrial plant according to Claim 9, characterized in that the metallurgical unit (1) is a converter, an electric arc furnace, or a metallurgical melting device.

14. Computer program, which comprises machine code which can be executed by an open-loop control device of an extraction or dust removal installation (4) according to Claims 9-13, wherein the execution of the machine code by an open-loop control device causes the extraction or dust removal installation (4) according to Claims 9-13 to be operated by a method according to Claims 1-8.

15. Computer-readable medium on which the computer program according to Claim 14 is stored.