Suction or dust extraction system for metallurgical industrial plants, method for operating the suction or dust extraction system, and computer program

Abstract

The present invention relates to the field of extraction or dust removal systems for metallurgical industrial plants. The object of the invention is to provide a method that reacts very quickly to the occurrence of outbursts of flue gas in order to prevent such outbursts.The task is solved by the overflow control (5) determining the quantity of the overflowing flue gas (15) detected by the camera system (8) and calculating an additional required overflow extraction quantity, whereby the additional required overflow extraction quantity is used to set a new operating point of the extraction device from the current operating point of the extraction device, whereby the overflow control (5) transmits the new operating point directly to the extraction device (9) and the control of the extraction device (9) is taken over exclusively by the overflow control (5) from the time of transmission until a predefined handover event defines the time at which only the extraction control (6) and / or extraction regulation is used again to control and / or regulate the extraction device (9).

Description

Title of the invention field of technology

[0001] The present invention relates to the field of extraction or dedusting systems of metallurgical industrial plants.

[0002] On the one hand, the invention relates to a method for operating an extraction and / or dedusting system of a metallurgical industrial plant and an extraction or dedusting system, wherein the extraction and / or dedusting system has at least the following components: a metallurgical unit, an extraction channel, an extraction device, an extraction control and / or extraction regulation of the extraction device based on at least one preset value dependent on the operating state of the metallurgical unit, a camera system for detecting escaping flue gas in the area of ​​the metallurgical unit, an escaping control for quantifying the escaping flue gas detected by the camera system and for controlling the extraction device when flue gas is escaping.

[0003] On the other hand, the invention relates to a computer program and a computer-readable medium. State of the art

[0004] Steel production processes are equipped with extraction and dust extraction systems. For the most part, the required extraction rate remains largely constant. The selected extraction rate can be determined by the process conditions of the primary process, for example, due to the oxygen blowing rate in a steelmaking converter and / or the current hood pressure. Typically, a pressure control in the extraction duct influences a flow control of the extraction system. The flow control influences the speed control. The interplay of various control loops leads to a certain inertia of the control function during normal operation. This inertia can also lead to a slow response in the event of large flame formation and / or escaping flue gas from emissions.In such steelmaking processes, material additions or process fluctuations can, for example, lead to pulsating pressure increases in the transition area between the primary unit and the extraction and dust collection system, which subsequently lead to flame formation or the release of emissions. These can lead to excessive emissions or the release of toxic gases in the production hall area. Summary of the invention

[0005] The object of the invention is to provide a method which reacts very quickly to the occurrence of escaping flue gas in order to prevent escaping flue gas.

[0006] The task is solved by a surge control which determines the quantity of escaping flue gas detected by the camera system and calculates an additional surge extraction quantity required. The additional surge extraction quantity required is used to set a new operating point for the extraction system from a current operating point of the extraction system. The surge control transmits the new operating point directly to the extraction system and, from the time of transmission, control of the extraction system is exclusively taken over by the surge control until a predetermined handover event defines the point in time at which the extraction control and / or extraction regulation is again used exclusively to control and / or regulate the extraction system. A handover event can be, for example, that no more flue gas is escaping or that only 10% of the previously determined escaping flue gas remains.

[0007] By directly specifying a new operating point using the surge control of the extraction system, it is possible to react very quickly and the escaping flue gas and flame formation can be suppressed very quickly. The surge control therefore controls the extraction system exclusively based on the current operating point and the quantity of escaping flue gas, the quantity of which is quantified by the camera system. However, the extraction control and / or regulation controls and / or regulates based on preset values, which are preferably dependent on the operating state of the metallurgical unit. The preset values, for example in the case of an LD converter, can depend on the current oxygen blowing rate introduced by the oxygen blowing lance. Preset values ​​can be, for example, a volume flow or a pressure and / or pressure loss.

[0008] 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.

[0009] In an advantageous embodiment, the quantity of the escaping flue gas is determined by an optical flow method and / or flame analysis.

[0010] The surge control, for example, uses the optical flow method and / or flame analysis to determine the additional surge extraction rate required. The optical flow of an image sequence is a vector field of a velocity projected onto an image plane. These velocity vectors are calculated and displayed for different pixels. This means that the movement of, for example, characteristic smoke clouds can be determined based on the movement of characteristic patterns in image sequences. When the smoke cloud moves, the characteristic pattern retains its geometric shape during the movement, which means that the movement of this characteristic pattern is recognized in an image sequence. This allows a speed to be determined. In flame analysis, the size of the flame is a criterion for determining the additional extraction rate 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 when controlling the smoldering. Furthermore, the size of the flames / smoke clouds can be used to determine the intensity of the smoldering. However, it is also conceivable that the scale-invariant feature transformation method (SIFT method) could be used.

[0011] In a practical design, the extraction device is an induced draft fan, a support fan or a compressor.

[0012] A preferred embodiment provides for the transfer event to be a change in the process phase, the presence of escaping flue gas, or an operator defining a corresponding event. For example, an operator can specify that the escaping control should only be active until 90% of the escaping has disappeared. How precisely the operator defines this event depends on the specific requirements of the extraction system and its regulations. For example, the event can also be that the transfer should occur at least one minute after the escaping has disappeared.

[0013] A further advantageous embodiment provides that the metallurgical unit is a converter, an electric arc furnace or a metallurgical melting device, for example an induction furnace.

[0014] The default values ​​for the extraction control and / or regulation, for example in the case of an LD converter, can depend on the current oxygen blowing rate introduced by the blowing lance.

[0015] In the electric arc furnace (EAF), the carbon injection rate, a burner volume flow of a refining combined burner (RCB), a current strength of the melting electrodes, a process progress and charged materials during the ongoing process can influence a setpoint value.

[0016] In a preferred embodiment, the new operating point is determined based on a fan characteristic curve and a system characteristic curve of the extraction and / or dust extraction system.

[0017] A new operating point can be determined using a fan characteristic curve and the system characteristic curve of the extraction or dust extraction system. This new operating point is transmitted to the extraction system and adjusted using setting parameters to ensure that the new operating point is reached. In a simple implementation, a relative speed increase is carried out proportional to the current amount of escaping flue gas. This speed increase is achieved using fixed values ​​– which are based on empirical values ​​from the operation of such systems – or is determined empirically.

[0018] A practical embodiment provides for the temperature of the escaping flue gas to be determined and used to determine the required escaping extraction rate. This temperature is determined, for example, using a calculation model. Based on the temperature of a product to be produced by the metallurgical unit, the temperature of the flue gas can be calculated.

[0019] A particularly preferred embodiment provides that the camera system has a detectable wavelength range of 380nm - 780nm, 780nm - 3000nm and / or 3µm - 50µm. Images can be taken in both the visible and infrared light ranges. The wavelength range to be used must be selected accordingly depending on the recording situation and interference situation. If the lighting conditions in the metallurgical industrial plant are consistently good, a visible wavelength range of 400nm - 780nm is preferred. If the lighting conditions are poor and / or frequently changing, a near-infrared wavelength range of 780nm - 3000nm or a mid-infrared wavelength range of 3µm - 50µm is preferred. Such changing lighting conditions occur, for example, if the hall lighting is switched on and off frequently or the sunlight changes frequently.

[0020] The task is solved by an extraction system described below.

[0021] The extraction control and / or extraction regulation and the surge control are connected to the extraction device via a switch. The switch receives signals indicating whether the extraction control and / or extraction regulation is controlling and / or regulating the extraction device, or whether the surge control is controlling the extraction device. The surge control is configured in such a way that, based on the quantification of the surged flue gas detected by the camera system and based on a current operating point of the extraction device, it can determine a new operating point for the extraction device in order to prevent surged flue gas. The switch can be a physical switch or part of a program code. In either case, switching from the extraction control and / or extraction regulation to the surge control is necessary.The extraction system and / or dust extraction 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.

[0022] An advantageous embodiment provides that the extraction device is an induced draft fan, a support fan or a compressor.

[0023] A suitable embodiment provides that the metallurgical unit is a melting unit or a heating unit, for example an induction furnace.

[0024] A particularly advantageous embodiment provides that the metallurgical unit is a converter, an electric arc furnace, a metallurgical melting device.

[0025] The object is further achieved by a computer program comprising machine code that can be processed by a control device according to a previously described extraction or dust extraction system, wherein the processing of the machine code by a control device causes the extraction or dust extraction system to be operated according to a previously described method.

[0026] The task is also solved by a computer-readable medium on which the previously described computer program is stored. Short description of the drawings

[0027] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of an embodiment, which is explained in more detail in conjunction with the drawings. 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 fan characteristic curve and a system characteristic curve Description of the embodiments

[0028] In the Fig. 1 1 schematically shows an extraction system or dedusting system 4 for a metallurgical unit 1, which can be, for example, an LD converter or an arc furnace. The extraction system or dedusting system 4 has an extraction hood 2, an extraction duct 3, and an extraction device 9, which is designed, for example, as an induced draft fan. The extraction device 9 is connected via a switch 7. The switch 7 can switch back and forth between an extraction control 6 and a surge control 5. A preset value 6b is transmitted to the extraction control 6; this can be, for example, a volume flow, a pressure, or a desired pressure loss. 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 6 and the surge control 5 to a control line 9a. The switch is controlled via control signals 7a, 7b.These control signals 7a, 7b can be transmitted directly from the surge control 5 and the extraction control 6, but it is also conceivable that these signals come from a higher-level control of the entire process of the extraction system or dedusting system 4 and / or the metallurgical unit 1. The surge control 5 is connected to a camera system 8, which can detect the escaping flue gas 15. If escaping flue gas 15 is detected, the surge control 5 determines a volume flow of the escaping flue gas 15.

[0029] Based on the volume flow of the escaping flue gas 15, the escaping control system 5 uses the current operating point of the extraction device 9 to determine a new operating point for the extraction device 9 in order to eliminate the escaping flue gas 15. This new operating point is transmitted to the extraction device 9 via switch 7. If the camera system 8 does not detect any escaping flue gas 15, a signal is sent to switch 7, for example via data line 7b, and the extraction control system 5 takes over again. It is also conceivable that a signal is sent from the extraction control system 7 via data line 7a because, for example, a change has occurred due to changed process conditions of the metallurgical unit 1. An example of a changed process condition is an increase in the oxygen blowing rate in an LD converter.

[0030] In the Fig. 2 A schematic representation of an extraction system or dust extraction system for a metallurgical unit 1 is also shown. In contrast to Fig. 1 is in Fig. 2 an extraction control is shown. This control consists of a volume flow control 6a and a hood pressure control 11. The hood pressure control 11 is intended to regulate the hood pressure such that the pressure setpoint 11a is reached. The hood pressure is measured by a pressure measurement 12. An output of the hood pressure control 11 is passed to an input of an addition element 10, whereby the hood pressure regulator output is added to a volume flow setpoint 10a and then transmitted as setpoint 6b to the volume flow control 6a. In addition to the setpoint 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 escaping flue gas 15 is detected by the camera system 4, the switch is switched back to the escaping control 5 until no escaping flue gas 15 is present or, for example, when the operating state changes.

[0031] In the Fig. 3 is a diagram with a system characteristic curve 20 and with fan characteristic curves 21. The pressure loss and the volume flow V are plotted on the two axes. Each fan characteristic curve 21 represents a constant speed n1 - n4 of the fan. The surge control can, for example, determine a new operating point 23 based on the determined volume flow of the escaping flue gas and a first operating point 22. The escaping flue gas is eliminated again through this new operating point 23.

[0032] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. List of reference symbols

[0033] 1Metallurgical unit 2Extraction hood 3Extraction duct 4Extraction system or dust extraction system 5Flush control 6Extraction control 6aVolume flow control 6bSetpoint 7Switch 7aData line 7bData line 8Camera system 9Extraction device 9aControl line 10Adder 10aVolume flow setpoint 11Hood pressure control 11aPressure setpoint 12Pressure measurement 13Measuring device 15Flue gas 20System characteristic curve 21Fan characteristic curve 22First operating point 23New operating point n1 ... n4Speed ​​VVolume flow

Claims

1. A method for operating an extraction or dedusting system (4) of a metallurgical industrial plant, wherein the extraction or dedusting system has at least the following components: - a metallurgical unit (1), - an extraction duct (3), - an extraction device (9), - an extraction control (6) and / or an extraction regulation of the extraction device (9), preferably based on at least one preset value dependent on the operating state of the metallurgical unit, - a camera system (8) for detecting escaping flue gas (15) in the region of the metallurgical unit (1), - an escaping control (5) for quantifying the escaping flue gas (15) detected by the camera system (8) and for controlling the extraction device (9) when escaping flue gas (15), characterized in thatthe surge control (5) determines the quantity of the escaping flue gas (15) detected by the camera system (8) and determines an additionally required surge extraction quantity, wherein the additionally required surge extraction quantity is used to set a new operating point of the extraction device from a current operating point of the extraction device, wherein the surge control (5) transmits the new operating point directly to the extraction device (9) and the control of the extraction device (9) is taken over exclusively by the surge control (5) from the time of transmission until a predetermined handover event defines the time at which the extraction control (6) and / or extraction regulation is again used exclusively to control and / or regulate the extraction device (9).

2. Method for operating an extraction or dust extraction system (4) of an industrial plant according to claim 1, characterized in thatthe quantity of the escaping flue gas (15) is determined by an optical flow method and / or a flame analysis method and / or a scale-invariant feature transformation method.

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

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

5. Method for operating an extraction or dust extraction system (4) of an industrial plant according to claim 1, characterized in thatthe 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 extraction system (4) of an industrial plant according to claim 1, characterized in that the new operating point is determined using a fan characteristic curve (21) and a system characteristic curve (20) of the extraction or dust extraction system (4).

7. Method for operating an extraction or dust extraction system (4) of an industrial plant according to claim 1, characterized in that the temperature of the escaping flue gas (15) is determined and used to determine the required escaping extraction quantity.

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

9. Extraction system or dedusting system (4) for a metallurgical industrial plant comprising - an extraction duct (3), - an extraction device (9), - an extraction control (6) and / or an extraction regulation of the extraction device (9), preferably based on at least one preset value dependent on the operating state of the metallurgical unit (1), - a camera system (8) for detecting escaping flue gas (15) in the area of ​​the metallurgical unit (1), - an escaping control (5) for quantifying the escaping flue gas (15) detected by the camera system (8) and for controlling the extraction device (9) when escaping flue gas (15), characterized in thatthe extraction control (6) and / or extraction regulation and the surge control (5) are connected to the extraction device (9) via a switch (7), and the switch (7) is configured to receive signals to connect the extraction control (6) and / or extraction regulation to the extraction device (9) or to connect the surge control (5) to the extraction device (9), wherein the surge control (5) is configured such that, based on the quantification of the surged flue gas (15) detected by the camera system (8) and based on a current operating point of the extraction device, it can determine and transmit a new operating point of the extraction device (9) in order to prevent surged flue gas (15).

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

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

13. Extraction system or dust extraction system (4) for a metallurgical industrial plant according to claim 9, characterized in that the metallurgical unit (1) a converter, an electric arc furnace, a metallurgical melting device 14. A computer program comprising machine code that can be processed by a control device of an extraction or dedusting system (4) according to claims 9-13, wherein the processing of the machine code by a control device causes the extraction or dedusting system (4) according to claims 9-13 to be operated according to a method according to claims 1-8.

15. A computer-readable medium on which the computer program according to claim 14 is stored.