Steel-making secondary smoke dust collecting system and method

Abstract

The invention relates to a steelmaking secondary smoke dust collecting system and method.The steelmaking secondary smoke dust collecting system comprises a hot air flow direction calculating module, a smoke dust self-adaption collecting module and a dust collecting opening overturning plate automatic opening and closing module, based on the high-temperature characteristic of steelmaking secondary smoke gas, the hot air flow direction of a discharging point is measured through thermal imaging equipment, and the smoke dust self-adaption collecting module and the dust collecting opening overturning plate automatic opening and closing module are calculated; according to the high-temperature flue gas fixed channel continuous flow principle, hot flue gas stably enters a dust collection pipeline, high-temperature dust flue gas entering a dust removal system is increased by means of the heat effect in a flue, and the problems of air volume interference, difficult arrangement of a dust collection cover and the like caused by forced dust collection of multiple dust removal systems are solved; in addition, automatic linkage of the air door of the dust collection opening of the intermittent equipment is achieved through temperature signals of the thermal imaging equipment, and the problem of waste of dust collection air volume is solved.

Description

Technical Field

[0001] The invention relates to the technical field of unorganized particle control in steelmaking areas, and in particular to a steelmaking secondary smoke capture system and method. Background Art

[0002] Converter steelmaking is equipped with converters, ladle furnaces, vacuum furnaces, steel ladle tilting tables and argon stations, etc. These equipment generate a large amount of smoke and dust emissions during the production process.

[0003] To solve the above problems, most steel mills have classified the secondary dust emission points in the steelmaking area, using multiple dust collectors to serve steelmaking equipment in different areas, and multiple dust collectors run in parallel to achieve efficient capture of secondary smoke in the steelmaking area. However, due to the scattered dust removal points in the steelmaking area and the large number of dust source points, the converter secondary smoke capture system is equipped with a large number of dust collectors, a large dust collection air volume, and high power consumption.

[0004] In order to solve the problem of large air volume and high power consumption in the secondary dust collection of the steelmaking system, some steel enterprises have added a tertiary dust removal system in the plant air tower, and used the coordination of the secondary and tertiary dust removal systems to achieve energy saving and economic operation of the dust removal system. Some steel enterprises have improved the efficiency of secondary dust collection by transforming and optimizing the dust collection device and control system, including improving the sealing performance around the converter, changing the steelmaking fume capture method, and adding a slag fume capture hood. These technologies still have certain defects, mainly manifested in: (1) There are many dust removal systems, and multiple dust removal systems are synchronously operated in parallel to serve the steelmaking area. There is a problem of competition for air among the dust removal systems, which makes it difficult for some dust removal systems to cover the air volume required for their dust collection areas, resulting in uneven dust collection loads among the dust removal systems; (2) The effective height or width of the dust collection hood of the dust collection device is affected by the working radius of the steelmaking equipment, which makes it difficult to meet the dust collection requirements, resulting in too low wind speed at the hood opening, making it difficult for dust to be captured and enter the dust removal system; (3) A single dust removal system corresponds to multiple devices, and there is intermittent operation between multiple devices. The idle equipment needs to close the damper. Repeated manual intervention and adjustment are too complicated and prone to errors, resulting in waste of dust collection air volume. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a steelmaking secondary smoke capture system and method, which will not cause dust collection air volume interference, the hood mouth wind speed meets the requirements, and can effectively avoid the waste of dust collection air volume.

[0006] The technical solution adopted by the present invention is: a steelmaking secondary smoke capture system, characterized in that: it includes a hot air flow direction calculation module, a smoke adaptive collection module and a dust collection port flip automatic opening and closing module, the hot air flow direction calculation module includes a thermal imaging device and a hot air flow direction calculation unit, the thermal imaging device is arranged at the smoke emission point of the steelmaking equipment, is responsible for thermal imaging of the steelmaking equipment at the smoke emission point, and transmits the thermal imaging data to the hot air flow direction calculation unit; the hot air flow direction calculation unit establishes a thermal diffusion model for the diffusion of the rising hot air flow according to the thermal imaging data, uses the thermal diffusion model to calculate the main direction of the hot air flow diffusion, and combines the three-dimensional model of the steelmaking equipment to obtain the optimal variable air door dust collection hood height and dust collection area;

[0007] The smoke and dust adaptive collection module includes a variable damper dust collecting hood, a vertically movable flue duct and a control unit. The control unit is responsible for receiving the main direction of hot air flow diffusion, the height of the variable damper dust collecting hood and the dust collecting area data of the variable damper dust collecting hood obtained by the hot air flow direction calculation unit. The control unit controls the vertically movable flue duct to move the variable damper dust collecting hood to the calculated height, and controls the opening degree of the variable damper dust collecting hood to achieve the controllable dust collecting direction and dust collecting area targets.

[0008] The automatic opening and closing module of the dust collection port is used when a single dust collector collects dust for multiple sets of equipment. It opens and closes the damper of the current equipment by accepting the equipment thermal airflow parameters obtained by the thermal airflow direction calculation module, thereby reducing manual intervention and achieving energy saving in the dust removal system.

[0009] Preferably, the vertically movable flue duct and the variable damper dust collecting hood are integrated equipment, the lifting and lowering of the vertically movable flue duct is driven by a vertically arranged reciprocating hydraulic cylinder, and the vertically movable flue duct is connected to the flue main pipe with a folding pipe.

[0010] Preferably, the moving range of the vertically movable flue duct does not exceed 0.5 m, and the moving height signal is determined by the control unit according to the result calculated by the heat diffusion model.

[0011] Preferably, the variable damper dust collecting hood is a two-section or four-section circular ring, the center of the ring is the center of the dust source device, the radius of the ring is the radius of the dust source device plus 0.5 to 0.8 m, and the thickness of the ring is 12 to 16 cm.

[0012] Preferably, an air collecting port is provided on the inner side of the circular ring of the variable air door dust collecting hood, and a vertically movable flue duct is connected to the outer side.

[0013] Preferably, a slide gate is provided at the air collecting port, which is connected to a slide gate cylinder, and the slide gate cylinder is used to control the dust collecting area of ​​the air collecting port, the closing of the air collecting port in the non-hot air flow direction, and the opening of the air collecting port in the hot air flow direction.

[0014] Preferably, the air collecting port is a rectangular air collecting port.

[0015] Preferably, two sets of thermal imaging equipment are arranged around the steelmaking equipment. The two sets of thermal imaging equipment are arranged at different heights and are arranged perpendicular to each other.

[0016] Preferably, the hot air flow direction calculation unit obtains a heat flame pattern according to a thermal imaging device, and calculates the high-temperature flue gas diffusion direction according to a heat flame inclination angle of the heat flame pattern.

[0017] A method for using a steelmaking secondary smoke capture system, characterized in that:

[0018] S1. The thermal imaging device performs thermal imaging of the steelmaking equipment at the smoke emission point, and transmits the thermal imaging data to the thermal air flow direction calculation unit;

[0019] S2, the hot air flow direction calculation unit establishes a heat diffusion model based on the thermal imaging data to diffuse the rising hot air flow, uses the heat diffusion model to calculate the main direction of the hot air flow diffusion, and combines the three-dimensional model of the steelmaking equipment to obtain the optimal variable air door dust collection hood height and dust collection area;

[0020] S3, the control unit receives the main direction of hot air flow diffusion, the height of the variable air door dust collecting hood and the dust collecting area data obtained by the hot air flow direction calculation unit, controls the vertically movable flue duct to move the variable air door dust collecting hood to the calculated height, and controls the air collecting port opening of the variable air door dust collecting hood to achieve the controllable targets of the dust collecting direction and the dust collecting area.

[0021] The beneficial effects achieved by the present invention are as follows: based on the high temperature characteristics of secondary flue gas from steelmaking, the present invention uses thermal imaging equipment to measure the direction of hot air flow at the discharge point, and uses the principle of continuous flow in a fixed channel of high-temperature flue gas to achieve stable entry of hot flue gas into the dust collection duct. Relying on the thermal effect in the flue, the high-temperature dust flue gas is increased to enter the dust removal system, and the wind volume interference caused by forced dust collection of multiple dust removal systems and the difficulty in arranging dust collection hoods are reduced. In addition, the temperature signal of the thermal imaging equipment is used to realize automatic interlocking of the air door of the dust collection port of the intermittent equipment, thereby solving the problem of waste of dust collection air volume. The present invention has the following advantages:

[0022] 1. By setting up the hot air flow direction calculation module, the main direction of the hot air flow of the steelmaking equipment can be positioned, and the dust hood height and dust collection area calculation can be completed, which is conducive to the intelligent positioning of the unorganized wind direction of the secondary chimney of the steelmaking, and can reduce a large amount of invalid dust collection air volume in the unorganized dust collection process;

[0023] 2. By setting up the smoke adaptive collection module, the dust hood can be arranged flexibly, and sufficient dust collection area can be achieved without affecting the equipment transportation. It is conducive to the installation and positioning of the dust hood in the narrow dust collection area of ​​steelmaking, which is conducive to implementation;

[0024] 3. By setting up the automatic opening and closing module of the dust collection port, when a single dust collector collects dust for multiple devices, the dust collection air volume can be automatically put into operation unmanned according to the working conditions of the equipment, which is beneficial to reducing the operating energy consumption of the dust removal system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 It is a connection diagram of the slide gate and the slide gate cylinder at the air collecting port;

[0027] Among them: 1. Steelmaking equipment; 2. Thermal imaging equipment; 3. Hot air flow direction calculation unit; 4. Control unit; 5. Variable air door dust collection hood; 6. Vertically movable flue duct; 7. Reciprocating hydraulic cylinder; 8. Slide gate cylinder; 9. Slide gate; 10. Air collecting port. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] A secondary smoke capture system for steelmaking of the present invention comprises a hot air flow direction calculation module, a smoke adaptive collection module and a dust collecting port flap automatic opening and closing module, the hot air flow direction calculation module comprises a thermal imaging device 2 and a hot air flow direction calculation unit 3, the thermal imaging device 2 is arranged at the smoke emission point of the steelmaking equipment 1, is responsible for thermal imaging of the steelmaking equipment 1 at the smoke emission point, and transmits the thermal imaging data to the hot air flow direction calculation unit 3; the hot air flow direction calculation unit 3 establishes a thermal diffusion model for the diffusion of the rising hot air flow according to the thermal imaging data, calculates the main direction of the hot air flow diffusion by using the thermal diffusion model, and obtains the optimal height and dust collection area of ​​the variable air door dust collecting hood 5 in combination with the three-dimensional model of the steelmaking equipment 1;

[0030] The smoke adaptive collection module includes a variable damper dust collecting hood 5, a vertically movable flue duct 6 and a control unit 4. The control unit 4 is responsible for receiving the main direction of hot air flow diffusion, the height of the variable damper dust collecting hood 5 and the dust collecting area data of the variable damper dust collecting hood 5 obtained by the hot air flow direction calculation unit 3. The control unit 4 controls the vertically movable flue duct 6 to move the variable damper dust collecting hood 5 to the calculated height, and controls the opening degree of the variable damper dust collecting hood 5 to achieve the controllable dust collecting direction and dust collecting area.

[0031] The automatic opening and closing module of the dust collection port is used when a single dust collector collects dust for multiple sets of equipment. It opens and closes the damper of the current equipment by accepting the equipment thermal airflow parameters obtained by the thermal airflow direction calculation module, thereby reducing manual intervention and achieving energy saving in the dust removal system.

[0032] The steelmaking secondary smoke capture system of the present invention is based on the high temperature characteristics of the secondary smoke from steelmaking, uses thermal imaging equipment to measure the direction of the hot air flow at the emission point, and uses the continuous flow principle of a fixed channel for high-temperature smoke to achieve stable entry of the hot smoke into the dust collection pipeline. Relying on the thermal effect in the flue, the high-temperature dust smoke is increased to enter the dust removal system, and the wind volume interference caused by the forced dust collection of multiple dust removal systems and the difficulty in arranging the dust collection hood are reduced. In addition, the temperature signal of the thermal imaging equipment is used to realize automatic interlocking of the air door of the dust collection port of the intermittent equipment to solve the problem of waste of dust collection air volume.

[0033] In this embodiment, the vertically movable flue duct 6 and the variable damper dust collecting hood 5 are integrated devices. The vertically movable flue duct 6 is driven by a vertically arranged reciprocating hydraulic cylinder 6. The vertically movable flue duct 6 is connected to the flue main pipe by a folding pipe. The vertically movable flue duct 6 has a moving range of 0.2 to 0.4 m, and the moving height signal is determined by the control unit 1 according to the result calculated by the heat diffusion model.

[0034] In this embodiment, the variable damper dust hood 5 is a two-stage or four-stage circular ring, the center of the ring is the center of the dust source point equipment, the radius of the ring is the radius of the dust source point equipment plus 0.5 to 0.8 m, and the thickness of the ring is 12 to 16 cm; an air collecting port 10 is provided on the inner side of the ring of the variable damper dust hood 5, and the outer side is connected to a vertically movable flue duct 6.

[0035] In this embodiment, a slide gate 9 is provided at the air collecting port 10, and the slide gate 9 is connected to the slide gate cylinder 8, and the slide gate cylinder 8 is used to control the dust collecting area of ​​the air collecting port 10, the closing of the air collecting port in the non-hot air flow direction, and the opening of the air collecting port in the hot air flow direction. The air collecting port 10 is a rectangular air collecting port.

[0036] In this embodiment, two sets of thermal imaging devices 2 are arranged around the steelmaking equipment 1. The two sets of thermal imaging devices 2 are arranged at different heights and are arranged perpendicular to each other.

[0037] In this embodiment, the hot air flow direction calculation unit obtains a hot flame pattern according to the thermal imaging device, and calculates the high-temperature flue gas diffusion direction according to the hot flame inclination angle of the hot flame pattern.

[0038] A method for using a steelmaking secondary smoke dust capture system, characterized in that: the steelmaking secondary smoke dust capture system is used to capture and collect smoke discharged from steelmaking equipment, specifically comprising the following steps:

[0039] S1, the thermal imaging device 2 performs thermal imaging on the steelmaking equipment 1 at the smoke emission point, and transmits the thermal imaging data to the thermal air flow direction calculation unit 3;

[0040] S2, the hot air flow direction calculation unit 3 establishes a heat diffusion model for the diffusion of the rising hot air flow according to the thermal imaging data, calculates the main direction of the hot air flow diffusion using the heat diffusion model, and obtains the optimal variable air door dust collecting hood 5 height and dust collecting area in combination with the three-dimensional model of the steelmaking equipment 1;

[0041] S3, the control unit 4 receives the main direction of hot air flow diffusion, the height of the variable air damper dust hood 5 and the dust collecting area data obtained by the hot air flow direction calculation unit 3, controls the vertically movable flue duct 6 to move the variable air damper dust hood 5 to the calculated height, and controls the opening of the air collecting port 10 of the variable air damper dust hood 5 to achieve the controllable targets of the dust collecting direction and the dust collecting area.

[0042] Example 1: A steelmaking ladle turntable

[0043] The smoke dust efficient capture system is equipped with three modules (hot air flow direction calculation module, smoke dust adaptive collection module and dust collection port automatic opening and closing module) running in series. The hot air flow direction calculation module is equipped with a thermal imaging device unit and a hot air flow direction calculation unit. The hot air flow direction calculation module is equipped with two sets of thermal imaging devices 2, which are located 2m high in front of and to the left of the steelmaking ladle turntable. The thermal imaging data is transmitted to the hot air flow calculation unit 3 through a data transmitter. The hot air flow calculation unit 3 extracts the hot flame direction signal from the thermal imaging data and calculates the hot flame direction, the height of the variable air door dust collection hood 5 and the dust collection area based on the data of the two thermal imaging devices 2 at the same time.

[0044] The direction of the hot flame can be selected according to the following table:

[0045] Thermal imaging heat flame direction 1 Thermal imaging heat flame direction 2 Thermal direction ← ← Northwest direction ← → Northeast direction → → Southeast → ← Southwest ↑ ← True North ↑ → due south direction ← ↑ due west direction → ↑ Due east ↑ ↑ Vertical

[0046] The dust hood height is selected according to the following table:

[0047] Thermal imaging flame height 1 Thermal imaging heat flame height 2 Dust hood and equipment height 1cm 1cm 0.2m 1cm 2cm 0.3m 2cm 2cm 0.4m

[0048] The dust hood area is selected according to the following table:

[0049] Thermal imaging flame width 1 Thermal imaging flame width 2 Dust hood opening 0.5cm 0.5cm 1 / 6 0.5cm 1cm 1 / 3 1cm 1cm 1 / 2

[0050] The smoke adaptive collection module includes a variable damper dust hood 5, a vertically movable flue duct 6 and a control unit 4. The control unit 4 is mainly responsible for receiving the moving direction, height and dust collection area data of the variable damper dust hood 5 obtained by the hot air flow direction calculation unit 3. The control unit 4 controls the vertically movable flue duct 6 to move the variable damper dust hood 5 to the calculated height, and controls the opening degree of the variable damper dust hood 5 to achieve the controllable goals of the dust collection direction and the dust collection area.

[0051] The vertically movable flue duct 6 and the variable damper dust collecting hood 5 are integrated devices. The movable range of the vertically movable flue duct 6 does not exceed 0.4m. The specific moving height signal is determined by the control unit 4 according to the result calculated by the heat diffusion model. The lifting and lowering of the vertically movable flue duct 6 is driven by a reciprocating hydraulic cylinder 7. The vertically movable flue duct 6 is connected to the flue main pipe with a folding pipe.

[0052] The variable damper dust collecting hood 5 is a two-stage circular dust collecting hood, the center of the circle is the center of the dust source point device, the radius of the circle is the radius of the dust source point device plus 0.6m, and the thickness of the circle is 12cm. The inner side of the circle is a rectangular air collecting port 10, and the outer side is connected to the vertical movable flue duct 6. The rectangular air collecting port 10 is provided with a slide gate 9, and the slide gate 9 is connected to the slide gate cylinder 8. The slide gate cylinder 8 is used to control the dust collecting area of ​​the air collecting port 10, the air collecting port in the non-hot air flow direction is closed, and the air collecting port in the hot air flow direction is opened.

[0053] The variable air door dust collecting hood 5 is divided into two sections, which are separated in the common moving direction of the hook and do not affect the lifting of the equipment.

[0054] The automatic opening and closing module of the dust collection port is mainly used when a single dust collector collects dust from multiple sets of equipment. It accepts the equipment thermal airflow parameters obtained by the thermal airflow direction calculation module, executes the opening and closing of the current equipment damper, reduces manual intervention and realizes energy saving of the dust removal system.

[0055] Example 2: A RH refining furnace

[0056] The smoke dust efficient capture system is equipped with three modules (hot air flow direction calculation module, smoke dust adaptive collection module and dust collection port flap automatic opening and closing module) running in series. The hot air flow direction calculation module is equipped with a thermal imaging device unit and a hot air flow direction calculation unit. The hot air flow direction calculation module is equipped with two sets of thermal imaging devices 2, which are located 2.5m high in front of and to the left of the steelmaking ladle turntable. The thermal imaging data is transmitted to the hot air flow calculation unit 3 through a data transmitter. The hot air flow calculation unit 3 extracts the hot flame direction signal from the thermal imaging data, and calculates the hot flame direction, the height of the variable air door dust collection hood 5 and the dust collection area based on the data of the two thermal imaging devices 2 at the same time.

[0057] The direction of the hot flame can be selected according to the following table:

[0058] Thermal imaging heat flame direction 1 Thermal imaging heat flame direction 2 Thermal direction ← ← Northwest direction ← → Northeast direction → → Southeast → ← Southwest ↑ ← True North ↑ → due south direction ← ↑ due west direction → ↑ Due east ↑ ↑ Vertical

[0059] The dust hood height is selected according to the following table:

[0060] Thermal imaging flame height 1 Thermal imaging heat flame height 2 Dust hood and equipment height 1cm 1cm 0.3m 1cm 2cm 0.4m 2cm 2cm 0.5m

[0061] The dust hood area is selected according to the following table:

[0062] Thermal imaging flame width 1 Thermal imaging flame width 2 Dust hood opening 0.5cm 0.5cm 1 / 5 0.5cm 1cm 2 / 5 1cm 1cm 3 / 5

[0063] The smoke adaptive collection module includes a variable damper dust hood 5, a vertically movable flue duct 6 and a control unit 4. The control unit 4 is mainly responsible for receiving the moving direction, height and dust collection area data of the variable damper dust hood 5 obtained by the hot air flow direction calculation unit 3. The control unit 4 controls the vertically movable flue duct 6 to move the variable damper dust hood 5 to the calculated height, and controls the opening degree of the variable damper dust hood 5 to achieve the controllable goals of the dust collection direction and the dust collection area.

[0064] The vertically movable flue duct 6 and the variable damper dust collecting hood 5 are integrated devices. The movable range of the vertically movable flue duct 6 does not exceed 0.5m. The specific moving height signal is determined by the control unit 4 according to the result calculated by the heat diffusion model. The lifting and lowering of the vertically movable flue duct 6 is driven by a reciprocating hydraulic cylinder 7. The vertically movable flue duct 6 is connected to the flue main pipe with a folding pipe.

[0065] The variable damper dust collecting hood 5 is a two-stage circular dust collecting hood, the center of the circle is the center of the dust source point device, the radius of the circle is the radius of the dust source point device plus 0.8m, and the thickness of the circle is 16cm. The inner side of the circle is a rectangular air collecting port 10, and the outer side is connected to the vertical movable flue duct 6. The rectangular air collecting port 10 is provided with a slide gate 9, and the slide gate 9 is connected to the slide gate cylinder 8. The slide gate cylinder 8 is used to control the dust collecting area of ​​the air collecting port 10, the air collecting port in the non-hot air flow direction is closed, and the air collecting port in the hot air flow direction is opened.

[0066] The variable air door dust collecting hood 5 is divided into two sections, which are separated in the common moving direction of the hook and do not affect the lifting of the equipment.

[0067] The automatic opening and closing module of the dust collection port is mainly used when a single dust collector collects dust from multiple sets of equipment. It accepts the equipment thermal airflow parameters obtained by the thermal airflow direction calculation module, executes the opening and closing of the current equipment damper, reduces manual intervention and realizes energy saving of the dust removal system.

[0068] It should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solutions of the present invention are limited only by the scope of the claims.

[0069] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

Claims

1. A secondary smoke capture system for steelmaking, characterized by: It includes a hot air flow direction calculation module, a smoke adaptive collection module and a dust collection port flap automatic opening and closing module. The hot air flow direction calculation module includes a thermal imaging device and a hot air flow direction calculation unit. The thermal imaging device is arranged at the smoke emission point of the steelmaking equipment, and is responsible for thermal imaging the steelmaking equipment at the smoke emission point, and transmitting the thermal imaging data to the hot air flow direction calculation unit; the hot air flow direction calculation unit establishes a thermal diffusion model for the diffusion of the rising hot air flow according to the thermal imaging data, calculates the main direction of the hot air flow diffusion using the thermal diffusion model, and obtains the optimal variable air door dust collection hood height and dust collection area in combination with the three-dimensional model of the steelmaking equipment; The smoke and dust adaptive collection module includes a variable damper dust collecting hood, a vertically movable flue duct and a control unit. The control unit is responsible for receiving the main direction of hot air flow diffusion, the height of the variable damper dust collecting hood and the dust collecting area data of the variable damper dust collecting hood obtained by the hot air flow direction calculation unit. The control unit controls the vertically movable flue duct to move the variable damper dust collecting hood to the calculated height, and controls the opening degree of the variable damper dust collecting hood to achieve the controllable dust collecting direction and dust collecting area targets. The automatic opening and closing module of the dust collection port is used when a single dust collector collects dust for multiple sets of equipment. It opens and closes the damper of the current equipment by accepting the equipment thermal airflow parameters obtained by the thermal airflow direction calculation module, thereby reducing manual intervention and achieving energy saving in the dust removal system.

2. The steelmaking secondary smoke capture system according to claim 1, characterized in that: The vertically movable flue duct and the variable air door dust collecting hood are integrated equipment. The lifting and lowering of the vertically movable flue duct is driven by a vertically arranged reciprocating hydraulic cylinder. The vertically movable flue duct is connected to the flue main pipe by a folding pipe.

3. The steelmaking secondary smoke capture system according to claim 2, characterized in that: The moving range of the vertically movable flue duct does not exceed 0.5m, and the moving height signal is determined by the control unit based on the result calculated by the heat diffusion model.

4. The steelmaking secondary smoke capture system according to claim 1, characterized in that: The variable damper dust collecting hood is a two-stage or four-stage circular ring, the center of the ring is the center of the dust source point device, the radius of the ring is the radius of the dust source point device plus 0.5 to 0.8m, and the thickness of the ring is 12 to 16cm.

5. The steelmaking secondary smoke capture system according to claim 4, characterized in that: An air collecting port is arranged on the inner side of the circular ring of the variable air door dust collecting hood, and the outer side is connected to a vertically movable flue duct.

6. The steelmaking secondary smoke capture system according to claim 5, characterized in that: A slide gate is arranged at the air collecting port, which is connected to a slide gate cylinder. The slide gate cylinder is used to control the dust collecting area of ​​the air collecting port, the closing of the air collecting port in the non-hot air flow direction, and the opening of the air collecting port in the hot air flow direction.

7. The steelmaking secondary smoke capture system according to claim 5, characterized in that: The air collecting port is a rectangular air collecting port.

8. The steelmaking secondary smoke capture system according to claim 1, characterized in that: Two sets of thermal imaging equipment are installed around the steelmaking equipment. The two sets of thermal imaging equipment are set at different heights and arranged perpendicular to each other.

9. The steelmaking secondary smoke capture system according to claim 1, characterized in that: The hot air flow direction calculation unit obtains a hot flame pattern according to the thermal imaging device, and calculates the high-temperature flue gas diffusion direction according to the hot flame inclination angle of the hot flame pattern.

10. A method for using a steelmaking secondary smoke capture system, characterized in that: The steelmaking secondary smoke capture system as claimed in any one of claims 1 to 9 is used to capture and collect smoke emitted by steelmaking equipment, specifically comprising the following steps: S1. The thermal imaging device performs thermal imaging of the steelmaking equipment at the smoke emission point, and transmits the thermal imaging data to the thermal air flow direction calculation unit; S2, the hot air flow direction calculation unit establishes a heat diffusion model for the diffusion of the rising hot air flow according to the thermal imaging data, calculates the main direction of the hot air flow diffusion using the heat diffusion model, and obtains the optimal variable air door dust collecting hood height and dust collecting area in combination with the three-dimensional model of the steelmaking equipment 1; S3, the control unit receives the main direction of hot air flow diffusion, the height of the variable air door dust collecting hood and the dust collecting area data obtained by the hot air flow direction calculation unit, controls the vertically movable flue duct to move the variable air door dust collecting hood to the calculated height, and controls the air collecting port opening of the variable air door dust collecting hood to achieve the controllable targets of the dust collecting direction and the dust collecting area.

Images