Furnace pressure control device and method for ladle refining furnace

Abstract

The invention relates to a ladle refining furnace pressure control device and method, the device comprises a furnace cover used for covering the top of a ladle and an air draft pipeline arranged on the furnace cover, an air mixing structure is arranged on the air draft pipeline, and the air mixing amount is adjustable. The method comprises the following steps: furnace pressure control: detecting the furnace pressure, judging whether the furnace pressure is within a set range or not, if the furnace pressure is within the set range, maintaining the current air draft quantity, and if the furnace pressure exceeds the set range, increasing and decreasing the air draft quantity in a matching manner; and controlling the temperature of the air draft pipeline: detecting the temperature of the pipe wall of the air draft pipeline, judging whether the temperature of the pipe wall exceeds the set temperature or not, and if the temperature of the pipe wall exceeds the set temperature, mixing low-temperature gas into the air draft pipeline so as to reduce the temperature of the pipe wall. The air mixing structure is arranged on the air draft pipeline, low-temperature gas can be mixed when the temperature of the air draft pipeline is too high, the temperature of the gas in the pipeline is reduced, the effect of cooling the air draft pipeline is achieved, the air draft pipeline is prevented from being too hot and red, and therefore the air draft pipeline is well protected, and the service life of the air draft pipeline is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of steelmaking, and in particular relates to a device and method for controlling the furnace pressure of a ladle refining furnace. Background Art

[0002] The LF furnace is a crucial refining equipment in the steelmaking process, and controlling its furnace pressure is crucial for both process control and environmental protection. Traditional LF furnace pressure control methods primarily extract gases from the furnace through exhaust ducts installed on the furnace cover, relying on air volume control valves to regulate air flow to maintain the furnace pressure within a set range. However, since the high-temperature gases from the furnace directly enter the exhaust duct, the duct can overheat and even turn red, seriously impacting the lifespan and safety of the equipment. Summary of the Invention

[0003] The present invention relates to a ladle refining furnace pressure control device and method, which can at least solve some of the defects of the prior art.

[0004] The invention relates to a furnace pressure control device for a ladle refining furnace, comprising a furnace cover for covering the top of the ladle and an exhaust duct arranged on the furnace cover. The exhaust duct is provided with an air mixing structure and the mixed air volume is adjustable.

[0005] As one embodiment, the exhaust duct includes a first pipe section and a second pipe section, the head end of the first pipe section is connected to the furnace cover, and the tail end of the first pipe section is provided with an inner pipe section extending into the second pipe section;

[0006] The air mixing structure includes an air mixing cone and an air mixing drive unit for driving the air mixing cone to move along its own axial direction. The air mixing cone includes an air mixing straight pipe section and an air mixing cone section whose small-diameter end is connected to the air mixing straight pipe section. The air mixing straight pipe section is sleeved on the inner pipe section, and the large-diameter end of the air mixing cone section is located outside the second pipe section and is connected to the air mixing drive unit.

[0007] As one of the embodiments, the air mixing drive unit includes an electric push rod, which is installed on the first pipe segment or the second pipe segment through a support. The output end of the electric push rod is connected to the air mixing cone pipe segment and its driving direction is parallel to the axial direction of the air mixing cone pipe.

[0008] As one of the implementation modes, the inner pipe section is connected to the tail end of the first pipe section through a tapered pipe transition section.

[0009] As one of the implementation modes, the exhaust duct is provided with a temperature detection unit for detecting the temperature of the duct wall.

[0010] As one of the embodiments, the ladle refining furnace pressure control device also includes a controller, and the temperature detection unit and the air mixing structure are electrically connected or communicatively connected to the controller, and the controller is used to obtain the temperature data detected by the temperature detection unit and control the mixed air volume of the air mixing structure based on the temperature data.

[0011] As one of the implementation modes, a furnace pressure detection module is provided on the furnace cover, and an air volume regulating valve is provided on the exhaust duct, and the air volume regulating valve is interlocked with the furnace pressure detection module.

[0012] The present invention also relates to a method for controlling furnace pressure of a ladle refining furnace, the method comprising:

[0013] Furnace pressure control: Detect the furnace pressure and determine whether it is within the set range. If the furnace pressure is within the set range, maintain the current exhaust volume. If the furnace pressure exceeds the set range, increase or decrease the exhaust volume accordingly.

[0014] Exhaust duct temperature control: Detect the wall temperature of the exhaust duct and determine whether the wall temperature exceeds the set temperature. If the wall temperature exceeds the set temperature, low-temperature gas is mixed into the exhaust duct to lower the wall temperature.

[0015] As one of the implementation methods, after adjusting the exhaust air volume or adjusting the mixed air volume, the furnace pressure control step is re-executed.

[0016] As one of the implementation methods, when the exhaust volume is increased, the mixed air volume is simultaneously increased to reduce the situation where the pipe wall temperature exceeds the set temperature.

[0017] The present invention has at least the following beneficial effects:

[0018] In the present invention, by arranging an air mixing structure on the exhaust duct, low-temperature gas can be mixed into the exhaust duct when the temperature of the exhaust duct is too high, thereby lowering the gas temperature in the duct, achieving the effect of cooling the exhaust duct, preventing the exhaust duct from overheating and reddening, thereby better protecting the exhaust duct and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic structural diagram of a ladle refining furnace pressure control device provided by an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the exploded structure of the ladle refining furnace pressure control device. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. 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 making any creative efforts are within the scope of protection of the present invention.

[0023] Example 1

[0024] like Figure 1 and Figure 2 An embodiment of the present invention provides a ladle refining furnace pressure control device, comprising a furnace cover 1 for covering the top of the ladle and an exhaust duct arranged on the furnace cover 1, wherein the exhaust duct is provided with an air mixing structure and the mixed air volume is adjustable.

[0025] The above-mentioned air mixing structure is used to mix gas, especially low-temperature gas, into the exhaust duct. Low-temperature gas refers to gas with a temperature lower than the temperature of the gas in the furnace.

[0026] By setting up an air mixing structure on the exhaust duct, low-temperature gas can be mixed in when the temperature of the exhaust duct is too high, thereby lowering the gas temperature in the duct, achieving the effect of cooling the exhaust duct, preventing the exhaust duct from overheating and reddening, thereby better protecting the exhaust duct and extending its service life.

[0027] In one embodiment, the low-temperature gas mixed into the air mixing structure is air, for example, the air around the exhaust duct is directly introduced into the exhaust duct.

[0028] Optionally, an air mixing pipe may be directly connected to the exhaust pipe, the air mixing pipe is connected to the low-temperature gas source (for example, a blower is directly connected to the end of the air mixing pipe), and an air mixing valve is provided on the air mixing pipe.

[0029] In another embodiment, Figure 1 and Figure 2 The exhaust duct includes a first pipe section 21 and a second pipe section 22. The head end of the first pipe section 21 is connected to the furnace cover 1, and the tail end of the first pipe section 21 is provided with an inner pipe section 211 extending into the second pipe section 22.

[0030] The air mixing structure includes an air mixing cone 3 and an air mixing drive unit 4 for driving the air mixing cone 3 to move along its own axial direction. The air mixing cone 3 includes an air mixing straight pipe section 31 and an air mixing cone section 32 whose small-diameter end is connected to the air mixing straight pipe section 31. The air mixing straight pipe section 31 is sleeved on the inner pipe section 211, and the large-diameter end of the air mixing cone section 32 is located outside the second pipe section 22 and is connected to the air mixing drive unit 4.

[0031] Preferably, the first and second pipe sections 21 and 22 have the same inner diameter, while the outer diameter of the inner pipe section 211 is smaller than the inner diameters of the first and second pipe sections 21 and 22. In this configuration, the inner pipe section 211 is connected to the tail end of the first pipe section 21 via a tapered transition section, the smaller diameter end of which butts against the inner pipe section 211. A certain distance exists between the tail end of the first pipe section 21 and the head end of the second pipe section 22 (i.e., the end closest to the first pipe section 21), facilitating the installation and movement of the air mixing cone 3. This design facilitates the connection between the inner pipe section 211 and the first pipe section 21, ensuring relatively smooth flow of flue gas between the first and second pipe sections 21 and 22. Furthermore, the first pipe section 21, inner pipe section 211, and second pipe section 22 form a Venturi tube structure, with the throat ejection effect at the inner pipe section 211 facilitating air mixing.

[0032] The straight air mixing pipe section 31 is movable relative to the inner pipe section 211 , and preferably there is a clearance fit between the two, for example, the straight air mixing pipe section 31 is slidably sleeved on the inner pipe section 211 .

[0033] The air mixing cone 3 moves along its own axial direction, that is, the air mixing cone section 32 can move relative to the second pipe section 22, thereby adjusting the air mixing volume. In one embodiment, the air mixing drive unit 4 includes an electric push rod, which is mounted on the first pipe section 21 or the second pipe section 22 via a support. The output end of the electric push rod is connected to the air mixing cone section 32, and its driving direction is parallel to the axial direction of the air mixing cone 3.

[0034] Optionally, a first flange is provided on the pipe wall of the second pipe section 22, and a second flange is provided on the outer wall of the air mixing cone pipe section 32. A plurality of long screws are used to connect the second flange and the first flange in series in sequence, and the long screws and the first flange can move relative to each other (for example, a light rod section of a certain length is provided corresponding to the position of the first flange).

[0035] In the aforementioned scheme for mixing air through the mixing cone 3, ambient air can be mixed directly through the mixing cone 3, or a cold air duct can be connected to the mixing cone section 32. This cold air duct is sleeved around the second pipe section 22 and connected to the large-diameter end of the mixing cone section 32. The cold air duct can include a corrugated pipe section to facilitate its adaptation to the movement of the mixing cone section 32. In this structure, the required low-temperature gas can be mixed in according to process requirements. By providing a flow control valve on the cold air duct, the mixed air volume can be actively controlled. Coupled with the movement of the mixing cone section, the adjustment accuracy of the mixed air volume can be further improved. Even the power source on the cold air duct can actively mix low-temperature gas into the exhaust duct. Furthermore, because the cold air duct is sleeved around the second pipe section 22, the wall of the second pipe section 22 can be pre-cooled. Combined with the cooling effect of the mixed air within the second pipe section 22, multi-stage cooling of the second pipe section 22 and multi-stage utilization of the low-temperature gas can be achieved, resulting in better energy efficiency and environmental protection.

[0036] In one embodiment, an annular cyclone is disposed on the outer wall of the straight air mixing duct section 31. In this structure, the annular cyclone is movable relative to the second duct section 22. Alternatively, an annular cyclone is disposed between the inner duct section 211 and the second duct section 22, located on the side of the straight air mixing duct section 31 away from the air mixing cone section 32 (the annular cyclone's location should obviously meet the required movement of the straight air mixing duct section 31). The annular cyclone allows the incoming low-temperature gas to quickly mix with the high-temperature gas within the duct, thereby improving the cooling efficiency and effectiveness of the gas within the duct.

[0037] Preferably, if Figure 1 and Figure 2 The exhaust duct is provided with a temperature detection unit 6 for detecting the temperature of the duct wall. The temperature detection unit 6 can be a temperature detection probe, etc. Furthermore, the ladle refining furnace pressure control device also includes a controller. The temperature detection unit 6 and the air mixing structure (corresponding to the aforementioned air mixing drive unit 4) are both electrically connected or communicatively connected to the controller. The controller is configured to obtain temperature data detected by the temperature detection unit 6 and control the air mixing volume of the air mixing structure based on the temperature data.

[0038] In one embodiment, Figure 1 and Figure 2 The furnace cover 1 is provided with a furnace pressure detection module 7, and the exhaust duct is provided with an air volume control valve 5, which is interlocked with the furnace pressure detection module 7. The furnace pressure detection module 7 can be a furnace pressure detection probe provided on the furnace cover 1. The furnace pressure detection module 7 and the air volume control valve 5 are both electrically connected or communicatively connected to a controller, which is configured to obtain furnace pressure data detected by the furnace pressure detection module 7 and control the opening of the air volume control valve 5 based on the furnace pressure data.

[0039] Example 2

[0040] An embodiment of the present invention provides a method for controlling furnace pressure of a ladle refining furnace, the method comprising:

[0041] Furnace pressure control: Detect the furnace pressure and determine whether it is within the set range. If the furnace pressure is within the set range, maintain the current exhaust volume. If the furnace pressure exceeds the set range, increase or decrease the exhaust volume accordingly.

[0042] Exhaust duct temperature control: Detect the wall temperature of the exhaust duct and determine whether the wall temperature exceeds the set temperature. If the wall temperature exceeds the set temperature, low-temperature gas is mixed into the exhaust duct to lower the wall temperature.

[0043] The ladle refining furnace pressure control method can be implemented based on the ladle refining furnace pressure control device provided in the first embodiment.

[0044] Optionally, a furnace pressure setting value P is preset, and the furnace pressure setting range can be a range formed by increasing or decreasing the furnace pressure setting value by 5%: 95% P ~ 105% P. Of course, the furnace pressure setting value and the furnace pressure setting range can be adjusted according to actual working conditions.

[0045] Among them, if the furnace pressure is greater than the upper limit value of the furnace pressure setting range, the opening of the air volume regulating valve 5 is increased; if the furnace pressure is less than the lower limit value of the furnace pressure setting range, the opening of the air volume regulating valve 5 is reduced.

[0046] Preferably, after adjusting the exhaust air volume or adjusting the mixed air volume, the furnace pressure control step is re-executed.

[0047] Preferably, the furnace pressure control step and the exhaust duct temperature control step are both performed in real time during production to ensure normal production of the ladle refining furnace.

[0048] In one embodiment, when the exhaust volume is increased, the mixed air volume is simultaneously increased to reduce the situation where the pipe wall temperature exceeds the set temperature.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A ladle refining furnace pressure control device, comprising a furnace cover for covering the top of the ladle and an exhaust duct arranged on the furnace cover, characterized in that: The exhaust duct is provided with an air mixing structure and the air mixing volume is adjustable.

2. The ladle refining furnace pressure control device according to claim 1, characterized in that: The exhaust duct includes a first pipe section and a second pipe section, the head end of the first pipe section is connected to the furnace cover, and the tail end of the first pipe section is provided with an inner pipe section extending into the second pipe section; The air mixing structure includes an air mixing cone and an air mixing drive unit for driving the air mixing cone to move along its own axial direction. The air mixing cone includes an air mixing straight pipe section and an air mixing cone section whose small-diameter end is connected to the air mixing straight pipe section. The air mixing straight pipe section is sleeved on the inner pipe section, and the large-diameter end of the air mixing cone section is located outside the second pipe section and is connected to the air mixing drive unit.

3. The ladle refining furnace pressure control device according to claim 2, characterized in that: The air mixing drive unit includes an electric push rod, which is installed on the first pipe section or the second pipe section through a support. The output end of the electric push rod is connected to the air mixing cone pipe section and its driving direction is parallel to the axial direction of the air mixing cone pipe.

4. The ladle refining furnace pressure control device according to claim 2, characterized in that: The inner pipe section is connected to the tail end of the first pipe section through a tapered pipe transition section.

5. The ladle refining furnace pressure control device according to any one of claims 1 to 4, characterized in that: The exhaust duct is provided with a temperature detection unit for detecting the temperature of the duct wall.

6. The ladle refining furnace pressure control device according to claim 5, characterized in that: It also includes a controller, and the temperature detection unit and the air mixing structure are both electrically connected or communicatively connected to the controller. The controller is used to obtain temperature data detected by the temperature detection unit and control the mixed air volume of the air mixing structure based on the temperature data.

7. The ladle refining furnace pressure control device according to claim 1, characterized in that: The furnace cover is provided with a furnace pressure detection module, and the exhaust duct is provided with an air volume regulating valve, which is interlocked with the furnace pressure detection module.

8. A method for controlling furnace pressure of a ladle refining furnace, characterized in that: The method comprises: Furnace pressure control: Detect the furnace pressure and determine whether it is within the set range. If the furnace pressure is within the set range, maintain the current exhaust volume. If the furnace pressure exceeds the set range, increase or decrease the exhaust volume accordingly. Exhaust duct temperature control: Detect the wall temperature of the exhaust duct and determine whether the wall temperature exceeds the set temperature. If the wall temperature exceeds the set temperature, low-temperature gas is mixed into the exhaust duct to lower the wall temperature.

9. The ladle refining furnace pressure control method according to claim 8, characterized in that: After adjusting the exhaust air volume or adjusting the mixed air volume, the furnace pressure control step is executed again.

10. The ladle refining furnace pressure control method according to claim 8, characterized in that: When increasing the exhaust volume, the mixed air volume is increased synchronously to reduce the situation where the pipe wall temperature exceeds the set temperature.

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