A device for treating flue dust in front of a submerged arc furnace

Abstract

This invention provides a dust control device for front-end dust in a submerged arc furnace, including a dust collector, a tail exhaust fan, and a dust duct assembly. The dust duct assembly includes a main dust duct, at least two sets of branch dust ducts, and a dust concentration sensor installed on the main dust duct. Each branch dust duct has a dust collection hood at its end, and a dust sensor is installed inside the dust collection hood. Each branch dust duct has a control valve, and the dust sensor on the corresponding branch dust duct is communicatively connected to its corresponding control valve. The dust concentration sensor is communicatively connected to the tail exhaust fan to convert the monitored dust concentration change signal into a control value for the tail exhaust fan frequency to control the operation of the tail exhaust fan. This invention can automatically adjust the frequency based on the high-temperature dust conditions in front of the submerged arc furnace, reducing equipment energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of high-temperature flue gas treatment technology, and in particular to a flue gas treatment device for front of a submerged arc furnace. Background Technology

[0002] Currently, in the treatment of high-temperature flue gas in front of electric arc furnaces in my country's metallurgical industry, there are two main operating modes for dust removal systems: one is to set the tail exhaust fan to operate at a fixed frequency, and the other is to rely on manual adjustment of the operating frequency of the variable frequency tail exhaust fan to control the treatment effect of the flue gas at the front end of the electric arc furnace.

[0003] In actual industrial production processes, the generation of high-temperature flue gas in front of the electric arc furnace is characterized by dynamic changes. Therefore, the above two traditional dust removal system operation modes have the following problems:

[0004] 1. Running a fan at a fixed frequency continuously will result in high energy consumption for dust removal equipment;

[0005] 2. Manual frequency tuning may have response delays, be limited by the operator's experience, and may have adverse effects on the operator in high-temperature and dusty working environments.

[0006] Therefore, there is an urgent need for a dust control device for electric arc furnaces that can automatically adjust the frequency based on the high-temperature dust conditions in front of the furnace to reduce equipment energy consumption. Utility Model Content

[0007] The purpose of this invention is to provide a dust control device for front-end dust in electric arc furnaces, which aims to solve the technical problems of high energy consumption and difficulty in automatic frequency adjustment in traditional dust removal systems.

[0008] To achieve the above objectives, this utility model provides a dust control device for front-end flue gas of a submerged arc furnace, including a dust collector, a tail exhaust fan installed at the outlet end of the dust collector, and a dust duct assembly installed at the inlet end of the dust collector.

[0009] The dust duct assembly includes a main dust duct, at least two sets of dust branch ducts connected to the main dust duct, and a dust concentration sensor installed on the main dust duct.

[0010] Each of the aforementioned dust branch pipes is equipped with a dust collection hood at its end, and a dust sensor is installed inside the dust collection hood;

[0011] Each of the aforementioned dust branch pipes is equipped with a control valve, and the dust sensor on the corresponding branch pipe is communicatively connected to its corresponding control valve so as to control the opening and closing of the corresponding dust branch pipe based on whether the corresponding dust sensor detects high-temperature dust.

[0012] The dust concentration sensor is communicatively connected to the exhaust fan to convert the monitored dust concentration change signal into a frequency value for controlling the exhaust fan's operation.

[0013] As a further improvement to the above solution, each of the dust collection hoods is located at a different position around the electric arc furnace, and is used to collect high-temperature dust near the electric arc furnace.

[0014] As a further improvement to the above solution, the tail exhaust fan is a variable frequency centrifugal tail exhaust fan.

[0015] As a further improvement to the above solution, the dust collector may include, but is not limited to, a bag filter dust collector.

[0016] As a further improvement to the above solution, the control valve is an electric butterfly valve, which is installed on the corresponding flue gas branch pipe via brackets.

[0017] As a further improvement to the above solution, each control valve includes a drive motor, a rotating shaft, and a valve plate mounted on the rotating shaft, all mounted on the bracket.

[0018] One end of the rotating shaft is driven and connected to the power output end of the drive motor, and the other end extends through the corresponding branch pipe into the inside of the branch pipe. The shape of the valve plate is matched with the inner wall of the corresponding branch pipe.

[0019] Because this utility model adopts the above technical solutions, the beneficial effects of this application are as follows:

[0020] This utility model provides a dust control device for front-end dust in a submerged arc furnace. A dust concentration sensor is installed on the main dust duct at the inlet of the dust collector to monitor changes in the concentration of high-temperature dust entering the dust collector in real time. This concentration signal is then converted into frequency control commands for the exhaust fan. When the dust concentration increases (e.g., due to charging of the submerged arc furnace or intensified smelting conditions leading to a surge in dust volume), the system automatically increases the fan frequency to increase the exhaust air volume, ensuring dust removal efficiency. When the dust concentration decreases (e.g., due to stable operating conditions or reduced dust volume during intermittent periods), the system promptly reduces the fan frequency to minimize energy consumption. Compared to traditional fixed-frequency fans, this dynamic control mechanism avoids the energy waste of over-powered fans, precisely matching the fan output power according to actual dust volume requirements, thereby reducing equipment energy consumption.

[0021] In addition, dust sensors are installed in the dust collection hoods at the ends of each dust branch duct, and these sensors are connected to the control valves of the corresponding branch ducts to form an integrated "detection-control" closed loop. Specifically, when a dust collection hood in a branch duct detects high-temperature dust (indicating dust generation in the area), its corresponding control valve automatically opens, guiding the dust into the main duct. When no dust is generated in the branch duct (e.g., work at the corresponding workstation is suspended or dust has spread to other areas), the control valve automatically closes, preventing the fan from ineffectively sucking up dust-free branches. This setup completely replaces the manual operation of opening and closing valves, eliminating the need for operators to frequently inspect and adjust valve status, effectively reducing the frequency of manual intervention and the risk of operational errors, and significantly improving the automation and reliability of the system.

[0022] To address the issue that the amount of high-temperature dust generated during the production process of electric arc furnaces is easily affected by fluctuations in operating conditions (such as changes in raw material composition, smelting temperature fluctuations, and adjustments to the feeding rhythm), the device constructs a multi-level monitoring system of "local sensing in branch lines + overall sensing in the main pipeline." On the one hand, the dust sensors in the branch lines can independently sense the dust dynamics in their respective areas and achieve branch-level on / off control through control valves, avoiding the impact of sudden changes in local dust volume on the main pipeline. On the other hand, the dust concentration sensor in the main pipeline can provide real-time feedback on the overall dust load and achieve global airflow matching by adjusting the fan frequency. The synergistic effect of these two systems ensures accurate control of each branch line in the presence / absence of dust and ensures the stable operation of the overall dust removal system under complex operating conditions. This effectively solves the problems of system pressure fluctuations and reduced dust removal efficiency caused by uneven dust distribution in branch lines in traditional solutions, significantly enhancing the adaptability to operating conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional schematic diagram of a dust control device for front-end of a submerged arc furnace disclosed in this utility model;

[0025] Figure 2 This is a three-dimensional structural diagram of the flue gas duct assembly disclosed in this utility model;

[0026] Figure 3 This is a three-dimensional structural diagram of a flue gas duct assembly disclosed in this utility model.

[0027] Figure 4 This is a three-dimensional structural diagram of the control valve disclosed in this utility model.

[0028] Figure label:

[0029] 0. Mineral arc furnace; 1. Dust collector; 2. Tail exhaust fan; 3. Dust duct assembly; 31. Main dust duct; 32. Branch dust duct; 33. Dust concentration sensor; 34-1. First dust collection hood; 34-2. Second dust collection hood; 35-1. First dust sensor; 35-2. Second dust sensor; 36-1. First control valve; 36-2. Second control valve; 361. Drive motor; 362. Rotating shaft; 363. Valve plate; 4. Support.

[0030] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0034] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0035] See Figures 1-4 This utility model provides a dust control device for the front of a submerged arc furnace, including a dust collector 1, a tail exhaust fan 2 installed at the outlet end of the dust collector 1, and a dust duct assembly 3 installed at the inlet end of the dust collector 1.

[0036] See Figure 2 and Figure 3 The dust duct assembly 3 includes a main dust duct 31, at least two sets of dust branch ducts 32 connected to the main dust duct 31, and a dust concentration sensor 33 installed on the main dust duct 31; specifically, in this embodiment, the example of having two sets of dust branch ducts 32 is used for illustration.

[0037] Correspondingly, an umbrella-shaped first dust collection hood 34-1 is provided at the end of a dust branch pipe 32. The first dust collection hood 34-1 is provided with a first dust sensor 35-1 for real-time monitoring of the dust concentration inside the hood. A first control valve 36-1 is provided on the dust branch pipe 32. The first dust sensor 35-1 on the dust branch pipe 32 is communicatively connected to the first control valve 36-1.

[0038] At the end of another dust branch pipe 32, there is an umbrella-shaped second dust collection hood 34-2. Inside the second dust collection hood 34-2, there is a second dust sensor 35-2 for real-time monitoring of the dust concentration inside the hood. The dust branch pipe 32 is equipped with a second control valve 36-2. The second dust sensor 35-2 on the dust branch pipe 32 is communicatively connected to the second control valve 36-2.

[0039] The dust concentration sensor 33 is communicatively connected to the exhaust fan 2 to convert the monitored dust concentration change signal into a frequency value for controlling the exhaust fan 2 to control its operation.

[0040] Specifically, when high-temperature dust is generated in front of the blast furnace (such as dust raised during discharge or flue gas emitted from the furnace opening), the first dust sensor 35-1 or the second dust sensor 35-2 collects the dust concentration signal inside the hood in real time (the threshold is set to 100 mg / m³). If the dust concentration in a certain area exceeds the threshold (such as the area corresponding to the first dust branch pipe 32), the corresponding sensor transmits an analog signal to the PLC controller. The controller sends an opening command to the corresponding first control valve 36-1 through the relay output module, so that the corresponding dust branch pipe 32 is open, and the dust enters the main dust pipe 31 through the dust collection hood and the dust branch pipe 32. Similarly, when the dust concentration in the area corresponding to another dust branch pipe 32 exceeds the standard, the second control valve 36-2 opens simultaneously.

[0041] The dust concentration sensor 33 on the main dust duct 31 monitors the total dust concentration entering the dust collector 1 in real time and transmits the signal to the frequency converter of the tail exhaust fan 2. The frequency converter dynamically adjusts the fan frequency according to the total concentration value. Preferably, when the total concentration is >1500mg / m³, the frequency is increased to 45Hz (90% of the rated air volume); when the total concentration drops to below 500mg / m³, the frequency drops to 20Hz (low load operation) to ensure that the fan air volume matches the dust volume and avoid the phenomenon of "overpowered fan".

[0042] When the flue gas emission in front of the furnace ends (such as when the material is discharged), the sensors of each flue gas branch pipe detect that the concentration is lower than the threshold (such as <50mg / m³), and the PLC controller sends a closing command to the corresponding control valve (the valve slowly closes to the fully closed state); at the same time, after the sensor 31 of the main flue gas pipeline confirms that the total concentration meets the standard, the frequency converter reduces the frequency of the fan to 10Hz for standby until the next trigger.

[0043] This invention utilizes a dust concentration sensor 33 installed on the main dust duct 31 at the inlet of the dust collector 1 to monitor changes in the high-temperature dust concentration entering the dust collector 1 in real time, and converts this concentration signal into a frequency control command for the exhaust fan 2. When the dust concentration increases (e.g., due to charging of a submerged arc furnace or a surge in dust volume caused by intensified smelting conditions), the system automatically increases the fan frequency to increase the exhaust air volume, ensuring dust removal efficiency. When the dust concentration decreases (e.g., due to stable operating conditions or reduced dust volume during intermittent periods), the system promptly reduces the fan frequency to minimize energy consumption. Compared to traditional fans operating at a fixed frequency, the dynamic control mechanism avoids the energy waste of "overpowered power," and can precisely match the fan output power according to the actual dust volume requirements, thereby reducing equipment energy consumption.

[0044] In addition, dust sensors are installed in the dust collection hoods at the ends of each dust branch duct 32, and are connected to the control valves of the corresponding branch ducts to form an integrated "detection-control" closed loop. Specifically, when the dust collection hood of a branch duct detects high-temperature dust (indicating that dust is generated in the area), its corresponding control valve automatically opens, guiding the dust into the main duct. When no dust is generated in the branch duct (such as when the corresponding workstation is suspended or the dust spreads to other areas), the control valve automatically closes to prevent the fan from ineffectively sucking up dust-free branches. This setup completely replaces the manual operation of opening and closing valves, eliminating the need for operators to frequently inspect and adjust valve status, effectively reducing the frequency of manual intervention and the risk of operational errors, and significantly improving the automation and reliability of the system operation.

[0045] In a preferred embodiment, each dust collection hood is located at a different position around the electric arc furnace 0, for collecting high-temperature smoke and dust near the electric arc furnace 0;

[0046] Preferably, at least three sets of dust branch pipes 32 are provided, and correspondingly, three dust collection hoods are evenly distributed in a ring around the periphery of the electric arc furnace 0. The bottom edge of the dust collection hood is at least 10cm away from the furnace body of the electric arc furnace 0 (to avoid excessive damage to the hood body by high temperature radiation, and to collect high temperature dust in a timely and effective manner), so as to achieve efficient and comprehensive collection of high temperature dust around the electric arc furnace 0.

[0047] When the electric arc furnace is running, the high-temperature flue gas inside the furnace spreads to the surroundings due to pressure fluctuations and material reactions. At this time, the dust collection hoods distributed in different directions guide the hood openings to face the main direction of dust diffusion through the guide plates, and use negative pressure to draw the dust into the hood.

[0048] As a preferred embodiment, the tail exhaust fan 2 is a variable frequency centrifugal tail exhaust fan 2; specifically, a centrifugal fan (rated air volume 22000m³ / h, rated air pressure 1500Pa) is selected, the motor power is 30kW, and the frequency is adjusted (range 0-50Hz) through a frequency converter to adapt to the smoke exhaust requirements under different working conditions.

[0049] In a preferred embodiment, the dust collector 1 is, but is not limited to, a bag filter 1; specifically, in this embodiment, a pulse bag filter 1 (model LDM-120, handling air volume 20000m³ / h) is used; the dust collector 1 is equipped with filter bag groups and a pulse-jet system to filter particulate matter in the flue gas, the clean gas is discharged through the tail exhaust fan 2, and the dust falls into the bottom ash hopper.

[0050] As a preferred embodiment, see Figure 4 The first control valve 36-1 and the second control valve 36-2 are both electric butterfly valves, which are respectively installed on the corresponding flue gas branch pipes 32 through the corresponding brackets 4; however, those skilled in the art should understand that the technical solution of this utility model is not limited to the number of pipes and the specific application scenario.

[0051] Specifically, each control valve includes a drive motor 361, a rotating shaft 362, and a valve plate 363 mounted on the bracket 4.

[0052] The drive motor 361 is fixedly installed on the top (or side, depending on the pipeline layout) of the bracket 4 by bolts. Its power output end is rigidly connected to one end of the rotating shaft 362, which is used to drive the rotating shaft 362 to rotate around its own axis.

[0053] The rotating shaft 362 is a cylindrical metal rod. One end of it is connected to the power output end of the drive motor 361, and the other end extends through the pipe wall of the corresponding pipe into the pipe. An annular gap is formed between the outer circumference of the extension section and the pipe wall.

[0054] The valve plate 363 is an arc-shaped plate (or a disc-shaped structure) that matches the curvature of the inner wall of the pipe. Its outer diameter is slightly smaller than the inner diameter of the corresponding pipe to ensure that the valve plate 363 can rotate flexibly inside the pipe. The center position of the valve plate 363 is fixedly connected to the extension end of the rotating shaft 362 (such as through a flange or welding), so that it rotates synchronously with the rotating shaft 362 to realize the on / off control of the pipe (when the valve plate 363 rotates to be perpendicular to the pipe axis, the valve is closed; when it rotates to be parallel to the pipe axis, the valve is open).

[0055] The first control valve 36-1 and the second control valve 36-2 have the same structure, and can be quickly assembled through mass production of standardized parts, reducing the cost of customized design. At the same time, when a valve fails, only the same model of drive motor 361, rotating shaft 362 or valve plate 363 and other common parts need to be replaced to complete the repair, without the need to select parts separately for different valves, which greatly improves maintenance efficiency.

[0056] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A device for treating flue dust in front of a submerged arc furnace, characterized in that, It includes a dust collector, a tail exhaust fan installed at the outlet end of the dust collector, and a dust duct assembly installed at the inlet end of the dust collector. The dust duct assembly includes a main dust duct, at least two sets of dust branch ducts connected to the main dust duct, and a dust concentration sensor installed on the main dust duct. Each of the aforementioned dust branch pipes is equipped with a dust collection hood at its end, and a dust sensor is installed inside the dust collection hood; Each of the aforementioned dust branch pipes is equipped with a control valve, and the dust sensor on the corresponding branch pipe is communicatively connected to its corresponding control valve, so as to control the opening and closing of the corresponding dust branch pipe based on whether the corresponding dust sensor detects high-temperature dust. The dust concentration sensor is communicatively connected to the exhaust fan to convert the monitored dust concentration change signal into a frequency value for controlling the exhaust fan's operation.

2. The dust control device for a submerged arc furnace according to claim 1, characterized in that, Each of the dust collection hoods is located at a different position around the electric arc furnace and is used to collect high-temperature dust near the electric arc furnace.

3. A dust control device for a submerged arc furnace according to claim 1 or 2, characterized in that, The exhaust fan is a variable frequency centrifugal exhaust fan.

4. A dust control device for a submerged arc furnace according to claim 1 or 2, characterized in that, The dust collector is a bag filter.

5. A dust control device for a submerged arc furnace according to claim 1 or 2, characterized in that, The control valves are electric butterfly valves, which are installed on the corresponding flue gas branch pipes via brackets.

6. The dust control device for front-end flue gas of a submerged arc furnace according to claim 5, characterized in that, Each control valve includes a drive motor, a rotating shaft, and a valve plate mounted on the rotating shaft, all mounted on the bracket. One end of the rotating shaft is driven and connected to the power output end of the drive motor, and the other end extends through the corresponding branch pipe into the inside of the branch pipe. The shape of the valve plate is matched with the inner wall of the corresponding branch pipe.

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