White steel jade smelting electric arc furnace waste heat recovery device and control method

Abstract

This invention discloses a waste heat recovery device for a stainless steel smelting electric arc furnace, comprising a stainless steel smelting electric arc furnace body, on which a waste heat recovery device body is mounted; the waste heat recovery device body includes a waste heat recovery box, and a mounting frame is fixedly installed on the outer surface of the waste heat recovery box. This invention establishes an automatic dust removal mechanism by setting up a servo motor, a first lead screw, a second lead screw, a first gear, a second gear, a threaded assembly, and a cleaning brush. During waste heat recovery, the servo motor drives the first lead screw to rotate, and the meshing of the first and second gears drives the second lead screw to rotate synchronously in the opposite direction, causing the threaded assembly to drive the cleaning brush to reciprocate on the surface of the dust collector filter screen, achieving real-time automatic cleaning of the filter screen. This effectively prevents dust in the high-temperature flue gas from clogging the filter screen pores, ensuring smooth flue gas flow and stable heat exchange efficiency, eliminating the need for frequent manual shutdowns for cleaning, and improving the continuous operation capability of the device.

Description

Technical Field

[0001] This invention belongs to the technical field of waste heat recovery devices, specifically relating to a waste heat recovery device and control method for an electric arc furnace for smelting stainless steel alumina. Background Technology

[0002] In the field of special refractory material manufacturing, electric arc furnaces generate a large amount of high-temperature flue gas during the smelting of white corundum, which contains abundant waste heat resources. The waste heat recovery of such flue gas is a key link to improve energy utilization and reduce production costs, and the corresponding waste heat recovery technology and equipment are particularly important.

[0003] Existing waste heat recovery devices for electric arc furnaces in smelting stainless steel alumina have shortcomings in dust removal. Dust in high-temperature flue gas easily adheres to heat exchange surfaces or filter screens, and conventional dust removal methods mostly rely on manual labor or simple mechanical vibration. Not only is the dust removal effect difficult to guarantee, but frequent shutdowns are also required, affecting the continuity of the smelting process and the stable operation of the waste heat recovery device. Furthermore, in the heat exchange stage, the flue gas flow design of traditional devices is usually relatively simple, resulting in a short residence time of flue gas in the device and insufficient heat exchange with the cooling medium. A large amount of medium and low temperature waste heat cannot be effectively recovered, which in turn reduces the practical performance of the waste heat recovery device. Summary of the Invention

[0004] The purpose of this invention is to provide a waste heat recovery device for electric arc furnaces used in the smelting of stainless steel alumina, so as to solve the problems mentioned in the background art.

[0005] In a first aspect, the present invention provides a waste heat recovery device for an electric arc furnace used in the smelting of white corundum, comprising: Includes a stainless steel alumina smelting electric arc furnace body, wherein a waste heat recovery device body is mounted on the stainless steel alumina smelting electric arc furnace body; The waste heat recovery device includes a waste heat recovery box. A mounting frame is fixedly installed on the outer surface of the waste heat recovery box. A servo motor is mounted on the mounting frame. A first lead screw and a second lead screw are rotatably inserted inside the waste heat recovery box. The output end of the servo motor rotatably passes through the waste heat recovery box and is fixedly connected to the end of the first lead screw. A first gear and a second gear are respectively fixedly installed at the ends of the first and second lead screws away from the servo motor. The first gear and the second gear are meshed together. Threaded fittings are threaded onto the outer surfaces of the first and second lead screws. A cleaning brush is provided at the opposite end of the threaded fittings. A dust filter is provided inside the waste heat recovery box. The cleaning brush is in contact with the outer surface of the dust filter.

[0006] In one possible implementation of the first aspect, the dust filter screen is fixedly mounted on a mounting plate on one side of the servo motor, and the mounting plate is connected to the waste heat recovery box by bolts.

[0007] In one possible implementation of the first aspect, the electro-arc furnace body for smelting stainless steel is provided with an air inlet pipe, which is connected to a waste heat recovery box.

[0008] In one possible implementation of the first aspect, the waste heat recovery box has a collection box inside, and the collection box is connected to the waste heat recovery box by bolts.

[0009] In one possible implementation of the first aspect, the waste heat recovery box is equipped with symmetrically distributed exhaust pipes, which are spiral structures.

[0010] In one possible implementation of the first aspect, the waste heat recovery box is provided with an inlet pipe and an outlet pipe.

[0011] Compared with the prior art, the present invention provides a waste heat recovery device for electric arc furnace smelting of stainless steel alumina, which has the following beneficial effects: I. This invention establishes an automatic dust removal mechanism by setting up a servo motor, a first lead screw, a second lead screw, a first gear, a second gear, a threaded assembly, and a cleaning brush. During the waste heat recovery process, the servo motor drives the first lead screw to rotate, and the meshing of the first and second gears drives the second lead screw to rotate synchronously in the opposite direction. This causes the threaded assembly to drive the cleaning brush to reciprocate on the surface of the dust filter screen, achieving real-time automatic cleaning of the filter screen. This effectively prevents dust in the high-temperature flue gas from clogging the filter screen pores, ensuring smooth flue gas flow and stable heat exchange efficiency. It eliminates the need for frequent manual shutdowns for cleaning, improving the continuous operation capability of the device. Second, this invention improves heat exchange efficiency by setting a spiral structure exhaust pipe inside the waste heat recovery box. The spiral structure extends the flow path and residence time of high-temperature flue gas in the box, allowing the flue gas and cooling water to fully exchange heat, maximizing the recovery of waste heat from the flue gas. The heated water can be used for production or domestic purposes, realizing the recycling of energy. By setting a detachable collection box and mounting plate, it is convenient to regularly clean the collected dust and replace and clean the filter screen, improving the overall energy-saving and environmental protection performance of the device.

[0012] Secondly, the present invention provides a control method for a waste heat recovery device for an electric arc furnace used in the smelting of stainless steel alumina, comprising: The furnace temperature data of the white ferrule smelting electric arc furnace body is measured, and the flue gas flow data and flue gas sample of the flue gas discharged from the white ferrule smelting electric arc furnace body are collected. Based on the furnace temperature data and the flue gas flow data, the recoverable heat corresponding to the waste heat recovery device body is calculated. The dust concentration of the flue gas sample is measured, and the flue gas sample is subjected to component analysis to obtain the flue gas composition. The dust accumulation rate of the dust filter screen in the waste heat recovery device body is determined by combining the flue gas composition and the dust concentration of the sample. By combining the ash deposition rate and the recoverable heat, the operating interval of the cleaning brush is set. Based on the flue gas flow data, the rotational speed parameter of the induced draft fan in the exhaust pipe is determined. Combining the operating interval and the rotational speed parameter, the operation control of the waste heat recovery device body is executed to obtain the control result.

[0013] In one possible implementation of the second aspect, calculating the recoverable heat corresponding to the waste heat recovery device body based on the furnace temperature data and the flue gas flow rate data includes: Based on the furnace temperature data and the flue gas flow rate data, the total heat carried by the flue gas is calculated. Query the specific heat capacity and density values ​​of the flue gas corresponding to the flue gas; By combining the total heat value, the specific heat capacity of the flue gas value, and the density of the flue gas value, the theoretical recoverable heat of the flue gas is calculated. Obtain the rated heat exchange efficiency value corresponding to the main body of the waste heat recovery device; Based on the theoretically recoverable heat of the flue gas and the rated heat exchange efficiency, the recoverable heat corresponding to the main body of the waste heat recovery device is calculated.

[0014] In one possible implementation of the second aspect, measuring the dust concentration corresponding to the flue gas sample includes: The flue gas sample was subjected to isokinetic sampling to obtain a representative flue gas sample; The representative flue gas sample is passed through a preset filter membrane to obtain a dust-laden filter membrane, and the initial mass of the filter membrane is determined. Weigh the total mass of the dust-carrying filter membrane, and combine the initial mass and the total mass to obtain the dust mass of the filter membrane; Record the volume of flue gas passing through the filter membrane during the isokinetic sampling process, and calculate the dust concentration corresponding to the flue gas sample by combining the dust mass and the flue gas volume.

[0015] In one possible implementation of the second aspect, determining the ash deposition rate of the dust filter screen within the waste heat recovery device body by combining the flue gas composition and the sample dust concentration includes: The average particle size data of dust and the mass fraction of viscous substances were extracted from the flue gas components. Based on the average particle size data of the dust and the dust concentration of the sample, the initial amount of dust adhering to the filter surface is calculated; Based on the mass fraction of the viscous substance and the initial amount of adhesion, the dust deposition rate of the dust collector filter is calculated using the following formula: G = H × (1 + K × L) Where G represents the dust deposition rate of the dust collector filter, H represents the initial amount of dust adhering to the filter surface, K represents the mass fraction of viscous substances, and L represents the viscosity constant.

[0016] As can be seen, this invention calculates the recoverable heat corresponding to the main body of the waste heat recovery device based on the furnace temperature data and the flue gas flow data, and can obtain the specific value of the waste heat of the flue gas during the smelting of stainless steel alumina, providing data support for the subsequent operation and control of the main body of the waste heat recovery device. This invention can understand the dust content in the flue gas by measuring the dust concentration of the corresponding sample of the flue gas, and provides a quantitative basis for determining the ash deposition rate of the dust removal filter screen in the main body of the waste heat recovery device. This invention sets the operating interval of the cleaning brush by combining the ash deposition rate and the recoverable heat, so as to reasonably control the ash cleaning frequency and improve the heat exchange efficiency of the main body of the waste heat recovery device. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a three-dimensional structural schematic diagram of a waste heat recovery device for an electric arc furnace for smelting stainless steel alumina according to an embodiment of the present invention. Figure 2 This is a cross-sectional schematic diagram of the waste heat recovery box structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a servo motor structure proposed in an embodiment of the present invention; Figure 4 This is a schematic diagram of an exhaust pipe structure according to an embodiment of the present invention; Figure 5 This is a flowchart of a control method for a waste heat recovery device for an electric arc furnace in the smelting of stainless steel alumina, according to an embodiment of the present invention. In the diagram: 1. Body of the electric arc furnace for smelting stainless steel alumina; 11. Inlet pipe; 2. Body of the waste heat recovery device; 21. Waste heat recovery box; 22. Mounting bracket; 23. Servo motor; 24. First lead screw; 25. First gear; 26. Second lead screw; 27. Second gear; 28. Threaded fitting; 29. ​​Cleaning brush; 211. Dust filter; 212. Mounting plate; 213. Collection box; 214. Water inlet pipe; 215. Water outlet pipe; 216. Exhaust pipe. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0019] Please see Figure 1-4 The system includes a stainless steel alumina smelting electric arc furnace body 1, on which a waste heat recovery device body 2 is mounted to recover waste heat from the high-temperature flue gas generated during the electric arc furnace smelting process, thereby achieving energy recycling and reducing energy consumption. The waste heat recovery device body 2 includes a waste heat recovery box 21, on which a mounting frame 22 is fixedly installed. A servo motor 23 is mounted on the mounting frame 22. A first lead screw 24 and a second lead screw 26 are rotatably inserted inside the waste heat recovery box 21. The output end of the servo motor 23 rotatably passes through the waste heat recovery box 21 and is fixedly connected to the end of the first lead screw 24. A first gear 25 and a second gear 27 are respectively fixedly installed at the ends of the first lead screw 24 and the second lead screw 26 away from the servo motor 23. The first gear 25 and the second gear 27 are meshed together. Threaded fittings are threaded onto the outer surfaces of the first lead screw 24 and the second lead screw 26. 28. A cleaning brush 29 is provided at the opposite end of the threaded assembly 28. The two ends of the cleaning brush 29 are in contact with the inner wall of the waste heat recovery box 21. The waste heat recovery box 21 is provided with a dust filter 211. The cleaning brush 29 is in contact with the outer surface of the dust filter 211. When the dust filter 211 needs to be cleaned, the servo motor 23 is started. The servo motor 23 drives the first lead screw 24 and the first gear 25 to rotate. The first gear 25 drives the second gear 27 to rotate, thereby driving the second lead screw 26 to rotate. As the first lead screw 24 and the second lead screw 26 rotate, a set of threaded assemblies 28 will move in opposite directions, thereby driving a set of cleaning brushes 29 to move in opposite directions, thereby cleaning the dust filter 211. When the cleaning brush 29 moves to the inner wall of the other side of the waste heat recovery box 21, the servo motor 23 is started to reverse, thereby driving the cleaning brush 29 to move back and forth in a cycle, improving the cleaning efficiency of the dust filter 211.

[0020] The dust filter 211 is fixedly mounted on a mounting plate 212 on one side of the servo motor 23. The mounting plate 212 is connected to the waste heat recovery box 21 by bolts, which facilitates the disassembly, replacement or cleaning of the dust filter 211. The body 1 of the stainless steel alumina smelting electric arc furnace is provided with an air inlet pipe 11, which is connected to the waste heat recovery box 21. The air inlet pipe 11 is provided with a control valve. By opening and closing the control valve, the high-temperature flue gas generated by the electric arc furnace can be introduced into the waste heat recovery box 21 through the air inlet pipe 11. The waste heat recovery box 21 is provided with a collection box 213 inside. The collection box 213 is connected to the waste heat recovery box 21 by bolts and is used to collect the dust cleaned by the cleaning brush 29. The collection box 213 can be removed for cleaning by periodically opening the bolts.

[0021] The waste heat recovery box 21 is internally fixedly equipped with symmetrically distributed exhaust pipes 216. The exhaust pipes 216 have a spiral structure, which increases the flow path and heat exchange time of the flue gas in the box, thereby improving the heat exchange efficiency. After the flue gas enters from the inlet pipe 11, it is filtered by the dust filter screen 211 and then flows through the exhaust pipe 216 to exchange heat with the water outside the pipe. The exhaust pipe 216 is equipped with an induced draft fan, which is a mature existing technology and will not be described in detail here. The waste heat recovery box 21 is equipped with an inlet pipe 214 and an outlet pipe 215 for connecting to an external water source. Cold water enters the waste heat recovery box 21 from the inlet pipe 214, exchanges heat with the high-temperature flue gas, and then hot water is discharged from the outlet pipe 215 for production or domestic use.

[0022] The working principle and usage process of a waste heat recovery device for a white alumina smelting electric arc furnace according to the present invention are as follows: In use, the waste heat recovery device body 2 is first moved to a suitable position on the white alumina smelting electric arc furnace body 1. The flue gas outlet of the electric arc furnace is connected to the waste heat recovery box 21 through the air inlet pipe 11. The water inlet pipe 214 and the water outlet pipe 215 are respectively connected to the cooling water source and the hot water collection system. The white alumina smelting electric arc furnace body 1 is started for smelting operations. High-temperature flue gas enters the waste heat recovery box 21 through the air inlet pipe 11. After being filtered by the dust removal filter screen 211, it flows through the spiral structure exhaust pipe 216, where it undergoes sufficient heat exchange with the cooling water entering from the water inlet pipe 214. The heated water is discharged from the water outlet pipe 215. For example, the waste heat can be used to heat the silo. Heating treatment is performed to recover waste heat, and the servo motor 23 is started. The servo motor 23 drives the first lead screw 24 to rotate. Through the meshing transmission of the first gear 25 and the second gear 27, the second lead screw 26 rotates synchronously in the opposite direction, thereby driving the threaded assembly 28 and the cleaning brush 29 to move back and forth along the surface of the dust filter screen 211 to automatically clean the filter screen. During the flue gas heat exchange process, the cleaning brush 29 works continuously to brush the dust on the filter screen into the collection box 213 to prevent the filter screen from clogging. After use, the electric arc furnace and the servo motor 23 are turned off. The bolts are opened periodically to remove the collection box 213 to clean the dust, and the dust filter screen 211 is cleaned or replaced by disassembling the mounting plate 212 to ensure long-term stable operation of the device.

[0023] See Figure 5 The image shows a control method for a waste heat recovery device in an electric arc furnace for smelting stainless steel alumina, according to an embodiment of the present invention, comprising: S1. Measure the furnace temperature data of the white ferrule smelting electric arc furnace body, and collect the flue gas flow data and flue gas sample of the flue gas discharged from the white ferrule smelting electric arc furnace body. Based on the furnace temperature data and the flue gas flow data, calculate the recoverable heat corresponding to the waste heat recovery device body.

[0024] This invention calculates the recoverable heat corresponding to the main body of the waste heat recovery device based on the furnace temperature data and the flue gas flow rate data, thereby obtaining the specific value of the waste heat in the flue gas during the smelting of stainless steel alumina, providing data support for the subsequent operation and control of the main body of the waste heat recovery device. Specifically, the furnace temperature data refers to the temperature value of the smelting zone inside the electric arc furnace body for stainless steel alumina smelting; the flue gas flow rate data is the volume of flue gas discharged from the electric arc furnace body per unit time; the flue gas sample is a representative gas sample collected from the discharged flue gas; and the recoverable heat is the energy that can be effectively utilized by the main body of the waste heat recovery device from the total heat energy carried by the flue gas, estimated based on the furnace temperature and flue gas flow rate.

[0025] As an embodiment of the present invention, the step of calculating the recoverable heat corresponding to the main body of the waste heat recovery device based on the furnace temperature data and the flue gas flow data includes: Based on the furnace temperature data and the flue gas flow rate data, the total heat carried by the flue gas is calculated. Query the specific heat capacity and density values ​​of the flue gas corresponding to the flue gas; By combining the total heat value, the specific heat capacity of the flue gas value, and the density of the flue gas value, the theoretical recoverable heat of the flue gas is calculated. Obtain the rated heat exchange efficiency value corresponding to the main body of the waste heat recovery device; Based on the theoretically recoverable heat of the flue gas and the rated heat exchange efficiency, the recoverable heat corresponding to the main body of the waste heat recovery device is calculated.

[0026] Wherein, the total heat value is an estimated value of the heat released when the flue gas temperature drops from the furnace temperature to the ambient temperature; the specific heat capacity of the flue gas is the heat required to raise the temperature by a unit mass of flue gas; the flue gas density is the mass of a unit volume of flue gas; the theoretically recoverable heat of the flue gas is the heat that can be extracted under ideal heat exchange conditions; and the rated heat exchange efficiency is the proportion of heat transferred from the flue gas to the heat medium by the waste heat recovery device under the design operating conditions.

[0027] Optionally, based on the furnace temperature data and the flue gas flow rate data, the total heat carried by the flue gas is calculated using the enthalpy calculation formula in thermodynamics, combined with the ambient temperature. After calculating the difference between the furnace temperature and the ambient temperature based on the furnace temperature data, this difference is multiplied by the flue gas flow rate and the specific heat capacity of the flue gas to obtain the total heat of the flue gas per unit time. The specific heat capacity and density of the flue gas can be obtained by consulting a flue gas property database, such as a national standard material database. Combining the total heat value, the specific heat capacity, and the density, the theoretically recoverable heat of the flue gas is calculated, i.e., multiplying the total heat value by the flue gas density and then dividing by the conversion factor of the specific heat capacity, to obtain the heat under standard conditions. The heat value that can be extracted per unit time; the rated heat exchange efficiency can be obtained by retrieving historical data from historical operation records, such as retrieving flue gas inlet and outlet temperatures, heat medium flow rate, and temperature change data of the equipment running continuously for a week under stable operating conditions. According to the principle of heat balance, the actual heat recovered each day is calculated from the heat medium flow rate and temperature difference, and the theoretical heat release of the flue gas is calculated from the flue gas flow rate and temperature difference. The ratio of the daily recovered heat to the theoretical heat release is calculated as the measured efficiency for that day. The average measured efficiency over a certain period is calculated to obtain the rated heat exchange efficiency value. The theoretical recoverable heat of the flue gas and the rated heat exchange efficiency value are multiplied to obtain the recoverable heat corresponding to the main body of the waste heat recovery device.

[0028] S2. Measure the dust concentration of the flue gas sample, perform component analysis on the flue gas sample to obtain the flue gas composition, and determine the ash deposition rate of the dust removal filter screen in the waste heat recovery device body by combining the flue gas composition and the dust concentration of the sample.

[0029] This invention, by measuring the dust concentration in the corresponding flue gas sample, can determine the dust content in the flue gas, providing a quantitative basis for determining the ash deposition rate of the dust removal filter screen within the waste heat recovery device. The dust concentration in the sample is the mass concentration of dust in the flue gas sample, reflecting the magnitude of the dust load in the flue gas. As an optional embodiment of the present invention, the measurement of the dust concentration corresponding to the flue gas sample includes: The flue gas sample was subjected to isokinetic sampling to obtain a representative flue gas sample; The representative flue gas sample is passed through a preset filter membrane to obtain a dust-laden filter membrane, and the initial mass of the filter membrane is determined. Weigh the total mass of the dust-carrying filter membrane, and combine the initial mass and the total mass to obtain the dust mass of the filter membrane; Record the volume of flue gas passing through the filter membrane during the isokinetic sampling process, and calculate the dust concentration corresponding to the flue gas sample by combining the dust mass and the flue gas volume.

[0030] The representative flue gas sample is a sample that has the same flow characteristics as the actual flue gas in the flue through isokinetic sampling; the filter membrane is a special filter medium for retaining dust, such as a glass fiber filter membrane or a quartz filter membrane; the dust mass is the weight of the dust obtained by weighing; and the flue gas volume is the total amount of flue gas that passes through the filter membrane during the sampling process.

[0031] Furthermore, a representative flue gas sample can be obtained by sampling at preset sampling points within the flue using an isokinetic sampler. This representative sample is then passed through a pre-weighed filter membrane, which must be dried in an oven and weighed initially. After sampling, the dust-laden filter membrane is placed in a desiccator for equilibration and weighed to obtain the total mass. The difference is calculated to obtain the dust mass. The sampling volume is recorded using a flow meter and converted to the dry flue gas volume under standard conditions based on temperature and pressure. This invention determines the ash deposition rate of the dust filter screen within the waste heat recovery device by combining the flue gas composition and the dust concentration of the sample. This provides a basis for setting the operating interval of the cleaning brush. Specifically, the sample dust concentration is the mass of dust contained in a unit volume of flue gas; the flue gas composition is the component obtained from chemical or physical analysis of the flue gas sample; the dust filter screen is a filtration component installed inside the waste heat recovery device to intercept dust in the flue gas; and the ash deposition rate describes the rate at which dust is deposited on the filter screen. Furthermore, the dust concentration of the flue gas sample can be measured using dust concentration detection methods such as filter membrane weighing; and the analysis of the flue gas composition can be performed using gas chromatography, laser particle size analyzer, or chemical composition analysis instruments.

[0032] As an embodiment of the present invention, determining the ash deposition rate of the dust removal filter screen within the waste heat recovery device by combining the flue gas composition and the dust concentration of the sample includes: The average particle size data of dust and the mass fraction of viscous substances were extracted from the flue gas components. Based on the average particle size data of the dust and the dust concentration of the sample, the initial amount of dust adhering to the filter surface is calculated; Based on the mass fraction of the viscous substance and the initial amount of adhesion, the dust deposition rate of the dust collector filter is calculated using the following formula: G = H × (1 + K × L) Where G represents the dust deposition rate of the dust collector filter, H represents the initial amount of dust adhering to the filter surface, K represents the mass fraction of viscous substances, and L represents the viscosity constant.

[0033] The average particle size of the dust is the average diameter of the dust particles in the flue gas sample, reflecting the fineness of the dust. The mass fraction of sticky substances is the mass proportion of sticky substances in the flue gas composition, such as tar and unburned carbon particles. The initial adhesion amount is the mass of dust deposited on a unit area of ​​the filter screen per unit time based on the dust concentration and particle size. The stickiness constant is a proportionality coefficient reflecting the enhanced ash accumulation effect of sticky substances, and its value is related to the activity of sticky components such as tar in the flue gas.

[0034] Optionally, the average dust particle size data and the mass fraction of sticky substances can be extracted from the flue gas composition analysis report using data reading software compiled from a scripting language. The average dust particle size data and the dust concentration of the sample are input into a pre-compiled quick reference table for adhesion amount. The initial adhesion amount of dust on the filter surface is obtained by looking up the table. The pre-compiled quick reference table for adhesion amount is a lookup table for initial adhesion amount established by fitting experimental data or theoretical calculation based on different average dust particle sizes and sample dust concentrations. The sticky action constant L can be calibrated through short-term operation tests based on the actual dust accumulation on site. For example, the actual dust accumulation thickness per unit time is measured at the beginning of the device operation, and the L value is calculated after comparing it with the theoretical initial adhesion amount.

[0035] Furthermore, the initial adhesion amount H in the above formula has the dimension of mass per unit area per unit time, such as mg / (m²). 2 Since the mass fraction of viscous material K and the viscosity constant L are both dimensionless coefficients, the calculated ash deposition rate G retains the same dimensions as the initial adhesion amount H.

[0036] S3. Combining the ash deposition rate and the recoverable heat, set the operating interval of the cleaning brush, determine the rotational speed parameter of the induced draft fan in the exhaust pipe based on the flue gas flow data, and combine the operating interval and the rotational speed parameter to execute the operation control of the waste heat recovery device body to obtain the control result.

[0037] This invention combines the ash deposition rate and the recoverable heat to set the operating interval of the cleaning brush, thereby rationally controlling the ash cleaning frequency and improving the heat exchange efficiency of the waste heat recovery device. The operating interval is the time interval between two cleaning brush activations.

[0038] Furthermore, a high ash deposition rate indicates that the filter screen is prone to ash accumulation, requiring a shorter operating interval to prevent clogging. A significant decrease in recoverable heat also suggests the need for timely ash cleaning to restore heat exchange efficiency. By considering these two factors, the operating interval of the cleaning brush can be dynamically adjusted to keep the filter screen in good working condition. For example, when the ash deposition rate increases from the normal value of 1.2 to 2.5, it indicates an accelerated dust deposition rate on the filter screen surface. In this case, the operating interval of the cleaning brush is shortened from the original 4 hours to 2 hours to prevent filter screen clogging from affecting heat exchange. When the recoverable heat is monitored to decrease from the design value of 2000kW to 1600kW, the cleaning brush is activated even if the ash deposition rate has not yet increased significantly, restoring heat exchange efficiency to above 1900kW through ash cleaning. By considering these two factors, the cleaning brush automatically shortens its operating interval when the ash deposition rate exceeds 2.0 or the recoverable heat decreases, ensuring the filter screen remains unobstructed.

[0039] This invention determines the rotational speed parameters of the induced draft fan in the exhaust pipe based on the flue gas flow rate data. This allows the fan's suction capacity to match the flue gas generation, maintaining stable negative pressure within the furnace and ensuring the normal operation of the smelting process. The induced draft fan is a suction device installed on the exhaust pipe to guide the flow of flue gas; the rotational speed parameter is the set rotational speed of the induced draft fan during operation. Furthermore, when the flue gas flow rate increases, the induced draft fan speed is appropriately increased to enhance suction and prevent flue gas overflow; when the flue gas flow rate decreases, the speed is reduced. Adjusting the rotational speed parameter according to the real-time flue gas flow rate ensures that the exhaust system always operates at high efficiency.

[0040] This invention, by combining the operating interval and the rotational speed parameters, performs operational control of the waste heat recovery device, thereby optimizing dust removal and smoke extraction and ensuring the stable operation of the waste heat recovery system. Furthermore, the preset operating interval is input into the servo motor controlling the cleaning brush, causing it to automatically start and stop according to the interval; simultaneously, the fan speed of the induced draft fan is adjusted according to the rotational speed parameters, thus achieving the goal of optimizing dust removal and smoke extraction.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery device for an electric arc furnace for smelting white ferrite, comprising the main body of the electric arc furnace for smelting white ferrite (1), characterized in that: The main body (1) of the electric arc furnace for smelting stainless steel is equipped with a waste heat recovery device body (2). The waste heat recovery device body (2) includes a waste heat recovery box (21). A mounting frame (22) is fixedly installed on the outer surface of the waste heat recovery box (21). A servo motor (23) is provided on the mounting frame (22). A first lead screw (24) and a second lead screw (26) are rotatably inserted inside the waste heat recovery box (21). The output end of the servo motor (23) rotatably passes through the waste heat recovery box (21) and is fixedly connected to the end of the first lead screw (24). The first lead screw (24) and the second lead screw (26) are far from each other. A first gear (25) and a second gear (27) are fixedly installed at one end away from the servo motor (23). The first gear (25) and the second gear (27) are meshed together. The outer surfaces of the first lead screw (24) and the second lead screw (26) are respectively threaded with threaded fittings (28). The opposite end of the threaded fittings (28) is provided with a cleaning brush (29). The interior of the waste heat recovery box (21) is provided with a dust removal filter (211). The cleaning brush (29) is in contact with the outer surface of the dust removal filter (211).

2. The waste heat recovery device for an electric arc furnace for smelting stainless steel alumina as described in claim 1, characterized in that, The dust filter (211) is fixedly mounted on a mounting plate (212) on one side of the servo motor (23), and the mounting plate (212) is connected to the waste heat recovery box (21) by bolts.

3. The waste heat recovery device for an electric arc furnace for smelting stainless steel alumina as described in claim 1, characterized in that, The main body (1) of the white steel alumina smelting electric arc furnace is provided with an air inlet pipe (11), which is connected to the waste heat recovery box (21).

4. The waste heat recovery device for an electric arc furnace for smelting stainless steel alumina as described in claim 1, characterized in that, The waste heat recovery box (21) is equipped with a collection box (213) inside, and the collection box (213) is connected to the waste heat recovery box (21) by bolts.

5. The waste heat recovery device for an electric arc furnace for smelting stainless steel alumina as described in claim 1, characterized in that, The waste heat recovery box (21) is fixedly installed with symmetrically distributed exhaust pipes (216), which are spiral structures.

6. The waste heat recovery device for an electric arc furnace for smelting stainless steel alumina as described in claim 1, characterized in that, The waste heat recovery box (21) is equipped with an inlet pipe (214) and an outlet pipe (215).

7. A method for controlling the waste heat recovery device of the electric arc furnace for smelting stainless steel alumina according to any one of claims 1 to 6, characterized in that, The method includes: The furnace temperature data of the white ferrule smelting electric arc furnace body is measured, and the flue gas flow data and flue gas sample of the flue gas discharged from the white ferrule smelting electric arc furnace body are collected. Based on the furnace temperature data and the flue gas flow data, the recoverable heat corresponding to the waste heat recovery device body is calculated. The dust concentration of the flue gas sample is measured, and the flue gas sample is subjected to component analysis to obtain the flue gas composition. The dust accumulation rate of the dust filter screen in the waste heat recovery device body is determined by combining the flue gas composition and the dust concentration of the sample. By combining the ash deposition rate and the recoverable heat, the operating interval of the cleaning brush is set. Based on the flue gas flow data, the rotational speed parameter of the induced draft fan in the exhaust pipe is determined. Combining the operating interval and the rotational speed parameter, the operation control of the waste heat recovery device body is executed to obtain the control result.

8. The method according to claim 7, characterized in that, The calculation of the recoverable heat corresponding to the main body of the waste heat recovery device based on the furnace temperature data and the flue gas flow data includes: Based on the furnace temperature data and the flue gas flow rate data, the total heat carried by the flue gas is calculated. Query the specific heat capacity and density values ​​of the flue gas corresponding to the flue gas; By combining the total heat value, the specific heat capacity of the flue gas value, and the density of the flue gas value, the theoretical recoverable heat of the flue gas is calculated. Obtain the rated heat exchange efficiency value corresponding to the main body of the waste heat recovery device; Based on the theoretically recoverable heat of the flue gas and the rated heat exchange efficiency, the recoverable heat corresponding to the main body of the waste heat recovery device is calculated.

9. The method according to claim 7, characterized in that, The measurement of the dust concentration corresponding to the flue gas sample includes: The flue gas sample was subjected to isokinetic sampling to obtain a representative flue gas sample; The representative flue gas sample is passed through a preset filter membrane to obtain a dust-laden filter membrane, and the initial mass of the filter membrane is determined. Weigh the total mass of the dust-carrying filter membrane, and combine the initial mass and the total mass to obtain the dust mass of the filter membrane; Record the volume of flue gas passing through the filter membrane during the isokinetic sampling process, and calculate the dust concentration corresponding to the flue gas sample by combining the dust mass and the flue gas volume.

10. The method according to claim 7, characterized in that, The determination of the ash deposition rate of the dust filter screen within the waste heat recovery device, based on the flue gas composition and the dust concentration of the sample, includes: The average particle size data of dust and the mass fraction of viscous substances were extracted from the flue gas components. Based on the average particle size data of the dust and the dust concentration of the sample, the initial amount of dust adhering to the filter surface is calculated; Based on the mass fraction of the viscous substance and the initial amount of adhesion, the dust deposition rate of the dust collector filter is calculated using the following formula: G = H × (1 + K × L) Where G represents the dust deposition rate of the dust collector filter, H represents the initial amount of dust adhering to the filter surface, K represents the mass fraction of viscous substances, and L represents the viscosity constant.

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