Rotary furnace for secondary aluminum and operation method

Abstract

The rotary furnace for secondary aluminum comprises a rotary rack, a rotary furnace body, a double-furnace-door assembly and a burner assembly, hydraulic leveling supporting legs and a rail wheel set are arranged at the bottom of the rotary rack, and the rail wheel set is matched with a preset ground guide rail; the rotary furnace body is rotationally mounted on the rotary rack, a reaction cavity and a reaction opening are formed in the rotary furnace body, and the step reaction cavity is communicated with the reaction opening; the double-furnace-door assembly comprises two furnace doors which are symmetrically arranged, the two furnace doors are mounted on the rotary rack in a sliding manner, and the two furnace doors are suitable for being completely closed after sliding in place so as to form a sealing wall, so that the reaction opening is shielded; and the burner assembly comprises a burner base and a telescopic spray gun, the burner base is rotationally installed in the reaction cavity, and high-efficiency smelting, temperature control optimization, energy consumption and emission reduction, smelting quality improvement, metal aluminum content reduction in slag and environmental pollution reduction can be achieved.

Description

Technical Field

[0001] This invention relates to a rotary kiln for recycled aluminum and its operating method, belonging to the field of rotary kiln technology. Background Technology

[0002] As a key area of ​​resource recycling, the energy efficiency and environmental performance of the smelting equipment in the recycled aluminum industry directly affect production efficiency. Currently, the industry generally uses stationary reverberatory furnaces or traditional rotary furnaces to process aluminum ash raw materials. The furnace temperature of traditional equipment relies on manual experience to adjust the fuel supply, resulting in uneven temperature distribution in the smelting zone. Aluminum ash has poor thermal conductivity, and local overheating can easily cause oxidation and burning of metallic aluminum, while cold zones form solidified slag blocks, requiring secondary treatment. Traditional rotary kiln dust removal systems mostly use single bag filters, which have an efficiency of less than 60% in removing submicron-sized dust and organic pollutants. This makes it difficult to meet the dioxin limit of 0.1 ng-TEQ / m³ in GB 25465-2010 "Emission Standard for Pollutants from Aluminum Industry". After smelting, manual slag removal causes a sharp drop in furnace temperature (about 200-300℃), increasing energy consumption per ton of aluminum ash smelting by 15%-20%. The residual metallic aluminum content in the slag is as high as 12%-15%, and the exposure of high-temperature molten slag causes dust pollution, affecting the accuracy of subsequent alloying composition. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a rotary kiln for recycled aluminum and its operation method, which can achieve high-efficiency smelting, optimize temperature control, reduce energy consumption and emissions, improve smelting quality, reduce the metallic aluminum content in slag, and reduce environmental pollution.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a rotary kiln for recycled aluminum, comprising: A slewing frame, the bottom of which is equipped with hydraulically leveling outriggers and a set of track wheels, the set of track wheels being matched with a preset ground guide rail; A rotary furnace body is rotatably mounted on a rotary frame. The rotary furnace body has a reaction chamber and a reaction port inside, and the reaction chamber is connected to the reaction port. A double furnace door assembly, comprising two symmetrically arranged furnace doors, which are slidably mounted on the rotary frame. The two furnace doors are adapted to be fully closed after sliding into position to form a sealing wall, thereby blocking the reaction port. A burner assembly, comprising a burner base and a telescopic spray gun, wherein the burner base is rotatably mounted on the rotary support, and the telescopic spray gun is mounted on the burner base, and the telescopic spray gun is adapted to heat the rotary furnace body to melt aluminum ash in the reaction chamber.

[0005] Furthermore, a rotary furnace for recycled aluminum also includes a temperature control component, which includes an array of thermocouples, an infrared thermal imager, and a PID controller. The array of thermocouples is uniformly installed on the inner wall of the reaction chamber, the infrared thermal imager is installed on the inner wall of the reaction chamber, and the PID controller is installed on the frame. The PID controller is electrically connected to the telescopic spray gun and the infrared thermal imager. The infrared imager is adapted to monitor the temperature distribution and melting state of the aluminum ash molten material surface in the reaction chamber and feeds the data back to the PID controller. The array of thermocouples is adapted to monitor the real-time temperature of different areas in the reaction chamber. The PID controller dynamically adjusts the power and position of the telescopic spray gun based on the set temperature curve, the area temperature fed back by the array of thermocouples, and the surface temperature and melting state information fed back by the infrared thermal imager.

[0006] Furthermore, a rotary kiln for recycled aluminum also includes a waste gas treatment component, which includes a cyclone dust collector, a treatment flue, and an activated carbon adsorption tank. One end of the treatment flue is connected to the reaction chamber, the cyclone dust collector is installed in the treatment flue, and the activated carbon adsorption tank is connected to the other end of the treatment flue.

[0007] Furthermore, a rotary kiln for recycled aluminum also includes a slag cleaning assembly, which includes a slag collection box, a slag cleaning port, and a telescopic slag baffle. The slag cleaning port is located at the central axis of the bottom of the rotary kiln body and communicates with the reaction chamber. The telescopic slag baffle is slidably installed below the slag cleaning port and is adapted to open and close the slag cleaning port. The slag collection box is located directly below the slag cleaning port and is adapted to receive and hold the molten aluminum slag discharged from the slag cleaning port.

[0008] Furthermore, a rotary furnace for recycled aluminum also includes a speed control component, which includes a variable frequency motor, a speed sensor, and a central controller; the variable frequency motor drives the rotary furnace body to rotate, the speed sensor monitors the furnace body speed in real time, and the central controller receives temperature distribution data from the PID controller and melting state information from the infrared thermal imager, and dynamically adjusts the output frequency of the variable frequency motor.

[0009] Furthermore, the rotary kiln body comprises, from the inside out, an anti-corrosion layer, a fiber insulation layer, and a steel protective layer.

[0010] Furthermore, a weighing sensor is also installed at the bottom of the slag collection box.

[0011] The present invention also provides a method for operating a rotary kiln for recycled aluminum, comprising the following steps: S1. Loading preparation: Adjust the level of the rotary frame by hydraulic leveling legs, and move the track wheel set to the loading station along the ground guide rail; Open the double furnace door assembly, and the two furnace doors slide along the track to the fully open position. The external feeding device feeds aluminum ash raw material into the reaction chamber through the reaction port. S2. Melting Start-up: Close the double furnace doors to form a sealed wall. The burner base drives the telescopic spray gun to rotate to the preset tilt angle. Start the spray gun to heat the rotary furnace body to melt the aluminum ash in the rotary furnace body. The temperature control component starts synchronously. The array thermocouple collects the axial temperature gradient of the reaction chamber in real time. The infrared thermal imager monitors the temperature field distribution and phase change state of the melt surface. The PID controller compares the set temperature curve and dynamically adjusts the spray gun power and telescopic stroke. S3. Dynamic control: The central controller receives temperature distribution data and melting state information, and dynamically adjusts the rotary furnace speed through the variable frequency motor. In the early stage of melting, a low speed of 3-5 r / min is used to promote heat conduction, and after complete liquefaction, the speed is increased to 8-12 r / min to enhance the uniformity of the melt. S4. Waste gas treatment: The flue gas generated in the reaction chamber enters the cyclone dust collector for primary dust removal through the treatment flue, and then removes harmful substances such as dioxins through the activated carbon adsorption tank. S5. Slag Discharge Treatment: When the melt reaches the set fluidity, heating is stopped and the furnace body is rotated so that the slag removal port is vertically downward. The weighing sensor monitors the weight of the slag collection box in real time. The central controller opens the telescopic slag baffle in conjunction with the molten aluminum slag. The molten aluminum slag is automatically discharged by centrifugal force. The slag baffle is closed after the preset slag amount is reached. S6. Waste heat treatment: After slag removal, the furnace body is kept rotating at a low speed. The heat storage of the anti-erosion layer is used to preheat the next batch of raw materials, and the fiber insulation layer maintains the thermal stability of the reaction chamber.

[0012] After adopting the above technical solution, the present invention has the following beneficial effects: 1. In this invention, through temperature control and rotary furnace rotation design, high-efficiency smelting can be achieved, smelting time can be shortened, and production efficiency can be improved; The temperature control component, which combines array thermocouples and infrared thermal imagers, can monitor the temperature of different areas in the reaction chamber, as well as the temperature distribution and melting state of the melt surface, in real time, thereby achieving precise temperature control. By dynamically adjusting the power and position of the telescopic spray gun and the rotation speed of the furnace, energy consumption and emissions can be reduced, production costs can be lowered, and environmental impact can be minimized.

[0013] 2. In this invention, the waste gas treatment component can effectively remove harmful substances from the flue gas, reducing environmental pollution. The use of hydraulic leveling legs and automatic slag removal components reduces manual operation, increases automation, reduces labor intensity, and improves the working environment. After slag removal, the waste heat of the furnace body is used to preheat the next batch of raw materials, improving energy utilization efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a rotary furnace for recycled aluminum according to the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a rotary furnace for recycled aluminum according to the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the reaction chamber of the present invention; Figure 4 This is a schematic diagram of the rotary kiln body of the present invention. Detailed Implementation

[0015] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0016] Example 1: As Figure 1-4 As shown, a rotary kiln for recycled aluminum includes: The rotary frame 1 has hydraulic leveling legs 11 and track wheel set 12 at its bottom, and the track wheel set 12 is matched with the preset ground guide rail. Rotary furnace body 2 is rotatably mounted on rotary frame 1. Rotary furnace body 2 has a reaction chamber 21 and a reaction port inside, and the reaction chamber 21 is connected to the reaction port. The double furnace door assembly includes two symmetrically arranged furnace doors 3, which are slidably mounted on the rotary frame 1. The two furnace doors 3 are adapted to be completely closed after sliding into position to form a sealed wall, thereby blocking the reaction port. The burner assembly includes a burner base 41 and a telescopic spray gun 42. The burner base 41 is rotatably mounted on the rotary frame 1, and the telescopic spray gun 42 is mounted on the burner base 41. The telescopic spray gun 42 is suitable for heating the rotary furnace body 2 to melt the aluminum ash in the reaction chamber 21.

[0017] Specifically, a rotary circuit for recycled aluminum also includes a temperature control component, which includes an array of thermocouples, an infrared thermal imager, and a PID controller. The array of thermocouples is uniformly installed on the inner wall of the reaction chamber 21. The infrared thermal imager is installed on the inner wall of the reaction chamber 21. The PID controller is installed on the frame and is electrically connected to the telescopic spray gun 42 and the infrared thermal imager. The infrared imager is suitable for monitoring the temperature distribution and melting state of the aluminum ash molten material surface in the reaction chamber 21 and feeding the data back to the PID controller. The array of thermocouples is suitable for monitoring the real-time temperature of different areas in the reaction chamber 21. The PID controller dynamically adjusts the power and position of the telescopic spray gun 42 based on the set temperature curve, the area temperature fed back by the array of thermocouples, and the surface temperature and melting state information fed back by the infrared thermal imager.

[0018] Specifically, such as Figure 1-3 As shown, a rotary kiln for recycled aluminum also includes a waste gas treatment component, which includes a cyclone dust collector 51, a treatment flue 52, and an activated carbon adsorption tank 53. One end of the treatment flue 52 is connected to the reaction chamber 21, the cyclone dust collector 51 is installed in the treatment flue 52, and the activated carbon adsorption tank is connected to the other end of the treatment flue 52.

[0019] Specifically, such as Figure 1 As shown, a rotary kiln for recycled aluminum also includes a slag cleaning assembly, which includes a slag collection box 61, a slag cleaning port, and a telescopic slag baffle. The slag cleaning port is located at the central axis of the bottom of the rotary kiln body 2 and communicates with the reaction chamber 21. The telescopic slag baffle is slidably installed below the slag cleaning port and is adapted to open and close the slag cleaning port. The slag collection box 61 is located directly below the slag cleaning port and is adapted to receive and hold the molten aluminum slag discharged from the slag cleaning port.

[0020] Specifically, a rotary furnace for recycled aluminum also includes a speed control component, which includes a variable frequency motor, a speed sensor, and a central controller. The variable frequency motor drives the rotary furnace body 2 to rotate, the speed sensor monitors the furnace body speed in real time, and the central controller receives temperature distribution data from the PID controller and melting state information from the infrared thermal imager, and dynamically adjusts the output frequency of the variable frequency motor.

[0021] Specifically, such as Figure 4 As shown, the rotary kiln body 2 consists of an anti-corrosion layer 22, a fiber insulation layer 23, and a steel protective layer 24 from the inside out.

[0022] Specifically, a weighing sensor is also installed at the bottom of the slag collection box 61.

[0023] Example 2: This example describes an operation method for a rotary kiln used for recycled aluminum, as described in Example 1, including the following steps: S1. Loading preparation: Adjust the level of the rotary frame 1 by hydraulically leveling outriggers 11, and move the track wheel set 12 along the ground guide rail to the loading station; Open the double furnace door assembly, and the two furnace doors 3 slide along the track to the fully open position. The external feeding device feeds aluminum ash raw material into the reaction chamber 21 through the reaction port. S2, Melting Start-up: Close the double furnace door 3 to form a sealed wall. The burner base 41 drives the telescopic spray gun 42 to rotate to the preset tilt angle. Start the spray gun to heat the rotary furnace body 2 to melt the aluminum ash in the rotary furnace body 2. In this embodiment, the rotary furnace body 2 needs to be heated to 700-1000℃ to reduce the burn-off of aluminum ash caused by direct melting of the spray gun. The temperature control component starts synchronously. The array thermocouple collects the axial temperature gradient of the reaction chamber 21 in real time. The infrared thermal imager monitors the temperature field distribution and phase change state of the melt surface. The PID controller compares the set temperature curve and dynamically adjusts the spray gun power and telescopic stroke. S3. Dynamic control: The central controller receives temperature distribution data and melting state information, and dynamically adjusts the rotation speed of the rotary furnace body 2 through the variable frequency motor. In the early stage of melting, a low speed of 3-5 r / min is used to promote heat conduction, and after complete liquefaction, the speed is increased to 8-12 r / min to enhance the uniformity of the melt. S4. Waste gas treatment: The flue gas generated in the reaction chamber 21 enters the cyclone dust collector 51 through the treatment flue 52 for primary dust removal, and then passes through the activated carbon adsorption tank 53 to remove harmful substances such as dioxins. S5. Slag Discharge Treatment: When the melt reaches the set fluidity, heating is stopped and the furnace body is rotated so that the slag removal port is vertically downward. The weighing sensor monitors the weight of the slag collection box 61 in real time. The central controller opens the telescopic slag baffle in conjunction with the molten aluminum slag. The molten aluminum slag is automatically discharged by centrifugal force. The slag baffle is closed after the preset slag amount is reached. S6. Waste heat treatment: After slag removal, the furnace body is kept rotating at a low speed. The heat storage of the anti-erosion layer is used to preheat the next batch of raw materials. The fiber insulation layer maintains the thermal stability of the reaction chamber 21.

[0024] In this embodiment, through temperature control and the rotation design of the rotary furnace body 2, high-efficiency smelting can be achieved, smelting time can be shortened, and production efficiency can be improved; The temperature control component, which combines array thermocouples and infrared thermal imagers, can monitor the temperature of different areas in the reaction chamber 21 in real time, as well as the temperature distribution and melting state of the melt surface, thereby achieving precise temperature control. By dynamically adjusting the power and position of the telescopic spray gun 42 and the rotation speed of the furnace, energy consumption and emissions can be reduced, production costs can be lowered, and environmental impact can be minimized.

[0025] In this embodiment, the exhaust gas treatment component can effectively remove harmful substances from the flue gas, reducing environmental pollution. The use of hydraulic leveling support legs 11 and automatic slag removal components reduces manual operation, increases automation, reduces labor intensity, and improves the working environment. After slag removal, the waste heat of the furnace body is used to preheat the next batch of raw materials, improving energy utilization efficiency.

[0026] The above specific embodiments further illustrate the technical problems solved by the present invention, the technical solutions, and the beneficial effects. It should be understood that the above are only specific embodiments of the present invention and are 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 within the protection scope of the present invention.

Claims

1. A rotary furnace for recycled aluminum, characterized in that, include: A rotary frame (1) is provided with hydraulic leveling legs (11) and a track wheel assembly (12) at the bottom of the rotary frame (1), and the track wheel assembly (12) is matched with a preset ground guide rail; Rotary furnace body (2), the rotary furnace body (2) is rotatably mounted on the rotary frame (1), the rotary furnace body (2) is provided with a reaction chamber (21) and a reaction port inside, the reaction chamber (21) is connected to the reaction port; The double furnace door assembly includes two symmetrically arranged furnace doors (3), which are slidably mounted on the rotary frame (1). The two furnace doors (3) are adapted to be completely closed after sliding into place to form a sealing wall, thereby blocking the reaction port. The burner assembly includes a burner base (41) and a telescopic spray gun (42). The burner base (41) is rotatably mounted on the rotary frame (1), and the telescopic spray gun (42) is mounted on the burner base (41). The telescopic spray gun (42) is adapted to heat the rotary furnace body (2) to melt aluminum ash in the reaction chamber (21).

2. The rotary path for recycled aluminum according to claim 1, characterized in that: It also includes a temperature control component, which includes an array of thermocouples, an infrared thermal imager, and a PID controller. The array of thermocouples is uniformly installed on the inner wall of the reaction chamber (21). The infrared thermal imager is installed on the inner wall of the reaction chamber (21). The PID controller is installed on the frame. The PID controller is electrically connected to the telescopic spray gun (42) and the infrared thermal imager. The infrared imager is suitable for monitoring the temperature distribution and melting state of the aluminum ash molten surface in the reaction chamber (21) and feeding the data back to the PID controller. The array of thermocouples is suitable for monitoring the real-time temperature of different areas in the reaction chamber (21). The PID controller dynamically adjusts the power and position of the telescopic spray gun (42) based on the set temperature curve, the area temperature fed back by the array of thermocouples, and the surface temperature and melting state information fed back by the infrared thermal imager.

3. The rotary kiln for recycled aluminum according to claim 1, characterized in that: It also includes a waste gas treatment component, which includes a cyclone dust collector (51), a treatment flue (52) and an activated carbon adsorption tank (53). One end of the treatment flue (52) is connected to the reaction chamber (21), the cyclone dust collector (51) is installed in the treatment flue (52), and the activated carbon adsorption tank is connected to the other end of the treatment flue (52).

4. A rotary kiln for recycled aluminum according to claim 1, characterized in that: It also includes a slag cleaning assembly, which includes a slag collection box (61), a slag cleaning port and a telescopic slag baffle. The slag cleaning port is located at the bottom center axis of the rotary furnace body (2) and communicates with the reaction chamber (21). The telescopic slag baffle is slidably installed below the slag cleaning port and is adapted to open and close the slag cleaning port. The slag collection box (61) is located directly below the slag cleaning port and is adapted to receive and hold the molten aluminum slag discharged from the slag cleaning port.

5. A rotary kiln for recycled aluminum according to claim 2, characterized in that: It also includes a speed control component, which includes a variable frequency motor, a speed sensor and a central controller; the variable frequency motor drives the rotary furnace body (2) to rotate, the speed sensor monitors the furnace body speed in real time, and the central controller receives the temperature distribution data of the PID controller and the melting state information of the infrared thermal imager, and dynamically adjusts the output frequency of the variable frequency motor.

6. A rotary kiln for recycled aluminum according to claim 1, characterized in that: The rotary kiln body (2) consists of an anti-corrosion layer (22), a fiber insulation layer (23), and a steel protective layer (24) from the inside out.

7. A rotary kiln for recycled aluminum according to claim 4, characterized in that: A weighing sensor is also installed at the bottom of the slag collection box (61).

8. A method for operating a rotary kiln for recycled aluminum as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Loading preparation: Adjust the level of the rotary frame (1) by hydraulic leveling legs (11), and move the track wheel set (12) along the ground guide rail to the loading station; Open the double furnace door assembly, and the two furnace doors (3) slide along the track to the fully open position. The external feeding device feeds aluminum ash raw material into the reaction chamber (21) through the reaction port. S2, Smelting Start-up: Close the double furnace door (3) to form a sealed wall, the burner base (41) drives the telescopic spray gun (42) to rotate to the preset tilt angle, start the spray gun to heat the rotary furnace body (2) to smelt the aluminum ash in the rotary furnace body (2), the temperature control component starts synchronously, the array thermocouple collects the axial temperature gradient of the reaction chamber (21) in real time, the infrared thermal imager monitors the temperature field distribution and phase change state of the melt surface, and the PID controller compares the set temperature curve to dynamically adjust the spray gun power and telescopic stroke; S3, Dynamic control: The central controller receives temperature distribution data and melting state information, and dynamically adjusts the rotation speed of the rotary furnace body (2) through the variable frequency motor. In the early stage of melting, a low speed of 3-5 r / min is used to promote heat conduction. After complete liquefaction, the speed is increased to 8-12 r / min to enhance the uniformity of the melt. S4. Waste gas treatment: The flue gas generated in the reaction chamber (21) enters the cyclone dust collector (51) through the treatment flue (52) for primary dust removal, and then removes harmful substances such as dioxins through the activated carbon adsorption tank (53); S5. Slag removal: When the melt reaches the set fluidity, stop heating and rotate the furnace body so that the slag removal port is vertically downward. The weighing sensor monitors the weight of the slag collection box (61) in real time. The central controller opens the telescopic slag baffle in linkage. The molten aluminum slag is automatically discharged by centrifugal force. After the preset slag amount is reached, the slag baffle is closed. S6. Waste heat treatment: After the slag is removed, the furnace body is kept rotating at a low speed. The heat storage of the anti-erosion layer is used to preheat the next batch of raw materials. The fiber insulation layer maintains the thermal stability of the reaction chamber (21).

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