After the application of electromagnetic stirrer, the aluminum alloy production technical indicators have reached the domestic advanced level, saving energy, reducing costs, enhancing market competitiveness, and greatly improving its survivability. Some of the materials in the "Research on energy-saving technologies for aluminum alloy furnaces" are now extracted as follows:
Design report
Advanced technology and equipment must be combined with a high-level rapid smelting process to obtain higher comprehensive technical and economic indicators. In the premise of ensuring the quality of the melt, try to increase the melting speed. From the viewpoint of energy conservation, all invalid heat losses increase with time. Therefore, shortening the operation time of each step of the metal melting can increase the productivity of the furnace, reduce the energy consumption, and have obvious economic benefits.
The heating and melting of the charge occupies about 70%-80% of the entire smelting time, which is a large energy-consuming process in aluminum smelting. The heat load should be increased to achieve forced melting to increase the melting capacity of the furnace. When melted, the temperature difference between the surface layer of the melt and the bottom of the melt is about 200°C. The unmelted temperature is at the bottom of the furnace. If the melt is not stirred, the melting time will be prolonged and the surface melt will burn. Therefore, the melt must be agitated to enhance convective heat transfer and to accelerate the melting of the furnace bottom charge. At the same time, the liquid surface temperature becomes lower, and the temperature difference with the high-temperature combustion gas increases, which is favorable for accelerating the exchange of heat. Practice has proved that after forced stirring, the temperature difference between the upper and lower sides of the melt decreases from 200° C. to about 10° C., and is the alloying element. Homogenization creates good dynamic conditions. Electromagnetic stirring can work with a small amount of melt, can increase the melting rate 10-45%, electromagnetic equipment is easy to automate, and can work according to a given procedure.
The bottom induction electromagnetic stirrer is a device that does not contact with the aluminum solution and stirs the aluminum liquid by electromagnetic force. The device can completely replace the external force stirring device such as artificial and mechanical, basically realizes the closed door operation, and can improve The overall homogeneity of the various types and gold shortens the melting time, reduces metal burnout, and improves the quality of the product.
The company uses a set of plate-type furnace bottom stirring device to stir the two stirring furnaces through the walking of the sensor, which greatly reduces the equipment cost.
Industrial Application Report
Smelting test process record
Material preparation According to the calculation and material conditions, a total of 9946 kg of raw materials are prepared. See Table 1 for the smelting process.
Table 1 Smelting records (ZL102)
Step Time Furnace Condition Operation
1 9:20 Air Furnace 750°C
2 9:20-9:40 Solid material Add cutting head 3252kg, add aluminum ingot 3210kg, ignite two burners and begin to melt
3 10:20 Start melting Stop fire, add 30kg cover agent, ignite, continue to melt
4 11:20 Melt all on Electromagnetic stirring for 10 minutes
5 11:35 All melting Temperature measurement 695°C, ceasefire, ready to add remaining material
6 11:50 Solids Add 3295kg of remaining aluminum ingot, add 187kg of ZLD102 alloy, ignite and melt after adding.
7 12:20 All melted, electromagnetic stirring for 10 minutes
8 12:30 All melting Temperature measurement 736°C
9 12:45 All Melted Sampling and Analysis
10 13:00 Fully melted Analyzes, purifies, puts residue
11 13:20 Fully Melted Start Casting, Casting Furnace Temperature 731°C
Electromagnetic stirrer test
The electromagnetic stirrer test was carried out in the smelting furnace. The equipment was in good operation and the mixing force was adjusted in four steps. From visual inspection and sampling analysis, the stirring effect was very good. At the same time, the smelting time and burn damage were significantly shortened.
Stirring effect
1 Aluminum alloy quality
The fluid composition deviation of the entire furnace is less than 0.3%, which improves the quality of the aluminum alloy. Table 2 is a sample analysis report of alloy composition.
Table 2 Sample analysis report of ZL102 alloy composition
Sample No. Si Fe Cu Al
1 11.5 0.48 <0.005 balance
2 11.6 0.47 <0.005 balance
3 11.4 0.47 <0.005 margin
4 11.4 0.49 <0.005 margin
5 11.3 0.48 <0.005 margin
6 11.5 0.46 <0.005 balance
7 11.4 0.49 <0.005 balance
8 11.3 0.49 <0.005 balance
9 11.6 0.50 <0.005 balance
10 11.4 0.48 <0.005 Balance
11 11.5 0.49 <0.005 Balance
12 11.5 0.48 <0.005 balance
2 Melt temperature difference is small
Usually, the upper heated melt, without further stirring, can have a temperature difference of up to 20 degrees per 100 millimeters of melt depth and is electromagnetically stirred for 15 minutes. The measured temperature difference is generally about 10 degrees Celsius. The measured conditions are as follows in Table 3:
Table 3 Electromagnetic stirring is not performed Melt surface and bottom temperature (°C)
Sample No. Surface Lower Temperature Difference
1
2
3 800 702 98
4
5
Average
Table 4 Electromagnetic stirring for 15 minutes Melt surface and bottom temperature (°C)
Sample No. Surface Lower Temperature Difference
1 755 745 10
2 750 744 6
3 746 743 3
4 748 745 3
5 750 744 6
Average 750 744 6
3 Does not pollute the melt
Electromagnetic stirring is not non-contact stirring, so the mixing process will not cause pollution to the melt, which is of great significance for maintaining the original alloy composition and controlling the content of iron.
4 Shorten the smelting time and increase the production capacity of the equipment
Because the electromagnetic stirrer can fully stir the melt, so that the melt temperature is uniform, the alloy composition can be well dispersed, and the mass transfer and heat transfer of the melt are promoted, thereby shortening the smelting time. The smelting of the ZL102 alloy with one pass of the component shortens the smelting time by more than 20%, and the production capacity of the equipment has been improved.
5 can reduce energy consumption
Unlike the previously used manual stirring method, since the use of electromagnetic stirring does not have to open the furnace door, heat loss can be reduced. In addition, melting can be performed at a low temperature, so that the temperature of the gas in the furnace can be lowered, thereby reducing the heat loss of the exhaust gas and the heat loss through the furnace wall. In addition, since the melting time is shortened, and because the melt temperature is uniform, the melt temperature can be lowered by 50° C. during the smelting process, and energy consumption can be reduced by more than 20%.
6 can reduce the labor intensity of workers
The electromagnetic stirrer is simple and easy to operate. During the operation, there is no need to power off and open the furnace door, and the labor intensity and working environment of the workers are improved.
7 Fuel Consumption and Metal Balance
9:20 Before the ignition, the fuel flowmeter showed a quantity of 237,589 litres, the 13:20 showed a quantity of 238,501 litres, and the previous test process shared 912 litres of heavy diesel oil, which was approximately 729.6kg. The average fuel consumption is 73.36kg/t-AL.
The various aluminum slags in the production process are measured as follows:
Product: 9459kg
Residual aluminum in the furnace (estimated): 400kg
Loss of aluminum: 87kg
Loss of metal: 0.88%.
Design report
Advanced technology and equipment must be combined with a high-level rapid smelting process to obtain higher comprehensive technical and economic indicators. In the premise of ensuring the quality of the melt, try to increase the melting speed. From the viewpoint of energy conservation, all invalid heat losses increase with time. Therefore, shortening the operation time of each step of the metal melting can increase the productivity of the furnace, reduce the energy consumption, and have obvious economic benefits.
The heating and melting of the charge occupies about 70%-80% of the entire smelting time, which is a large energy-consuming process in aluminum smelting. The heat load should be increased to achieve forced melting to increase the melting capacity of the furnace. When melted, the temperature difference between the surface layer of the melt and the bottom of the melt is about 200°C. The unmelted temperature is at the bottom of the furnace. If the melt is not stirred, the melting time will be prolonged and the surface melt will burn. Therefore, the melt must be agitated to enhance convective heat transfer and to accelerate the melting of the furnace bottom charge. At the same time, the liquid surface temperature becomes lower, and the temperature difference with the high-temperature combustion gas increases, which is favorable for accelerating the exchange of heat. Practice has proved that after forced stirring, the temperature difference between the upper and lower sides of the melt decreases from 200° C. to about 10° C., and is the alloying element. Homogenization creates good dynamic conditions. Electromagnetic stirring can work with a small amount of melt, can increase the melting rate 10-45%, electromagnetic equipment is easy to automate, and can work according to a given procedure.
The bottom induction electromagnetic stirrer is a device that does not contact with the aluminum solution and stirs the aluminum liquid by electromagnetic force. The device can completely replace the external force stirring device such as artificial and mechanical, basically realizes the closed door operation, and can improve The overall homogeneity of the various types and gold shortens the melting time, reduces metal burnout, and improves the quality of the product.
The company uses a set of plate-type furnace bottom stirring device to stir the two stirring furnaces through the walking of the sensor, which greatly reduces the equipment cost.
Industrial Application Report
Smelting test process record
Material preparation According to the calculation and material conditions, a total of 9946 kg of raw materials are prepared. See Table 1 for the smelting process.
Table 1 Smelting records (ZL102)
Step Time Furnace Condition Operation
1 9:20 Air Furnace 750°C
2 9:20-9:40 Solid material Add cutting head 3252kg, add aluminum ingot 3210kg, ignite two burners and begin to melt
3 10:20 Start melting Stop fire, add 30kg cover agent, ignite, continue to melt
4 11:20 Melt all on Electromagnetic stirring for 10 minutes
5 11:35 All melting Temperature measurement 695°C, ceasefire, ready to add remaining material
6 11:50 Solids Add 3295kg of remaining aluminum ingot, add 187kg of ZLD102 alloy, ignite and melt after adding.
7 12:20 All melted, electromagnetic stirring for 10 minutes
8 12:30 All melting Temperature measurement 736°C
9 12:45 All Melted Sampling and Analysis
10 13:00 Fully melted Analyzes, purifies, puts residue
11 13:20 Fully Melted Start Casting, Casting Furnace Temperature 731°C
Electromagnetic stirrer test
The electromagnetic stirrer test was carried out in the smelting furnace. The equipment was in good operation and the mixing force was adjusted in four steps. From visual inspection and sampling analysis, the stirring effect was very good. At the same time, the smelting time and burn damage were significantly shortened.
Stirring effect
1 Aluminum alloy quality
The fluid composition deviation of the entire furnace is less than 0.3%, which improves the quality of the aluminum alloy. Table 2 is a sample analysis report of alloy composition.
Table 2 Sample analysis report of ZL102 alloy composition
Sample No. Si Fe Cu Al
1 11.5 0.48 <0.005 balance
2 11.6 0.47 <0.005 balance
3 11.4 0.47 <0.005 margin
4 11.4 0.49 <0.005 margin
5 11.3 0.48 <0.005 margin
6 11.5 0.46 <0.005 balance
7 11.4 0.49 <0.005 balance
8 11.3 0.49 <0.005 balance
9 11.6 0.50 <0.005 balance
10 11.4 0.48 <0.005 Balance
11 11.5 0.49 <0.005 Balance
12 11.5 0.48 <0.005 balance
2 Melt temperature difference is small
Usually, the upper heated melt, without further stirring, can have a temperature difference of up to 20 degrees per 100 millimeters of melt depth and is electromagnetically stirred for 15 minutes. The measured temperature difference is generally about 10 degrees Celsius. The measured conditions are as follows in Table 3:
Table 3 Electromagnetic stirring is not performed Melt surface and bottom temperature (°C)
Sample No. Surface Lower Temperature Difference
1
2
3 800 702 98
4
5
Average
Table 4 Electromagnetic stirring for 15 minutes Melt surface and bottom temperature (°C)
Sample No. Surface Lower Temperature Difference
1 755 745 10
2 750 744 6
3 746 743 3
4 748 745 3
5 750 744 6
Average 750 744 6
3 Does not pollute the melt
Electromagnetic stirring is not non-contact stirring, so the mixing process will not cause pollution to the melt, which is of great significance for maintaining the original alloy composition and controlling the content of iron.
4 Shorten the smelting time and increase the production capacity of the equipment
Because the electromagnetic stirrer can fully stir the melt, so that the melt temperature is uniform, the alloy composition can be well dispersed, and the mass transfer and heat transfer of the melt are promoted, thereby shortening the smelting time. The smelting of the ZL102 alloy with one pass of the component shortens the smelting time by more than 20%, and the production capacity of the equipment has been improved.
5 can reduce energy consumption
Unlike the previously used manual stirring method, since the use of electromagnetic stirring does not have to open the furnace door, heat loss can be reduced. In addition, melting can be performed at a low temperature, so that the temperature of the gas in the furnace can be lowered, thereby reducing the heat loss of the exhaust gas and the heat loss through the furnace wall. In addition, since the melting time is shortened, and because the melt temperature is uniform, the melt temperature can be lowered by 50° C. during the smelting process, and energy consumption can be reduced by more than 20%.
6 can reduce the labor intensity of workers
The electromagnetic stirrer is simple and easy to operate. During the operation, there is no need to power off and open the furnace door, and the labor intensity and working environment of the workers are improved.
7 Fuel Consumption and Metal Balance
9:20 Before the ignition, the fuel flowmeter showed a quantity of 237,589 litres, the 13:20 showed a quantity of 238,501 litres, and the previous test process shared 912 litres of heavy diesel oil, which was approximately 729.6kg. The average fuel consumption is 73.36kg/t-AL.
The various aluminum slags in the production process are measured as follows:
Product: 9459kg
Residual aluminum in the furnace (estimated): 400kg
Loss of aluminum: 87kg
Loss of metal: 0.88%.
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