Casting, forging, welding as the three baSiC thermal processing technology, for the modern equipment manufacturing industry to provide most of the parts rough. With the mass production of automobiles, construction machinery, rail transportation and other products rapid development, foundry industry, forging industry usher in a rare opportunity for development. After nearly 30 years of rapid development, casting modeling process, sand treatment process, cleaning process and melting (thermal insulation) equipment, such as automation, energy efficient, environmentally friendly development, product upgrading transformation is imminent.
At present, the power consumption per ton of molten iron in China's intermediate frequency melting furnace is 550 ~ 650kW · h, and the power consumption of molten iron per ton of foreign advanced melting equipment can reach 500 ~ 560kW · h. To narrow the gap need to be implemented from the following aspects: medium frequency induction furnace variable power distribution equipment, circuit type and control system, electric furnace capacity frequency and power density, furnace structure, and cooling water system and other manufacturing processes, operation and management, Standardized operation, scientific management.
Medium frequency melting (insulation) with its energy saving in the casting has been vigorously promoted in recent years with the hot air cupola double melting (insulation), short casting process is the national industry to promote new technology. Vigorously develop new energy-saving IF power supply, supporting the exhaust emission treatment device is mandatory environmental requirements. Energy conservation is a systematic project, requiring equipment manufacturers, manufacturers and supporting manufacturers to work together to improve the technical level and management level. Based on the rare development opportunities in China at the current price, continuous technological innovation, promotion of structural adjustment, product upgrading, proper standardization and utilization, maximizing the potential of equipment, we believe that reaching or approaching the level of foreign advanced equipment and technology will be just around the corner.
The following IF melting furnace, for example, explain the application of the business in the use of precautions:
(1) IF induction furnace should be used special rectifier transformer to improve the supply voltage and limit the transformer no-load operation.
(2) regulate the installation, shorten the high voltage, transformer, IF power supply, the connection between the furnace, the selection of high purity T2 copper or oxygen free copper, especially the induction coil and water-cooled cable, increasing its cross-sectional area can effectively reduce the current Heat loss.
(3) According to the casting process to select the appropriate capacity and frequency IF electric furnace, increasing the power density to improve the melting efficiency and reduce additional losses.
(4) give priority to the furnace shell with furnace cover to reduce the furnace wall and the mouth of the heat loss and electromagnetic loss. Furnace shell connection at the operation to prevent metal contact to form a short circuit.
(5) Develop a reasonable casting process, from the modeling, material selection, melting, pouring, heat treatment, cleaning and other standardized process operations, scientific management, in order to reduce energy consumption.
(6) Strengthen equipment management and maintenance, reduce failure rate and ensure smooth production.
(7) Often check the connection parts of the conductive system contact is good, especially the water-cooled cable and the induction coil connected to the screws are tightened, insulating table, insulating boots must be tested once a year.
(8) During the melting process, it is strictly forbidden to shut off the power when the power is off. In the smelting process, the water temperature and water pressure should be paid attention at any time to keep the water pressure at 0.1 ~ 0.3MPa and the water temperature below 55 °.
(9) feeding operation, the cold and dry charge should be dried first, can not be directly added to the melt, the metal cut in the first furnace is best to avoid use, because the metal cut can penetrate the gap lining; hearth must be heated to 1000 ℃ or so, before pouring into the molten iron, the furnace heating can be added to the induction heating iron.
(10) charge frozen seal time can not be too long, so as not to cause furnace explosion; good sintered lining, should use 30 to 50% of the rated power, continuous work of 5 or more furnaces.