The following takes the medium frequency melting furnace as an example to explain the precautions that the application enterprises should pay attention to during use:
(1) The medium frequency induction furnace should use a special rectifier transformer to increase the power supply voltage and limit the no-load operation of the transformer.
(2) Standardize the installation, shorten the connection between high voltage, transformer, medium frequency power supply, and electric furnace, and select T2 copper or oxygen-free copper with higher purity, especially the induction coil and water-cooled cable. Increasing its cross-sectional area can effectively reduce the current heat loss.
(3) Select a medium frequency electric furnace with appropriate capacity and frequency according to the casting process, increase the power density to improve the melting efficiency, and reduce additional losses.
(4) Give priority to steel shell furnace body with furnace cover to reduce the heat loss and electromagnetic loss of the furnace wall and furnace mouth. The connection of the furnace body shell prevents metal contact from forming a short circuit during operation.
(5) Formulate a reasonable casting process, standardize the process operation from modeling, material selection, melting, pouring, heat treatment, cleaning, etc., and manage scientifically to reduce energy consumption.
(6) Strengthen equipment management and maintenance, reduce the failure rate, and ensure smooth production.
(7) Check the connection parts of each conductive system for good contact, especially the screws at the connection between the water-cooling cable and the induction coil. The insulation platform and insulation boots must be inspected once a year.
(8) It is strictly forbidden to cut off power and water supply during the smelting process. During the smelting process, the outlet water temperature and water pressure should be paid attention to at any time to keep the water pressure at 0.1~0.3MPa and the outlet water temperature below 55°.
(9) When adding materials, the cold and wet furnace charge should be dried first and cannot be directly added to the molten metal. It is best to avoid using metal scraps when using the first furnace, because metal scraps can penetrate the gap of the furnace lining; the furnace must be heated to about 1000℃ before pouring in the molten iron. The heating of the furnace can be heated by adding iron blocks for induction heating.
(10) The freezing and sealing time of the furnace charge should not be too long to avoid causing furnace explosion accidents; after the furnace lining is sintered, it is advisable to use 30~50% of the rated power and work continuously for more than 5 furnaces.