1 , the intermediate frequency power supply 

a . Inductive melting furnace power density configuration. The configuration is high, the melting speed is fast, and the energy saving effect is good. Whether the electric furnace can maintain a high power factor to supply power to the furnace is also a difference in energy consumption. 

b . The efficiency of the induction melting furnace and the electrical efficiency of the induction coil. (The total efficiency of foreign advanced induction melting furnaces is as high as 75 %, the induction coil is as high as 85 %, and the domestic is 73 % and 80 % respectively). 

c , IF power conversion efficiency. Foreign countries accounted for 97 % to 98 %, and domestically close to 97 %, mainly in the efficiency of reactance and capacitance.

d , the arrangement of the electric furnace unit. The distance from the power supply to the furnace body, the length of the power supply copper bus, the length of the water-cooled cable, the power supply voltage, and the distance from the high-voltage transformer to the power supply point are all influencing factors. 

2 , the impact of the melt

1 ) The cleanliness of the surface of the charge (if there are 5 % impurities, 5 % of electrical energy to melt these impurities), will also affect the life of the lining. 

2 ) The appropriate length of the furnace block will affect the electrical efficiency and melting quality of the electric furnace. Generally, the block size of 200 to 300 mm is suitable. 

3 ) Whether there is liquid metal liquid in the furnace when melting. The residual liquid is preferably 15 % of the furnace capacity . If too little, the overheating condition of the molten iron will be intensified. Too much will reduce the effective use of molten iron and increase the unit energy consumption. The emptying of molten iron reduces the power factor and decreases the melting rate during use. 

3 , refractory materials 

1 ) Reasonable material thickness. Increasing the melting rate can reduce the thickness, but the service life is reduced, the cost of building the furnace rises, and the safety hazard rises. 

2 ) The correct bottom thickness also affects electrical efficiency and lining life. When the height of the bottom of the furnace exceeds 100 mm of the effective coil , the bottom refractory material will strongly wash the bottom due to the induction stirring force, which will drastically reduce the service life. 

3 ) the correct furnace lining material. The insulation material is called a lining material (such as asbestos cloth, etc.).

The use of asbestos cloth as a lining material harm: human inhalation will stay in the lungs and have a carcinogenic tendency; asbestos cloth generally has a high water content, and it is easy to cause cracking of the knot with quartz water after the use of quartz sand for a period of time. The function of the lining material is insulation, waterproof and the coil of the inductor is refractory. The surface of the cement is isolated and the lining is replaced. Quartz sand hot back, we hope to have a layer of loose layer so that the hot metal will stop here. The cooling water temperature of the inductor is a necessary condition for creating a loose layer. If you use a well-insulated asbestos cloth and water, the trace amount of boric acid in the quartz sand will cause it to be knotted. Mica paper is the best choice. Treated with high-grade coil cement, the surface is smooth, no need to use the lining material, but it must have the convenience of processing, no crack after drying, and no reaction with acidic substances.

4 , energy saving during operation

Timing timing. The first time the solid charge is added to reach about 1/3 of the furnace capacity , otherwise it will affect the power output, and will also cause ignition (discharge) to pull the arc and consume electricity, and may cause cracks on the surface of the lining. Great destruction. When the first batch of material reaches the molten state, the solid charge sinks, and the material should be refilled immediately. This can melt the softened solid material and melt it at the fastest speed. The feeding is not normal in the furnace, and the liquid violent tumbling is normal (the liquid violent tumbling means that the molten metal is overheated, and the furnace wall is washed, and the lining material is consumed). This requires that the power input for the melting time be changed by a regularity of less than 20 % (first charge) → 50 % (softening) → 65 % (feed) → 100 % feed-to the temperature required by the process. Then power off the liquid.  

5 , to avoid high energy consumption caused by improper operation 

a , the molten metal is overheated. 

b , do not stop the furnace liquid. Not only is it unsafe, it is also wrong in terms of energy consumption and melting process. Generally, the electric furnace sensor is divided into two parts. When the metal liquid level in the furnace is lower than half of the upper inductor, the upper inductor no longer has an induced current passing due to the resistance change, and all of the lower inductors are concentrated in the lower inductor to make the lower metal liquid. Overheating, flushing the furnace wall, the life of the lining drops sharply. 

c , high temperature insulation. Long-term high temperature will change the metallographic phase, C and Si change phase, the white mouth of the casting tends to be serious, and the machining performance deteriorates.