Compact middle frequency heater modified for OSTROJ JSC Opava is used for induction heating of steel billets with circular cross-section up to forging temperature. The original induction heater KSO 250/8-A30 with the output of 250 kW has been modified to KSO 400/4-A25P with the output of 400 kW. In this way the amount of heated material has risen from the original 600 kg/hr to 850 kg/hr. Especially these parts have been changed: separating transformer, fuses and thyristor in frequency converter, units of frequency converter controller and starting and compensating capacitors. To keep the external dimensions of the original heater, new inductors have been made including the inductor 65-400/600/1,8/CR in which the method of high-speed heating has been used.
Heated Material | magnetic steel | |
Billet Dimensions | Ø D, [mm] | 30 - 65 |
Length l [mm] | 1,2D - 250 | |
Maximum Process Capacity [kg/h] | 850 | |
Billet Delivery Temperature [°C] | max. 1299 | |
Nominal input values (power circuits) | ||
Power Input [kVA] | 480 | |
Input voltage from separating transformer [V] | 3 x 400 | |
Frequency [Hz] | 50 | |
Nominal input values (control circuits) | ||
Power Input [kVA] | 5 | |
Voltage [V] | 3 x 400 | |
Frequency [Hz] | 50 | |
Nominal output values | ||
Power [kW] | 400 | |
Frequency [kHz] | 1,33 - 4 | |
Nominal output voltage [V] | 600 |