The heater is used for induction heating of steel billets with circular or square-shaped cross-section up to forging temperature. The thyristor frequency converter is built in the heater box thus the built-up space is saved and losses in MF cables are eliminated. A twelve-pulse rectifier is used in it, whose advantage is a lower share of spurious harmonic frequencies emitted into the supply network.
The input mechanism enables either fully automatic or manual insertion of cold billets. The manual insertion is used for short billets which, in the automatic mode, are not able to be oriented in the right way.
In the automatic mode the operator, by means of a forklift truck, gradually dumps cold billets from the pallet into the vibratory feeder. From it the cold billets are directed (one by one) onto the input conveyor.
In the manual mode the operator puts the billets directly from the palett to the above mentioned input conveyor. It moves the billets to the roller feeder which consists of a lower prismatic pulley and an upper pressure pulley. Both pulleys are driven and their speed can be set up on the communication panel.
The roller feeder inserts the billets into the inductor in a heating cycle. When one cold billet is pushed in, another heated one is pushed out of the inductor.
The inductor is connected with inlet and oulet cooling water by means of quick couplers which enables quick exchange for another type. It is not necessary to discharge the cooling water from the inductor into the sewer system and, thereby, the operating costs of the cooling are reduced.
A part of the heater box is an inductor shifter, with two fixed inductors. They are possible to be moved to the working position or the preparatory position. The shift from the preparatory position to the working one does not take more than 3 minutes.
The heated billet is pulled out to the output conveyor by means of the separator. It is designed in a way to separate billets which are partly stuck. Furthermore, the heater is equipped with a hot billet sorter, which blocks improperly-heated billets (either underheated or overheated) from being delivered to the press.
The temperature of the heated billet is measured by a contactless thermometer UPF V. The output of the heater and the function of the heated billets separator are regulated according to the temperature value.
The induction heater is controlled by Programmable Logic Controller (PLC) made in Siemens. The operation is done from the control box with buttons and the communication panel. The heating parameters (required temperature, output, temperature limits in etc.) are set up on the communication panel. All failures of the heater are displayed in text on this panel.
Heated Material | magnetic steel | |
Billet Dimensions | Ø D, square (one side) D [mm] | 46 - 90 |
Length l [mm] | 1,4D - 400 | |
Maximum Process Capacity [kg/h] | 3000 | |
Billet Delivery Temperature [°C] | max. 1299 | |
Nominal input values (power circuits) | ||
Power Input [kVA] | 1440 | |
Input voltage from separating transformer [V] | 3 x 625 | |
Frequency [Hz] | 50 | |
Nominal input values (control circuits) | ||
Power Input [kVA] | 25 | |
Voltage [V] | 3 x 400 | |
Frequency [Hz] | 50 | |
Nominal output values | ||
Power [kW] | 1200 | |
Frequency [kHz] | 0,5 - 1,5 | |
Nominal output voltage [V] | 900 |