According to the different output induction heating frequency, induction heating equipment can be roughly divided into: super audio frequency induction heating equipment, high frequency induction heating equipment, medium frequency induction heating equipment, etc. And different heating processes require different frequencies. If the frequency selection cannot meet the heating requirements, such as slow heating time, low work efficiency, uneven heating, and temperature not meeting the requirements, it is easy to cause damage to the workpiece.
Therefore, the frequency of induction heating equipment is adjustable. The advantages of different frequencies of induction heating equipment are as follows:
1. Low frequency induction heating type
The frequency is the lowest, the frequency range is from power frequency (50HZ) to about 1KHZ, and the commonly used frequency is mostly power frequency. The relative heating depth is the deepest, and the heating thickness is the largest, about 10-20mm. Mainly used for overall heating, annealing, tempering and surface quenching of large workpieces.
2. Medium frequency induction heating method
Frequency range: normal 1KHZ to 20KHZ, the typical value is about 8KHZ. The heating depth and thickness are about 3-10mm. It is mostly used for heating, annealing, tempering, quenching and tempering and surface quenching of larger workpieces, large diameter shafts, large diameter thick wall pipes, large modulus gears, and red punching and forging of smaller diameter bars.
3. Super audio frequency induction heating method
Frequency range: normal 20KHZ to 40KHZ (because the audio frequency is 20HZ to 20KHZ, so it is called super audio). The heating depth and thickness are about 2-3mm. It is mostly used for deep heating, annealing, tempering, quenching and tempering of workpieces with medium diameter, heating, welding, thermal assembly of thin-walled pipes with larger diameter, and medium gear quenching, etc.
4. High frequency induction heating method
Frequency range: common 40KHZ to 200KHZ, commonly used 40KHz to 80KHZ. The heating depth and thickness are about 1-2mm. Induction heating surface hardening equipment is mostly used for deep heating, red punching, forging, annealing, tempering, quenching and tempering, surface quenching, heating and welding of medium diameter pipes, hot assembly, pinion quenching, etc.
5. Ultra-high frequency induction heating method
The frequency is relatively highest, the frequency range: above 200KHZ, up to dozens of MHZ. The heating depth and thickness are the smallest, about 0.1-1mm. It is mostly used for the quenching and welding of local very small parts or very thin bars, and the surface quenching of small workpieces, etc.
At the same time, these five kinds of induction heating equipment have certain advantages. They all use IGBT induction heating power supplies. They are the most energy-saving and environmentally friendly induction heating equipment in the 21st century.
① Main features: small size, high power, fast heating, transparent core, low power consumption.
② Power saving situation: Compared with the old-fashioned thyristor intermediate frequency, the thyristor intermediate frequency heating uses about 470 degrees per ton of workpiece.
Our company's new intermediate frequency power consumption is about 350 degrees.
Each ton burned saves more than 100 kilowatt-hours of electricity. As long as about 500 tons are burned, the equipment investment can be recovered by saving electricity.
③ Circuit characteristics: The main device adopts IGBT module, the circuit does not control full bridge rectification, capacitor filtering, bridge inverter, series resonance output. It is fundamentally different from the old-fashioned intermediate frequency using thyristor parallel resonance.
④ Power saving principle: Uncontrollable rectification, and the rectifier circuit is fully conductive. High power factor, voltage type series resonance, etc., determine the substantial power saving of this equipment.