Medium frequency heating furnace technical requirements

1. Thyristor intermediate frequency inverter :

1.1 With full furnace cold start function, start success rate: 100 %; hot material 100 %. The blast furnace begins to heat the third material to reach the process temperature. And can be forged to the last material.

1.2 The power supply is equipped with components of 500 kw , and the overload is allowed to be 20 % for a short time .

1.3 rated output power of 500 kw running power factor above 0.9.

1.4 Main components such as thyristors in the IF inverter cabinet and the main components of the whole line are preferably imported from foreign or domestic famous brand advanced devices. All design parts need to be replaced by one level due to procurement difficulties, ensuring stable and reliable operation of the equipment.

1.5 medium frequency induction heater has heat preservation function (low frequency operation of medium frequency power supply).

1.6 After heating, the various blanks reach the process temperature of different materials ( 1150 °C) , and the material does not stick.

1.7 Circuit structure: parallel inverter.

1.8 In the case of grid voltage fluctuations of 15 %, the IF output voltage fluctuation is not more than ± 1 %.

1.9 brass dual reactor configuration, connected to the internal cross-sectional area of copper is sufficiently large to reduce fever.

2. Induction heater :

2.1 Temperature uniformity: The temperature difference of the heart surface of the billet is reduced to the minimum when it is discharged.

2.2 The sensor is made of high-quality knotting, and the normal life of the sensor coil is more than 3 years. The sensor lining has a normal service life of more than one year.

2.3 The inner guide rail of the sensor has wear-resistant materials.

2.4 using parallel inductor design, the blank is gradually increased from the feed end to the discharge temperature to ensure that the blank does not produce micro-cracks in the heating process, over-temperature burnt and other defects.

2.5 The inductor coil, bus bar and connecting wires have a large cross-sectional area to reduce heat generation.

2.6 The internal connection of the inductor coil is reliable, the inductor is manufactured strictly according to the process requirements , and the high-pressure leak test is performed before assembly.

3. Temperature control system

3.1 Thermometer:

3.1.1 American Raytheon infrared thermometer can be used for peak hold and automatic reset. In the range of 1150 °C, the temperature measurement error is not more than ± 0.3% , and the repeat accuracy is not more than ± 0.1% .

3.1.2 The temperature measuring device is not affected by surface oxide scale, dust, smoke and water vapor.

3.1.3 Set the thermometer at the discharge port to ensure power closed-loop control ;

3.2 Control instrument: The temperature control system has the “ PID ” adjustment function and the closed-loop control of the furnace temperature.

Control system control principle:

Power regulation control during heating :

In the process of heating the workpiece, the power adjustment is mainly based on two factors.

The temperature is controlled in a closed loop according to the set tapping temperature.

According to the running beat requirement of the workpiece, the speed requirement is met by the closed loop adjustment of the power.

4. Electrical control system:

4.1 The complete set of equipment can be controlled in front of the control cabinet or in the operating position.

4.2 can realize fully automatic, semi-automatic, manual adjustment work mode.

4.3 Control part Add PLC to man-machine interface, set parameters in real time, display power, voltage, current, temperature and other parameters, intuitive and reliable.

5. Safety measures:

5.1 Equipment electrical connection parts are equipped with necessary warnings (lightning symbols, warnings, partitions, etc.), protection and shielding to protect the maintenance and operator safety.

5.2 Interlocking and protection performance of the whole set; emergency stop, over voltage, over current, phase loss, inverter failure, voltage cutoff, current cutoff, over temperature of components and under pressure and cooling of cooling system, high water temperature (each return water) All the branches are equipped with temperature detection), and the next process (less than 15 minutes of fault power reduction, more than 15 minutes of fault shutdown) and other interlocking, fault alarm, fault diagnosis, etc., complete operation, reliable. It is guaranteed that the equipment will not be damaged, and the failure of the materialization in the induction heater and personal safety will occur.

5.3 The whole set of equipment is reliable and has reasonable timing, which can effectively avoid the harm caused by misoperation to equipment and human body.

5.4 Manufacturing and installation are carried out in accordance with the Machinery Industry Safety Evaluation Standards of the Ministry of Machinery Industry.

5.5 It is manufactured according to the national induction heating furnace standard and meets the national environmental protection and safety standards.