Vacuum induction smelting process temperature real-time measurement, control and calibration system and method

Abstract

The invention discloses a vacuum induction smelting process temperature real-time measurement, control and calibration system and method. The system comprises an infrared temperature measuring device,a programmable logic controller PLC, and a medium-frequency power supply power control port; the programmable logic controller PLC is connected with the medium-frequency power supply power control port, and controls a heating power of a vacuum induction furnace according to a preset anticipant temperature value; the infrared temperature measuring device continuously measures the temperature of amelt in a crucible of the vacuum induction furnace; a thermocouple pair continuously measures the temperature of the melt in the crucible of the vacuum induction furnace, and sends measured temperature signals to the programmable logic controller PLC; and the programmable logic controller PLC calibrates according to the measured temperature signals of the thermocouples, and adjusts the heating power of the vacuum induction furnace. The system exerts the advantages of high instantaneity of infrared temperature measurement and high temperature measuring accuracy of the thermocouples at the sametime, so that the temperature numerical values needing measurement and control are more accurate, and the quality of produced products is improved.

Description

technical field [0001] The invention belongs to the technical field of casting equipment and automation, and in particular relates to a real-time measurement, control and calibration system and method for vacuum induction melting process temperature. Background technique [0002] In the alloy smelting process, the requirements for the precision and purification of the alloy composition are getting higher and higher. Vacuum induction melting technology is the key technology to ensure the purity and accuracy of alloy components. Vacuum induction melting process includes charging, melting period, refining period, pouring and other processes, realizes the precise control of temperature at each stage in the vacuum induction melting process, especially the refining temperature and pouring temperature, and ensures the high purity and accuracy of the final alloy composition. plays a key role. [0003] At present, the vacuum induction melting process is generally controlled by the ...

AI Technical Summary

Problems solved by technology

The determination of process parameters in the smelting process is generally based on operating experience. Usually, a certain heating power and a certain smelting time are used as the refining process parameters, but this is not accurate for the temperature control of the smelting process.

Because even under a certain power condition, the temperature of the melt may still change, and only when the temperature changes significantly, the operator will manually adjust the heating power; obviously, this temperature adjustment method is hysteresis , and it is easy to have too much temperature fluctuation, which cannot guarantee the long-term stability of the temperature during the refining process, and cannot guarantee the stability of the quality of the smelted alloy.

And this unstable change will eventually affect the melting effect of the alloy

The melt temperature in the vacuum induction furnace is difficult to monitor continuously and in real time online, let alone realize automatic control

[0004] At present, in the application of industrial furnaces, the commonly used means of temperature control is to use thermocouples for temperature measurement, and use temperature control instruments or PLC to receive temperature signals and output control signals to the power supply to adjust the power of industrial furnaces. During the process, if the thermocouple is immersed in the alloy liquid for a long time, the thermocouple will easily melt into the metal liquid, resulting in the inability to continue the temperature measurement.

So this method is not suitable for vacuum induction melting technology

[0005] However, the infrared temperature measurement + PLC control method alone can only measure and control the temperature data on the surface of the melt. In the case of long-term refining, the infrared thermometer itself is easily polluted by steam and dust in the vacuum induction furnace, causing temperature On the other hand, the amount of dross on the surface of the melt will gradually change with the refining process, resulting in deviations in temperature measurement; these two aspects work together, making it impossible to use infrared thermometers alone. Accurate temperature measurement and control

Images