Device and method for real-time measurement, control and adjustment of molten metal temperature

Abstract

The invention discloses a metal melt temperature real-time measurement and control adjustment device and method. The device comprises an infrared temperature measuring device, a programmable logic controller PLC and an intermediate frequency power control port. The programmable logic controller PLC is connected to the intermediate frequency power control port and controls the heating power of a vacuum induction furnace according to a preset desired temperature value. The infrared temperature measuring device continuously measures the temperature of a melt in a vacuum induction furnace crucible, and a thermocouple carries out discontinuous measurement on the temperature of the melt in the vacuum induction furnace crucible and sends a measured temperature signal to the programmable logic controller PLC. The programmable logic controller PLC performs calibration according to the temperature signal measured by the thermocouple and adjusts the heating power of the vacuum induction furnace.According to the device and method, the advantages of strong real-time performance of infrared temperature measurement and high accuracy of thermocouple temperature measurement are simultaneously exerted, thus a temperature value which needs to be measured and controlled is more accurate, and the quality of a produced product is improved.

Description

technical field [0001] The invention belongs to the technical field of casting equipment and automation, and in particular relates to a device and method for real-time measurement, control and adjustment of molten metal temperature. Background technique [0002] In the alloy melting and refining process, the requirements for the precision and purification of the alloy composition are getting higher and higher. Vacuum induction melting technology is currently an important 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 controlle...

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

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