Research On Height Detection System Of Metal And Bath In Aluminum Production Cell

Base on the basic law of thermodynamics and the difference of heat transfer between aluminum and electrolyte, the paper brought forward a new method to detect the aluminum and electrolyte's height. The designed detection system consists of the sensor, Microcontroller systems and PC data processing software.The sensor system adopts NiGr-NiSi multi-node thermocouple. Its branch nodes distribute at different height. Their position relative to the melted substances can be detected according as the nodes' temperature rising speed. In order to meet the measurement precision, the sensor was required to have 16 nodes. These nodes distribute unevenly in the same steel cannula.The Microcontroller system adopts ADuC812 MicroConverter of AD Company. It is an in-system programmable and intelligent data acquisition system. The MCU consists 8KB Flash/EE program memory (It can download program by serial port), and its analog interface function has 8way/12bit high precision self-adjust ADC, realized 100/s data sampling rate. The detection system can complete the data processing, storage, display and sending functions. Then, the collection process of the thermocouple's temperature rising data can be controlled by PC.By using Visual C++ as the development tool, the PC software was programmed for further dealing with the measured data. The friendly interface was designed. The software can realize the data storage and display functions. Multithreading programming technique was adopted. We can watch the serial I/O by assistant thread. When the data arriving, assistant thread will depend on the event-driven, read data and report it to the main thread. Under control of the PC, the hardware system can collect the temperature rising data of thermocouple, then send them to PC via Serial I/O to display the curve.