Design Of Intelligent Temperature Measure-control System For Slag Analyzer By Hot-wire Method

With the development of metallurgical industry, slag and steel slag melting temperature should be tested rapidly and accurately. It is significant to improve product quality and conserve energy by studying on slag and steel slag melting temperature, melting temperature range, crystallization temperature and crystallization rate and other important physical properties. The accuracy of temperature measurement directly affects the results of the analysis. But the traditional test equipments have some problems, such as large temperature-measurement deviation, slow heating rate, long testing time and high consumption. It is necessarily to protect the slag melting temperature of fast and accurate measurements. How to solve these problems has been a hot topic in this field.In order to solve these problems mentioned above, a intelligent temperature control method which is based on the platinum rhodium thermocouple was proposed. In other word, the thermocouple is in the TDM (Time Division Multiplexing) working state to monitor and heat temperature.The thermocouple was both used as temperature measure and heater parts. System uses a PWM (Pulse Width Modulation) mode of the temperature control.STC12C5A60S2 was selected as the core component of whole system. Improved PID measure-control algorithm was used to design a new system, which has good stability and fast heating rate. The hardware design, software design and control methods have been described in details.System uses PID control algorithm to improve the speed. The heating temperature range is divided into paragraphs, in different temperature stages of the control using different heating methods. Improved control algorithm is better than traditional PID control algorithm.The chip ICL7765 and AD7705 were used in the temperature measure circuit of the system. It not only simplifies the design of hardware and software but also improves precision of control system. The output program is simplified because the output control is carried out mainly by output circuit. The design of anti-jamming is adopted in hardware circuit and software. It enhanced anti-jamming capability.The design of software in this system adopts module structure. It makes the program have stronger portability and interoperability. PC moniter and control system software development uses Visual Studio.NET platform.Finally, the effects has been compared and analyzed. Experimental results show that the system of control is better than conventional PID. The temperature measurement and control system, which has small deviation, good stability and fast heating rate can enhance the overall performance of the blast furnace method analyzer. The system has good application prospects.