Abstract: To improve the low and unstable quality of the lithopone product under manual control in Guangzhou Lithopone Factory, a computer control system is introduced to control the running of the key device-Lithopone Kiln and Calcinator. A two pole control scheme is adopted on the basis of full analysis of the on spot conditions: at one pole, it applies an anti saturation PID arithmetic to control the head kiln temperature so as to keep the energy supply stable; and at the other pole, it adopts a control scheme based on the concept of energy to control the specifications of achromic ability so as to improve the quality and keep it stable. After eight month on spot application and evaluation, the head kiln temperature is controlled within the range of the given value±5 ℃, and the high quality product rate is increased by more than 30% .

Key words: lithopone, kiln and calcinator, process control, achromic ability, energy