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НаименованиеAutomatic control and monitoring system for a rotating kiln

 

JSC Kombinat Magnezit (Satka) is Russia’s largest producer of the refractory materials. More than tens of various process control systems have been introduced in the plant with the participation of the Research and Development Center Lider (Ozersk). When implementing, the big challenge was the control and monitoring system of the rotary kilns designated as the MAIS (a Multifunctional Adaptable Information System).
The rotary kilns are designed to burn a mixture of caustic and raw magnesite. The developed control algorithm forms the values of the parameters required to optimize the burning process: kiln charging (speed), natural gas flow rate and vacuum. This is based on the following measured and calculated variables:

  • Mean value of charging for the last one hour and the last five minutes;
  • Rate of change and speeding of change, average rate of change in temperature in a settling chamber for the last five minutes;
  • Rate of change and speeding of change in temperature in a gas flue;
  • Temperature difference in the settling chamber: 1) between the average and preset temperatures, 2) between the forecasting and current temperatures, 3) between the forecasting and preset temperatures.

The heating conditions controller has a special place in the system. Several tens of the process variables incoming to the said controller determine the dynamics and statics of the kiln and characterize the kiln-controller system.
The basic requirement for the heating conditions controller is to control the process while introducing minimum disturbances. To this end, the controller has been made as a multimode and self-tuning device.  
The self-tuning of the heating conditions controller is based on the statistic processing of the process variables taking into account its weight and closeness of the current value to the extreme value. Actually, the heating conditions controller is a multiloop and multivariable adaptive system incorporating the forecasting elements.
As far as the hardware is concerned, the MAIS system consists of four components networked via the IPX/SPX protocol:

  

Complex of the Rotary Kilns in the Magnesian Powder Shop


By Oleg Shatilov, Anatoliy Chelpanov and Sergey Chuykov

Oleg Shatilov,  Anatoliy Chelpanov ,  Sergey Chuykov