Coordinated Control Of Suspension Density And Viscosity In The Dense Medium Coal Preparation

The property of dense medium suspension is related to the effect of coal washing.At present,the coal washing plant only pays attention to the regulation of density,and only takes the liquid level and viscosity of the intercalated barrel as the observed value.Only when the liquid level is too low and the content of coal slime is too high can the manual adjustment be adopted.However,the viscosity of the suspension is directly related to the stability and rheological characteristics of the suspension,The control of suspension viscosity can not only ensure the stability and separation effect of suspension,but also reduce medium consumption,reduce equipment wear,and save costs.Therefore,it is necessary to study the coordinated control of density and viscosity of dense medium suspension.Based on the existing technology of Shijietai and Zhangcun Coal Washing Plant,this paper establishes the dense medium cyclone as the research object by analyzing the dense medium shallow tank sorting process and the dense medium cyclone sorting process;Through the analysis of the key parameters of dense medium washing,the control objects of three inputs(clear water valve,addition valve,diverter opening)and three outputs(suspension density,liquid level,solid volume concentration)of dense medium coal preparation are established.Firstly,the structural form of the transfer function of the control object is obtained by mechanism analysis,and then the parameters of the transfer function are identified by the experimental method,and finally the transfer function matrix of the control object is obtained.Based on the three-input and three-output heavy medium coal preparation process parameter control models established in this paper,the feedforward compensation control algorithm,the feedforward decoupling-Smith control algorithm and the decoupled Smith-GA-PID control algorithm are used respectively for control.It can be seen from the experimental results that all three methods have met the actual production requirements,and the decoupled Smith-GA-PED control algorithm has better control effect.In this paper,through the coordinated control of the density and viscosity of key control parameters of heavy medium coal preparation,the effective coordinated control of suspension density,liquid level and solid volume concentration is realized,which solves the difficulty in maintaining the density and viscosity of suspension in the actual production process.The problem of stability has certain theoretical significance for solving practical production problems.