Study On The Automatic Dosing System Of Coal Slurry Sedimentation Process Based On Image Gray Feature

At present,in the flocculation and sedimentation of coal slurry treatment,the manual dosing method is adopted by most domestic coal preparation plants.However,the accuracy of manual dosing and the adaptability to the quality of incoming materials are not enough,which has a great influence on the continuity and stability of production.However,due to the complex nature of the coal slurry treatment system and the development of measuring instruments,the effect of automatic dosing is not ideal.In view of this,this paper adopts industrial camera to collect images of flocculation and sedimentation process,and based on the offline condition to explore the optimal dosing system,through the preprocessing and feature extraction of the image,the image gray feature and sedimentation velocity are analyzed.The correlation and the automation of the drug dosing process is explored.In this study,the concentrator feed and raw coal products of a coal preparation plant are analyzed.Under the condition of coal slurry concentration of 40 g/L,two coals’dosage amounts are determined according to the single factor of coagulant and flocculent and joint test.The optimum dosage of flocculent PAM is 0.15 kg/t dry coal slime and 0.2 kg/t dry coal slime.The best dosage of coagulant CaCl₂ is 5 kg/t dry slime,which provides the experimental foundation for the sedimentation image acquisition feedforward control based on the amount of dry coal.In order to obtain an accurate image of the sedimentation process of coal slurry,this study sets up an image acquisition platform to select industrial cameras,apertures,light sources and related supporting hardware,and selected the corresponding data transmission and communication methods.In order to reduce the interference of ambient light on the sedimentation image and the system noise brought by the acquisition system hardware,this study tries to use the mean filtering and median filtering algorithm to denoise the sedimentation image;the result of image graying indicates that the color characteristics of the image are not significant.The gray level co-occurrence matrix of the image indicates that the image has thick texture;the statistical characteristic parameters such as average gray level,variance and smoothness of the image are extracted,and the characteristics of these characteristic values change with time are analyzed,and finally,the average gray value is taken as an investigation feature.The variation of the average gray value of the sedimentation image with time under different dosages and coal slurry concentration is explored,and the linear relationship is used to fit the law.The results show that the fitting degree is higher;the correlation analysis between the change rate of the average gray value and the sedimentation velocity of the coal slurry shows that there is a strong linear correlation between the two;the average gray-scale change rate of the image is evaluated as the feasibility of the flocculation and sedimentation effect index of the coal slurry.Finally,the automatic dosing system of coal slurry water sedimentation process based on image gray feature is constructed,and the automatic dosing control strategy and automatic dosing process is discussed.