Study On Mechanism Of Flocculant Dissolving And Automatically Adding

This study is supported by the project in Shanxi Province PR (automatically add the flocculant preparation and study of key technology and equipment 051169),Yangquan Coal Industry's major technology project (flocculant automatically adding system of washers GY0426) , Xishan Coal and Electricity Company's major technology project (research and application of flocculant preparation equipment and adding technology 07140109200705) and Taiyuan University Students innovation fund project(study on anti-pressuring rake of thickener and alarming device 8122005)With rapid development of the mechanized mining technology and clean coal technology, the amount of coal selection increases, resulting in more and more slime water. In order to reduce costs and save water and coal resources, many researchers concerne about how to accelerate slime water settling and water recycling. The emergence of flocculant improved one of the key process enrichment technology developments for treatment of the slime water and improved the efficiency on certain extent. Which that the characteristics of flocculant difficult to be dissolved and the significant role of flocculent about slime water settlement rules make the control of its water-soluble slime to add constraints become a major problem.Slime water settlement is complex physical and chemical processes which is impacted by variety factors. First, effected by flocculant dissolution. Flocculant is a long molecular chain of organic matter. The more adequate dissolved, the more active group exposed flocculant will be absorbed more suspended particles. Second, effected by flocculant adding. Practice shows that flocculant adding must be appropriate, otherwise, it would not achieve the effect of accelerating settlement and wastage and may occur pressure rake accident. Furthermore, it is impacted by pressure rake state detection. Only which ensuring the concentrator running normally, flocculant adding in order to work laws make concentrate machine has a normal settlement rules. These three parts complement each other in order to maintain the harmonization of effective role and to improve slime water treatment effects, and create benefits for enterprises and the society. Therefore, the authors propose that key technology research about preparation of flocculant dissolution and automatically add the dissolved flocculant's liquid and thickener operation condition monitoring.The nature and factors impact slime water sedimentation are analyzed in this paper .Modern computational fluid dynamics software FLUENT are used to simulate the concentrated pool of internal flow field in different feeding modes and then deeply analysis the concentrated pool of water flow field for the settlement of slime water. On this basis, application of multi-phase flow theory concentrated pool of slime on the settlement of law of the simulation of water. Thesis has been concentrated pool of slime water sedimentation law mathematical model.The actual measured sedimentation law is used to optimized the mathematical model. That provides a theoretical basis for automatically flocculant adding controlThe flocculant physical and chemical properties is analyzed in this paper, and the method useing the overflow water to disperse flocculant and the cyclone turbulent field to soak flocculant is presented. Orthogonal experimental method is used to study critical factors impact of flocculant dissolution temperature and of stirring speed and stirring time. And dissolution recommends conditions is given. Based on above, the flocculant dissolving liquid preparation device is designed in this paper. And in this paper computer simulation technology is use to determine the structure parameters of the overflow pre-dissolving device. Experimental results show that the flocculant dissolving liquid preparation device has a good effect.The combining method of feed-forward and feedback controll is used in flocculant automatically adding controll. Flocculant adding control mechanism basing on the net amount of slime is proposed in studying on feed-forward part. Study on the feedback part, author put forward a indirect detection technique about concentration of thickener overflow which bases on the law of the of slime water. This technology can detect a number of indicators, such as the slime interface, overflow concentration, the concentration of underflow's. In the control strategy using fuzzy control strategy, based on experience building a fuzzy control rule table and the application of stimulant tool for fuzzy control rules, a computer simulation was studied. That the system of flocculant automatically adding based on feed-forward and feedback control access to national patent (ZL200610102033. 2) and Shanxi Provincial Science and Technology Department experts confirmed that it reached the international advanced level (061160).The failure mechanism that current-pressure rake detection alarm device is used on driving around the thickener is analyzed and the servo anti-pressure rake alarm device is proposed. Pressure rake alarm mathematical model is stablished and according model the alarm threshold is set. In the experiment author amended the target setting again and achieved satisfactory results. The device obtains the national invention patent (ZL200610102034.7).Based on above study the modular design method and module configuration table about the system of flocculant dissolving and automatically adding is designed in this paper. Industrial experiments shows that the fuzzy control-based flocculant dissolution fluid preparation, automatically adding controls and servo anti-pressure rake alarm can be either used by organic combination of applications or individual. The system is very significant about effective controlling overflow and reducing production costs and preventing pressure rake and improving the enterprise's economic and social benefits.