Research On Dewatering Mechanism Of Fine Clean Coal Tube Type Filter Pressing

With the increase of pressure on the world environment and the improvement of scientific and technological content of clean coal technology, domestic and foreign coal enterprises'requirement on coal product moisture is becoming higher and higher. The difficulty to dewater for micro-fine flotation clean coal becomes an indisputable fact. Although coal dewatering techniques, methods and equipment have been used in production at present, the related mechanism of fine coal dewatering is still lacking, and development of efficient dewatering technology and equipment has become an important and critical content of clean coal technology development.The dewatering mechanism of hard-dewatered micro-fine flotation clean coal was researched, and heterogeneous separation characteristics of dewatering mechanism of fine clean coal tube type filter pressing were researched with advanced micro-mapping research techniques of Bei Keman laser particle size analyzer,microscopy, scanning electron microscopy, and Autosorb-1 specific surface area maps. The dynamic rule of heterogeneous phase separation, factors, basic theoretical ideas, and related parameters of micro-fine flotation clean coal dewatering were researched through advanced theory and experimental methods of mathematical modeling, regression analysis, linear regression, orthogonal design and Design-Expert software. Fine clean coal tube type dewatering theory was established and improved through advanced detection methods of Lack of fit analysis, damage detection, F test, structure and size analysis of cake slicing, objective weight analysis ,three-dimensional response, analog calculation and scheme optimization. The detailed research contents and innovations were summarized as follow.In this dissertation, membrane pressing tube type fine clean coal filter with swirling flow and variable filter chamber was designed innovatively. According to the tube type pressing equipment, the dynamic self-reinforced structure effects in pressing process and mechanical properties of the tube type filter were analyzed; the materials fundamentals of the ring cylinder to pressure and the good carrying capacity of the Inside and outside tube to different ways of pressure dissolution were pointed out.A new type of tube type fine clean coal filter and the operating system were designed. The filter can achieve general filtering and pressure filtering accompanies filter pulp carrying pressure. Two-dimensional pressure dewatering and two-dimensional membrane press dewatering can be achieved after the formation of cake. In addition, the above two processes and four ways can achieve free combination or use alone to form advanced comprehensive new dewatering techniques.This research first established the mechanism of heterogeneous phase separation of flotation fine clean coal filter pressing dewatering. Experimental results demonstrated innovatively that influential factors to fine coal slurry filtration rate of two-dimensional solid-liquid separation were: the nature of the cake, fluid viscosity and density, medium materials, filtration pressure, and the structure of the filtration equipment.Dynamic rule of fine clean coal tube type filter pressing dewatering and the dynamic mechanism were first obtained by simplifying and solving the dynamic equations of fine clean coal dewatering. The specific equation of fine clean coal tube type filter pressing dewatering was established according to specific coal.5 characteristics of squeezing process of fine clean coal filter pressing dewatering were established innovatively. According to above research, squeezing ratio was obtained in the squeezing phase of fine clean coal two-dimensional tube type filter pressing, so was the simple expression of a very important coefficient C e in the squeezing process.Functional relationship in connection with specific coal between filter cake moisture, solid content of filtrate,and factors was established innovatively by researching parameters and evaluating indicator of fine clean coal filter pressing dewatering. In the dissertation, 10 optimized programs and the optimal program were given about filter cake moisture and solid content of filtrate. The filter cake moisture of optimal program was 12.28%, and the solid content of filtrate of optimal program was 0.30g/l .At the end of this dissertation, problems and development of the research were pointed out.The dissertation hesis contains 82 figures, 60 tables and 216 references.