Research On Optimum Operating Cycle Of Chamber Type Diaphragm Filter Press

Chamber Type Diaphragm Filter Press, which was invented in mid-20^th century, characterizes high filtration pressure, large filtration area, low moisture content of filter cake, good anti-corrosion ability and economical operation cost. It is widely used in many industries such as chemical engineering, petroleum, pharmacy, paint and ceramics. Recently, it also becomes dispensable equipment in the process of wastewater treatment.During its operation period, filtration and consolidation with constant pressure are applied respectively. Actually, filtration is the first stage of solid-liquid separation and the key point of determining the moisture content of filter cake and production capacity is the operation parameters of filter press. Because of the great difference in dewatering theory of filtration and consolidation, it is necessary for confirming them in order to make full use of the filter press. Finally, the targets of lowering the moisture content of filter cake and energy costing, improving the production capacity can be achieved.In this paper, theoretical study of optimum operating cycle on Chamber Type Diaphragm Filter Press has been advanced by considering the main three steps (1. pressure filtration; 2.squeeze filtration; 3.consolidation dewatering of filter cake) in the process of solid-liquid separation. As we know, an operating cycle of Chamber Type Diaphragm Filter Press is equal to the sum of dewatering time and auxiliary time. In a general way, auxiliary time is associated with the structure of filter press characteristics of slurry and application of automatic system, given thickness of filter chamber filtration pressure squeeze pressure, moisture of filter cake, we can regard it as a constant which is independent of production capacity. Based on certain auxiliary time, we can find optimum filtration time by analyzing and calculating directly time spent in the process of the main three steps respectively. The maximum production capacity of filter press can be derived from optimum operating time rapidly and accurately.In addition to the above theoretical part, a special experiment in a workshop is carried out and real-time data related to solid-liquid separation of fine CaCO₃ slurry is recorded to testify the feasibility and accuracy of theoretical modeling by comparing the theoretical data with the recorded data. Finally, a summary of this research and research prospect are given to improve the current theory of solid-liquid separation for chamber type diaphragm filter press.