Experimental Study On New Conductive Drainage Plate And Assembled Sludge Dewatering Device

In order to protect the ecological environment of urban rivers and improve the hydrodynamic conditions of rivers,it is necessary to conduct dredging on the rivers regularly and study a fast and effective dewatering method of dredged silt to reduce the water content and volume of dredged silt and facilitate transportation and utilization.In this thesis,firstly,a new prefabricated dewatering device for electroosmotic drainage of dredged sludge is designed.The device consists of a new conductive plastic drain plate and a special interface.Secondly,the mechanism of electroosmotic drainage of dredged mud by a new conductive plastic drainage plate was revealed by numerical test and model test.Finally,the electroosmotic drainage capacity of a new type of conductive plastic drainage plate on dredged mud with larger thickness was studied by the model test.The main research work and achievements of this paper are as follows:(1)A prefabricated sludge dewatering device is designed,which is composed of a new conductive plastic drain plate and a special interface.The traditional plastic drainage plate and graphite carbon felt were combined to form a new type of conductive drainage plate,and the new conductive plastic drainage plate was quickly assembled to form a set of prefabricated electroosmosis dewatering device for dredging sludge.(2)The finite element software was used to simulate the effect of electroosmotic silt of conductive plastic drainage plate with different cathode and anode width ratios,and the optimal cathode and anode width ratios of conductive plastic drainage plate in electroosmotic silt were obtained.The drainage effect of conductive plastic drainage plate with different width ratio of anode and cathode on electroosmotic sludge was analyzed from the aspects of potential,electric field and drainage rate.The results show that when the width ratio of anode to cathode is set at 3:2,the electrode material can be saved in the case of higher drainage rate.(3)Through the indoor model test,the electroosmotic drainage effect of the conductive plastic drainage board was compared with that of the traditional tubular electrode,and the superiority of the conductive plastic drainage board in corrosion resistance and electroosmotic drainage effect was verified.The results show that no electrochemical corrosion occurs at the anode of the conductive plastic drainage plate under constant voltage,the final moisture content of the sludge after electroosmosis is lower than that of the tubular electrode,and the average energy consumption coefficient is also 28.9% lower than that of the tubular electrode.(4)A laboratory test model of the conductive plastic drainage board with single layer and double layer was established to reveal the electroosmotic drainage performance of the conductive plastic drainage board with multi-layer arrangement under the condition of large silt thickness.The results show that compared with the onelayer arrangement,the average discharge rate of electroosmosis is higher in the twolayer arrangement,the final water content is lower,but the average energy consumption coefficient is slightly higher.The electroosmotic drainage effect of double layer conductive plastic drainage plate with different electrode spacing was analyzed by finite element method.The results show that when the electrode distance is set at 35 cm,the number of layers of conductive plastic drainage plate can be reduced under the condition of better electroosmotic effect.Generally speaking,the electroosmotic effect of the conductive plastic drainage plate is more ideal when it is arranged in multiple layers,which can meet the electroosmotic drainage needs of the thick silt.