Study On Dewatering Performance Of Diaphragm Filter Press For Sewage Treatment In Iron And Steel Industry

With the increasing production capacity of iron and steel enterprises in our country,wastewater treatment,recycling,discharge and so on,has become a new environmental management problem.The discharge of these wastewater to the nature has a very bad impact on the environment,so the advanced treatment of these industrial wastewater has become one of the key research topics.In this paper,the factors affecting the filter performance of diaphragm filter press are studied,the reasons are found out,the countermeasures are made,and the corresponding measures are taken to guide the daily production.The main work is as follows:(1)Study the solid-liquid separation process of the diaphragm filter press,and divide the process into three processes: Analyze the different influence factors of the three stages,and finally think that the medium pressure filtration stage takes the longest time and has the most relevant influence factors.The subject will mainly carry out the relevant research on the medium pressure filtration stage.(2)The Fluent software is used to simulate and analyze the filtration speed,filtration time,pressure distribution and solid phase distribution of sludge in a single filtration chamber,to study the formation and change law of mud cake and the flow law of solid-liquid two-phase flow,and to explore the change law of water content of filter cake through simulation.(3)Analyze and study the influence of relevant operation parameters and structural parameters of the diaphragm filter press on the dehydration performance of the filter press,mainly from four aspects of changing the feed speed,feed pressure,changing the feed mode and medicament adjustment.Comparing the difference between the two different ways of sludge feeding from the center of the filter chamber and that from the upper part of the filter chamber,the law of cake formation and the uniformity of cake formation were studied.The results showed that the way of sludge feeding from the center of the filter chamber was better than that from the upper part of the filter chamber.Taking into account economic factors,the idea that the higher the feed pressure was,the better the dewatering performance was,and the optimal feed pressure was determined.The influence of the combined addition of Fe Cl3 and Ca(OH)2 on the specific resistance of sludge and the influence on the final cake moisture content and dewatering rate was studied.(4)The Italian imported diaphragm filter presses and related equipment and facilities of the sewage treatment department model HB-1500 shall be selected as the experimental equipment to verify the accuracy of the preliminary simulation experiment.(5)Through experiments,the optimum operating parameters,structure,filter chamber thickness and medicament use of the diaphragm filter press are determined,which further reduces the water content of the filter cake,improves the production capacity and meets the environmental protection requirements of daily production.At the same time,some reference bases are provided for the design and use of the diaphragm filter press.