Research On The Technique Of Industrial Water Saving

Industrial water accounts for about a quarter of the total water in China. Industrial water reuse and wastewater minimization technology makes great sense and it is the focus of the world's attention.In this paper, synthesized theory of"water-pinch point"technology is explored, and factory M of petroleum-refinery industry in China was selected as the test site. In this paper, three operations are selected in factory M. Three contaminants, H2S (contaminant A), suspended solids (contaminant B), and oil (contaminant C) are selected for the multiple-contaminant system. The transfer of H2S will be proportional to the transfer of SS and oil, which is the proportional mass-transfer assumption.In this paper, based on the proportional mass-transfer assumption, preliminary concentration-interval graph is produced; based on feasibility analysis of water reuse, concentration shifts are carried through, and the final concentration-interval graph is constructed; to allow for the maximum reuse of water between each concentration-interval and each water-using operation is the premise, based on the basic formula of mass and concentration, freshwater requirement, water reused between each concentration interval and operation, inlet-concentration and outlet-concentration are found through synthesized analysis and calculation, and finally, the minimum freshwater flowrate is obtained; according to the results above, water-using network is designed. Distributed effluent-treatment systems is selected as effluent-treatment systems of Plant M. Using water-pinch technology for wastewater minimization, a distributed effluent-treatment system segregates the different streams for separate treatments and only combines them if it is appropriate. For this multiple-contaminant and multiple-treatment processes, the minimum treatment flowrate of each contaminant is determined first; the true minimum treatment flowrate is the maximum frowrate among the minimum treatment flowrates for all contaminants; design a subnetwork for the treatment of each contaminant; then merge all the subnetworks and make all possible simplifications to obtain the final optimum treatment network.