Study On Filtration Characteristic And Dynamics Of The Long Fiber Efficient Filter

With its excellent performance and perfect filtering bed structure, fibrous filter media is showing great superiority in using and being promoted rapidly.Through long time filtering experiment in supply-water factory, the filtration and backwashing performance of a long fiber efficient filter, which has been patented with national invention, was studied in this paper. By comparing with performance of other fibrous filter and through oprating long fiber filtering and the quartz sand filtering at the meantime, the performance superiority of the long fiber efficient filter was opened out. The optimized oprating condition (filtering and backwashing condition) of the long fiber filter was also given in the study. The results show that with fewer time of fibrous bed growing(the turbidity of filtrate will drop to 0.2NTU within 4 minutes), hige quality of filtrate(the turbidity of filtrate is always below 0.2NTU), longer time of filtering period and more quantities of saved dirt(the quantities of saved dirt are 20 to 30 kg/m3), lower pressure drop in the filtering process, thoroughly backwashing and less using of backwashing water, steady filtering process in long time filtration and adapting to direct filtration for raw water, the long fiber efficient filter has obvious superiority in technology compairing with other deep-bed filters. Just due to its great performance, it is possible to rebuild the filtering pool using long fiber in supply-water factory, and the change can bring obvious economic benefit.It is also studied of the changing of filtering bed structure, turbidity of filtrate and loss of filtering pressure along the depth of filtering bed, and the deposit Morphology. On the basis of opening up the filtering mechanism of the long fiber filter, the function of filtering pressure loss is educed by using drag theory, and the function of mass transfer efficiency is made by adapting Shekhtman and Heeryes-Lerk mode. The dynamics functions are testified to be reliability and applicability by using it to calculate the filtering process and optimize the design of long fibrous bed.