抄録
We have recently developed a rigid tubular filter media, namely, "T-type" media made of a polyolefin resin that allows for easy precise filtration and excellent backwashing performance at once. "T-type" media is not susceptible to deformation, such as swelling or contraction, during all processes on filtration and backwashing. In this filtration system, the "T-type" media are precoated directly with the filter-aids. The consumption of the filter-aids is less than approximately a half of volume as compared with its conventional method, and furthermore achieves its cycle-time for precoat method to shorten down to approximately one third as of the past as well. The filter cake on the "T-type" is backwashed with the filtrate, and an entire backwashing procedure is carried out within 10-15 seconds, then this media lend themselves to repeated use over an extended period of time. The drain slurry resulting from the filter is filtered and separated through a smaller bag-filter, and the solution in the drain tank is returned back to the process by way of the tubular filter media so as to recover any loss of the process solutions. The features of "T-type" media have acquired favorable reputation in several major industries as ensuring them not only a filtrate clarity, a simplified method on precoating, filtration and backwashing, but also such effects to reduce a certain load on the environment as well as its operation costs because of both the recovery of drain solution from the filter and minimized treatment for wastes.
