| 摘要 |
PURPOSE:To prevent concn. polarization from being generated and to inhibit scaling by closing a rapid on-off valve provided to a flow route of slurry passed through a filter in a short time. CONSTITUTION:Slurry having non-Newtonian flow characteristics such as activated sludge slurry at a time for treating excretion and marine products working waste liquid is filtered with an ultrafiltration membrane. In this case, an automatic on-off valve 6 is provided between a filter 7 and a circulation pump 4 and when repeating operation for closing and opening this valve 6 in a short time while keeping an interval, pressure pulse is impressed to the filter 7. Since concn. polarization is prevented from being generated by such a way, slurry which is difficult-to filter and has non-Newtonian flow characteristics can be continuously filtered at high filtration velocity. |
