| 摘要 |
<p>7861-430 A filtering apparatus suitable for being cleaned by backwashing includes an outer housing and an inner filter disposed in the outer housing defining an outer annular flow passage and an inner flow passage. The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments stacked end to end on which a filter medium is mounted. U.S. No 375,554 518,346 Div.I</p> |
