| 摘要 |
<p>In multi-disc cylindrical filters commonly used for filtering the water of swimming baths, filtering efficiency is improved by placing baffles to spread the incoming liq. evenly along the filter surface, but this tends to impede the clearance of filter-blocking waste when back-flushing takes place. To overcome this disadvantage, a fairly large, non-return flap valve is fitted in the main baffle and arranged so that it remains closed during the filtering operation and is automatically opened by reverse flow liq. as soon as the back-flushing operation starts.</p> |
