| 摘要 |
<p>A distributor arm 11 for a waste water treatment plant is fitted with a discharge valve 15 at one end. The distributor arm has a plurality of sparge holes 14 along the length thereof for the discharge of waste water during the ordinary operation thereof, and the discharge valve 15 has a discharge port 18 of a considerably greater size than the size of the sparge holes. The valve 15 is periodically opened during the operation of the distributor arm, so permitting a high volume flow rate along the length of the arm, to purge the arm of solid matter accumulating within the arm. <IMAGE></p> |
