in the sandfreien entnahme von wasser aus einem r and a hierzu geeignete vorrichtung.

摘要

PCT No. PCT/BE86/00017 Sec. 371 Date Feb. 9, 1987 Sec. 102(e) Date Feb. 9, 1987 PCT Filed Jun. 10, 1986 PCT Pub. No. WO86/07408 PCT Pub. Date Dec. 18, 1986.In a well with filter tube and filter gravel fill a slot profile for a collection element forming the suction tube has larger suction cut-outs at the bottom than at the top and effects an equalization of the flow velocity of the water passing into the filter gravel layer on the basis of the combination of calculations and empirical investigations.