VERFAHREN ZUM ABBAU UND ZUR FOERDERUNG EINER UNTER WASSER LAGERNDEN BODENSCHICHT UND VORRICHTUNG ZUR DURCHFUEHRUNG DES VERFAHRENS

摘要

A layer of material which is situated under water, for example sand and gravel, where the layer is overlaid with non- exploitable or unwanted bottom layers is extracted by a casing-conveying pipe 1 with a displaceable drill bit 2 and an oscillating rotating mechanism 4. In operation the drill bit passes through the unwanted layers in the closed position together with simultaneous flushing with water and/or air in the drill bit region. The drill bit 2 is opened in the bottom layer for extraction and the suspension is conveyed away through an inner pipe by the air-lift method. <IMAGE>