Apparatus for collecting sand and gravel from a gravel layer existing at the lower part of a subaqueous soil layer

摘要

1,085,156. Suction dredgers; jetting equipment, ASIA DREDGING CO. Ltd. July 16, 1965, No. 30323/65. Heading E1F.. Sand and pebbles are collected from a gravel layer existing at the lower part of a soil layer beneath the sea by means of a downwardly directed hydraulic jets 40, 42 and horizontally directed jets 37 and removed solely by hydraulic ejection created by an ejector formed by a nozzle 32, flexible pipes 10, 11, 15, 17 connecting the jets to a floating work platform having a pump or pumps for feeding water to the jets and having winding means mounted thereon for raising and lowering the apparatus housing the jets. The jetting nozzle 42 comprises an inverted cone with a digging nozzle opening in its vertex and an upwardly directed nozzle 41 in its base to assist the ejector.