FLOATING CLAMSHELL DREDGER FOR MINING SAND AND GRAVEL Russian patent published in 1995 - IPC

FIELD: mining. SUBSTANCE: floating clamshell dredger for mining sand and gravel has craft carrying hoist with, at least, one clamshell and vessel located in water reservoir for emptying of clamshell. To reduce power consumption and increase efficiency, vessel is mounted on craft. Receiving opening of vessel is installed at the water level in water reservoir, and dredger is provided with inclined multibucket excavator whose lower end is located in vessel. Vessel has spraying nozzles in the bottom and walls to produce ascending flow. Arranged between clamshell and vessel may be chain grate or scraper grate. On upper end of vessel along waterline, along the entire periphery, overflow trough may be located to which discharge trough is connected. Vessel may be connected with chain and scraper grate with the aid of funnel whose side walls are directed towards vessel bottom in form of gravity flowing tray. Located on craft is pump sump for transportation of wastes to dump. Machine for water diversion may be installed behind multibucket excavator and connected with vessel by means of tray for returning dropping fine-grain material. Craft may be made in form of catamaran. EFFECT: higher efficiency. 9 cl, 9 dwg