Airlift

Claim 1

An airlift for lifting liquids and pulps from the bottoms of seas and rivers, comprising a submerged suction unit for sucking in a mass being transported which is a mixture of a liquid and solids; a mixer rigidly fixed to, communicating with said suction unit, and serving to mix the mass with compressed air; a partly submerged air duct rigidly fixed to said mixer for supplying the compressed air thereto; an air separator for separating the mass from the compressed air; a partly submerged pipeline respectively fixed to both said mixer and said air separator and extending below said mixer and said suction unit, for lifting the mass together with the compressed air from the former to the latter, and having an open end remote from said mixer; said air duct and said pipeline having vertical portions, each being made up by a pair of pipe sections, fitted one into the other for vertical movement relative to each other, and for simultaneously changing the combined lengths of said pipe sections; a lifting gear attached to the lower ones of said pairs of pipe sections for simultaneous vertical movement thereof, for varying the combined length of said air duct and of said pipeline, for lifting said suction unit and said mixer; wherein said suction unit has a chamber open from below and communicating with a submerged feed pipe for supplying the liquid to said chamber from the surrounding sea and river, said pipeline having a bottom end portion extending below the open, lower edge of said chamber; means for causing phase separation in said air separator between the compressed air, that is allowed to move upwards through said open end of the pipeline, and the mass, that accumulates at the bottom of said air separator; and means for discharging the mass from said air separator.