Jet pump

Claim 1

A jet pump comprising a cylindrical open-ended hollow chamber having a suction inlet at one end and a discharge tube at the opposite end; a streamlined body mounted in the chamber, with one end facing the suction inlet and the opposite end facing the discharge tube; a nozzle head situated at that end of the body which facs the discharge tube and with its discharge directed along said tube; a duct extending into the body through the wall of the chamber and communicating with the nozzle head; means to couple a primary flow of high-pressure fluid to the inlet of the duct; and means to couple a suction tube to the suction inlet of the chamber; the arrangement being such that, in use, the high-pressure primary fluid flow issuing from the nozzle and along the discharge tube will entrain material into and along the suction tube, over the streamlined surface of said body, and out along the discharge tube, in which the nozzle head incorporates multiple nozzles arranged in a ring around a central nozzle, and the nozzles are so angled in the head that the initially separate streams of high-pressure fluid which they discharge all converge downstream of the nozzle head, and in which channels are formed in the nozzle head between each nozzle and the circumferentially succeeding one, along which channels fluid can be entrained into the streams issuing, in use, from the nozzles.