Arrangement for generating a local water flow

摘要

An arrangement for generating a local water flow or water jet in a body of water so that bottom material of the bottom can be put underneath, said body of water comprises a jet pipe, a screw accommodated rotatably in the jet pipe, and means for providing a countertorque opposite to the torque exerted on the arrangement by the rotation of the screw. According to the invention, the jet pipe contains a second screw which can rotate in the direction opposite to the direction of rotation of the first screw and whose pitch angle is opposite to that of the first screw.