Patent ID: 6935418

Claim:
A fluid conveying tube for vehicle coolers, which on its interior comprises: first and second opposing longitudinal primary heat-exchange surfaces, said surfaces having flow-directing surface structures; each surface structure extending laterally across said primary surfaces, each surface structure comprising at least one row of elongate directing elements, said elongate directing elements being arranged obliquely with respect to the longitudinal direction of the primary surfaces, said elongate directing elements in each row being mutually parallel; said surface structures being alternatingly arranged in the longitudinal direction on the first and second primary surfaces, the directing elements in each laterally extending row of each surface structure being substantially parallel to the directing elements in the succeeding row of the succeeding surface structure on the opposing primary surface in the longitudinal direction of the tube; said surface structure further comprising a laterally extending second row of mutually parallel directing elements, the directing elements of the second row being arranged at an angle (γ) relative to the directing elements of the first row; wherein for a plurality of the mutually parallel directing elements in at least one of the first row and the second row, a corresponding plurality of lines tangent to corresponding elongated edges of each of the plurality of mutually parallel directing elements intersect a tip of a corresponding directing element in the other of the first and second rows.