METHOD OF UNDERWATER HYDRODYNAMIC CLEANING OF SHIP'S HULL AND DEVICE FOR REALIZATION OF THIS METHOD Russian patent published in 1998 - IPC

FIELD: technology of hydrodynamic cleaning of underwater surfaces of ship's hulls and water-development works from biological fouling. SUBSTANCE: cavitation is formed in zone of cleaning due to simultaneous action of water jet and acoustic radiation on this surface; radiation is obtained from acoustic generator which is located inside working member. Generator employs energy of dynamic head of water jet. Water jet is directed to surface to be cleaned at angle of no more than 45 deg. Cleaning nozzle has straight-flow passage and profile formed by inlet confuser, cylindrical and outlet parts located coaxially and engageable in succession. Cylindrical part is made in form of resonance chamber and outlet part is made form of horn. Diameter of chamber exceeds diameter of outlet hose of confuser and inlet hole of outlet part. Walls of chamber form inlet and outlet nozzles of chamber together with outlet hole of confuser and inlet hole of horn, respectively. Chamber together with nozzles forms acoustic generator. Difference in diameters of nozzles does not exceed 0.3 of length of chamber. Diameter of outlet hole of horn is no less than 0.04 of length of wave of basic frequency of chamber. Taper angle of confuser ranges from 10 to 20 deg. EFFECT: enhanced efficiency of cleaning due to extended zone of cleaning; reduced power requirements and increased productivity. 3 cl, 2 dwg