Method and apparatus for generating water sprays, and methods of cleaning using water sprays

摘要

A water spray has a nozzle (6) for carrying a pressurised flow of water to an outlet (7) thereof, and a conduit (12) surrounding the nozzle outlet (7) for carrying a flow of gas contiguously around the flow of cleaning liquid exiting said nozzle outlet (7). The ratio of velocities of gas and water immediately downstream of the nozzle is in the range 0.5 to 2. This enables good control of water droplet size in the spray, to a volume median diameter in the range 0.5 to 2 mm at 1 m from the nozzle. Low water pressures may be employed in cleaning using such a spray.