Water misting gun

Abstract

A high-velocity water misting gun with a very high-speed radial inflow hydraulic turbine mounted on the same shaft with an axial flow air compressor wheel compressing air discharged at high velocities through an exhaust air nozzle. A preferred embodiment utilizes a plastic-metal hydraulic turbine wheel in which the plastic portion of the wheel other than blades is solidly anchored within a metal containing wheel. High pressure water drives the hydraulic turbine and provides water lubrication to high-speed bearings supporting a rotating shaft. The preferred embodiment utilizes hybrid bearings (part hydrodynamic, part hydrostatic) suitable for low-viscosity fluids such as water. In the preferred embodiment all of the water discharging from the hydraulic turbine wheel is channeled through a hollow shaft to a set of high-speed, shaft-mounted rotating orifices providing a fine water mist discharging into a high-velocity air flow provided by the axial-flow compressor. Thus, the entire water flow supplied to the misting gun is discharged into the high-velocity air flow discharging from an exhaust air nozzle so that no return hose is needed. Preferred embodiments utilize a manually operated ball valve to control water pressure supplied to the turbine. Increased hydraulic turbine power increases the power input into the compressor resulting roughly proportional air flow to water flow ratio.