Abstract: A spray apparatus includes an outlet connected to a cyclone chamber with at least one gas inlet to the chamber connected to a pressurized source of gas, and at least one liquid inlet to the chamber for connection to a liquid source. The cyclone chamber has a cross section that decreases in a direction away from the outlet and a closed base such that in use at least one of the liquid and gas entering the chamber forms a reverse flow cyclone, in which the liquid or gas travels in a first direction away from the inlet to the closed base and thereafter reverses direction and travels towards the outlet.