The invention relates to a sprayer of the type comprising a turbine generating an air flow that is conveyed through a main duct to a distributor from where the air flow is conveyed through ports to a plurality of secondary ducts which direct the air flow to the exterior, bringing same into contact with the product mixture metered by nozzles located in the area through which the outgoing air stream flows, where the invention is characterised in that the air flow from the secondary ducts can be regulated by means of opening and closure elements that operate in a coordinated manner with at least one overflow channel, such as to help maintain a constant pressure inside the air ducts, preventing air from flowing back to the turbine, which could alter the operating conditions selected for the equipment.