Abstract: The present invention may be used for discharging a fire retardant material. A container element may be connected to a pressurized gas source controllable to pressurize the container element and to flow a gas and fire retardant material mixture through a discharge conduit. A discharge device may be connected at an inlet to the discharge conduit. The discharge device may have an inlet duct attached to an inlet end of an expansion section. The expansion section may be connected to an inlet end of an outlet duct having an outlet nozzle. A diffuser may be disposed in the inlet duct and an upstream portion and may be attached in the upstream portion. The diffuser may have a nose element attached by a diffuser shaft to a base element with a rotor element having multiple vanes rotatably attached to the diffuser shaft intermediate the nose and base elements.