Abstract: An air distributing device mounted into the sloping wall of a hopper containing finely divided material, such as flour or cement, aerating and causing the discharge of the material with a pressurized air flow and keeping the material in constant motion toward the discharge outlet of the hopper, the air distributing device being substantially hemi-spherical in form and providing a wide distribution of the pressurized air.

Abstract: An air distributor head mounted in a sloping wall for a hopper for pulverulent material to agitate and aerate the material as it travels down the wall surface toward the discharge opening in the bottom of the hopper; the head assembly including a generally cylindrical head with air flow passages and having an expandable generally cylindrical resilient skirt surrounding the body thus permitting air supplied through the passages under the skirt to be discharged into the pulverulent material to incorporate a flow of agitating and fluidizing air into the material.