Abstract: An air diffusion device is provided. The device includes a base coupled to an air supply pipe for supply of air. The base has an air discharge hole for discharge of air supplied from the air supply pipe. The device further includes a perforated cover in the form of a multi-layered stepped plate the height of which is reduced stepwise from the center to the edge. The perforated cover has a plurality of through-holes for discharge of air, and it is coupled to an upper surface of the base to cover the air discharge hole, thus defining an air guide chamber between the perforated cover and the base. The device further includes a securing mechanism configured to secure the perforated cover to the base.

Abstract: Disclosed is an air diffusion device including a base coupled to an air supply pipe and having an air discharge hole for discharge of air supplied from the air supply pipe, a perforated cover having a single-layered flat plate shape, and a securing mechanism to secure the perforated cover to the base. The perforated cover having through-holes is coupled to an upper surface of the base to cover the air discharge hole, defining an air guide chamber between the perforated cover and the base. The air diffusion device has ease in assembly/disassembly thereof because the perforated cover is assembled to the base via the securing mechanism separably coupled to the base. Further, through provision of a diaphragm cover to open or close an air discharge hole for discharge of air into the air guide chamber, it is possible to prevent wastewater, sludge, or impurities from entering the air supply pipe.