Coarse Bubble 9" Disc Diffuser · 9"

The coarse bubble 9" disc diffuser, with its 230 mm effective diameter and 2-60 m³/h capacity range, handles the highest air flow in the series. Large bubbles leaving a wide surface create a strong rising current that keeps the entire contents of deep, high-volume tanks in motion. For mixing duty the number of diffusers is calculated from the mixing energy required per unit tank volume, and far fewer units are needed than with fine bubble systems. Coarse bubble diffusers are not favoured for biological aeration because of their low oxygen transfer efficiency: large bubbles rise so quickly that they have little time to release their oxygen. That same property turns into an advantage in high-solids environments — the risk of clogging is almost nil and no periodic chemical cleaning is required. Typical applications are therefore equalisation tanks, sludge storage and thickening tanks, grit chambers and pre-aeration stages. The EPDM silicone membrane closes on shutdown to prevent backflow and ensures trouble-free restart. At 0.57 kg and 48 mm height it adds no meaningful load to the floor grid. Because the 3/4" male outlet uses the same connection standard as the fine bubble models, converting part of an existing grid — for example switching one section of a basin to coarse bubble mixing — requires no pipework changes.