When should I use Coarse Bubble Diffusers?
By: Tom Frankel
Post Date: November 29th 2016
Coarse bubble diffusers provide the following benefits:
a) High air capacity
b) Strong mixing and pumping
c) Usually a higher alpha factor than fine bubble diffusers
d) Very low maintenance
e) Some types can be left in direct sunlight
f) Rolling action is desirable for some processes
There are some differences between coarse bubble diffuser products. For example, some applications are designed to run intermittently. In this case, you may want to select a diffuser like the Relia-Ball which has a strong built-in check-valve. In other cases, like in an equaliz
ation basin, the tank may sit empty for long periods of time, subject to UV rays and freezing. In this case, a wide band coarse bubble diffuser with a stainless steel piping system would be a good choice.
Coarse bubble diffusers, as a general rule, will provide oxygen transfer at about half the rate of fine bubble diffusers, given the same volume of air. There are some tanks where mixing is a higher priority than oxygen transfer, like in channels and EQ tanks. In aerobic digesters with high solids concentrations, sometimes no diffuser is suitable (above 5% solids), but between 3% and 5% solids, coarse bubble diffusers with a check valve are often a better choice than fine bubble.
Are you interested in checking which kind of aeration system is in a tank? Visit the Image Classifier on the SSI Technology Portal and self-generate a report.