Patent ID: 9533267
Date: 2017-01-03
CPC Classifications: B01F,C02F

Claim:
1. A multi-stage aeration apparatus, comprising: at least three vertically oriented aeration modules comprising a first aeration module that receives a gas and liquid mixture from a gas and liquid source and two or more underlying aeration modules, each aeration module defining a vertically elongated aeration chamber having a top inlet and a bottom outlet, the bottom outlet of each of the aeration modules feeding a fluid stream comprising liquid and gas into the top inlet of an underlying one of the aeration modules, wherein one or more underlying aeration modules comprises a supplemental gas inlet; and each aeration module having an aeration head connected to the top inlet and positioned in a headspace of the underlying aeration module such that the fluid stream passing through the top inlet into the aeration chamber must pass through the aeration head, the aeration head aerating the liquid with the gas in the fluid stream in the headspace of the underlying aeration module.