Question

Describe various designs of airlift reactors using schematics.

Answer 1

An airlift reactor is one type of bubble reactor with an internal draft-tube that promotes gas–liquid mass transfer and mixing [52,53]. Airlift reactors have been largely used for algae cultures [54–59]. As shown in the left of Figure 7, an airlift reactor contains three regions: air-riser, down-comer, and disengagement zone. Bubbles are sparged into the air-riser, which may be on the inside or the outside of the draft-tube. The latter design is preferred for large-scale PBRs because it provides better heat transfer efficiencies. Rising bubbles in the air-riser cause the liquid to flow vertically. To counteract these upward forces, liquid will flow downward in the down-comer.