Air-driven bioreactor

Eig. 5. Examples of air driven bioreactors (a) bubble column, (b) draught tube, and (c) external loop. 

Fig. 1. Different types of bioreactors for plant cell, tissue and organs. (A) mechanically-agitated bioreactors, a aeration-agitation, b rotating drum, c spin filter. (B) air-driven bioreactors, a bubble column, b draft tube, c external loop, (C) non-agitated bioreactors, a gaseous phase (mist), b oxygen permeable membrane aerator, c surface aeration, (D) light emitting draft tube...

Air Driven Bioreactors. The simplest design is the air-driven bioreactor equipped with sparger at the bottom of the vessel. It is widely used for plant cell, tissue, and organ cultures. In cases where the cells grow rapidly and the cell mass occupies 40-60% of the reactor volume, the flow characteristics become non-Newtonian and the culture medium can no longer be agitated by simple aeration. 

A second important category is non-stirred bioreactors, of which bubble columns and, to a lesser extent, the air-lift reactor are the most important members. The bubble column is driven by gas, and the demand for sufficient gas energy can be higher than in a stirred tank. Because of absence of rotating parts and simpler construction, the vessel sizes can be bigger more than 1000 m has been reported. 

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