Design and Aspect Ratio

A vertical cylindrical, and mechanical agitated pressure vessel, equipped with baffles to prevent vortex formation is the most widely used fermenter configuration. The baffles are typically one-tenth of the fermenter diameter in widtli, and are welded to supports tliat extend from the sidewall. A small space between the sidewall and the baffle enables cleaning. Internal heat transfer tube bundles can also be used as baffles. The vessels must withstand a 45 psig internal pressure and full vacuum of -14.7 psig, and comply with the ASME code. 

Standard components for a bioreactor comprise the vessel, the agitator and impeller, heat exchangers, seals, and valves. Other components include utilities such as clean-in-place (CIP), and steam-in-place (SIP) systems, auxiliary tanks, pH and foam control, inlet tubes, 

Fig ure 11-12. Reaotors with meohanioal stirring M, moter G, gas (air) SB, baffles LR, oonduit tube SZ, foam breaker W, roller F, liquid. (Source Schuger [11].) 

Fig ure 11-14. Reactors with energy input by compression. (Source Schuger [11]-) 

An ASME 2 1 elliptical heads can ensure an increase in pressure resistance of die vessel. Fermenter jackets (e.g., half-pipe, diameter, or true type) should be constructed to sustain die vessel s rated pressure and, thus, enhance its strength. The construction material is type 316L stainless steel, which features an internal mechanical-polish finish of 2B-mill or 25-Roughness Average (Ra) depending on the nature of the fermentation. 

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