
46
ssf for foods and beverages
e air pressure pulsation in the bio reac tor with the double- dynamic
gas phase is realized by charging and releasing the sterile air. e
course of pressure pulsation in this bio reac tor is shown in Figure2.12.
e pressure in the bio reac tor is periodically changed between high
and low air pressures. e periodic processes consist of four phases:
compressed air phase, stable phase of high air pressure, discharged air
phase, and the stable phase of low air pressure. erefore, the time
(t
2
) required to maintain the upper limit of air pressure pulsation is
comparatively short (generally 2 min) while the time (t