Bubble suppression regime

A bubble suppression regime in which h/h, increases with decreasing Co. Line AB represents the limit of pure convective boiling. Note that the curves for given values of Bo asymptote to line AB as Co reduces. 

Avidan and Edwards (1986) successfully scaled up from bench scale to demonstration plant from 0.04 m to 0.6 m diameter while maintaining nearly 100% conversion for a fluid bed methanol to gasoline process. In this case, they ran at a superficial gas velocity which was high enough to be in the turbulent flow regime suppressing bubbles. By this technique they eliminated the losses associated with gas bypassing in bubbles. 

The metastable superheat AT attainable by a liquid above its saturation temperature is important in nucleate boiling. Aside from the boiling description, however, a knowledge of AT also provides criteria for heat transport transition when bubble formation is entirely suppressed. A nonboiling liquid may be heated to the maximum metastable superheat before it disintegrates [ ]. As soon as the wall excess temperature increases beyond the limiting superheat value, the system will enter the Leidenfrost regime, within which liquid is converted into the completely disordered phase when it approaches the hot walls. 

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