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[antogam]

Dear all,

I'm studying the fluid dynamics of bubble column reactors.

 

I have trouble understanding the difference between:

 

superficial gas velocity of the gas (gas flow rate / cross-sectional area) and bubblerise velocity (I found this through the correlation between Reynolds number and drag coefficients).

 

I don't understand what value to insert in the correlations for the calculation of the mass transfer coefficients.

 

furthermore, are there any correlations between these velocities?

 

 

 

Thanks in advance

 

 

[PingPong]

superficial gas velocity of the gas (gas flow rate / cross-sectional area)

Or in other words: superficial gas velocity is the gas velocity if the column would be empty.

 

bubble rise velocity

That is the velocity with which gas bubbles rise upward through a liquid. Apart from gas and liquid properties that also depends on the bubble size: smaller bubbles rise slower than big bubbles.

 

I don't understand what value to insert in the correlations for the calculation of the mass transfer coefficients.

Normally some text explains which variables to insert in a correlation, and in which units of measurement.

So read all text surrounding the correlation carefully.

 

are there any correlations between these velocities?

No.

Edited by PingPong, 04 November 2020 - 01:16 PM.