Agitated Vessels, Hot Gassed Systems

When an inert gas is passed through a boiling liquid, there is a change in the thermodynamic equilibrium. Since the bubbles consist of a mixture of vapor and inert gas, the partial vapor pressure of the condensable components is less than the total pressure at which the liquid was previously boiling. The liquid is therefore superheated relative to the mixed gas phase and there will be an immediate increase in the evaporation rate so that latent heat can remove the excess energy. The liquid temperature will fall until the energy supply and removal rates are in balance. A steady equilibrium temperature will be established when there are constant net heat input and gas throughput rates. 

When an existing boiling reactor is sparged, the sparged gas rate can be corrected using the vapor pressure of the liquid at the temperature measured. Assuming that the partial pressure of the vapor pv is then known, the total volumetric rate, Qov, is given by 

When the liquid vapor pressure is known in terms of the usual relationship, pv = Ae , the correction can be expressed as 

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