Flowing liquid film

Annular flow (A) existed at high gas superficial velocities and at the entire range of liquid superficial velocities. In annular flow, liquid film formed at the side wall with part of the liquid remaining in the three corners of the channel, while the continuous gas core flowed concurrently with the liquid phase. 

Ito, K. Nakamura, K. 1996. Preparation of ZnO thin films using the flowing liquid film method. Thin Solid Films 286 35-36. 

A knowledge of the thicknesses of flowing liquid films is of importance in a wide range of practical problems involving film flow. Such problems include the calculation of heat transfer in evaporators and condensers, mass transfer in film-type equipment, the design of overflows and downcomers, etc. 

Al. Adomi, N., Casagrande, I., Cravarolo, L., Hassid, A., and Silvestri, M., Experimental Data on Two-phase Adiabatic Flow Liquid Film Thickness, Phase and Velocity Distribution, Pressure Drops in Vertical Gas-Liquid Flow . Centro Informazioni Studi Esperienze, Milan, Report R-35, March 1961. 

H6. Hershman, A., The effect of liquid properties on the interaction between a turbulent air stream and a flowing liquid film. Ph.D. thesis, Univ. Illinois, Urbana, Illinois, 1960. 

Reaction is first order in gas reactant. 3. Gas and liquid stream are in plug flow. 4. Reactor is isothermal. 5. Gaseous reactant concentration in the gas phase is constant throughout the reactor. 6. A fraction of the catalyst external surface (tice) is covered by a flowing liquid film while the rest is exposed to a thin stagnant liquid film. Assumption 2 was verified by already reported kinetic studies. A water cooled reactor with low feed concentrations of a-methylstyrene operated between 15°C and 20°C satisfies assumptions 1 and 4 due to low volatility of the liquid reactant and due to small overall heat effects, respectively. 

The influence of viscosity, interfacial tension and difference of the density between the coexisting phases on hydrodynamics and mass transfer are discussed. When the activity of the near-critical extractant exceeds a certain limit a flowing liquid film becomes instable. Thereby the alternative exists to carry out a separation process in the film regime or... 

Film flow liquid film in gas film cooling... 

A novel UV detector has been reported for preparative scale HPLC in which the solvent is allowed to flow over a supporting plate where it assumes the thickness characteristic of the flowing liquid film. The UV radiation falls on the film a little below the delivery tube from the column. The detector has been used for concentrations from lmg to 30 g and for flow rates from 1ml min-1 to 400 ml min-1. 

Two situations involviag tmasport of a species lo a liquid in laminar flow can he mudeled by the system in Fig, 2.3-16. One might represent absorption (tom a gas stream into liquid Rowing over pieces of packing in a column, The other geometry could represent dissolution of a solid into a flowing liquid film or the transport from a membrane surface into a solution in laminar flow over the membrane. Both these simple systems illustrate die efleet of velocity profiles or shear rales on mass transfer to a fluid. 

Adsorption Process at the Surface of Laminar Flowing Liquid Films... 

Annular flow Liquid film on inside walls with gas in centre range of velocities >6 ... 

Alekseenko, S. V., Nakoryakov, V. E., and Pokusaev, B. T. (1979). Waves on the surface of vertically flowing liquid film. Preprint 36-79, IT SO AN USSR, Novosibirsk. 

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