International Journal of Heat and Mass Transfer, Vol.39, No.7, 1489-1501, 1996
Experimental-Study of Heat-Transfer to Boiling Binaries in a Reboiler Tube
An experimental investigation of heat transfer to boiling binaries under natural convective flow through a reboiler tube has been carried out to study the effect of composition on heat transfer coefficient. The heat transfer section consisted of an electrically heated stainless steel tube of 25.56 mm i.d. and 1900 mm long. Three binary systems : methanol-water, benzene-toluene and water-ethylene glycol were used for a variety of concentrations. The heat flux values ranged from about 4.1 to 33.0 kW m(-2). The liquid submergence levels were maintained around 100, 75, 50 and 30%. A significant reduction in the heat transfer coefficient is observed for binary mixtures attributable to the effect of mass diffusion on heat transfer. The heat transfer coefficients in the non-boiling and boiling regions for all the binary mixtures have been correlated by two separate correlations in terms of dimensionless groups.