Heat Transfer Studies in Ejector-induced Downflow Bubble Column

Abstract

Temperature control in bubble columns is of great importance, since chemical reactions in many of the chemical, pharmaceutical, fertilizer, etc. industries are usually accompanied by heat supply or heat removal operations. In the present research work, the heat transfer coefficient of a two-phase co-current vertical downflow bubble column (i.d. 0.05 m x 1.6 m height) was evaluated. Experimental studies were carried out to calculate the heat transfer coefficient for operating temperature ranges from 60 degrees C to 90 degrees C. The effects of the superficial gas velocity (4.25 x 10(-3) to 9.58 x 10(-3) m/s), liquid velocity (8.50 x 10(-2) to 16.98 x 10(-2) m/s), gas holdup, and axial position were investigated. Empirical correlation was developed, based on a multiple regression analysis to calculate a heat transfer coefficient as a function of dimensionless numbers, including the Reynolds number, the Prandtl number, and the Froude number.