تعيين ضريب انتقال حرارت مخلوط سه فازي جامد- مايع - گاز در مخزن جداره دار مجهز به همزن مكانيكي به همراه تيغه غير استاندارد

Determination Of Heat Transfer Coefficient In Jaketed Mechanically Agitated Multi-Phase Gas-Liquid-Solid Vessel Equipped With Non-Standard Baffle

Steady-state heat transfer in agitated multi-phase gas-liquid-solid cylindrical vessel has been investigated. The vessel was a flat bottom type equipped with four Non-standard symmetrical baffles. The conventional jacket was used for cooling the mixture in the vessel. An up pumping 45° four blade pitched turbine was used for efficient agitation. Three materials, sand, water and air are used as solid, liquid and gas phases, respectively. Air was introduced through a ring sparger located below the impeller. Agitation speed of 800, 1000 and 1400 rpm were used. Linking the multiphase hydrodynamics to the heat transfer is essential to properly understand the heat transfer process in solid containing stirred vessels. in this study the mean size of particles were varied from 0.1 to 0.4 mm and the solid loading was used with variation of weight percentages of 2.14 to 10.3. The effect of rate of gas on the rate of heat transfer was investigated by variation of flow number (Qg l Nd ^3) from 0.008 to 0.02. A correlation is derived relating the heat transfer coefficient to the operating variables through dimensionless numbers.