Heat Transfer Coefficients for Particulate Airflow in Shell and Coiled Tube Heat Exchangers

In this work, we experimentally study heat transfer from exhaust particulate air of detergent spray drying tower to water by using coiled tube heat exchanger. Water flows in the coiled tubes, where air loaded with detergent particles of 43 micrometers in diameter flows within the shell. Four coiled tubes with different coil pitches are used in a counter-current flow configuration. We investigate heat transfer coefficients of inside and outside the heat transfer surfaces through 400 experiments. The correlations between Nusselt number and Reynolds number, Prandtl number, mass flow rate of particulates to mass flow rate of air ratio and coiled tube pitch parameter are proposed. The correlations procured can be used to predicted heat transfer between tube and shell of the heat exchanger.

Authors:

• W. Witchayanuwat
• S. Kheawhom

Keywords:

• Shell and coiled tube heat exchanger
• Spray drying tower
• Heat transfer coefficients.

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