Heat transfer in a reciprocating plate column

A pilot-scale (5.08 cm internal diameter) reciprocating plate column has be en modified by the insertion of a brass test section for heat transfer meas urements. Heat is supplied to liquid (water or a glucose solution) in the c olumn from an electrical heating tape wound round the brass section, the wa lls of which contain thermocouples. Reciprocation of the plates in the colu mn results in up to a seven-fold improvement in heat transfer coefficient, to single phase liquids. Conditions are turbulent with oscillatory Reynolds numbers up to 20 000. The effect of plate reciprocation is much less prono unced when the liquids are agitated by a stream of gas bubbles. The single- phase heat transfer coefficients have been correlated for 5 different types of plates using approaches already available in the literature for turbule nt systems in steady flow. The best-lit oscillatory flow correlation differ s slightly from the existing correlations for steady flow.