An overview on tube inserts configurations and performances in tubular exchangers

Purpose - The purpose of this paper is to update a previous review work (Abu-khader, 2006, Heat & Mass Transfer, Vol. 43 No. 2, pp. 123-134) and highlight the new research methods on the use of twisted tapes and the application of different configurations of these tape inserts. Also, based on a vast collection of experimental data in open literature, generalized Nusselt number (Nu) and friction factor (f) correlations as the function of twist ratio were developed with maximum error around +/- 15 per cent. The present paper examines several case studies which apply complex configurations of twisted inserts. Design/methodology/approach - Using the developed correlations, an equivalent Nusselt number and friction factor of typical type twist insert were generated which achieved the same performance of each complex configuration. Findings - The open literature contains large number of wired and complex configurations of twisted tape inserts. Their applicability to real industrial use is questionable. Originality/value - This paper presents an up-to-date review on the use of twisted tape in research, highlights the different tape configurations and proposes general correlations for traditional twisted tape inserts.