The effect of velocity ratio on thermal-hydraulic performance of reciprocating scraped surface heat exchangers at low Reynolds number

Abstract

The thermal-hydraulic performance of a reciprocating scraper inserted in a round tube at low Reynolds number is studied. Pressure drop and heat transfer characteristics have been experimentally determined in static conditions in laminar regime (Reh=30), and results are contrasted with dynamic performance at several velocity ratios (ω=0.1 - 1). Maximum increases of Fanning friction factor of the order of 1.2 have been found, together with increases in Nusselt number of the order of 2, using propylene-glycol as working fluid.