Ice pigging coolant jackets: Thermal analysis of the rate of ice melting

This paper describes an investigation into the use of ice pigging to clean individual independent sections of a coolant jacket from a large cylindrical storage vessel where sediment deposited on the interior walls of the coolant jacket could limit heat transfer. Removal of sediment can restore any deterioration of the heat transfer performance. The contents of the tank are at a constant 45⁰C; therefore there will be considerable heat gain into the ice pig body. For the ice pig to remain effective at removing sediment, the ice fraction ( 휙푣,푐푎푓) needs to remain higher than 60% at the exit of the cooling jacket.
A large scale model of the tank coolant arrangement was constructed, sharing the same depth and height as the real artefact, but the length was reduced by ten times in order to fit in the laboratory. To ensure a means of heat input, water from a heated tank was circulated to replicate the constant internal temperature of the storage tank. The coolant jacket was ice pigged whilst the inlet and outlet temperature of both fluid streams were measured; heat transfer calculations were completed to assess the heat gain to the ice pig and therefore the rate of ice melting.