Particulate fouling of polymeric hollow fiber heat exchanger

CATEGORY: HEAT EXCHANGERS
Proceedings of International Conference on Heat Exchanger Fouling and Cleaning, June 9-14, 2013, Budapest, Hungary
Particulate fouling of polymeric hollow fiber heat exchanger
I. Astrouski (1), M. Raudensky (1) and M. Dohnal (2)
astrouski@lptap.fme.vutbr.cz
1 Heat Transfer and Flow Laboratory, Brno University of Technology, Brno, Czech Republic
2 Center of Knowledge Economics, Brno University of Technology, Brno, Czech Republic
Abstract
Thermal effectiveness of heat exchangers is negatively affected by tube fouling caused by working in contaminated conditions. Surface of polymers is smooth and low-adhesion which provide additional antifouling resistance and defouling possibility. Authors prepared a polymeric hollow fiber heat exchanger and tested it to cool down water contaminated by titania particles.
Thermal performance tests showed it hight effectiveness and good fouling resistance. it was found that the particle deposit developed rapidly and achieved its asymptotic values during hours. It should be mentioned that the hight rates of fouling evolution were associated with low liquid velocities. The asymptotic (maximal) fouling level was low enough causing a small influence on heat transfer. The associated decrease of the overall heat transfer coefficient (HTC) was 5-20% depending on flow regimes. Moreover it was found that particle deposit is not strong and can be easily detached and removed from the fiber surface by local increase of liquid velocity. The injection of air bubbles in the heat exchanger shell was tested as the defouling procedure and showed good efficiency.
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