Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Investigations on Interactions Between Heat Exchanger Biofouling and Suspended Matter

Get access (open in a dialog) DOI: 10.1615/IHTC15.bma.008277
pages 1170-1180

Abstrakt

Heat exchangers used for treated sewage low grade energy recovery usually suffer from composite fouling problems which seriously impair the heat transfer efficiency. Treated sewage heat exchanger composite fouling is mostly composed of biofouling and is notably affected by interactions between the biofouling and suspended matter. Experiments were performed using simulated treated sewage and two kinds of simulated suspended matter, silicon dioxide particles and filaments, to model the interactions. Various flow velocities, particle sizes and concentrations were tested with their influences presented by the fouling wet weight. Flow velocity and particle size thresholds were found between positive and negative interactions, so criteria were developed based on the momentum and/or kinetic energy of the particles to predict whether the suspended matter promotes or impedes fouling growth. The results indicate that proper control of the flow velocities, particle sizes and concentrations of suspended matter using these criteria can enhance the heat transfer by reducing unwanted positive interactions and promoting beneficial negative interactions. The filament interaction mechanisms were analyzed to develop methods for filament interaction prediction and mitigation.