Fouling of enhanced heat exchanger tubes has been a significant problem in the industry since their
introduction. The intensity of fouling has been shown to be a function of the number of flutes present in
the enhanced tube.1,2,3 Field and laboratory data indicate that enhanced tubes biofoul more rapidly and to higher fouling factors than do traditional smooth tubes. Enhanced tubes have also been found to clean-up more rapidly than smooth tubes when comparable cleaning programs are employed. The enhanced tube is less susceptible to insitu inorganic crystallization fouling than a smooth tube.

A novel monitor has been developed to evaluate biomass deposition and removal under operating heat
exchanger conditions utilizing an enhanced tube test section. It has also been found that traditional
oxidizing biocides are relatively inefficient in the removal of biofilm from enhanced tubes. The use of
biodispersants in conjunction with oxidizing biocides has demonstrated a significant reduction in enhanced tube biofouling. This paper will review prior research and present findings from recent pilot cooling system studies.

Key words: enhanced heat exchanger tubes, inorganic crystallization fouling, annular heat transfer test section,biofouling, biodispersants, oxidizing biocides, bromine, chlorine, chlorine dioxide, biofilm monitoring.