Experimental study on microbial fouling characteristics of the plate heat exchanger

Iron bacteria (IB) and slime-forming bacteria (SFB) are the most common in circulating cooling water. In order to study on the characteristics of microbial fouling in plate heat exchangers, an experimental study was carried out for the fouling characteristics of IB and SFB. The fouling characteristics in the plate heat exchanger under the different flow velocity, temperature and concentration were investigated for these two bacteria and the mixture of them. The results show that the asymptotic value of fouling resistance and the time of reaching the asymptotic value decreases with the increase of fluid velocity. The asymptotic value of fouling resistance increases with the increase of concentration. And the influence of temperature is different for the two kinds of bacteria. When these two bacteria are mixed, the IB and the SFB grow synergistically because the IB have strong ability in microbial fouling and the SFB have the high secretion rate of extracellular polymeric substances.