A New Graphical Method Based on Pinch Technology for Increasing the Fouling Formation Time of Heat Exchanger Networks

In this paper a new graphical method is presented for analysis of the time of fouling formation of heat exchanger networks. By using this method more opportunity of fouling formation are given for streams that have a high fouling formation rate, and the number of cleaning process of heat exchanger will decrease in a specified period of time. In fact high fouling formation rate streams are replaced with low fouling formation rate streams among different heat exchangers so that more fouling formation opportunity may be given for HEN. Therefore the high fouling formation streams should pass from the path that the low fouling formation rate stream previously has passed, and inversely. Therefore the HEN cleaning time decreases in fixed time period and the high fouling formation streams should pass from the path that the low fouling formation rate stream previously has passed, and inversely. As a result, second stream with high fouling formation rate mixes with residues of primary stream (low fouling formation rate stream). Therefore we should consider to adoption and conformability of streams structures (for prevention of streams destruction) and thermal considerations (for desirable heat transfer). Outlet temperatures of hot and cold streams should state in predefined temperatures. This method can be applied in plants that fouling and its related cost are undesirable (e. g. dairy industry).