The Cost of Heat Exchanger Fouling in the U. S. Industries

Abstract

Fouling of heat exchangers costs the U.S. industries hundreds of millions of dollars every year in increased equipment costs, maintenance costs, energy losses and losses in production. The designer of heat exchangers usually allows for fouling by using a fouling factor in the design which results in additional capital cost of the heat exchanger. As fouling deposits build up in a heat exchanger, its performance will start to deteriorate and less energy will be transferred through the unit. A plot is provided that gives the percent decrease in heat flux, for a constant driving temperature difference, as a function of the clean overall heat transfer coefficient and the fouling factor. Another plot gives the increase in surface area due to fouling for the same heat transfer rate and driving temperature difference, as a function of the clean overall heat transfer coefficient and the fouling factor. The overall heat transfer market was divided into four sectors: the chemical, petroleum, electric utility and other industries. The 1982 U.S. sales of all industrial heat exchangers, excepting boilers and automotive radiators, was about 285,000 units amounting to about $1.6 billion. The total heat duty of all the heat exchangers in industrial operation, including electric utilities, was estimated at 11.7 Quads. If this represented the amount of heat transferred through clean heat exchangers, the decrease in energy transferred due to fouling or the cost of fouling in terms of energy lost was estimated at 2.9 Quads annually. The cost of fouling, in providing for additional surface area to compensate for a decrease in heat transfer, was conservatively estimated at $180 million in 1982.