7,000 lb/hr of aniline is to be heated from 100 to 150 °F bycooling 10,000 lb/hr of toluene with an initial temperatureof 185 °F in 2- by 1-in IPS double pipe hairpin exchangers15 ft long. Pressure drops of 10 psi are allowable, and a dirtfactor of 0.005 is required. (b) How many hairpin sectionsare required? (c) How shall they be arranged? (c) What is thefinal dirt factor?
