Liquid dimethyl ether (DME) flows across the outside of a bank of tubes. It enters at 100°C and leaves at 50°C. The DME enters at a flowrate of 20 kg/s, the shell diameter is 15 in, the baffle spacing is 6 in, the baffle cut (BC) is 15%, and 1-in OD tubes on a 1.25-in pitch are used. The fluid (cooling water) inside the tubes may be assumed to be at a constant temperature of 35°C and the inside coefficient is expected to be much higher than the shell-side coefficient, and thus the wall temperature may be taken as 35°C.

Use Kern’s method to determine the average heat transfer coefficient for the shell side for the following arrangements:

Square pitch Equilateral triangular pitch