A graphite heat exchanger is constructed by drilling circular channels in a solid block of graphite. Consider a large graphite block (k=800W/m· K) containing two 1- in. diameter channels spaced 2 in....

A graphite heat exchanger is constructed by drilling circular channels in a solid block of graphite. Consider a large graphite block (k=800W/m· K) containing two 1- in. diameter channels spaced 2 in. apart (center-to-center). A highly corrosive liquid (T =350◦F, h=120 Btu/h · ft2 ·◦F) flows through one channel and a coolant (T =170◦F, h=200 Btu/h · ft2·◦F) flows in the other channel. Calculate the rate of heat transfer from the corrosive liquid to the coolant per foot of exchanger length.