Problem 4. A hydrocarbon oil having the same physical properties as the oil in Example 4.5-5 (in Geankoplis) enters at 175F inside a pipe having an inside diameter of 0.0303ft and a length of 15ft. The inside pipe surface temperature is constant at 325F. The oil is to be heated to 250F in the pipe. How many 1bm/h oil can be heated? (Hint: This solution is trial and error. One method is to assume a flow rate of, say, m=75lbm/h. Calculate the NRe and the value of ha. Then make a heat balance to solve for q in terms of m. Equate this q to the q from the equation q=haATa. Solve for m. This is the new m to use for the second trial.) *Note See Section 4.5B in Geankoplis for correlations for the heat transfer coefficient for laminar flow inside a pipe. Also see Example 4.5-5. Answer: m84lbm/h Problem 4. A hydrocarbon oil having the same physical properties as the oil in Example 4.5-5 (in Geankoplis) enters at 175F inside a pipe having an inside diameter of 0.0303ft and a length of 15ft. The inside pipe surface temperature is constant at 325F. The oil is to be heated to 250F in the pipe. How many 1bm/h oil can be heated? (Hint: This solution is trial and error. One method is to assume a flow rate of, say, m=75lbm/h. Calculate the NRe and the value of ha. Then make a heat balance to solve for q in terms of m. Equate this q to the q from the equation q=haATa. Solve for m. This is the new m to use for the second trial.) *Note See Section 4.5B in Geankoplis for correlations for the heat transfer coefficient for laminar flow inside a pipe. Also see Example 4.5-5. Answer: m84lbm/h