Question

(b) The oil flows through the annuli, which are connected in two parallel banks ot lour halrpins each. (4.10) 50,000 lb/h of a fluid having a density of 53 Ibm/ft' and a viscosity of 1.5 cp will flow in the annulus of a double-pipe heat exchanger. The hairpins are 30 ft long with 3-in. schedule 40 outer pipe, 1.5-in. schedule 40 inner pipe, internal return bends and 1.5-in. schedule 40 nozzles. A total of six hairpins will be used, and the maximum allowable pressure drop for the stream is 12 psi. Determine which of the following configurations should be used in connecting the annuli of the hairpins: . Six hairpins in series . Two parallel banks of three hairpins each · Three parallel banks of two hairpins each (4.11) In designing a double-pipe heat exchanger for a particular service it is found that the pressure drop for the stream flowing through the inner pipe is excessively high (35 psi) compared with the allowable pressuie drop (7 psi). It is decided to remedy the problem by using a series-parallel configuration of hairpins. Assuming the same size and number of hairpins are used how many parallel branches should the stream be divided into if (a) The flow is turbulent? (b) The flow is laminar?

subject is Heat Transport
Plz show all steps and write neatly

Answer 1