Ethylene glycol at 100,000 \(\mathrm{lb} / \mathrm{hr}\) enters the shell of a 1-6 shell-and-tube heat exchanger at \(250^{\circ} \mathrm{F}\) and is cooled to \(130^{\circ} \mathrm{F}\) with cooling water heated from 90 to \(120^{\circ} \mathrm{F}\). Assume that the mean overall heat-transfer coefficient (based on the inside area of the tubes) is \(100 \mathrm{Btu} /\left(\mathrm{ft}^{2}-\mathrm{hr}^{\circ} \mathrm{F}\right)\) and the tube-side velocity is \(5 \mathrm{ft} / \mathrm{sec}\). Use \(3 / 4\)-in. . 16 BWG tubing (O.D. \(=0.75\) in., I.D. \(=0.62\) in.) arranged on a 1 -in. square pitch.

(a) Calculate the number of tubes, length of the tubes, and tube-side heat-transfer coefficient.

(b) Calculate the shell-side heat-transfer coefficient to give an overall heat-transfer coefficient of \(100 \mathrm{Btu} /\left(\mathrm{ft}^{2}-\mathrm{hr}^{\circ}{ }^{\circ} \mathrm{F}\right)\).

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Cp. Blu/1bF k, Btu/hr-ft-F Sp. gr. Ethylene Glycol 190F 0.65 DATA Water 105F 1.0 3.6 0.154 0.67 0.363 1.110 1.0