A floating-head shell-and-tube heat exchanger with one shell and one tube pass is being designed for use as a heater. The heating medium is hot water (shell side). The liquid that needs to be heated is toluene (tube side, 22 kg/s flow rate). The inlet and outlet water temperatures are 90 C and 30 C. The inlet and outlet toluene temperatures are 20 C and 50 C.

The shell has an inner diameter of 0.635 m. There are 260 tubes in the heat exchanger, arranged in a square pitch. These tubes have an outer diameter of 0.0254 m, a pitch of 0.0317 m, and a Birmingham wire gauge (BWG) of 14. The tube clearance is 0.00635 m. The length of the tubes is to be determined. The shell side has segment baffles with a 25% baffle cut. The baffles are spaced 0.1524 m apart, and they have a thickness of 0.010 m. The bundle-to-shell diametral clearance is 0.035 m.

1. Use the Kern method to estimate the convective heat transfer coefficient on the shell side. 2. Determine the convective heat transfer coefficient on the tube side. Please note that the first number in the Sieder and Tate correlation should be 0.023, not 0.23. 3. Use Table 14-3 to select an appropriate fouling coefficient (hd) for both the shell side and tube side of the heat exchanger. Toluene can be regarded as a light organic. 4. Taking the tube-side and shell-side h and hd values into account, calculate the overall heat transfer coefficient (U) for the shell-and-tube heat exchanger in the following three scenarios: a. 1.5% carbon steel shell and tubes b. 1.5% carbon steel shell, 304L stainless-steel tubes c. 1.5% carbon steel shell, monel tubes Use the equation provided in Example 14-5 to calculate the U values, but you should also include the fouling terms. D1 is the outer diameter of the tubes, and D2 is the inner tube diameter. 5. For all three heat exchanger designs outlined in step 4, calculate the required heat transfer area. 6. For all three heat exchanger designs, determine the required tube length. 7. For the carbon steel heat exchanger, calculate the pressure drop on both the shell side and the tube side. a. Use the Kern method for the shell side b. Use Equation 14-23 for the tube side. Ignore the correction factor for sudden contraction/expansion.

8. For all three heat exchanger designs, estimate the cost of the heat exchanger. a. Determine the base installation cost of the floating-head heat exchanger. b. Correct the cost for the effect of tube diameter. c. Correct the cost for the effect of tube length. d. Correct the cost for the effect of construction material.

For ease of calculation, you may evaluate fluid properties at the average bulk temperature. Ignore the viscosity correction when calculating the convective heat transfer coefficient and pressure drop values.

You will need to refer to outside resources to determine physical properties. When you do so, cite your sources. Tables and graphs from the textbook (Plant Design and Economics for Chemical Engineers, 5 th ed.) will also need to be used. If you obtain a value from a table, state which table it is from.