Ethylbenzene is manufactured by alkylation of benzene with ethylene. The reaction products are separated in a series of distillation columns. Ethylbenzene is obtained as the distillate from the last column (called the ethylbenzene column). In a 70 ton per day ethylbenzene plant, the final product leaves the overhead condenser at 135°C. This is required to be cooled to 40°C before pumping it to the storage tank. Cooling water is available at 30°C for cooling. Please provide a proposal for the design of a multi-pass counter-current Shell & Tube Heat Exchanger (Figure-1) that fulfils the specifications in Section 3 (Process Data) and includes the following items:
Item 1: Do energy balance and find heat duty (Q) and water flow rate
Item?: First start trial with 1-1 pass counter current exchanger and do LMTD calculation and find out area, assuming overall heat transfer coefficient based on outside area, Udc,
Item 3: Select tube BWG (i.d, o.d and length) from available market and number of tubes required and linear velocity of water (a velocity above 1 m/s should be maintained).Do selection of tube side and shell side fluid with proper justification