Ammonia vapor, 4500kg/h at 6.7 bara pressure, is to be cooled from 120^oC to 40^oC, using cooling water. The maximum supply temperature of the cooling water available is 30^oC, and the outlet temperate is to be restricted to 40^oC. The pressure drops over the exchanger must not exceed 0.5 bar for the ammonia stream and 1.5 bar for the cooling water.

A contractor has proposed using a shell and tube exchanger with the following specification for this duty:

Shell: E-type, inside diameter 590mm

Baffiles: 25% out, 300 mm spacing

Tubes: Carbon steel, 15 mm inside diameter, 19 mm outside diameter, 2400 mm long, number 360.

Tube arrangement: eight passes, triangular tube pitch, pitch 23.75 mm

Nozzles: shell 150 mm inside diameter, tube headers 75 mm inside diameter.

It is proposed to put the cooling water though the tubes.

Is the proposed design suitable for the duty?

Physical properties of ammonia at the mean temperature of 80^oC: specific heat 2.418 kJkg-1^oC-1, thermal conductivity 0.0317 W/m^oC, density 4.03 kg/m3, viscosity 1.21 * 10-5 Nm -2s.