Chemical Engineering - Heat Transfer

The purpose of providing expansion bellows in the shell of tubular exchanger is to

A graph between __________ is called Wilson plot.

Grashhoff number is given by

The overall heat transfer co-efficient for a shell and tube heat exchanger for clean surfaces is U₀ = 400 W/m².K. The fouling factor after one year of operation is found to be h_d0 = 2000 W/m².K. The overall heat transfer co-efficient at this time is

In a laboratory test run, the rate of drying was found to be 0.5 x 10^-3 kg/m².s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m²/kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is