Process Equipment and Plant Design
Ratio of tube length to shell diameter for a shell and tube heat exchanger is

Both B & C
8 : 1 to 12 : 1 for both liquid-liquid and gas-gas heat exchangers
< 4 : 1 for gas-gas exchangers
4 : 1 to 8 : 1 for liquid-liquid exchanger

ANSWER DOWNLOAD EXAMIANS APP

Process Equipment and Plant Design
In a double pipe (concentric) heat exchanger, the hydraulic radius for heat transfer (for a fluid flowing through the annulus) would be

Less than that for fluid flow
More than that for fluid flow
D₂ - D₁ (D₁ and D₂ are I.D. of inner and outer pipes respectively)
Same as that for fluid flow

ANSWER DOWNLOAD EXAMIANS APP