By Baher Elsheikh, SABIC
Fluid allocation in shell and tube heat exchangers is a key decision during the design of the exchanger to ensure the achievement of the required thermal duty with optimized cost and satisfactory in-service reliability. The selection of the correct side for each fluid depends on many interacting factors, some related to the thermal design and some others related to the mechanical design and future considerations of inspection and integrity monitoring of the exchanger.
The best choice of routing can only be decided after designing both options in many cases. In some cases, the selected side for each fluid is a tradeoff decision as there might be no one single selection which satisfies all the required factors, and some may conflict with others. Hence, understanding the effect of each pa-rameter and the main features of each heat exchanger type is very important to help in selecting the right optimized design.
In addition, each of the exchanger types (fixed tubesheet, floating head tubesheet, or U tube heat exchanger) has its own characteristics, which will be preferred for specific fluid applications over other types.