“….0032 m to 0.011 m Follow the description of the variables: ap is the tube layout pattern, np is the number of tubes passes, Lt is the tube length, esp is the tube wall thickness, do is the tube outer diameter, Lb is the baffle spacing, bc is the baffle cut, dtb is the tube-to-baffle diametrical clearance, dsb is the shell-to-baffle diametrical clearance. Considering the material of the tube (70%Cu, 30%Ni) and of the shell (carbon steel), the total anual cost estimation ) (TC that includes direct and indirect costs ) ( BM C and operational costs ) (OC , was conducted in the same manner as in [1,2]:…”