Heat exchanger design for high-fouling liquid hydrocarbons requires careful consideration to minimize the frequency of costly shutdowns. In an earlier article, an alternative methodology was presented that aimed at achieving a critical velocity made possible by a reduced amount of excess surface area.¹ This was recommended in lieu of typical fouling resistances that result in large excess surface areas with lower velocities for the same pressure drop. Here we discuss:
• Importance of shear stress by controlling the fluid velocity
• Role of allowable pressure drop
• Fouled performance of “low-foul” designs compared to conventional designs.