Flow Modifiers for Preventing Sedimentation in Heat Exchangers

Abstract

Heat exchangers are commonly used in process industries; however, fouling, such as sedimentation of particulate material is a significant challenge hindering the efficient use of heat exchangers in a wide range of industrial processes. This research studied the prevention of sedimentation in tube heat exchanger header sections, which typically are the critical areas for sediment accumulation. Numerous flow modifiers were explored, of which the most advantageous ones are presented in this paper. The study included construction and analysis of a miniature, validation of the used CFD model, and finally simulating an industrial scale heat exchanger. This research considered both flow fields and wall shear stresses for reducing sedimentation. The study showed that CFD models are capable of describing flow fields and their spatial variations in heat exchangers especially in their header sections. The selected flow modifier setups increased wall shear stresses in critical areas and hence reduced sedimentation. The presented solution consisted of utilizing different flow modifiers, filling elements, and their combinations. Industry should consider utilizing flow modifiers in heat exchangers as a potential solution to prevent sedimentation. Industrial cases are worth analyzing by using miniatures and CFD modeling. Analyses should pay special attention to flow fields and wall shear stresses. Heat exchangers include also other fouling mechanisms beside sedimentation; however, further study is required to clarify how flow modifiers influence these mechanisms.