| A theoretical and experimental study of particulate fouling in repeated rib tubes is presented. A rationally based fouling model is developed. This is the first attempt to model fouling in enhanced tubes. The model, with experimentally determined sticking probability and deposit bond strength, can predict the fouling behaviour of repeated rib tubes.;The mass transfer rate is assumed to control the particle transport process, and the wall shear stress is assumed to control the removal process. The mass transfer coefficients for the repeated rib tubes are obtained from the corresponding heat transfer correlations. The wall shear stress is modeled based on the flow structure between the ribs.;Particulate fouling tests were conducted. The range of variables investigated in this study are the roughness variables (0.015 ;Empirical correlations were developed that define the effect of geometric and flow parameters on the sticking probability and deposit bond strength. These correlations show that the sticking probability and deposit bond strength increase as p/e increases, and as e/D and Reynolds number decreases.;An analysis was performed that accounts for forces acting on the particles at the wall. The analysis suggests that the hydrodynamic force is dominant for the present tests. This analysis qualitatively supports the empirically obtained geometric and Reynolds number dependencies of the sticking probability.;The repeated rib tubes showed higher fouling resistances than did the smooth tube at low Reynolds numbers. At a high Reynolds number (Re = 26,000), however, they were approximately the same as the smooth tube value. Within the test range, the fouling resistance increases as p/e increases, and as e/D and Reynolds number decreases. |
