To investigate the effect of CaCO3 concentration and velocity on CaCO3 scaling fouling process on plain and saw-tooth oblique fin tubes

experiments have been done at different CaCO3 concentration and velocity on the two kinds of tubes. The results show that the homogeneous nucleation rate and the growing rate are both increased when CaCO3 concentration increases. This makes the scaling particle concentration and foulantions concentration increase. The former increase gets more scaling on tubes and the later enlarges the heterogeneous nucleation rate and growing rate. Higher velocity decreases the nucleation of scaling

scaling crystal and fouling resistance

but it can prolong the induction period. Higher velocity increases nucleation rate on saw-tooth oblique fin tube first

but the induction period extends and the mass of scaling and fouling resistance decrease. Saw-tooth oblique fin tube has a bigger heat transfer coefficient than plain tube at both clean and fouling conditions and it has smaller fouling resistance and a little more scaling.