Minimum Solution Shear Stress Preventing MgSO₄·7H₂O Incrustation on Stainless Steel Plates

MgSO₄·7H₂O deposits are investigated on steel (X5CrNi18-10) plates with different finishing qualities. At a supercooling temperature of 9 °C, these deposits are detected on all plates. Shear stress is found to have a noticeable influence on the incrustation phenomenon. In the range of investigated variables, it increases deposition and removal rates. These rates are the highest for mirror-like surface (plate I). On the other hand, the contact angle of solution has no clear impact on the process under investigation. Solution minimal shear stress preventing incrustation on the plates is also inspected. It is done experimentally and then by interpreting the plot of G_eff vs τ. Data analysis shows that simple surface parameters such as Ra, Rz, Rq, Sa, Sp, Sv, St, and Sq have no substantial influence on these values. On the contrary, more complex parameters like Sku and Ssk), which are measures of nonconventional finishing and sharpness profile shape, respectively, do have a significant effect. Additionally, the study examines the link between the crystal deposit mass and the Reynolds number, distinguishing four distinct zones. These variations between the zones are attributed to changes in the variables that affect fouling, which are influenced by fluctuations in the flow rate.