Inhibition of Gypsum Scales on MS metal surface using hydrodynamic forces

In industries where water is used for heating/cooling purpose i.e. water desalination, oil fields operations are carried out, one of the major problem is deposition of metal salts on the surface of the different heat transfer equipments reducing its overall heat transfer efficiency, increased pressure drop and increasing the maintenance cost of the unit and due to shut down of the plant there is a reduction in the production. It also decreases the purity of the desired product. When the various metal salts present in the process fluid combine with each other due to a change in the pH, pressure, concentration and temperature of the operating system, leads to a change in the solubility of the ions present in the system. This leads to the process of nucleation and crystal growth in the system. In the current work, we have examined the process of deposition of gypsum crystals in a supersaturated brine on the Mild steel (MS) metal surface and its inhibition under different hydrodynamic conditions. It was observed in this work that on increasing the severity of the hydrodynamic conditions the depositions of gypsum (CaSO4.2H2O) was increasing up to certain limit and beyond it the deposition of the salts was not observed. Even the particle or crystal structure was greatly influenced due to the changing hydrodynamic conditions.