Scaling and removal of calcium carbonate on electroless plating surface

The scaling; process of calcium carbonate on a low-energy heat transfer sur face-electroless plating surface was investigated in a simulated cooling wa ter system. Owing to the very low surface energy, the electroless plating s urface exhibited less scaling susceptibility. A longer induction period and a lower scaling rate were obtained on the low-energy surface compared to c opper surface under identical conditions. The calcite particles obtained on the electroless plating surface during the induction period were larger in size than those on copper surface because fewer crystals formed and grew a t the same time on the low-energy surface. With increasing surface temperat ure, the induction period reduced and the scaling rate increased for the lo w-energy surface. When initial surface temperature was fixed, an increase i n fluid velocity would reduce the induction period and increase the scaling rate due to the diffusion effect. However, when the heat flux was fixed, a n increase in fluid velocity would decrease the surface temperature, and le ad to a longer induction period and a lower scaling rate. The removal exper iments of calcium carbonate scale indicated that during post induction peri od, the detachment was not obvious, while during the induction period, appa rent removal of crystal particles was obtained on the electroless plating s urface owing to the weak adhesion force. The more frequently the transient high hydrodynamic force acted, the more the detached crystal particles were .