Calcium Carbonate Scale Formation in Copper Pipes on Laminar Flow

Abstract

Calcium carbonate is commonly precipitated as a scale in the transportation pipes of water. The presence of this mineral deposit becomes problematic, because it can block the pipes and lead to a decline in piping performance. Calcium carbonate precipitation from the synthetic solution was experimentally investigated in the present study. The aim of research was to predict the occurrence of precipitates and characterize the scale precipitated from the solutions. The synthetic solutions were prepared using CaCl2 and Na2CO3, which was mixed with distilled water (H2O). The concentrations of Ca 2+ at 2000, 3000, 4000 and 5000 ppm. in the solution were adjusted and the solution flow in the Cu pipes at the different flow rate of 30, 40 and 50 ml/min. It was found that in all the experiments, the conductivity decreased abruptly after a certain induction period. Higher temperature produced more mass of the scale indicating that the increasing temperature promote scale formation. SEM analysis showed that the scale was rhombohedral, while EDS revealed that the elemental composition of the scale consisted of Ca, C and O. The crystalinity of the scale was found to be mostly calcit as shown by the XRD

Scaling Resistance in Nanophotonics-Enabled Solar Membrane Distillation

“…Previous studies performed on membranes, pipes, or heat exchangers have shown an increase in scaling with increasing cross-flow velocities. 25,40,41 However, other studies have shown the opposite trend, 42,43 which suggest that the relationship between cross-flow velocity and scaling depends on the scale species and the type of surface considered. To discern if the cross-flow velocity alone had an impact on scaling, a set of MD PVDF (ΔT = 40 °C) and MD CB-PVDF (ΔT = 40 °C) experiments were performed at a similarly low cross-flow velocity as in NESMD.…”

Towards sustainable circular brine reclamation using seawater reverse osmosis, membrane distillation and forward osmosis hybrids: An experimental investigation

“…The solubility curves of different structural forms of calcium sulfate and calcium carbonate are presented as a function of temperature in Fig. 2 using data from the literature (Al-Rawajfeh et al, 2012;Al Rawahi et al, 2017;Choi et al, 2019;Raharjo et al, 2016;Van Driessche et al, 2017). Depending on the degree of hydration, calcium sulfate exists in three main forms, i.e., gypsum (the dihydrate, CaSO Whereas calcium carbonate can be found in the environment in its various forms, including anhydrous (e.g., calcite, aragonite, and vaterite) and hydrated (e.g., monohydrocalcite and ikaite).…”