Scale and Corrosion Prevention in Cooling Water Systems Part I : Calcium Carbonate
This paper presents the results of study that was undertaken to investigate the ability of a new antiscale, polyacrylamide in solving problems found in cooling water systems. The effects of the polymer on C-steel and copper dissolution in synthetic cooling water environment were studied through scale, Tafel, and Linear polarization measurements. The results obtained from this study showed that the new antiscale polymer can decrease scale build-up growth under experimental conditions. Both linear and Tafel polarization studies indicate that the polymer acted as an anodic type corrosion inhibitor on C-steel and mixed-type on copper, thus reducing metal dissolution. Morphological investigations of calcium carbonate deposits on both C-steel and copper surfaces were studied by optical microscopy. The polymer used in this study appears to have an excellent crystal modification effect on reducing calcium carbonate scale. The antiscale effect results from changes in crystallization behavior promoting bulk solution precipitation rather than formation of adherent scale.
The Scale and Antiscale Study of the Reclaimed Water Reused in Industrial Recycling Cooling System
The reclaimed water of municipal sewage reused in industrial recycling cooling system is an effective approach to save water resource and improve the ecological environment. One of its critical factors is controlling scale formation in recycling cooling system. In this paper, the scale formation and antiscale influence factors of the reclaimed water reused in Beijing thermoelectric plant were investigated. The scale of the reclaimed water was measured by SEM, XRD and XRF techniques. Through the static and dynamic simulation test, we obtained an optimum composite antiscale. Furthermore, the effects of ion components，COD and turbidity of the reclaimed water on the scale inhibition efficiency were examined. This can provide a useful information basis for controlling and estimating risks of the reclaimed water reused in industrial recycling cooling system.
General expression for the density effect for the ionization loss of charged particles
The equations for the density-effect correction $\ensuremath{\delta}(X)$ for the ionization loss as given in a previous paper have been extended to the case where $\ensuremath{\delta}({X}_{0})\ensuremath{\equiv}{\ensuremath{\delta}}_{0}g0$. Here ${X}_{0}$ is the lower limit of the range ${X}_{0}lXl{X}_{1}$, where a particularly simple expression for $\ensuremath{\delta}(X)$ applies; $X={log}_{10}(\frac{p}{{m}_{0}c})$, where $p$ is the momentum and ${m}_{0}$ is the mass of the incident particle. The case ${\ensuremath{\delta}}_{0}g0$ applies directly to the calculation of $\ensuremath{\delta}(X)$ for conductors (metals).