Flashing Phenomena in the Case of Two-Phase Flow (Liquid-Gas) in a Vertical Porous Channel

ABSTRACT In this paper, flashing phenomena are studied in the case of water-steam and air outflow in a vertical porous channel . The presence of air, the nature of the porous environment, as well as injected fluid thermo-physics parameters are analyzed. The separate flow model approach which takes the individual properties of air and water separately is considered. On the other hand, we consider that water and its steam are represented as a mixture characterized by the mean properties according to the quality (x)(the ratio of the vapor mass and the total mass). Some results show that the porous environment as well as the presence of air represent a resistance to the water outflow. When the effective permeability (or the relative permeability) decreases, the pressure of injection of water increases to maintain the same flow rate. In this case, a decrease of steam generated is observed

Corrosion Protection Effect of Chitosan on the Performance Characteristics of A6063 Alloy

This article outlines the behaviour of water-soluble chitosan as an effective inhibitor on aluminium alloy in 3.65% NaCl at room temperature. The inhibitive ability of water-soluble chitosan was examined using electrochemical potentiodynamic polarization techniques, mass loss measurements and computational studies. The outcome of the experiment reveals that chitosan inhibited aluminium alloy in sodium chloride solution exhibits better corrosion protection than the uninhibited because chitosan nanoparticles minimize the ingression of chloride ion into the active sites of aluminium alloy by forming thin film on its surface. The losses in mass by the inhibited aluminium alloy were found to reduce as the concentration of chitosan increases. Results obtained showed that chitosan could offer inhibition efficiency above 70%. Polarization curve demonstrated that chitosan in 3.65% NaCl at room temperature acted as a mixed-type inhibitor. Adsorption of chitosan nanoparticles on the aluminium alloy was found to follow Langmuir adsorption isotherm with correlation regression coefficient (R2 ) value of 0.9961

Chemical Additives for Corrosion Control in Desalination Plants

The addition of chemical additives has been considered as a standard operation in water treatment systems. This chapter discusses the chemical additives used for the control of corrosion in desalination systems. Specifically, corrosion inhibitors for various metallurgies, biocides, and oxygen scavengers are covered. The pros and cons of the additive chemicals have been highlighted. The need to utilize green corrosion inhibitors based on plants and ionic liquids materials have been emphasized. This class of materials are environmentally friendly, cheap, and readily available