Experimental Study on Flow Deposition Characteristics of Inorganic Salt Particles in a Transpiring Wall Reactor for Supercritical Water Oxidation

Supercritical water oxidation has a promising future in the treatment of highly toxic and refractory organic wastewater. However, harsh working environment hinders its commercial application due to reactor corrosion and salt deposition problems. Transpiring wall reactor has good performance in resistance to the two problems above because it can form a protective water film on its inner surface to dilute, dissolve and/or wash inorganic salts and corrosive species. In this work, the influences of operating parameters on the flow and deposition characteristics of type 1 salt, type 2 salt, and their mixture in a transpiring wall reactor were explored systematically under water film interference conditions. The results show that water film could significantly decrease the inorganic salt concentration near the porous wall and the salt deposition rate in the reactor. There is a negative linear relation between transpiration intensity and the concentration of type 1 salt, type 2 salt, or their mixture near the porous wall. The dilution multiple reduced with an increase in the initial salt concentration and in the dilution and solubility of water film. Runtime had a slight effect on salt distribution in the transpiring wall reactor, but water film could always exert protective action in the range of experimental measurement time. This information helps to theoretically guide the optimization of operating parameters of the transpiring wall reactor.