High Temperature Flow Visualization and Aerodynamic Window Protection of a 100-kWth Solar Thermochemical Receiver-reactor for ZnO Dissociation

Abstract

A 100-kW th receiver-reactor designed for the thermal dissociation of ZnO into metallic Zn is separated from atmosphere by use of a transparent quartz window, through which concentrated solar radiation is admitted. Protection of such windows from reactant and product particle deposition is critical for successful reactor operation. Using in-situ visualization techniques, the effectiveness of an auxiliary flow of inert gas in aerodynamically protecting a 600-mm-diameter quartz window mounted on the receiver-reactor has been directly assessed during high-temperature experimentation. This work has shown that: (i) hightemperature, in-situ flow visualization is possible and effective in assessing flow patterns developed inside the reactor; (ii) there exist three characteristic flow patterns inside the reactor that can be dynamically controlled by use of a set of tangential and radially oriented jets; and (iii) a region of stable protective flow, under a wide range of experimental and operational conditions, is capable of repeatedly and fully suppressing detrimental particle depositions on the quartz window.

Methane dry reforming via a ceria-based redox cycle in a concentrating solar tower

“…These experimental findings along with past studies investigating the effects of Reynolds and swirl numbers on window depositions motivated a flow configuration consisting of 50% through the reactor inlet and 50% through the window inlet using the 25°CCW seal for all subsequent testing to protect the window from depositions. 50 With this arrangement there was no evidence of dust depositions on the window for the redox reforming and co-feeding tests.…”