Clogging of the regenerator checkers and corrosion of the regenerator refractories are common problems in the glass industry. This paper is focused on simulating the refractory corrosion of regenerator checkers of container glass furnaces by cooling sodium vapours combined with sulfur dioxide. Results obtained by the application of dedicated laboratory equipment for testing regenerator checker refractory materials will be presented. The set-up of the experiment is a combustion chamber connected (downstream) to a laboratory scale tube furnace. The gases used for the flame inside the combustion space are adjustable (natural gas with air or oxygen) and are generally set to normal oxidizing conditions. But also near stoichiometric or slightly reduced conditions can be set. Inside the tube furnace a temperature gradient is formed by the heat of the incoming combustion gases. The refractory samples are placed inside the tube furnace with the flue gas cooling from about 100-650 deg C (corresponding to the condensation zone inside the regenerator). A sodium hydroxide solution is injected inside the flame, resulting in sodium vapours inside the system. Sulfur dioxide is injected near the connection point of the combustion space and the tube furnace. These two components create an atmosphere inside the tube furnace rich in SO2 and sodium vapours (high temperature) and sodium sulfate condensates (formed at low temperature from sodium vapours and SO2). The applied concentrations are much higher than in an industrial regenerator. Thus, test conditions are more severe in order to approach long time duration behaviour of the refractory exposed to these vapours and condensation products. After exposure to the corrosive components, the samples are tested on weight gain and are analysed with SEM/EDX. Results of testing different refractory materials will be shown.
