In‐Situ Testing of Superstructure Refractories

Almost all glass manufacturers--including Schuller--that have converted to oxy-fuel combustion have encountered superstructure refractory and flue refractory difficulties. Many problems have been encountered because of the higher vapor concentration in oxy-fuel melters that cause undesirable condensate species. Some testing laboratories have facilities for conducting tests on superstructure refractories by simulating the furnace atmosphere and temperature regime. Such tests provide an insight into what can be expected in the installation of a given refractory. However, the simulated atmosphere and the relatively short test period may not inspire confidence. Therefore, Schuller has experimented with in situ testing by placing refractory samples in peepholes, abandoned burner blocks and exhaust ports for relatively long periods of time to gain greater confidence in predicting refractory life for a given application. Furthermore, in situ testing places a refractory sample in close proximity to where it will be used, thus creating a true atmosphere and temperature regime for a given test. In situ testing is intended to determine the best service life for a given glass chemistry, or range of chemistries, that a particular furnace must produce during a campaign. This procedure is something that each operator can perform on any furnace to gain confidence in anymore » new product that a supplier might recommend for future refractory application. The procedure also can be used as head-to-head testing of refractory materials from different suppliers. Also, the material currently being used can be tested against a suggested new material. This article presents the test procedure used and some of the results obtained.« less