High Temperature Erosion of Dense Refractory Castables for CFBC Boilers

Abstract

The erosion resistance of dense refractory bricks or castables used in CFBC boilers is tested as per ASTM C 704. This method of testing determines the relative erosion of a refractory at room temperature only. Hence, solid particle erosion at elevated temperatures is desired in selecting the suitable refractory quality for boiler applications. The dense refractory materials for CFBC boilers are usually eroded at operating temperature (∼900°C) by hot circulating solids at high temperatures. In this work, low cement castable−45, low cement castable−80 and an 80% alumina-based plastic refractory castable, three varieties of dense refractory castables used in CFBC boilers, were selected for testing of erosion properties. The erosion tests were conducted at room temperature and boiler operating temperature of 900°C at three different angles of impingement (30°, 45° and 90°) using specially developed high temperature erosion test equipment following the ISO 16349 (2015) standard. The erosion loss result values (in cm3) were compared, and this comparison is useful in selection of suitable material for various erosion prone zones of the boiler.