Summary of results from the Berkely in-bed tube erosion simulator

The Berkeley rig was designed to simulate the particle hammering interactions between in-bed particles and tubes within bubbling fluidized bed combustors. To achieve this in a controlled manner, a rod shaped specimen is actuated a short distance within a partially fluidized bed, consisting quartz particles with an average size of 800 μm. The rig has been used to investigate the characteristics of tube metal loss and its dependence on temperature. Most of the tests were performed isothermally by varying the bed temperature within the studied range, some were carried out by internally cooling the specimen while keeping the bed temperature constant at 700°C. This paper reviews the results that have been obtained from these simulations. Earlier conclusions from cold model studies are summarized, and the effects of temperature, temperature gradient, bed condition and bed material deposits on tube wastage are presented and discussed.