THE EFFECT OF CIRCULATING FLUIDIZED-BED PARTICLE CHARACTERISTICS ON EROSION OF 1020-CARBON-STEEL

A series of erosion tests were performed to determine the erosivity of several different circulating fluidized bed materials. The tests were conducted with 1020 steel as the target material at 400 degrees C and particle velocities of 75 m s(-1). The bed material erosivity was fou nd by measuring the sample weight change with time and determining the steady-state erosion rate. It was found that for some conditions, the steel target showed a weight gain owing to soft constituents in the e rodent forming a deposit of particle fragments on the surface. Two bed materials were then separated by particle size, ranging from less tha n 106 mu m to greater than 1400 mu m, and each size fraction was erosi on tested. The shape of the particles was measured using a quantitativ e image analysis system and it was found that particle shape changed w ith the size fraction of the bed particles, Particle composition, whic h was also found to vary with particle size, was determined using elem ental analysis. Based on these results, the erosion of 1020 boiler tub e steel was correlated to the particle characteristics of size, shape, and composition.