Fluidised-Bed Combustion. Initial Results Obtained in a 1-Ft by 1-Ft Fluidised-Bed Combustor Operating at Pressures Up to 20 ATM

摘要

A 1 ft square pressurised fluidised-bed combustor has been built at Leatherhead (England) to obtain performance data at pressures up to 20 atm. It has a tube bank containing cooled and uncooled elements in which the geometry and the proportion of cooled elements can be changed readily, so that operation over a wide range of pressures, excess air values, temperatures and velocities is possible. The maximum tube bank height that can be accommodated requires a bed depth of about 9 ft. The facility was built with funds from US, UK, Swedish, and German organizations. The test program is financed by the US DOE. This report described the facility and summarizes the results from the first six tests. Data were acquired at different operating conditions during a total of 20 test periods, each of 15 to 24 hours duration. Most of the data were obtained at pressures of 6, 10, 16 and 20 atm; fluidising velocity of 3 ft/s; bed temperature of 1560 exp 0 F; bed depths of 6 1/2 and 9 ft. The other main variables were Ca/S mol ratio and excess air. The results showed that: a combustion efficiency of 99.5% was achieved for all operating conditions; no systematic effect of pressure on SO sub 2 retention has been established. Excess air greatly influences NO/sub x/ emissions which were 0.5 lb/10 exp 6 Btu with 100% excess air and 0.25 lb/10 exp 6 Btu at 30% excess air and heat transfer to the cooling circuits increased with increasing pressure. (ERA citation 08:015791)