Atomization of Coal Water Mixtures: Evaluation of Fuel Nozzles and a Cellulose Gum Simulant

摘要

An experimental evaluation of four air-assist fuel nozzles has been conducted to determine atomization levels of coal-water mixture (CWM) fuels at operating conditions simulating a high pressure combustor. Two of the nozzles were commercial units marketed for use in atmospheric burners, while two nozzles were specially designed for CWM operation in a high pressure combustor. Sprays from all four injectors were characterized in tests performed over a range of liquid and air flowrates. Most of the tests were performed using a cellulose-gum water solution prepared to match the viscosity and drip characteristics of an available CWM. Atomization data acquired from a limited test series using the CWM were found to be properly represented by the gum solution data. High levels of atomization (SMD 10 micron) were achieved by two of the nozzles - one commercial unit and one special unit - at an assist airflow level corresponding to a nozzle air-fuel ratio between 0.6 to 0.8. 4 references, 13 figures, 3 tables. (ERA citation 10:012211)