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Show Measurement and Interpretation -7 - IFRF-~ of Flames Issued from a Generic Multi-Fuel Bunter 3. SPRAY CHARACTERIZATION 3.1. Introduction Detailed spray characterization is essential for understanding the influence of the spray properties on industrial scale processes. Information of droplet size, velocity and concentration in oil flames is required to understand how burner and atomizer design affect the temperature distribution, efficiency, mixing rate and pollutant formation. Measurements of droplet velocities and size distributions were carried out with a Phase Doppler Particle Analyzer (pDP A) at a large number of axial and radial positions for different flow conditions in a collaborative research effort involving the International Flame Research Foundation (IFRF) and the University of Erlangen. 3.2. Experimental Apparatus The Heavy Fuel Oil (HFO) was preheated to 70°C with belt heaters before handling and heated to the final temperature with a steam heater. While not in use, the HFO was recirculated through a cooler to maintain a constant temperature in the storage container and to prevent blockage of the lines. The accuracy of the oil flow control system was 10 / 0 • The spray rig, Fig. 3.1, was constructed with a front section of 1.5 *1.5 m for providing free optical access to the spray and an efficient collection of the oil droplets. This pennitted the testing of fuel oils at the actual burner input conditions. The entire rig was steam traced to prevent solidification of the HFO upon cooling. Ventilation was supplied by a blower with a maximum capacity of 3.6 m3 / s. The PDPA transmitting and receiving optics were mounted on a 180° rail which allowed changing the detection angle without losing optical alignment. The measurements were performed by moving the spray nozzle relative to the PDP A optics which were maintained at a fixed location 0.5 m before the spray collector. side view Fig. 3.1. Schematic of Spray Rig. |