Advanced atomization concept for CWF (coal-water fuel) burning in small combustors

Atlantic Research has undertaken a program to design, fabricate and test this new concept in coal-water fuel atomizers. The device employs two diametrically opposed jets of CWF which impinge on each other at high velocity. An air blast is directed at the impact zone of the two jets and the resulting high energy collision of all streams serves to break up the slurry fuel into fine droplets which are then directed by the air blast into the combustion zone. Prototypes of this atomizer have been built and tested under cold flow conditions using both water and CWF sprays. Based on the cold flow result with the prototypes, an atomizer has been fabricated for installation in a 1 MMBTU/H research tunnel-type'' furnace. A comprehensive testing program was conducted to evaluate the atomizer under firing conditions. The parameters covered in the test plan included CWF firing rate, atomizing air pressure, secondary air preheat temperature, secondary air diffuser design, CWF viscosity and solid content, CWF preheat temperature, and coal type. The effects of these parameters on combustion efficiency have been determined. 3 refs., 20 figs., 26 tabs.