| OCR Text |
Show transported to us from Virginia in two 55 gallon barrels. The CWM was prepared by ARC at their old facility using "Quinwood", West Virginia coal having an average particle size of 50 microns. The coal was medium volatile (29%), low ash (3%). The CWM in the two barrels had average effective viscosity of 1000 and 2000 centipoise, respectively. The time elapsed from the manufacture of the CWM and testing was about a month. No hard pack was formed. Some settling occured (in the form of a jell) at the sides and bottom of the barrel, but the mixture returned to normal consistency and uniformity after blending. Atomization characteristics were studied by flow visualization employing the collimated shadowgraph technique (Figure 2). A high intensity short duration spark gap light source was used, and the shadowgraph pictures were photographed on high speed Polaroid films. The atomization was performed within a light-proof box using nitrogen as the atomizer fluid. The test set-up is shown in Figure 3. Various orifice diameters and cone angles for the orifices were tried and the configurations that gave the best atomization was selected for combustion tests. The test was repeated several times with this configuration to ensure consistant atomization results. Injected from the burner, the CWM splits into thin streams and then to ligaments as the atomizer velocity is increased. Further, the ligaments break into shorter ligaments and then into droplets . Figure 4 shows the atomized CWM using the configuration selected. The variation of Sauter Mean Diameter (SMD) of the particles with atomizer velocity and the effect of Reynolds number on SMD were investigated. Variation of SMD, normalized with respect to the inner diameter of injection orifice is shown in Figure 5. The SMD decreased with increase of Reynolds number of atomizing fluid in the range studied. COMBUSTION STUDIES Facility and Combustor Description The combustion tests were conducted at the TRW Fossil Energy Test Site (FETS) in Capistrano. The TRW FETS has been operating since 1979. Present operations consist of two test cells with two support bays for consumables. Test Cell 1 houses a 10 MM Btu/hr (nominal) atmospheric coal combustor. |
