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Show Figure 11 presents some representative results from one series of gas mixing tests. During this series of experiments the Tuel-air ratioS at pOints within the model were measured. If the fuel-air ratio is greater than that required for stoichlmetric combustion, it is assumed that complete combustion has occured at this point. This figure plots percent of fuel reacted as a function of the elevation above the fuel firing zone of the furnace. As can be seen, significant improvements in the speed at which the fuel and air mix can be achieved through changes to the fuel and air flring angles. ,----- - - - - - ---------, % FUEL REACTED VS FURNACE HEIGHT ;~~~~~ss~~~.I=n~~~~TS~~lY·'.~"~~~~~~T£-; ~-~-,.--, I ~ • I ~ . I § ~ ~ . I " I .. I • l£&611 • aN'Ii , I • aN'IS,2 • aN'18 a • aN'15 , 4 '~:li JIG Il 0 .;i-;.,oI ~-;;I4-0,1 o.----..}.I o.. ----.,o~ ---"112~! 0 ----:1II~,oI-."J...,jo- ...JJ 0 F~"'CE ELEVATION (FT) Fig. 11 - Furnace Tracer Gas Mixing Test Results The LSFATF Is currently being used for an EPA sponsored research program to develop sulfur capture sorbent Injection s~stems for tangentlal1y fired furnaces. The furnace flow modeltng portion of thls program is divided into two tasks: 1) Develop isothermal modeHng criteria for two phase injection systems, and 2) Apply these criteria to the actual development of 1njection systems for prototype and actual systems. ' In this respect Figure 12 shows the results of a gas-soUds jet frow visuaUzation that was taken 1n a small injection test facility. Such tests, as well as quantitatlve veloclty and Isoklnetlc evaluations have De en used to determlne the penetration and dispersion characteristics of a jet as a function of Injection and crossflow operaftng parameters. The results of these tests are beIng used to validate jet modeling techniques where the penetration and mixing of gaS-SOlids jets are accurately modeled t b y a gas only jet. Appl1cation of these model1ng echnlques to the furnace flow model will then aJlow the use of gas only jets to model the characteristics of gas-so ids Jets. And, by tagging the gas only jet with a tracer gas, Its penetration and dispersion can be evaluated using an instrument Ul<e the laser absorption spectrophotometer. 125 Fig. 12 - Two Phase Jet Flow Visualization Test Results Another phase of this model1ng program is the development of injection systems for application to tangential fired furnaces. During thts work simulated sorbent injection systems are under evaluation in a 0.46 scale isothermal flow model of Combustion Engineering'S new 50 MBtu Boiler Simulation Fact lity. These candidate injection systems are being evaluated through flow vlsual1zation, veloctty, concentration and residence time distribution experiments using the previosly described techniques. OTHER FURNACE DESIGNS - For the recovery boiler system previously shown In Figure 7, severa 1 system arrangements, varying secondary and tertiary air distrlbutlon, were tested. The tests performed on the model Included flow vlsual1zation using smoke Injection into the model, yarn tufts, and styrofoam beads, as well as velocity measurements. For the mixing tests the laser based gas tracer system was used and tracer gas was injected into the primary air ports. During tne model testing and the developement of secondary air injection methods attempts were made to reduce the down flow along the furnace walls by arranging the secondary nozzles to maximize jet penetration and mixing. In order to compare t'he results from the methane mixing tests, the RMS deviation of the normaUzed concentration in each plane was caluclated- with the result that mixing lncreases with decreases with decreasing values of RMS de.vi.ation. Typical results from thls type of mlxmg experlment are shown in Flgure 13. It should also be noted that slmilar type tests were performed on the wood fired bol1er that was previously described. This test program ls still in progress, with manr of the recommendations from fhe experimenta test program now being tested ln the field. |