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Show SLAGGING COMBUSTION EXPERIMENTS Fig. 5 shows a schematic of the experimental slagging apparatus. The sewage ash is mixed with the primary air before entering the burner and injec ted un i formly into the slagging combustor through the swirler of the burner. The wall temperature of the slagging combustor is kept, by means of butane gas combustion , at about 100·C higher than the ash fusion temperature. The sewage ash melts quickly after inject ion into the slagging combustor and the molten ash trickles down the combustor wall and is collec ted at the bottom of the combustor . Exhaust gas from the slagging combustor is sent to a combustion chamber and the temperature, O2 , CO, CO 2 , NOx and dust concentration are measured. Table 1 shows the experimental conditions and results of sewage sludge ash slagging. Three different types of sewage ash were supplied into the combustor. The following results were obtained: QD The slag capture rate for ash is over 95%. GD NOx emission is less than 100 p.p.m. corrected to 12%-02 • QD No slag shows any leaching of toxic substances over detection limits. I Sewage Ash >--, I Blower Combustion Air Table I E xper imen.tal conditions and results of sewage sludge ash slagglng RUN I RUN2 RUN3 Sewege Sludge Ash A Feed ing Rate ( kg / H) 250 Feeding Temp (OC ) 20 B 250 20 C 250 20 Atmosphere Wa ll Temp (OC) 11350-1450 1350- 15001350-1500 CombustIOn Chamber I @ S l udge S l agg i ng Co.bustor Fig. 5 Sewage ash slagging facility - 6- Air RatiO of Combustor i I 2 I 2 I 2 \II Air Temp (OC ) I 400 400 400 ~ r-----~--------------~~--~~ C. Hlo Flowrate (Nm3/ H)1 25 25 25 ~ r-------------~-- -------------~ o Slog Capture (%) 990 98 I 96 6 U 1--- -----------4-1 ----- ------------l Exhaust Gas NOx( ppm 12% -02) I 4 3 - 80 25 -75 90 -95 Temp (OC ) 1550 -1650 1500-16001500- 1550 T-Cr (mg /l) < 002 < 002 < 002 o ~ Cr" (mgl I) < 002 <002 <002 q; IV \II ~ J:i Hg (mgl I ) 1<00005 <00005 <0 0005 u r---------,-----------------~ ~ ~ i Cd (mgl I) < 0 01 < 0 0 I < 0 0 I ~ ~ 1r---------4-----------------~ I ii Pd (mg/l) < 001 < 001 <001 0 r---------4-----------------~ I ~ As (mg / l) < 001 < 001 < 001 |