OCR Text |
Show Figure 3 shows the HC, CO, NOx and O2 levels at each monitoring zone as measured at Olmsted faci I ity. According to these, the unburnt HC and CO disappear in the top portion of the furnace, whi Ie NOx rises slowly UP to the furnace exit where it levels off. 't:I CD ~ I CD CD CD e. CD CD -C 0 ~ CD . 0. C ° .C.D c: CD U c: ° () 11 10 9 8 7 6 5 4 3 2 Combultlon L'ower Grate OFA Upper OFA Refractory Furnace Exit Exit Dropout Paas Exit Sup~r heat~r Exit Boller Economizer Bank Exit Exit Figure 3 FURNACE GAS COMPOSITION HISTORY THROUGH THE OLMSTED WASTE TO ENERGY FACILITY DURING NORMAL FULL LOAD OPERAITON 2) Simulation Test 180 160 140 E0. 0. C 120 ° Q 00 c: 0 U c: ° () 40 The result obtained by tests performed at IGT testing furnace, using simulated gas equivalent to the exhaust gas of a MSW-incineration furnace, confirmed the fol lowing conclusions. (1) Natural gas, 15% in heat value of the MSW, which is injected into furnace can reduce NOx by 70%. (2) Residence time of 2.5 seconds, and the temperature of 1,040°C wi I I be sufficient for this process to be effective. (3) It also reduces CO whi Ie reducing NOx. 3) MSW burning test with a testing furnace Tests have been conducted using 5.5 TPD test furnace with crushed MSW, instal led at Ri ley's laboratory. The composition of the MSW used for this test was nearly the same as that fed to Olmsted furnace when the basel ine data was collected. For ease of feeding, the MSW was crushed, and was incinerated on the grate. Natural gas, mixed with the recirculated flue gas, was injected into the fu rnace, and the changes in NOx and CO we re mon i to red. The resu I ts are l is ted be low. 4 |