OCR Text |
Show • The total accumulation of slag was small, about 1/4 Ib; the total amount of waste burned was about 200 Ibs. • No slag was present in the base/slag receiver. Optimization Performance Tests The incinerator configuration was modified in an attempt to lower natural gas consumption per unit of liquid waste combusted. The first of these modifications involved introducing natural gas/air mixture, secondary combustion air, and liquid waste at different elevations. In addition, the chamber height was increased from 24 to 33 inches to accommodate the lower position of the atomizer by lowering the refractory orifice at the chamber floor. A performance test using the modified chamber was run and the data collected are shown in Table 13. From Table 13 it is seen that only Test No.4 achieved complete combustion (as indicated by low CO level). Using the data from Test No.4, the heat contribution of gas and waste can be calculated as previously done to yield the waste/gas ratio. The calculated waste firing rate is about 0.23 x 106 Btu/h and thus the total firing rate is 0.56 x 106 Btu/h. The waste/gas ratio is thus 41/59, which is similar to the results obtained during the 24-hour test configuration. A second performance test was run using a similar configuration, but changing the number of atomizers; data are shown in Table 14. The data indicate that stable combustion was achieved using a much higher total waste-flow rate. The waste/gas heat contribution ratio for Test No.1, calculated as shown earlier, is 59/41. For Test No.2, the waste firing rate is 0.55 x 106 Btu/h, the total firing rate is 0.88 x 106 Btu/h, and the waste/gas ratio is 63/37. 48-Hour Continuous Test A 48-hour continuous test was run using the incinerator configuration of the previous run. Waste containing approximately 35% solids was used. The 48-hour test had been planned to use 50% solids concentration waste, and although the lower concentration waste would require increased natural gas consumption and recalibration of system operating parameters, it was decided to proceed with the test to observe long-term system operation such as atomizer performance, ash deposition, slag formation, and combustion temperature. The data collected during the test were identical to those collected during earlier tests, except that heat removal data were also collected via the water cooled annulus of the incinerator chamber. Data were collected approximately every hour: results are shown in Table 15. As expected, the data indicate higher natural gas consumption 3S |