OCR Text |
Show The correlations presented in Table 2 show that an increase in the pa rtial pressure o f oxygen from 2% to 12% causes about one order of mag n i tude reduct ion in the puffs peak area, peak height and filter weight ( soot generation). The limitations of th i s correlation a r e t hat both the flame and k i ln temperatures are quite high, above 12000 C and 9500 C respectively, so that t here are no low temperature problems and the oxygen concentration was high e nough (greater than 2% in the flue gases at any time) so t h a t th e CO burnout was virtually complete, hence the insignific anc e of the b O, b 1 and b 2 values. Different correlations will be operable at lower temperatures and at lower partial pressures of oxygen. The results of the preliminary tests at Research Triangle Park were used to design the Pyretron Thermal Destruction System. This system was selected by the EPA to participate as a part of the Superfund Innovative Technologies Program (SITE) which was initiated to fast track the devel opment of innovative treatment technologies for the clean-up of Superfund sites. As a part of this program, the EPA made available the Combustion Research Facility in Jefferson , Arkansas for testing of the pyretron Thermal Destruction System [5]. A schematic of the CRF incineration system is shown in Figure 3 and the sampling matrix utilized during the testing is presented in Figure 4. The system includes a rotary kiln, an afterburner and air pollution control units. The kiln and the afterburner have been equipped with Pyretron burners and the pyretron computerized combustion control system has been installed. This computerized control system has the capability to recognize prefailure conditions such as: -batch charge overload ; -excessive CO exiting the kiln; -a deficiency of oxygen in the flue gases exiting the kiln; -abnormal temperature deviations in the kiln and afterburner ; and -undesired deviations from negative pressure levels in the kiln. Other prefailure conditions are indicated to the computerized control system from an additional set of dedicated temperature and pressure transducers and from CO and O2 analyzers measuring flue gas parameters at the kiln exit. When signals from these monitoring devices indicate a prefailure event, the system responds by prescribing the new flows of air, auxiliary fuel and oxygen to bring the process back to normal operating conditions through simultaneous feed forward and feed backward responses. These responses are based on the capability of the s y s t em t o control independently the partial pressure of oxygen, residence time and temperature needed to eliminate a prefailure cond i t i on. |