OCR Text |
Show Experimental evaluation of this technology and engineering philosophy was performed at two of the Environmental Protection Agency's pilot scale research facilities, both having rotary kilns as the primary incineration unit. The destruction efficiency and the throughput capacity of the systems at both facilities were compared using conventional (air only) and Pyretron based (air / oxygen) systems. SCOPE OF EXPERIMENTAL STUDY Two series of tests were performed at EPA's testing facility at Research Triangle Park [4]. The first provided a preliminary comparison of the pyretron combustion system with a conventional system using a surrogate waste and the second provided for an evaluation of the effects associated with temperature and the partial pressure of oxygen on the destruction of a surrogate waste. In light of the serious limitations of the kiln simulator used at this testing facility, the objectives of these series of tests were to obtain qualitative data on the effects associated with oxygen use in incineration processes and to establish a preliminary data base for the development of software for the computerized control algorithm used in the pyretron Thermal Destruction System. A schematic of the experimental facility at Research Triangle Park is shown in Figure 1. The facility consists of a kil n simulator (Section 1 in Figure 1), afterburner and an exhaust section. The kiln is equipped with an auxiliary burner located at the axis at the kiln entrance side. Both conventional (air/gas) and Pyretron burners were used during the tests. A simulated waste was batch charged into the kiln by the use of a ram feeder. The waste was incinerated in the kiln recess section wherein the solid material is retained. The combustion gases pass through the kiln and afterburner sections and are discharged via a stack. The afterburner burner was not operated during the tests. Controlled flows of fuel and air were provided to the conventional and pyretron burners, while the Pyretron burner was also provided with the controlled flow of oxygen. Temperature was measured in the kiln by the use of thermocouples. A sample of the flue gas was withdrawn from sample port 1 after the kiln and analyzed for the total hydrocarbons (CH4 equivalent), CO, CO 2 , O2 , NOx, and soot content. Samples for identification and quantification of organics (PICs) in flue gases by the use of GCMS were also taken periodically. The batch charges of surrogate wastes were assembled in cartons containing corn cobs spiked with toluene. The weight ratio between toluene and the rest of the charge was 1/1.8. Only toluene was used to represent a POHC during the entire series of tests. During the tests the kiln temperature was varied between 15000 F and 20000 F, kiln rotation speed was 0.5 rpm, the level of excess air was 100% and the residence time for combustion products was in the range of 2 to 3 seconds. |