OCR Text |
Show INTRODUCTION The objective of this paper is to describe the field testing results and computer modeling of the Linde® Oxygen Combustion System (OCS) . The system was retrofitted to the EPA's mobile incineration system (MIS) as part of the EPA's overall modifications . The EPA confirms that the modified MIS has passed all compliance tests using Denney Farm material at a solids feedrate of 4,000 lb/hr(l). The successful demonstration of the Linde OCS in the EPA/MIS represents a significant technical advancement in the field of chemical waste incineration . The MIS was designed and built by the EPA to provide a mobile facility to demonstrate on-site thermal destruction and detoxification of hazardous and toxic organic substances collected from clean-up operations at spills or at uncontrolled hazardous waste sites. The system is designed to provide highly efficient thermal destruction of all organic contaminants fed to the system. The EPA/MIS was in operation at the Denney Farm site in McDowell, Missouri, between July, 1985 and February, 1986 with a trial burn on dioxin-contaminated solids and liquids and subsequent field demonstration. During this field demonstration the MIS demonstrated the ability to destroy liquid and solid hazardous wastes and toxic organic wastes. However, its relatively low capacity and low on-stream factor limited the direct application of this technology for the massive task of cleaning up the myriad abandoned hazardous waste sites. The throughput of the MIS in decontamination of soil had been limited by the required gas residence time in the secondary combustion chamber (SCC) . The MIS had shown that only 2000 lb/hr of soild with relatively low moisture content could be incinerated. Higher moisture content feeds further reduced the system capacity. The low on-stream factor had been caused mainly by excessive dust carryover which required frequent SCC clean out . A detailed discussion of the problems encount'ered during the 1985-86 operation and the system modifications thereafter can be found in references 1 and 2. System modifications were undertaken to increase the MIS throughput and its on-stream factor . The modified system consists principally of: (1) a rotary kiln (2) an added refractory lined cyclone; (3) a secondary combustion chamber (SeC); (4) a wetted throat quench elbow with sump; (5) a wet electrostatic precipitator (WEP) to replace the particulate filter; (6) a mass transfer (MX) s crubber; and (7) an induced draft (10) fan. Ancillary support equipment consists of bulk fuel storage; waste blending, and feed equipment for both liquids and solids; scrubber solution feed equipment; ash receiving drums; and an auxiliary diesel power generator. As part of the system modifications, the conventional air burner system in the kiln was replaced by the Linde Oxygen Combustion System. The Linde OCS consists of the patented "A" Bu["ner(3&4], an oxygen flow control piping skid and a cont["ol console. The cont["ol console utilizes a prog["ammable cont["oller to optimally integrate all system components into a flexible combustion package while p["oviding for easy operato[" inte["facing and safety interlocking. The unique design of the p["op["ietary "A" Burner allows the use of up to 100To oxygen in place of air fo[" incineration without creating high flame temperatu["e, high NOx ' poor mixing and non-unifo~ heat distribution. However, for incine["ators under even a slight vacuum, close to 100To oxygen enrichment would be ve["y difficult to achieve due to the inevitable ai[" infilt["ation . - 2 - |