OCR Text |
Show combustor while the kiln was not operated. The purpose of this test was to demonstrate that a 99.9999% PCB destruction and removal efficiency and a scrubber effluent PCB concentration of less than 2 ppm could also be achieved when the secondary combustor was operated without the kiln. In the fifth test (trial burn #3), pre-shredded capacitors, having a PCB content of approximately 38%, were fed to the kiln and high-level PCB liquids, having a PCB concentration of approximately 46%, were fed to the secondary combustor. The purpose of this test was to demonstrate that (1) a 99.9999% PCB destruction and removal efficiency and a scr~bber effluent PCB concentration of less than 2 ppm could be achieved when burning capacitors in the kiln and PCB liquids in the secondary combustor: (2) the kiln could handle shredded capacitors: and (3) a detoxified kiln ash could be achieved when burning capacitors. An independent contractor was hired to sample and analyze stack gas emissions. Each test was divided into two portions. In the first portion, which took approximately one hour. stack emissions were sampled for HCI. particulate. 02, C02, NOx and SOx. In the second portion, which took approximately four hours, stack emissions were sampled for PCBs, PCDDs (dioxins), PCDFs (dibenzofurans) and Chlorinated Organics. Solids/Ash and scrubber effluent generated during the tests were sampled and analyzed for PCBs, PCDDs and PCDFs. All wastes. contaminated fuel, clean fuel were sampled and analyzed for · PCB. BTU and Chlorine content by the in-house personnel. PROCESS DESCRIPTION The modular waste processor (MWP-2000) has four main process modules; (1) Rotary Kiln, (2) Liquid Incinerator/Secondary Combustor, (3) Heat recovery system. and (4) Pollution control system. A process flow diagram is presented in Figure 1. The rotary kiln is a refractory lined, carbon steel cylinder mounted horizontally on a trailer and rotated by a trunnion drive mechanism. Contaminated solids are transported by belt conveyor to a charging hopper at the front of the kiln. A screw feeder at the bottom of the hopper feeds the solids into the front of the kiln at a controlled feed rate. Kiln outlet gas temperature is maintained around 1700 degrees F to assure vaporization and partial destruction of organic constituents. Solids residence time of approximately 30-40 minutes and kiln rotation of 2-3 rpm are maintained to ensure complete mixing and sufficient burn time for the solids. Residual ash drops out of the back end of the kiln into a water sealed ash receiving tank and is transported by a chain drag conveyor to a portable ash storage bin where it is sampled for potential contaminates before being sent to landfill. The liquid incinerator/secondary combustor is a large refractory lined shell sized to provide a combustion gas residence time of 2 seconds at a temperature exceeding 2200 degrees F. PCBs and other hazardous liquids are destroyed in the primary burner that completes -3- |