onto the conveyor belt behind the base plates. The loading ramp empties as 16 more mortar bodies are delivered for the next sequence. Mortars are spaced on 5.0-in. center lines on the conveyor belt.
The heated portion of the MTU furnace is divided into six control zones. The temperature of the munitions is ramped up at a controlled rate in the first four zones and allowed to remain at temperature in the last two zones. The zone length is determined by the kinetics of heating the munitions and the desired soaking time at temperature. Munitions leaving the heated portion of the MTU enter a water-jacketed cooling chamber zone designed to cool the munitions and the belt conveyor to approximately 650°F. Experiments with simulated equipment test hardware munitions have confirmed this temperature.
At the exit end of the cooling chamber, which is also the exit of the MTU, is a rotary valve used to remove treated metal parts. Munitions exiting the rotary valve are deposited onto a discharge conveyor and then leave the discharge conveyor by way of a discharge chute that penetrates the agent processing building wall. The discharge chutes dump the metal parts into a container. After discharging metal parts to the rotary valves, the MTU conveyor belt returns to the loading area, traveling underneath the MTU muffle. This lower return tunnel includes the belt drive components and water seals that prevent the belt return tunnel from becoming contaminated by liquids and gases originating within the MWS room.
Off-gas from the MTU is discharged to the OTS through a vent located at the first heating zone of the MTU. The vent is equipped with a filter to capture large particles from treated munitions (oxidized paint and so on) before the offgas flows into a flameless thermal oxidizer designated as the bulk oxidizer. The filter is rated for 1200ºF, and differential pressure is measured across the filter to provide an indication of the need to clean the filter. Filter cleaning is accomplished by using compressed air to blow particulates from the filter back into the MTU after the system is isolated by closing a damper on the MTU vent line.
Secondary and closure waste is not processed in the MTU. Some of this material is combustible and would burn in the MTU muffle, since the muffle has air flowing through it to the MTU off-gas treatment system. These waste materials will be processed in the PCAPP supplemental decontamination unit (SDU) or in one of two autoclaves. The SDU operates at temperatures up to 400°F. These temperatures will cause thermal decomposition or pyrolysis of agent to levels meeting guidance requirements of the State of Colorado for shipment to a commercial hazardous waste treatment storage and disposal facility. The SDU and autoclaves are designed to thermally destroy mustard agent contained in closed spaces in various waste items such as valves and pumps. They also will decontaminate demilitarization protective ensemble suits, other plastics, contaminated wiring and hoses, other operating and maintenance waste, and closure waste.
Testing of the MTU took place at Abbott Furnace Company’s facility in St. Marys, Pennsylvania. The testing protocol was designed to verify the ability of the MTU to process at the specified rates, heat all parts of each munition to at least 1000°F, and maintain that temperature for a minimum of 15 continuous minutes. Additionally, the testing was to validate the structural integrity of the MTU, and the ability of the MTU to control air flows and to control particulate matter generated by the thermal decontamination process.
The MTU performed to specification, demonstrating the ability to transfer all munitions types mechanically at the design rate, to heat all munitions types according to the required thermal profile, and to manage the air flows as specified. Generated particulate matter showed no propensity to impair function. Design changes are planned in order to control particulate matter dusting at the discharge to the rotary valves. Operating procedures and control settings are being modified as well.
The committee reviewed the applicability of the MTU as an alternate method of decontaminating munitions bodies and secondary waste at BGCAPP. As noted above, the MTU is currently planned for installation at PCAPP for thermal decontamination of 155-mm and 105-mm projectiles and of 4.2-in. mortars that have been drained of mustard agent and passed through a high-pressure wash. In Table 5-1 the committee compares various operating requirements and features of the metal parts treater (MPT) and the MTU and identifies changes that would be required for the MTU to be used at BGCAPP.
Finding. The MTU could be used at BGCAPP for all projectile bodies. Dimensional modifications of the PCAPP MTU would be required to process 8-in. projectile bodies.
Finding. The MTU is not designed for processing secondary or closure waste. If used, it would also require the installation of supplemental decontamination and autoclave units at BGCAPP to treat solid waste, including squibs and fuzes from the energetics batch hydrolyzers and secondary and closure waste.
Finding. Supplemental decontamination units and autoclaves, if used at BGCAPP, would require space in the Level B area of the munitions demilitarization building.
Finding. A change from the MPT to the MTU will require modifications to the environmental permits. The schedule impacts for such a change have been estimated at delays of 7