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Show In operation, the incinerator is capable of a maximum design firing rate of 2.0 x lOb Btu/h. Waste Storage and Feed Subsystem As shown earlier in Figure 1, the waste storage and feed subsystem consists of a storage tank, recirculation p~mp, heater, liquid-waste supply pump, in-line waste fIlter, and a flow meter (rotameter) that quantifies the waste flow rate. The tank has a 220-gallon capacity, is made of carbon steel, and is externally insulated. The interior surface of the tank has been treated with a chemically resistant paint to prevent rust and avoid chemical activity between liquid waste and steel. To maintain both a well mixed and sufficiently heated liquid waste, a recirculation pump and steam heater were integrated with the storage tank. The pump is a flexible impeller type capable of handling 8 gpm at 30 psig. The heater uses 25 psig steam passed through a single tube concentric to a cylindrical shell, to maintain the waste at the desired temperature of 150° to 160°F. Although the pump is normally used for recirculation, it also serves to transfer the waste from drums to the tank and, secondarily, helps flush the storage and recirculation system. A second pump is used to transport the waste from the storage tank to the incinerator. This pump has a highpressure (100 psig), low-volume (1 gpm) capability: it incorporates a variable-speed drive for precise control of the flow rate of waste supplied to the atomizers. Downstream of this pump is an inline canister-filter containing a 100-mesh filter element. A filter bypass is provided to facilitate cleaning and ensure continuous system operation. To quantify the waste-flow rate, a rotometer was used immediately upstream of the atomizers. The float of the rotameter is easily visible when the waste liquid is properly prepared. The pipelines to and from the rotameter are insulated: where appropriate, they are also electrically heat-traced to minimize heat losses. Combustion Air/Natural Gas Subsystem As shown in Figure 1, the combustion air/natural gas subsystem consists of a primary combustion air blower, air/gas mixer, various orifices to measure flow rates, and appropriate valves to control and direct either combustion air or gas. The natural-gas piping train contains a pressure regulator, an orifice connected to a standard inclined manometer, a Maxon manual safety shutoff valve and a metering valve, all in series. Primary combustion air is routed through an 8-inch diameter duct incorporating an orifice connected to an inclined manometer. The natural gas and primary combustion air are combined in a specially designed mixer in which the natural gas passes from a circumferential plenum surrounding the 8-inch air duct. The natural gas pressure is sufficient to provide good mixing 10 |