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Show and prevent backflow of the combustion air into the naturalgas piping. Subsequent to mixing, the air/gas mixture is routed to a manifold containing a water-cooled flame arrestor. From the manifold, the mixture enters the tangential nozzles at the top of the incinerator. Cooling-Water Subsystem Water is routed to the incinerator unit and manifold to the inlets of each cyclonic chamber section. Thermocouples are installed in the outlet water pipe of each section ann a single thermocouple monitors the inlet water temperature. The temperatures are read using a digital readout near the storage tank. None of the water used in the incineration system is pretreated. After use, the exiting water is gathered in a common trough and drained to a sewer. Total water usage is approximately 20 gpm. Atomizers and Atomizer Assemblies A key component in the design of the incineration unit is the geometry, orientation, atomizing technique and atomizer type used to introduce the liquid waste into the incineration chamber. Technical and cost information was collected from Delavan, Bete and Spraying Systems, Inc., to evaluate the optimum atomizer characteristics specific to the incinerator prototype unit, and the waste characteristics. Factors such as physical size, pneumatic versus mechanical operation, hollow-cone versus full-cone spray pattern, spray angle, droplet size, and material type were ~alu~ted for each type of atomizer considered. Certain of the pneumatic atomizers described above were examined in the incinerator. They produced droplets in the range of 50 to 150 microns for liquid waste pressures of 15 to 25 psig and compressed air pressures of 30 to 40 psig. The Delavan pneumatic atomizer employs a 90° hollow-cone spray pattern and the compressed air inlet was modified in order for the atomizer assembly to fit inside a typical tangential nozzle. The Spraying Systems pneumatic atomizer employs a 30° solid-cone spray pattern. None of the examined mechanical atomizers, which by definition use only liquid pressure to promote atomization without the assistance of a second medium such as compressed air or steam, produce relatively coarse droplets; thus none were used during any combustion tests. Regarding atomizer assemblies, several techniques for positioning an atomizer in a tangential nozzle were developed to perform three functions: 1) centering of the atomizer on the longitudinal axis of the tangential nozzle, 2) positioning of the atomizer along the length of the tangential nozzles, and 3) orientating the atomizer to spray either parallel with the air/gas stream entering the tangential nozzle or counterflow to the air/gas stream. 11 |