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Process Hazard Analysis Report July 2020 <br /> 2 Process Description <br /> Each refrigeration system uses anhydrous ammonia as the heat transfer fluid. The <br /> ammonia refrigeration processes are closed-loop, single-stage, mechanical <br /> refrigeration systems, with little or no need for operator involvement. The systems <br /> are automatically controlled by programmable logic controllers, which minimize the <br /> potential for human error. <br /> On-site personnel regularly monitor process parameters, including pressure, <br /> temperature, and vessel levels for proper operation. Abnormal conditions may be <br /> corrected by the refrigeration contractor technician. A qualified ammonia <br /> refrigeration company provides service, design, and regular preventive <br /> maintenance for the systems. <br /> The refrigeration equipment is located outdoors, most of which is under an <br /> approved exterior sheltered canopy. System components are connected with steel <br /> piping approved for ammonia refrigeration service and each system includes <br /> numerous safety devices, detection systems, alarms, and control valves. Physical <br /> protective measures and emergency shower and eyewash stations are located to <br /> enhance safety. <br /> Two design strategies are used to accomplish the required cooling, including <br /> pumped recirculated ammonia through wine tank jackets and high pressure liquid <br /> feed, direct expansion at the wine chillers. <br /> Each system is described with Piping and Instrumentation Diagrams (P&IDs) and <br /> the system operation is guided by written Standard Operating Procedures. The <br /> ammonia refrigeration systems are maintained regularly by the refrigeration <br /> contractor. <br /> The refrigeration cycle operates on the principle of the latent heat of vaporization <br /> and the transfer/absorption of heat that occurs as a result. First, the compressors <br /> provide high-temperature, high-pressure vapor as ammonia vapor is compressed. <br /> Next, the evaporative condensers remove the heat of compression generated <br /> when the ammonia vapor is compressed. <br /> The result of evaporative condensing is a high-pressure liquid, which drains to the <br /> receiver and is made available for cooling via control valves to other parts of the <br /> system. As cooling is required in wine chillers or wine tank jackets, the liquid is <br /> metered to provide the required heat exchange. As the liquid ammonia passes <br /> 5 <br />