Liquid ammonia storage tank

　　Liquid ammonia is a basic chemical raw material, widely used in metallurgy, textile, papermaking and other industries, and is a raw material for the synthesis of hydrochloric acid, polyvinyl chloride, plastics, and pesticides. Liquid ammonia is a yellow-green oily liquid, highly hazardous (Liquid ammonia toxicity is classified as Class II in GBZ230), strong oxidants, and Liquid ammonia gas are not explosive but can support combustion (classified as B in GB50016).

　　Liquid ammonia storage tanks mostly use horizontal storage. The materials of storage tanks are generally low alloy plates specially used for low alloy pressure vessels such as Q345R and 16MnDR. The design pressure is 60 ° C, which is the saturated vapor pressure of Liquid ammonia gas, and the volume is generally 25 ~ 100m3. The loading factor is ≤ 0.8. For Liquid ammonia, consider setting up a storage tank with the largest volume as the accident tank. Once the storage tank leaks, most of the Liquid ammonia can be poured into the accident tank. The equipment is provided with pressure, liquid level and temperature detection. At the same time, the signal should be concentrated to the DCS system. The pressure and liquid level detection should be provided with a root shut-off valveThe inlet and outlet of the storage tank shall adopt double valves. At the same time, the inlet and outlet of the storage tank shall be provided with an emergency shut-off valve, the storage tank shall be provided with a safety valve, and the safety valve shall be provided with a root shut-off valve. A sewage pipeline is set at the bottom of the Liquid ammonia storage tank, and the drainage cycle is determined according to the concentration of nitrogen trichloride in the Liquid ammonia. The Liquid ammonia drainage needs to be processed by an alkali absorption tank. If the tank farm reserves more than 5 tons, it will constitute a key hazard source, and the safety protection distance between the tank farm and the surrounding facilities shall meet the requirements of project establishment evaluation.