The liquid nitrogen product of the air separation unit is sent to the liquid nitrogen storage tank after passing through the subcooler.
When it is necessary to start the low-pressure liquid nitrogen backup system, the liquid nitrogen products in the storage tank can be vaporized in the water bath evaporator after being boosted to the required pressure by the low-pressure liquid nitrogen backup pump, and output as the backup low-pressure nitrogen products. A part of them is equivalent to the atmospheric nitrogen products output as the atmospheric nitrogen products after throttling.
When the medium pressure liquid nitrogen backup system needs to be started, the liquid nitrogen product in the storage tank can be boosted to the required pressure by the medium pressure liquid nitrogen backup pump, and then vaporized in the water bath evaporator as the backup medium pressure nitrogen product output in case of emergency.
When the high-pressure liquid nitrogen backup system needs to be started, the liquid nitrogen product in the storage tank can be boosted to the required pressure by the high-pressure liquid nitrogen backup piston pump, and then vaporized in the air bath evaporator as the backup high-pressure nitrogen product for emergency output.
When both the air separation unit and the downstream devices are shut down or the whole plant is cut off from water and power, the liquid nitrogen from the liquid nitrogen vacuum tank vaporizes through the air bath evaporator, one part of which is used as the emergency gas for the whole plant, and the other part is sent to the downstream device of the user through throttling.
The air separation backup system is equipped with high-pressure nitrogen buffer tank for downstream gas supply in a short time before the backup system reaches full load when the air separation unit trips.
DEAR Air Separation is specialized in R&D, manufacturing and installation of various complete sets of air separation equipment and high-purity nitrogen equipment, with advanced technology and reliable quality. It has won high recognition from customers all over the world.
