Air separationp plant is a kind of equipment that takes air as raw material, transforms air into liquid state by means of deep freezing of compression cycle, and then gradually separates and produces oxygen, nitrogen, argon and other inert gases from liquid air through rectification. Air separation plant is widely used in metallurgy, new coal chemical industry, large-scale nitrogen fertilizer, refining and chemical integration, professional gas supply and other fields. Air separation equipment recycling needs to evaluate the brand, model and status of the equipment.