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现场安装的硫磺储罐通常用于大量熔融硫磺的临时储存。然而由于腐蚀原因,特别是在正常液位上方的气相腐蚀,储罐的使用寿命十分有限。储罐腐蚀可能有若干机理,最可能的是因为在冷金属表面固体硫磺的沉积和痕量液态水的形成。这两种现象共同导致硫化铁的形成。硫化铁是自燃性物质,除了会造成储罐损坏外,如果突然与氧气接触还可能点燃罐内硫磺。抑制腐蚀的最佳方法是防止固体硫磺在罐壁和罐顶处形成。常规的加热技术,例如内部盘管,能有效地保持硫磺于熔融状态,却不能使蒸气相及罐壁维持足够高的温度。通过采用外部分布式加热系统,可将罐壁、罐顶以及蒸气相温度维持在硫磺凝固点之上,从而消除主要的腐蚀途径。论述潜在的腐蚀机理和操作数据,说明工程加热系统的重要性。
Sulfur tanks installed on site are often used for the temporary storage of large quantities of molten sulfur. However, the service life of the tank is very limited because of corrosion, especially in the gas phase above the normal level. Tank corrosion may have several mechanisms, most likely due to the deposition of solid sulfur on cold metal surfaces and the formation of trace amounts of liquid water. Both of these phenomena together lead to the formation of iron sulfide. Iron sulfide is a pyrophoric material, in addition to causing damage to the tank, if the sudden contact with oxygen may also ignite the tank of sulfur. The best way to prevent corrosion is to prevent the formation of solid sulfur at the tank wall and tank top. Conventional heating techniques, such as internal coils, effectively hold the sulfur in a molten state without maintaining the vapor phase and the tank wall at a sufficiently high temperature. By using an external distributed heating system, the temperature of the tank wall, roof and vapor phase can be maintained above the freezing point of sulfur, eliminating the major corrosion pathways. Discusses potential corrosion mechanisms and operating data and explains the importance of engineering heating systems.