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目前,国内制造的尿素合成塔较多采用多层包扎结构,厚壁筒节由不锈钢内筒、盲层板、多层板包扎而成。尿素生产工艺常用的水溶液全循环法、二氧化碳气提法和氨气提法,不论采用那种工艺流程,较高浓度的氨基甲酸铵溶液都具有很强的腐蚀性,尤其是对碳钢有强烈的腐蚀作用。为了防止不锈钢内筒泄漏引发的腐蚀破坏,在尿素合成塔的设计制造上考虑了检漏系统,并且要求在尿素合成塔的运行过程中检漏管道畅通无阻。 1 检漏系统的工作原理尿素合成塔检漏系统主要用在生产过程中对不锈钢内筒的检漏.在制造过程也用于检查内筒加工质量的氨渗透试验。在检漏系统畅通的状态下,当内筒因材料缺陷或内筒纵、环焊缝缺陷发生泄漏时,泄漏介质流人盲层板的通气槽,氨基甲酸铵溶液会很快分解为气相的NH_3和CO_2随着检漏蒸汽汇
At present, the domestic manufacture of urea synthesis tower more use of multi-layer bandaging structure, thick-walled tube section by the stainless steel inner tube, blind laminates, multi-layer board bandaged. Urea production processes commonly used in the full cycle of aqueous solution, carbon dioxide gas extraction and ammonia extraction, regardless of the kind of process, higher concentrations of ammonium carbamate solution are highly corrosive, especially for carbon steel has a strong Corrosion. In order to prevent the stainless steel cylinder leakage caused by corrosion damage, the design and manufacture of urea synthesis tower to consider the leak detection system, and requires the operation of the urea synthesis tower leak detection pipeline unobstructed. A leak detection system works The urea synthesis tower leak detection system is mainly used in the production process of stainless steel inner cylinder leak detection.In the manufacturing process is also used to check the inner cylinder processing quality ammonia penetration test. Leakage system in the state of the smooth, when the inner tube due to material defects or tube longitudinal, Girth weld defects leak, the leakage of media flow through blind shelves ventilation, ammonium carbamate solution will be quickly broken down into the gas phase NH_3 and CO_2 with leak detection steam sink