大型空分装置冷箱内铝合金焊接施工技术

Application of Aluminum Alloy Welding Technique in Cold Box of Large Air Separation Equipment

铝合金材料是空分装置冷箱中的主要材料,铝制设备和铝合金管道的现场焊接是空分装置冷箱施工的重点和难点,而空分冷箱的密闭和-196℃的操作温度决定了冷箱内所有连接头必须采用焊接方式,焊接接头的质量直接关系到装置的稳定运行。文章通过介绍安庆石化48000m3/h空分装置中冷箱内铝制分馏塔的现场组对和铝镁管道焊接过程的施工控制经验,重点分析大型冷箱内铝合金焊接特点和容易产生的缺陷,从而确定铝制设备与铝合金管道焊接工艺以及空分装置大型冷箱的施工要点。

Aluminum alloy is a main kind of material used in the cold box of air separation equipment. The field welding of aluminum-made equipment and aluminum alloy pipeline is critical and difficult in the cold box construction. The cold box working in a hermetic condition and at a temperature of -196℃ requires that all joints must be welded, and the welding quality relates directly to the working stability of the equipment. Based on the construction control experience of field assembly of an aluminum-made fractionating tower and welding of aluminum and magnesium alloy pipeline in the cold box of 48 000 m3/h air separation equipment at Anqing Petrochemical Co., this paper analyses the characteristics of aluminum alloy welding in a large cold box and the defects often occurred during the welding, than makes certain the welding process of aluminum made equipment and aluminum alloy pipeline as well as key points of large cold box construction.