塔设备大接管现场改造若干问题

从设计、焊接、热处理和耐压试验等方面对CO2汽提塔大接管改造中遇到的问题进行了探讨，改造接管部位最危险工况为内压＋重力载荷＋开孔面法线方向风载荷组合工况，此工况下大开孔和不规则补强应力校核满足JB4732—1995（（钢制压力容器——分析设计标准》要求。采用回火焊道技术并在焊接时采用专用夹具和优化的焊接顺序施焊，有效地降低了焊接残余应力。改造中严格执行改造工艺，在满足汽提塔结构强度和密封性的前提下免除了水压试验。改造后设备运行平稳，质量良好。

Study of Big Nozzle Modification for Tower Equipment

Because of the limitations of regulations and technology, large opening, welding, heat treatment and pressure test have been discussed during nozzle modification of CO2 stripper. The results indicate that, combined condition of pressure, gravity and wind load which along the nor mal direction of the opening is the most dangerous condition, stress analysis of opening under this condition meet the requirement of JB 4732-1995 ＂Steel Pressure Vessel Analysis Design Standard＂. To reduce welding residual stress and except heat treatment, temper bead welding, special fixture and optimized welding sequence have been performed. Pressure test is excepted when structural strength and leak tightness of CO2 stripper meet the application requirements.