焦炭塔鼓凸变形应力测试与分析

焦炭塔长期在高温及充焦、除焦的冷热疲劳作用下运行,常出现塔体局部严重变形和母材焊缝开裂问题。针对这一现象,对某厂焦化车间三号焦炭塔采用塔体表面贴应变片的方法,通过对其一个工作循环周期(48 h)进行塔体表面应变和温度测量并计算塔体应力,对整个焦炭塔的应力状况进行考察。结果表明,冷焦过程中液面逐渐上升,液面与塔壁相交圆周处的应力发生迅速的升高与回落,由此产生的温差应力是导致塔体残余应力和鼓凸变形的主要原因。同时,焊缝处较高的强度造成焊缝处变形较小而筒节中央变形较大,使焊缝热影响区应力较高也是塔体发生鼓凸变形的原因。此结论可为焦炭塔的设计、加工以及寻求解决鼓凸变形问题的方法与对策提供可靠的理论依据,对焦炭塔的操作也有一定的指导意义。

Stress testing and analysis to distortion of the coker

The coke towers are working under high temperature and coke in and out with hot and cold distress,and local severe distortion of the towers or dehiscence of welded seam appears frequently.Aiming at this,used the method of affixing the strain gauges to the coke tower,measured the strain and temperature of the coke tower outer face during the whole operating cycle, and calculated the stress to investigate the stress of the whole outer face of the coke tower,and also tried to find the solution to the problem of the distortion of the coke tower.The analysis indicates when the fluid level rise continuously,the strain where the inner circle of the coke tower contacting with the liquid level rises and falls down rapidly,and the thermal stress it caused is the main reason of the residual stress and distortion.The higher intensity of the welded seam caused the bigger distortion at the middle of the vessel course and a smaller one at the welded seam,and the coke tower is distorted like a cucurbit.This conclusion afforded reliable theoretical foundation,and also gives directions to locale construction and operation.