石化装置中弹簧支吊架的应用浅析

Application of Spring Hanger in Petrochemical Plant

当管道在支吊点处有垂直位移时,应选用弹簧支吊架;承载力随着管道位移有变化时,选用可变弹簧支吊架;荷载保持不变时,选用恒力弹簧支吊架。弹簧支吊架既有减小设备管嘴受力、避免脱空和过载的优点,也有价格贵、可靠性差、占用空间等缺点。在管道设计中,宜优先选用刚性支架;有垂直位移时,再选用弹簧支架;有水平位移时,还应考虑增设限位支架。当荷载过大或安装空间受限时,应调整装配型式。弹簧装配型式一般由管道走向及安装空间决定,有几种常见的装配型式。某石化厂新建柴油加氢装置,产品分馏塔塔底到柴油泵管线设计温度326℃,管径350mm;塔高36m,裙座高9m。先据经验分析,塔在裙座处为固定点,由于温度高,塔底部封头带着塔出口线在塔附近必然有向下位移。用CAESAR软件验证,管线在塔出口处确有向下的位移。根据工作荷载及位移量,并考虑支撑位置,最终选取到合适的弹簧,从而满足管系的安全运行需要,保证设备甚至装置的安全可靠。

Spring hanger is used when a pipeline has vertical displacement at the supporting point or hanging point.When the bearing capacity varies with the displacement of pipeline,variable spring hanger should be selected.When the load remains unchanged,constant spring hanger should be selected.Spring hanger can reduce the force on equipment nozzle and avoid the unsupported or overloaded pipelines,but it has disadvantages of high price,poor reliability and large occupied space.In piping design,rigid support is preferred,spring hanger should be selected when there is vertical displacement,and limited support should also be considered when there is horizontal displacement.The assembly type should be adjusted when the load is too high or the installation space is limited.The assembly type of spring is generally determined by the route of pipeline and the installation space,and there are several common assembly types.For a new diesel hydrogenation unit in a petrochemical plant,the designed temperature of the pipeline from the bottom of fractionation tower to the diesel oil pump is 326℃ and the pipe diameter is 350 mm.The tower is 36 meters high and the skirt is 9 meters high.Based on empirical analysis,the tower is fixed at the skirt,and there must be downward displacement of tower outlet pipe near the tower brought by the tower bottom head due to the high tempera-ture.It is verified by CAESAR software that there is downward displacement of the pipeline at the outlet of tower.Taking the support position into consideration, appropriate spring is finally selected according to the working load and displacement,thus satisfying the safe operation requirements of the piping system and ensuring the safety and reliability of the equipment and even the unit.