焊板式换热器冷流侧压力降增大原因及对策

介绍了国内某炼油厂连续重整装置运行过程中焊板式换热器冷流侧压力降增大的情况,从上游装置流程、重整原料水含量及原料带胺液等原因进行了分析,认为焊板式换热器冷流侧压力降增大的原因是原料所带胺液与循环氢中的HCl形成的热稳态盐(HSS)堵塞了板束,提出了以下应对措施:(1)在液化石油气吸收塔前增加一水洗塔洗去炼厂干气中的胺液;(2)将分馏塔塔底重沸器由浮头式更换为U型管式,且在换热管和管板焊头处采用先强度焊后贴胀的连接方式,解决重整原料水含量超标问题。

Analysis of high pressure drop in plate heat exchanger feed side of CCR unit and countermeasures

High pressure drop in plate heat exchanger feed side of the CCR unit during operation in a domestic refinery are introduced. The impacts of upstream process flow, higher water content and entrained amine in feedstock are discussed. It is concluded from the analysis that the main causes of high pressure drop is the bundle blocking by heat-stable salts （HSS） which formed from amine in feedstock with HCl in recycle hydrogen. Measures for controlling pressure drop are recommended： 1 ） a water wash tower is installed upstream of LPG absorber to remove amine from refinery dry gas ; 2） floating-head reboiler at bottom of fractionator is replaced with U-tube reboiler and strength welding followed by expansion is adopted for the connection of tubes and tubesheet to reduce the water in CCR feedstock.