Water-Induced Pressure Surges

Dehydration by purging with hot gas is fast, but seldom achieves complete water removed. In one case (23), numerous water-induced pressure surges occurred at startup due to incomplete diyout using this technique. When bone-drying is required, this technique is best used for initially removing the bulk of the water. The rest is removed by one of the above techniques, such as liquid circulation (23, 54). 

Figure 13.1 Water-induced pressure surge incident in a refinery coker combination tower. (Reprinted with permission of copyright owner from the Booklet "Hazards of Water," copyright 1984, Amoco Oil Company ...

The above case histories were described in detail here to illustrate the damage that even small quantities of water can do when they initiate a pressure surge. Several other incidents of water-induced pressure surges in fractionators have been described (4, 7, 23, 145, 146, 237, 296, 358) and the author is familiar with a few others. Amoco s booklet, in particular (4), contains excellent, well-illustrated descriptions of several such incidents. 

The following guidelines can help prevent water-induced pressure surges in columns containing hot, water-insoluble materials (Fig. 13.3) ... 

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