Acid settler drum

Figure 46.1 tells the tale. A faulty level indicator on the acid settler drum had caused the 90 percent sulfuric acid to carry over into the caustic settler drum. One pound of acid will neutralize 10 lb of the caustic solution. When I checked the pH of the circulating solution from the caustic settler, I measured a pH of less than 1. That is, the litmus paper turned red, not its normal blue. 

Fig. 15.19. Alkylation—Stratco, Inc. Includes contactor (1), acid settler (2), flash drum (3), deisobutanizer (4), compressor (5), and depropanizer (6). (Hydrocarbon Processing, 69, no. 11, p. 132, Nov. 1990 copyright 1990 by Gulf Publishing Co. and used by permission of the copyright owner.)...

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