I can't say why one tank car is okay while another is not. This mystery can only be unraveled by comparing historical data against shipping logs and operator shift records.
Dirk Willard, lead process engineer
Fluor Global Services, Inver Grove Heights, Minn.
LOOK AT SAMPLING
The popping and bubbling is a localized problem. I suggest that you do the following: 1) carry out a thorough inspection of the conveying systems for air ingress leakage; 2) dig back into the history to when there were no quality issues; 3) sample from the bottom as well as the top; 4) cross-check the loading process; 5) check your sampling procedures and personnel; and 6) take samples to the lab for a purity test.
Dennis Omenka, MS student, chemical engineering
University of Lagos, Akoka, Nigeria
Demurrage costs are prompting our refinery to install air diaphragm pumps as a backup for loading decanter oil on barges. We plan to use two pumps in tandem, each running at 200 gpm. Pump operation will require approximately 300 scfm of air at a minimum of 70 psig. The question is where to tie into the compressed air system (Figure 1). Refinery management is leery of tapping into nearby lines because of the variety of loads they serve. What's the best place to get the compressed air?
Send us your comments, suggestions or solutions for this question by June 8, 2012. We'll include as many of them as possible in the July 2012 issue and all on ChemicalProcessing.com. Send visuals — a sketch is fine. E-mail us at ProcessPuzzler@putman.net or mail to Process Puzzler, Chemical Processing, 555 W. Pierce Road, Suite 301, Itasca, IL 60143. Fax: (630) 467-1120. Please include your name, title, location and company affiliation in the response.
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