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I have difficulty in drawing product from my side stripper of the atmospheric distillation tower. Whenever I raise the Stripping steam rate, this problem will occur. My initial suspect is due to the hydraulic limitation when the stripping steam is above a certain value. The technical reasoning would be when there is high vapor rate rising up the stripper tower, the vapor load creates high pressure drop across the stripping trays. Liquid flowing from the top will ultimate be restricted from flowing down the stripper tower and creates hydraulic limitation. Do you all agree on this observation?
 
Answers
16/04/2018 A: Sudhakara Babu Marpudi, Oman Refineries and Petroleum Industries Company, m_sudhakarababu@yahoo.com
Wet stripping steam is one reason I have observed. Steam condensate from the bottom of the side stripper, will lead to pump cavitation too. Ensure the stripping steam header is free of condensate, if not dry. In Kero / Jet fuel stripper case this will lead to the bed compacting effect of the down stream Merox reactor. We were forced to bypass Merox till the bed was back flushed and loosened to improve the flow thru the Merox reactor from ZERO levels.
11/04/2018 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
The trays will have a maximum capacity (100% of flood), influenced by the combination of liquid and vapor rates. The stripping steam for a side stripper should be in the range of 0.1 lbs/gal. However, the rate can be optimized by trying different rates and performing an economics calculation by comparing any improvement in the yield distribution against the cost of the steam.