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Hello, In our hydrogen production plant we have our own steam generation system that produces 36 bar of steam at 390 degree C temperature. Steam produced in the steam drum has a continuous blow down vessel. We noticed that the conductivity analyzer goes so high that it reaches to NAN sometimes as it automatically reaches to its normal values without any external steps taken by us. We are curious about this automatic adjustment of conductivity in blow down. We have checked the instrument as well, but there is no issue with the analyzer. It is to be noted that the BFW is mixed with condensate separator before pressure swing adsoprtion. The condesate water first goes to degasifier and then mixed with demin water and then pumped to steam drum where steam is made. From couple of days pH of condensate is very low due to low inlet temperature due to dissociation of carbon dioxide, which made pH low. Kindly tell us if there is any reason for high conductivity as per our case.
 
Answers
29/10/2020 A: Joel Kaye, Retired from UOP & Tesoro, kaye13@gmail.com
I would be concerned about the high CO2 in feedwater causing low pH plus corrosion in both the boiler and steam side. This could be the cause of your conductivity. The automatic blow down is designed to reduce mineral salts. You should eliminate or reduce CO2 in the BFW.