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Thanks a lot Mr. Sam Lordo for your Answer on below question , Please also enlighten me whether the water injection rate should be 1-2% of the total overhead flow based on the query below?
"In our distillation column we are treating Natural Gas Condensate with 76 ppm sulphur, Acidity < 0.05 mg KOH and organic chloride <0.3 ppm and water content < 0.05%. but designer did not keep any caustic, corrosion inhibitor and Ammonia dosing provision due to combat corrosion at overhead line. Also they did not keep any DM water flushing provision (for fouling control within the tubes of aero condenser). Is it ok not to keep above provision as per above spec of NGC or NGL? But we are draining the overhead drum water separating boot approximately 10-15 litres per day where PH remains 5 to 5.5. So, do we need to use NH3, Caustic and corrosion inhibitor in order to keep PH more than 6?"
15/07/2019 A: sam lordo, Becht Engineering, salordo@comcast.net
water injection in these ovhd systems, isn't routine, but if you are seeing salt or corrosion by product then a water wash/flush would be appropriate. as you are already drawing some water ( not that much mind you), and you have a low side ph (typical you would like to see 5.5-6.5) without any caustic... i would suggest a trying a filming corrosion inhibitor over caustic or ammonia..
there are 2 types of these inhibitors (oil based and water based).
oil based would need a h/c diluent ( most time reflux)
water based could be used in DM water wash
both would require (quill and nozzle)
both would require a bleeder to inject thru..
does your unit have a high point bleed on the overhead line or near the coolers
the filmers would either go with the watre or down the tower and out the bottom of the tower