2017 Annual Meeting
(398aq) Revitalization of 18 Years Old Deceased Urea Stripper Offering Multiple Challenges and Marvels of Engro and Toyo Team
Author
Siddiqui, M. S. - Presenter, Engro Fertilizer company (Former Exxon chemical))
This paper includes intermittent multiple challanges of mechanical integrity and process efficiency of TECâs designed Urea plant ACES Stripper since itâs commissioning in 1998. This plant was relocated from Billingham UK and commissioned at Daharki-Pakistan in Oct-1993 originally having TOYO-total recycle C-Process built. Plant was debottlenecked from 1016 MeT/Day to 1283MT/day post Phase-1 Expansion, later on to 1467 MeT / day in june-1995 and finally debottlenecked to 1755MT/day name plate capacity by retrofitting ACES Technology in 1998. This Paper includes challenges faced on Stripper like Stripping efficiency loss, modification of swirls and trays, uneven distribution of solution; T-TS weld joint leakages, HAZ formation, crater corrosion of tubes and tubesheet. It also includes the complex identification of stripperâs tubes leakage among two vessels (CC-1 and stripper) during operation. This paper also covers Marvels of Engro and Toyo team to come out of every challenge with minimal investment to ensure safe and sustainable operation. This was achieved through indigenous efforts primarily covering highlights of process and Operational excellence like conducting Ammonia leak test and judging the type of problems in stripper, multiple seal-weld repairs, tubes plugging and reclamation of old deceased swirls. It will also benefit Urea-manufacturing sites to prolong the life of their equipment with minimal cost.