Dehydration Column Revamp in PTA Plant
Start-up time: Sep., 1997
Original dehydration column had 60 conventional valve trays. Process of this column was special, which hot stream direct flowed into bottom of column without reboiler to be as heat source and reflux rate was low and couldn’t be changed. To improve the capacity of dehydration column, the client asked AMT to adopt ADV® trays to revamp two same dehydration columns. Capacity was expected to increase by 17%.
Conventional valve trays were replaced by ADV® high performance trays. Welding parts could be reused, such as support rings, etc. There were no need to increase number of trays and site welding.
New-design indented downcomers, “Quick-Connect” active tray joints and bubble promoters were adopted to increase open area so as to improve bubble status in active area.
Capacity was increased by 30% and tray efficiency was increased by 10%. Tray pressure drop was decreased by 20% compared to original design with same capacity.
On-site installation was so easy because new design for tray joint was adopted. It took 58 hours to change 120 trays for two columns.