(34d) Modified Shed Decks Tackle Crude Tower Fouling Problems
AIChE Spring Meeting and Global Congress on Process Safety
2019
2019 Spring Meeting and 15th Global Congress on Process Safety
Kister Distillation Symposium
Kister Distillation Symposium 2019: Optimization and Operation in Refinery Distillation
Monday, April 1, 2019 - 3:20pm to 3:50pm
While Distillation practitioners seek improvements to the cross-flow or counter-flow tray designs, they rarely evaluate technology that simplifies the designs. The same practitioners consider sheds a necessary efficiency downgrade to gain fouling resistance. However, is this a fair evaluation for shed decks? A counter-flow tray revamp of a cross-flow trayed tower is rarely a one-for-one basis; so why do we apply the same limits to a potential shed deck revamp of a cross-flow tray. The authors propose to deviate from the traditional evaluation protocol and to consider a non-one-for-one scenario when revamping a conventional tray with a shed deck in a fouling system.
The authors will share a case study of several recent applications where shed decks replaced sieve trays on a non-one-for-one basis without a loss in operating efficiency. In each application, the shed deck conversion was preceded by multiple revamp iterations with designs intended to improve anti-fouling characteristics. The previous revamps not only provided limited success in improving run-length, but also provided lower hydraulic capacity than the final shed deck revamp.