high performance tray design dr. leon fan kenning engineering, llc
TRANSCRIPT
High Performance Tray High Performance Tray DesignDesign
Dr. Leon FanDr. Leon Fan
Kenning Engineering, LLC
July 2001
Dr. Leon FanDr. Leon Fan
Graduate Chinese Academy of SciencesPost Doctoral Work on Gas/Liquid Two
Phase Flow, University of IllinoisFRI Research EngineerGlitch Inc. Manager, Research DepartmentACS Separations Technology, Technical
DirectorSix Tray Patents & Numerous Publications
July 2001
High Performance TraysHigh Performance Trays
Uniform Gas/Liquid Flow Distribution Intimate Gas/Liquid Contact on the TrayCorrect Liquid Residence Time on the
Tray-Deck and in the Down-Comer
High Capacity + High Separation Efficiency
July 2001
Structured Packing (1)Structured Packing (1)
Advantages– Low Pressure Drop– High Gas Flow Capacity– High Mass Transfer Under Certain Conditions
July 2001
Structured Packing (2)Structured Packing (2)
Disadvantages– Unstable Performance at High Liquid Rates– High Bed Requires Liquid Re-distribution– Cannot be Used in Fouling Systems
Application– Low to Medium Liquid Rate Distillation
July 2001
Isobutane/N-Butane, 300 psiaIsobutane/N-Butane, 300 psia
0
5
10
15
20
25
30
HETP(inch)
Tested by FRI
July 2001
HistoryHistory
Glitch Nye TrayGlitch SuperFrac Tray (Early Version)Nutter MVGKoch MaxFracNorton TritonGlitch SuperFrac Tray (New Version)
Begins in Early 1990
July 2001
Development IncentivesDevelopment Incentives
Production Expansion Without Changing Column Size or Tower Attachments
Improved Product Quality Reduction of Reflux Rate and Energy
ConsumptionImproved Anti-Fouling Characteristics
July 2001
Common CharacteristicsCommon Characteristics
Use of Fixed or Moveable Valves, Instead of Sieve Tray
Use of Modified Down-Comers
July 2001
Kenning TrayKenning Tray
“Scallop Edged, Miniature-Valves” SEMV’s
– Scalloped Edges Divide Gas Stream to Several Small Streams to Enhance Gas/Liquid Contact
– Small Gas Streams Reduce Pressure Drop– Small Gas Streams Reduce Liquid Entrainment
July 2001
Gas-Liquid Flow Pattern on Gas-Liquid Flow Pattern on Conventional TrayConventional Tray
July 2001
Efficient Mass Transfer
Low Gas Flow
Low Liquid Flow
July 2001
Conventional Bubbling PromoterConventional Bubbling Promoter
Vessel Wall
Downcomer
Gas Flow
Liquid Flow
July 2001
Triangular Triangular BubblingBubbling Promoters Promoters
Diminish High, Horizontal Liquid Velocity out of Down-comer
Strong Gas Streams Blend Clear Liquid into Froth
Three Dimensional Velocity of all Gas Streams out of Bubbling Promoter
July 2001
Gas-Liquid Flow Pattern on Gas-Liquid Flow Pattern on Kenning TrayKenning Tray
Efficient Mass Transfer
July 2001
Downcomer DesignDowncomer Design
Create Best Initial Liquid Flow DistributionMinimize Down-comer Bottom to Increase
Active AreaMaximize Weir Length and Down-comer
Exit Length
July 2001
Kenning Tray Basic ComponentsKenning Tray Basic Components
Miniature ValvesBubbling PromotersDown-Comers
July 2001
1-1-Butene Separation SystemButene Separation System
Existing System– Two Consecutive Towers 1.3 m & 1.8 m I.D– 150 Conventional Trays in Each Tower– Existing Trays Japanese Design & Manufacture
Goal– Increase Feed Rate from 3.2 tons/hr to 5 tons/hr– Raise Yield from 89% to more than 90%
July 2001
ResultsResults
Feed Rate Increased to 5 tons/hrYield Raised to 93.6%Total Pressure Drop of the Columns did not
Increase No Tower Attachments ChangedNo Welding on the Vessels
July 2001
Reasons for Capacity GainReasons for Capacity Gain
SEMV’s allow increased gas flow with lower pressure drop.
Downcomer design increases active tray area and improves vapor/liquid flow distribution.
Bubbling Promoter aerates liquid more quickly.
High separation efficiency reduces reflux rate.