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High Performance Tray Design. Dr. Leon Fan. Kenning Engineering, LLC. Dr. Leon Fan. Graduate Chinese Academy of Sciences Post Doctoral Work on Gas/Liquid Two Phase Flow, University of Illinois FRI Research Engineer Glitch Inc. Manager, Research Department
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High Performance Tray Design Dr. Leon Fan Kenning Engineering, LLC
Dr. Leon Fan • Graduate Chinese Academy of Sciences • Post Doctoral Work on Gas/Liquid Two Phase Flow, University of Illinois • FRI Research Engineer • Glitch Inc. Manager, Research Department • ACS Separations Technology, Technical Director • Six Tray Patents & Numerous Publications
High Performance Trays High Capacity + High Separation Efficiency • Uniform Gas/Liquid Flow Distribution • Intimate Gas/Liquid Contact on the Tray • Correct Liquid Residence Time on the Tray-Deck and in the Down-Comer
Structured Packing (1) • Advantages • Low Pressure Drop • High Gas Flow Capacity • High Mass Transfer Under Certain Conditions
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
Isobutane/N-Butane, 300 psia Tested by FRI
History Begins in Early 1990 • Glitch Nye Tray • Glitch SuperFrac Tray (Early Version) • Nutter MVG • Koch MaxFrac • Norton Triton • Glitch SuperFrac Tray (New Version)
Development Incentives • Production Expansion Without Changing Column Size or Tower Attachments • Improved Product Quality • Reduction of Reflux Rate and Energy Consumption • Improved Anti-Fouling Characteristics
Common Characteristics • Use of Fixed or Moveable Valves, Instead of Sieve Tray • Use of Modified Down-Comers
Gas Liquid Flow Pattern Sieve Tray Valve Tray
Kenning 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
Gas-Liquid Flow Pattern on Conventional Tray Low Liquid Flow Efficient Mass Transfer Low Gas Flow July 2001
Conventional Bubbling Promoter Downcomer Vessel Wall Liquid Flow Gas Flow
Triangular Bubbling 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
Truncated Downcomer Koch MaxFracTM Tray with Truncated Downcomer
Gas-Liquid Flow Pattern on Kenning Tray Efficient Mass Transfer
Downcomer Design • Create Best Initial Liquid Flow Distribution • Minimize Down-comer Bottom to Increase Active Area • Maximize Weir Length and Down-comer Exit Length
Glitch New SuperFrac™ Tray Downcomer Design
Kenning Tray Downcomer Design
Kenning Tray Basic Components • Miniature Valves • Bubbling Promoters • Down-Comers
1-Butene 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%
Results • Feed Rate Increased to 5 tons/hr • Yield Raised to 93.6% • Total Pressure Drop of the Columns did not Increase • No Tower Attachments Changed • No Welding on the Vessels
Reasons 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.
Typical Vapor Horn Gas Flow In Gas Flow Out
Multi-Stage Vapor Distributor Gas Flow In
C4 & Solvent Mixing Section Fig. 5a Fig. 5b