Transcript High Performance Tray Design Dr. Leon Fan Kenning Engineering, LLC

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
July 2001
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
July 2001
Structured Packing (1)
 Advantages
– Low Pressure Drop
– High Gas Flow Capacity
– High Mass Transfer Under Certain Conditions
July 2001
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 psia
30
25
20
HETP
(inch)
15
10
5
July 2001
1.
08
1.
03
0.
32
8
0.
43
8
0.
64
6
0.
74
9
0.
85
6
0.
92
9
0.
92
4
0.
97
3
0
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)
July 2001
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
July 2001
Common Characteristics

Use of Fixed or Moveable Valves, Instead
of Sieve Tray
 Use of Modified Down-Comers
July 2001
Gas Liquid Flow Pattern
Sieve Tray
Valve Tray
July 2001
Normal Tray Valve
July 2001
New Mini-Valves, Gas Flow
Patterns
July 2001
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
July 2001
Gas-Liquid Flow Pattern on
Conventional Tray
Efficient Mass Transfer
Low Liquid Flow
Low Gas Flow
July 2001
Conventional Bubbling Promoter
Downcomer
Vessel Wall
Liquid Flow
Gas Flow
July 2001
Kenning Bubbling Promoter
July 2001
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
July 2001
Truncated Downcomer
Koch MaxFracTM Tray with Truncated Downcomer
July 2001
Gas-Liquid Flow Pattern on
Kenning Tray
Efficient Mass Transfer
July 2001
Downcomer Design

Create Best Initial Liquid Flow Distribution
 Minimize Down-comer Bottom to Increase
Active Area
 Maximize Weir Length and Down-comer
Exit Length
July 2001
Glitch New SuperFrac™ Tray
Downcomer Design
July 2001
Kenning Tray Isometric
July 2001
Kenning Tray
Downcomer Design
July 2001
Kenning Tray Basic Components
 Miniature
Valves
 Bubbling Promoters
 Down-Comers
July 2001
Kenning Tray Deck
July 2001
View of Tray
July 2001
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%
July 2001
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
July 2001
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.

July 2001
Modified Arrangement of Side
Draw
Fig. 10
July 2001
Typical Vapor Horn
Gas Flow In
Gas Flow Out
July 2001
Multi-Stage Vapor Distributor
Gas Flow In
Gas Flow
Out
July 2001
View of Multi-Stage Vapor
Distributor
July 2001
C4 & Solvent Mixing Section
a . Be fore re va mp
July 2001
Fig. 5a
b . Aft er re vam p
Fig. 5b