Enhanced Deck and Advanced Chordal Downcomer High Performance Trays

Our high performance trays combine special tray decks for superior vapor capacity with advanced chordal downcomer technology for increased liquid capacity.


VGPlus™ trays

VGPlus™ trays are Sulzer's high performance trays with enhanced deck and improved chordal downcomers. They offer industry-proven and Fractionation Research Inc (FRI) validated advanced tray technology for today’s market.

Advantages compared to conventional trays:

  • Higher capacity: up to 30% 
  • Lower pressure drop: up to 20% 
  • Equal or higher mass transfer efficiency 
  • Lower hydraulic gradient 
  • More uniform liquid flow 
  • More uniform vapor distribution 
  • More uniform L/V on tray deck 
  • Higher fouling resistance

Key characteristics

Enhanced tray deck design:

  • Optimized Mini V-Grid Valve (MVG) layouts
  • Redirecting and froth promoting devices such as baffle bar and push valves

Baffle bars

Improved downcomer technologies:

  • Truncated 
  • Highly sloped 
  • Steparc (Stepped) 
  • Modarc (Multi-chordal)

Conventional versus truncated downcomer

1-pass VGPlus with baffle bars and SteparcTM (stepped-multi-chordal) downcomer

FRI Validation:

  • Superiority of VGPlus tray technology has been confirmed by independent experiments at FRI 
  • VGPlus has been tested in the 1.2m diameter FRI tower at 7 and 11bar with i-C4/n-C4 system 
  • VGPlus provided up to 10% higher capacity compared to competitors’ high performance tray 
  • VGPlus tray efficiency was up to 15% higher than that of competitors’ high performance tray 
  • VGPlus is one of the best chordal downcomer trays ever tested at FRI

FRI test results

New ways in tray development:

  • Computational Fluid Dynamics (CFD) supported classical research and pilot testing in developing the VGPlus trays 
  • CFD allows complex two-phase phenomena to be studied, e.g. froth flow and liquid entrainment

CFD results

VG AF™ trays

VG AF™ (Anti Fouling) trays provide superior anti-fouling performance, while delivering high capacity and efficiency, thus making these trays ideal for debottlenecking fouling services.

  • Specially designed for fouling services 
  • Uses large fixed valves 
  • Tailored design features on tray deck reduces stagnation zones 
  • High performance downcomer technology enhances liquid disengagement on the tray deck

2-pass VG AF with push valves

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