Eclipse Engineering


Eclipse Engineering

Flue Gas Duct Systems

Eclipse can provide better industrial duct designs because our engineers consider flow characteristics and structural integrity simultaneously. Not doing so will likely lead to an expensive duct stiffening arrangement, excessive duct support-structure loads, and/or flow characteristics that don't meet specification or entrain and deposit undesired particulate. Eclipse has a proven methodology for determining how the fluid dynamics and structure facets affect performance, design time, and fabrication costs.

Eclipse's expertise is with large steel and alloy duct, typically with cross section dimensions greater than 10'. Usually the duct is exposed to pressure, thermal, and particulate loads, as well as external loading such as wind and seismic.

Eclipse has developed analysis techniques for quickly arriving at a workable solution that avoids problems such as:

  • Particulate fallout/build-up in regions of recirculation
  • Excessive pressure drop
  • Fan inlet velocity profiles outside of spec, which impede fan performance
  • Over-designed and therefore overly expensive duct
  • Poor selection of stiffener shape and connections that increase cost
  • Excessive load on the support structure due to incorrect duct leg fixivity or misplaced internal bracing
  • Turning vanes conflicting with internal bracing

Some examples of specific automated routines that allow Eclipse to reduce analysis time and cost:

  • Vane optimization thru automated CFD analysis quickly determines the vane radius and number such that particulate fallout due to areas of gas recirculation is minimized. The routine determines the sensitivity of the objective (minimal gas recirculation) to the design variables (vane radius and number) so the vane characteristic that affects fallout the most is most utilized. For example, if the particulate fallout is more affected by the radius of the vanes than is the number of vanes, then the radius should be varied to achieve the objective, rather than increasing the number of vanes. The result is less fallout, and a less costly vane design.
  • A routine that checks stiffener weld fatigue due to differential gas temperature across the gas stream.
  • An automated finite element post-processing routine that quickly calculates the loads on support steel for all load cases analyzed. This improves our delivery to the client of the support steel design, or the loads to their structural engineers if the support steel design is not in Eclipse's scope.

Analysis Tools Used

  • RISA
  • AutoCAD, Inventor
  • SolidWorks, Pro/ENGINEER
  • Excel
  • Mathcad
  • EKLIPSTM FEA service

Design Codes Used

  • AMCA Standard 803
  • AISC
  • ASME