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Oilseed Extraction Area Expansion

CLIENT: Multinational Oilseed Processor

PROJECT: Existing Plant Extraction Expansion including new Desolventizer Toaster & Dryer Cooler (DT and DC)

BACKGROUND: After a qualification based selection process involving several leading engineering companies, the client selected ADF Engineering to upgrade and increase capacity for their extraction process.


  • Classified Area. The project was in hazardous area tower image classified as Class I Div. 1. Information gathering of the existing layout needed to be done using intrinsically safe equipment or by hand.
  • Tight space. The new DT was too large to fit in the existing extraction building. A new tower had to be designed and built adjacent to the existing structure with a limited footprint to avoid interferences with existing structures and equipment. The equipment arrangement required the upper floors of the tower to have a larger area than the lower floors, so several upper sections were designed as cantilevers.
  • No interruption to operation. The design needed to accommodate installation phases to occur over a tight schedule during three separate plant shutdowns. The deep foundation system and its installation was designed not to disturb the operation of the adjacent existing Extractor.
  • Limited load capacity. The existing extraction building was used to house several new conveyors, the dryer cooler, a large vapor scrubber, and a steam heater. Several floors needed to be expanded for equipment and maintenance access and the existing framing needed to be re-evaluated to support the additional loading.
  • An existing stair tower needed to be removed and reinstalled in a different location to make room for the new DT tower. The DT tower was designed to match existing extraction building floor elevations and incorporate the stair tower for access to the lower four levels.
  • Construction schedule. Constructability was a major factor in design. Removing necessary demolition and bringing new construction materials into the existing tower was limited. The new tower and its foundations needed to be installed in a small area surrounded by existing equipment and structures. Additionally, the DT tower had to be designed with certain members left uninstalled so that the fully assembled DT could be lowered down through the tower without interferences.


ADF performed multi-discipline engineering services and completed preliminary and detail design, bid packages, and construction phase assistance. This project layout was ultimately designed to benefit plant operation and maintenance. It was comprised of renovation to the existing extraction building and designing a new independent DT tower in an unoccupied space. Approximately 3,000 design hours went in to designing this expansion and all the accessory items required.

Structural design of this new arrangement included:

  • Laser scanning of the area with an intrinsically safe camera to collect locations of all existing structures, equipment, ducting, and piping. These scans were used in conjunction with any available drawings to create a 3D model.
  • Support and access structures for multiple conveyors at ground level.
  • Expansion of an existing 13’ deep concrete skim pit using sheet piling.
  • A new chemical tank dike outside the existing vapor wall.
  • New fire tank pump house foundations.
  • Modifications to existing steel cyclone supports for upsized equipment.
  • Multiple piping and conduit support structures.
  • A nine story tower to provide access to all valves, manways, drives, and windows of the new DT. The tower also supports and provides access to the heads and drives of the feed conveyors.
  • Foundation design for 660,000 lb DT and access tower utilizing drilled piers and pile cap.
  • Modifications to existing extraction building to support and access new equipment as well as replace roof section once existing equipment is demolished.
  • Saddle design for 56” diameter vapor duct.
  • Design for a maintenance trolly for potential future removal of the 52,000 lb DT drive & motor
  • Upgrade and conversion of a storage building to house the new electrical gear and power distribution.

Process & Mechanical & Piping design of the extraction expansion included:

  • Point cloud modeling
  • 3D Building and equipment layouts
  • DT and other vendor equipment reviews
  • Steam and condensate piping associated with the new DT
  • Design of ductwork for hexane vapor recovery
  • General arrangement of drag conveyors to fit the existing space constraints.

The use of progressive 3D models allowed collaboration between all engineering disciplines, project stakeholders, vendors, and contractors. It allowed us to overcome multiple challenges and resulted in successful project completion on budget and schedule.

For additional information on Structural design for plant expansions or Process & Mechanical design of oilseed extraction, please contact or

Derek Jacobs, P.E., S.E.                                                                                                David Miller
Structural Engineering Manager                                                                                Director of Operations
937-847-2700 ext. 128                                                                                                  937-847-2700 ext. 154