2 stainless steel chimneys for a French potato factory

The challenge

A potato factory in France needed to safely discharge the process gases from its production lines high enough above the site to disperse cleanly. The project called for two large chimneys, each 4.5 m in diameter and 80 m tall, to be added to the plant as freestanding structures, without an external support frame.

The site sits close to the shoreline. Chloride-laden coastal air rules out standard carbon steel for any stack expected to stand for decades in that environment, so the material had to be specified for corrosion resistance from the outset. On top of that, the two stacks had to be near-identical so the factory could fabricate, install and maintain them as one type rather than as one-offs.

Our approach & engineering

Axces engineered the chimneys as a complete in-house scope, covering design, fabrication and on-site installation, and standardised the two stacks on a single design so that everything from the steel cutting list to the lift plan was repeated twice.

Material selection for a coastal site

Both chimneys are built entirely from stainless steel rather than coated carbon steel. With the plant sitting near the shoreline, stainless removes the recurring repaint and corrosion-inspection cycle a carbon-steel stack would need in that environment, and keeps the long-term integrity of the flue under constant salt exposure.

Freestanding single-flue design

Each chimney is a freestanding single-flue stack, self-supporting on its own base, with no external guy wires or support tower. At Ø4.5 m × 80 m that is a substantial structure, and the structural design covers wind loading and the dead weight of the flue across the full height.

Process gas dispersion at 80 m

The 80 m stack height was set to lift the factory’s process gases well above the plant and the surrounding terrain, so they disperse before reaching ground level downwind.

• Two identical chimneys engineered to a single repeatable design
• Stainless steel throughout, chosen for the coastal environment
• Freestanding single-flue stacks: no external support structure
• Ø4.5 m × 80 m, sized for the factory’s process gas flow and dispersion height
• Complete in-house scope: engineering, manufacturing and installation

Scope of supply

Axces delivered the complete chimney scope from drawing board to installed stack:

• 2 × freestanding single-flue chimneys, Ø4.5 m × 80 m
• Full stainless steel construction
• Structural and process engineering for the two stacks
• In-house fabrication in installation-ready sections
• On-site installation at the French plant

Results

Both chimneys were fabricated to one design and installed at the French factory as a matching pair: one engineering package, one fabrication programme, one installation method, repeated twice.

• 2 stainless steel chimneys in service at the plant
• Process gases discharged 80 m above grade for clean dispersion
• Stainless steel construction sized for the long-term coastal exposure
• Standardised design: one set of drawings, spares and maintenance procedures across both stacks

Related reading

• Freestanding, guyed, or self-supporting: choosing an industrial stack configuration: how site constraints, height, and structural loads determine the right stack type
• Industrial stack design loads: wind, seismic, and vortex shedding explained: the load cases that govern stack design and why vortex shedding often dominates
• Stack height and dispersion: how chimney height drives ground-level emission limits: why discharge height matters for keeping pollutants away from the surrounding area