Helisol® Solar Sludge Drying Process

The Helisol® sludge drying process is a technology at the heart of Saur’s drive to find environmental and economical solutions to operational needs. Based on natural evaporation, Helisol® relies on air and sun properties to remove vapour from the sludge, resulting in more efficient storing and evacuation.

The Helisol® process enables sludge spread on a slab to be dried by sunlight in a green-house like structure, where air pushed through the system picks up excess water vapour from the drying sludge. A ventilation system means the air is regularly replaced and as the sludge and air warm up, a natural ‘greenhouse’ effect makes drying quicker and more efficient.

The Helisol® process has achieved a sludge volume reduction down to 80% dryness (and by a factor of 3 to 4).

Helisol 1
Helisol 2

The Helisol® Channel Turner Sludge Management Software

The key to Helisol® is the combination of the channel turner sludge management software, alongside efficient air renewal which is regulated either by weather conditions or the ventilation system.

The channel turner software is designed to:

  • Move, spread and store the sludge on all greenhouse surfaces with a layer thickness from 0 to 45 cm
  • Use the entire greenhouse area by spreading in a thin layer to boost the drying and granulation effect
  • Mix and aerate the sludge in depth over its whole storage height
  • Operate independently and automatically with no need for human intervention

Safe and easy to operate - The circulation channels along the greenhouse allow maintenance without contact with the sludge and sampling at all points. For an easy access, the channel turner is positioned in the "dry sludge" area, opposite the sludge feeding zone.

Continuous or Seasonal Drying Options

Helisol® from Saur offers two main drying cycles:

  • Seasonal or annual operation: Here the sludge is stored all year in the greenhouse structure; wet sludge is stored during the winter, colder months and then finally dried during the warmer summer months.
  • Continuous operating cycle: The sludge is dried as soon as it is fed into the greenhouse structure by means of a high and permanent drying effect created by underfloor heating or ventilation.
Helisol 3