The Challenge 0
Wastewater treatment plants produce enormous volumes of sludge. The most economical and environmentally friendly method to dispose of it is to use it as fuel in a power and/or heating plant, which requires the water content to be reduced from around 70% to close to 10%.
The air in the drying process is cooled mainly using a scrubber system. This system is not only critical for clogging but also consumes large quantities of water (25 l/h per kW cooling effect).
Airec Cross 30 offers the first working condensing air heat exchanger solution.
With Cross 30, up to 90 % of the water in the recirculating drying air condenses in the heat exchanger. This extremely impressive performance is used by Krüger A/S / Veolia Water Systems, (a world-leading supplier of technology for treating fresh and waste water), Haapavesi, Finland, in their Biocon™ sludge drying system. The dried sludge is mixed with waste wood and used as fuel in the local power plant.
These excellent results mean Krüger is planning to replace inferior heat exchangers in other Biocon™ systems with Cross 30.