Wastewater and biosolid sludge drying is extremely energy-intensive because of very high water content and an odorous, corrosive off-gas. Reducing that energy load is central to affordable sludge handling.
Heat-pump dehumidification dryers with plate heat recovery, or belt and thin-film dryers with exhaust heat recirculation, cut energy dramatically by capturing the latent heat of evaporation in a closed loop.
The off-gas must be treated - condensation, biofilter, or scrubber - and cores need corrosion-resistant, cleanable materials to survive the aggressive atmosphere.
Contain odors, recover latent heat through closed-loop dehumidification, and size the system for variable feed solids. Savings of 30-60% of drying energy are achievable, plus major volume and weight reduction that lowers haul and disposal cost.