The need for advanced sewage sludge treatment is critical due to cost and health risks. High concentrations of toxic hydrogen sulfide, as well as the allergens, bacteria, and viruses emanating from these facilities, have the potential to make people sick.
Our process fully sanitizes the sludge and evaporated water. The drying level can be adjusted between 80-95% dry matter, with the process typically taking less than 5 minutes.
Exhaust air is treated within the closed system, binding ammonia with sulfuric acid to form ammonium sulfate, and a fine filter system removes almost all dust.
Our STR series exhaust drying system exceeds regulatory requirements by utilizing exhaust from various energy sources for highly efficient, emission-free drying, converting one ton of sludge into 250 kg (551 lbs) of sanitized biomass.
This process recovers valuable nutrients and prepares sludge for further sustainable use, ensuring environmental protection for future generations.
The dryer comprises multiple connected chambers with pneumatic gates, each containing rotating blades that keep the sludge suspended in air. Hot exhaust gas at 570°F initiates an efficient drying process, reducing sludge to a dry matter content of 45% and later to 80-95% in under 5 minutes.
The exhaust system, drawing from various energy sources, mixes with fresh air to maintain the necessary temperature. If needed, an additional burner provides extra heat. The system operates under negative pressure to prevent emissions and uses fine filters to remove dust. The dried sludge is then pelletized for further use in nutrient recovery, gasification, combustion, or as fertilizer.
Dewatered sludge is fed into the dryer’s push floor container via screw, loader, or conveyor, and dosed into a mixing trough where it’s combined with recycled dry sludge to achieve 45% dry matter.
The mixture is then moved to the first drying chamber, where rotating blades create an optimal material cloud for efficient drying.
The system, eliminates the need for additional air treatment and ensures high cleaning efficiency, producing dry, pelletizable sludge suitable for various uses.
