SOLAR SLUDGE DRYING

Sewage sludge disposal is a hot topic of discussion topic since years. Common ways of disposal are agricultural spreading as fertilizer, land re-cultivation, landfill and co-combustion of dewatered sludge. Especially because of heavy metals, antibiotics, and other harmful things, agricultural land and landfill became more and more critical. In times of increasing prices regarding fossil fuels, dried sewage sludge can be members of the new green energy sources: CO2 neutral and locally available.
 

THE SOLUTION

The Naturetech and i+M solution offer the unique possibility to dry in combination with the solar power of global radiation and free heat sources. After dewatering the system is able to dry the sludge up to 90% dry solid to reach the energy values between 9 to 12 MJ/kg according to organic content and digestion. Thus dry sludge replaces the fossil fuels in cement factories or other heavy industries.

PLANT & PROCESS

With options for automatic conveying and manual input, the Naturetech and the i+M system offers flexibility right from the start. With the help of a thin sludge layer in combination with the fast turning intervals and optimum air supply, Naturetech and i+M technology prevent anaerobic layers and charges the fresh air with evaporated water in a continuous process.

Evaporation energy is either covered by either solar or in a combination of solar and free thermal energy until ca. 85C is reached, which is used as an (optional) floor heating system under the sludge. Physical characteristics of the water vapor are efficiently used by the Naturetech and the i+M technology.
 
 
Warm floor heating surface causes vapor generating inside the sludge core and its exit at the sludge shell. By continuously turning and conveying the sludge is able to get in contact with the fresh non-saturated air that carries out the vapor. Maximum efficiency and least hassles are reached by reliable mechanical engineering. Unique air streaming control and precision sensors' data are all processed inside a Siemens PLC system. If necessary air scrubber can be equipped easily due to the flexible design of the Naturetech and the i+M system.

Drying sludge up to any required dry solid is influenced by named parameters, weather conditions, available energy and sludge quality.

ENHANCEMENT OPTIONS

Nautretech can provide a number of enhancements to the drying system to provide improved performance and versatility to the system.
Automated sludge handling systems for both feeding and output, which will be custom designed based on individual system requirements. It will minimize labor requirements and provide higher efficiency with the help of conveyors, pumping systems, and storage bins.
Repurposing external waste heat sources to provide additional heat within the greenhouse to raise the internal temperature, hence increasing performance.