💧 Water & Wastewater
Anaerobic digester heating, sludge conditioning, process water heating and desalination pre-treatment.
Water & Wastewater — DSI Applications
Anaerobic digester heating, sludge conditioning and industrial effluent pre-treatment
Anaerobic Digester Sludge Heating
Anaerobic digestion (AD) of sewage sludge and industrial effluent requires the digester contents to be maintained at either mesophilic (35–37°C) or thermophilic (52–55°C) temperatures to maximise biogas production. DSI systems on the sludge recirculation loop provide highly efficient heat input with no heat exchanger to block from fibrous sludge or grit. The direct contact also pasteurises the sludge during thermophilic operation, meeting regulatory requirements for biosolids disposal. Capacity requirements for AD plants are large — typically 50–200 m³/hr — and DSI systems can be supplied in multiple parallel units to meet demand.
Industrial Effluent Pre-treatment
Many industrial effluents — from textile dyeing, pharmaceutical manufacturing and food processing — contain organic compounds that require thermal pre-treatment before biological treatment to break complex molecules and improve biodegradability. DSI heaters are used to heat effluent streams to 70–90°C before holding tanks or activated sludge plants. The ability to handle coloured, viscous or particulate-laden streams without fouling makes DSI far more practical than plate or shell-and-tube pre-heaters for effluent service.