Thermal Biosolids Drying System

Downriver Utility Wastewater Authority | Wyandotte , Michigan

Osborn is designing the building mechanical systems to support the installation of two new biosolids thermal drying systems, including space ventilation, space heating, control room air conditioning, and combustion air supply to thermal oil skids. Osborn is also designing the odor control system ductwork serving the two biosolids dryers and the sludge bin. Fire protection design includes the space and process and providing NFPA space classification design guidance. 

The main operating floor ventilation system makes use of the four existing rooftop gas-fired heating and ventilating units. A new thermal oil room is being constructed to house the two 12.5 MMBtu/hr thermal oil heaters that generate the heat input for the biosolids thermal drying process. The mechanical systems for this thermal oil room include combustion air for the two heaters, plus a ventilation system to maintain the space temperature and pressure within the operating limits. A new exhaust fan will be provided for the Truck Bay to comply with NFPA requirements for potentially combustible dust concentrations. A new electrical room is being created under an existing mezzanine, which will be ventilated per applicable codes. Additionally, Osborn is assisting with a Life Safety Code analysis for the permitting process.