The system shall be designed and installed in a way that allows for potential future integration of septage and thickened sludge heating if desired, without requiring major rework. A. Tank Configuration Repurpose Septage Receiving Tank #3 for FOG service. Relocate glycol storage to Tank #2. Ensure all tanks are finished with corner edge grouting and radius as planned. B. Heating System Install stainless steel (or equivalent corrosion-resistant) multi-pipe heating loops, estimated 4–8" diameter (final sizing to be based on heat transfer performance requirements), mounted around the interior walls of Tank #3. Provide direct hot water supply from the existing plant hot water system (HWS), sourced from the turbine building and existing boiler/turbine loop. Minimize additional heat exchangers or glycol loops unless technically required. Direct HWS tie-in is the preferred approach; additional heat exchangers or glycol loops shall only be used if technically unavoidable, as they add unnecessary complexity and efficiency loss. C. Mixing & Suspension Utilize the existing in-tank grinder/mixer pump where possible. If mixing performance is inadequate, provide additional mixers to maintain proper suspension and consistent heat transfer. D. FOG Pumping Furnish and install a new diaphragm pump (or equivalent) suitable for FOG service. Pump must be sized to handle expected flow rates and viscosity. Existing Wemco septage pumps shall not be used for FOG transfer E. Piping & Distribution Install new insulated underground piping from the turbine building to the digester building. Route piping to avoid conflicts with existing infrastructure, including the concrete pad for the gas compression skid. Evaluate cost-saving options such as reusing existing insulated PEX piping currently stored onsite.
