ENG. ANDREW OMWENGA
Chemical & Process Simulation Engineer • Thermodynamic Specialist
Tissue & Paper Mill Hood Exhaust Heat Recapture System
Section 1.0 — Simulation & Facility Metadata
Section 2.0 — Executive Summary
Heavy-duty particulate-tolerant condensing heat recovery system capturing 5.2 MW of waste heat from paper machine Yankee dryer hoods to preheat process water and hall ventilation air.
Section 3.0 — Problem Statement & Operating Bottlenecks
Paper and tissue manufacturing machines consume enormous quantities of natural gas and high-pressure steam to dry paper webs. The Yankee hood exhaust releases 125 °C moist, dusty air loaded with paper fibers and moisture, representing 35% of total mill thermal energy losses.
Section 4.0 — Objectives & Rigorous Simulation Methodology
Aspen Plus multi-phase gas-liquid simulation with particulate holdup estimation. Sized heavy-duty stainless steel direct-contact towers and shell-and-tube economizers.
Section 5.0 — Simulation Results & Thermodynamic Findings
The self-cleaning design prevents paper dust from building up on heat transfer surfaces, providing uninterrupted 24/7 mill uptime. The captured energy preheats freshwater before it enters the boiler house and supplies low-pressure hot water to plant drying fans.
Section 6.0 — Core Engineering Takeaways
Section 7.0 — Model Assumptions & Future Recommendations
Requires stainless steel construction to withstand trace organic acids in paper vapors.
Coupling with black liquor recovery boiler economizer optimization.
Section 8.0 — Consultant Conclusion & Verification Sign-off
Heavy-duty condensing heat recovery transforms paper mill exhaust liabilities into reliable, high-yield energy assets.
