Exhaust Management for the 21st Century: 20 Years In Development
Walker, Bruce G. (TECHNOLOGY PERFORMANCE Group, Kuna, ID)
Exhaust and cleanroom air management is on an evolutionary curve where experience and engineering solutions have yielded significant improvements for processing equipment and cleanroom air management. Protecting personnel and the environment has top priority, but that priority is not always shared with equipment design and manufacturer specifications. Elevating the awareness of the long-term effects of exposure to toxic chemicals brings exhaust and air management into a new role in equipment design. However, few equipment designers have the depth of experience required to focus on the safe handling of toxic exhaust and optimal equipment performance. Comprehensive design requires knowledge of past sins. Repetitive learning should not mean repeated mistakes. Implementing case studies, process parameters and computational modeling leads to an inclusive air management design. The focus must remain on critical capture, containment and consumption making exhaust optimization a primary design element. Wet cleaning equipment is the extreme example since it typically exhausts at 1500 cfm and above but often does not adequately contain chemical fumes. Safely reducing the exhaust rate has significant EHS, operating, and capital cost avoidance implications. Isolation of the chemical processing tanks using an air manager system to effectively isolate and control fume emission, allows exhaust reductions in excess of 50%. Energy savings with this approach are estimated at $3-4/cfm per year. The capital cost to install cleanroom exhaust runs about $80-100 per cfm. Return on investment is quickly realized while a more effective chemical containment promotes the achievement of the energy reduction goals established in the National Technology Roadmap for Semiconductors.
[abstract as .pdf]