Air Squared will develop a first-of-its-kind large-scale, liquid-cooled, all-metal (LCAM) vacuum pump compatible with virtually any working fluid with Phase II SBIR funding from the Department of Energy (DOE).

Following a success Phase I Small Business Innovative Research (SBIR) effort to develop a small-scale (15 m³/hr) liquid-cooled, all-metal (LCAM) scroll vacuum pump compatible with radioactive Tritium, the Department of Energy (DOE) has awarded Air Squared Phase II funding to develop a full-scale (150 m³/hr) LCAM scroll vacuum pump by 2020. The award is funded under the topic Advanced Technologies and Materials for Fusion Energy Systems

Development of the full-scale LCAM will benefit from years of collaboration with various organizations that process radioactive tritium. If successful, the full-scale LCAM vacuum pump could support research institutes around the world (e.g., multi-national partnerships like JET, ITER, and DEMO) that are actively searching for a tritium-compatible pump with 150 m³/hr pumping capacity.

Air Squared has spent years researching and developing scroll vacuum pumps compatible with radioactive tritium:

• 2006 First Generation 15 m3/hr Scroll Vacuum Pump for Savannah River National Laboratory
• 2016 Second Generation 15 m3/hr All-Metal Scroll Vacuum Scroll Pump for Savannah River National Laboratory
• 2017 First Generation 15 m3/hr Liquid-Cooled, All-Metal (LCAM) Scroll Vacuum Pump for DOE
• 2018 Third Generation 15 m3/hr All-Metal Scroll Vacuum Pump for Commercial Use
• 2018-2020 First Generation 150 m3/hr Liquid-Cooled, All-Metal (LCAM) Scroll Vacuum Pump for DOE

Four key technology innovations set the 150 m³/hr LCAM apart from state-of-the-art radioactive gas-handling pumps:

• Liquid Cooling An integrated liquid-cooled jacket feeds water (or oil) to cool the inner and outer scrolls during operations. The cooling controls thermal expansion, increases component lifetime, and decreases maintenance.
• All-Metal Components An isotope of hydrogen (H3), radioactive tritium can permeate most materials, spilling hazardous amount of radiation into the air. To control leakage, every component within the LCAM is fabricated from aluminum or stainless steel.
• No Lubrication, No Tip Seals Tritium gas quickly eats away at polymer tip seals, causing premature failure. The LCAM has a tight axial clearance between the fixed scroll and orbiting scroll. This allows for oil-free operation witout tip seals.
• Triple-Containment Fail-safe tritium containment is essential with radioactive working fluids. The LCAM has included three redundant barriers with the tritium working fluid, liquid-cooling jacket, and semi-hermetic outer housing.

The LCAM will be designed to initiate a rough vacuum of tritium radioactive gas as it proceeds along an ever-larger vacuum train into a magnetic fusion chamber at high speeds to create a fusion reaction. This magnetic containment approach is fundamental to the tokamak reactor under research at the International Thermonuclear Experimental Reactor (ITER) and is the leading means to achieve sustained nuclear fusion. Development will continue through 2020 at Air Squared and if successful, testing will be conducted at various institutions.

This material is based upon work supported by the Department of Energy. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the Department of Energy.