Air Squared, Inc. — Department of Energy SBIR Phase I: 19b

Description

The DOE has identified the need for Blanket and Safety Technologies for fusion power systems. This includes plant level tritium management, containment, and safety tools and systems development. Currently, tritium compatible pumps for these systems are extremely limited. Traditional technologies, such as pistons, do not have the life and reliability needed to make tritium service useful. The scroll pump is the industry’s preferred technology because of its superior life and reliability, but standard scroll pumps have polymer components which rapidly fail when exposed to tritium. The current state of the art is an all metal, air cooled, tritium scroll pump, but the capacity of this pump suits only small research projects only. Larger scale demonstrations, and certainly full scale power, will require a similar pump of much higher capacity, something that is unachievable with an air-cooled scroll pump. To solve this problem, the company is proposing development of an all metal, liquid cooled, high capacity tritium scroll vacuum pump. The high capacity of the pump is the advancement of the state of the art that the fusion industry demands, but it is the liquid cooled feature that makes this actually feasible. The clearance between the walls is the key variable in scroll technology. Without tip seals or lubrication, the tritium scroll pump is defined only by holding the wall clearance to a minimum. Previous, the limit was based on the thermal expansion of the material, as thermal growth causes interference during operation resulting in catastrophic failure. However, the patented liquid cooling design has a superior thermal management system which maintains a low uniform scroll temperature, eliminating thermal growth and the associated concerns. The effectiveness of the novel cooling method now allows for higher capacity pumps to be designed and manufactured with improved life and reliability. In Phase One, the company will develop, prototype, and test a liquid cooled tritium scroll vacuum pump in a scaled down size of the high capacity unit as a proof of concept. The company already has an air-cooled prototype in this size, so a direct comparison can be made to the liquid cooled design for verification of the liquid cooling. The air-cooled prototype also offers the benefit that assumptions made during the design process can be verified by empirical data before again making them for the liquid-cooled design. After benchmarking the one tenth scale liquid-cooled prototype, the full scale high capacity product will be developed, prototyped, and tested in Phase Two. The immediate commercial applications focus on fusion energy demonstration projects where the current state of the art is too small to support. In the future, even larger demonstration projects, full scale fusion power, and also the numerous industries outside of fusion that require a high capacity all metal pump for handling highly corrosive and toxic gases will dwarf the immediate commercial applications.