Packed Bed test in low-g Aircraft
Volatile Reactor Assembly (VRA) on STS-89
A critical unit operation used with many of the leading water reclamation and air revitalization technologies for advanced life support systems is the fixed packed bed reactor. Examples of systems currently under development or in use in space that take advantage of this type of reactor include the Volatile Removal Assembly (VRA), the Aqueous-Phase Catalytic Oxidation (APCO) system, the Microbial Check Valve (MCV), the Activated Carbon/Ion Exchange (ACTEX), and the IntraVenous Fluid GENeration (IVGEN) system. However, despite the many applications, there is very little understanding of how the reduced gravity environment affects the performance and reliability of the reactors. This is especially critical when the reactor involves simultaneous gas and liquid flows. The Packed Bed Reactor Experiment (PBRE) is designed to specifically resolve these technology gaps. The expected outcome of this research effort is to develop a set of guidelines and tools to enable engineers to reliably design and operate fixed packed bed reactors for microgravity as well as the lunar and Martian environments.
The PBRE ISS flight experiment will provide critical hydrodynamic information for a project which also includes reduced gravity aircraft and ground-based (1-g) testing. The main objective is to develop and validate macroscopic equations that can be used in partial and microgravity conditions to accurately predict flow pattern transitions; pressure drops; and chemical and biological transport rates in gas-liquid flows through randomly packed beds. The hydrodynamic investigations will focus on the transitions between flow regimes (i.e., bubbly-to-pulse flow transition) and the associated pressure gradients for each flow regime over the range of relevant test parameters (e.g., liquid flow rates, gas flow rates, and particle sizes). These design tools will provide important information for specific water reclamation and air revitalization technologies for advanced life support systems.
The PBRE is being developed under the Space Flight Systems Development and Operations Contract, through the collaboration of ZIN Technologies and the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC), the International Space Station (ISS), the University of Houston, the National Center for Space Exploration Research (NCSER) and NASA Johnson Space Center (JSC). The success of the PBRE project is crucial to the development of technologies which will maintain the well-being of crew members participating in extended space missions.
• Investigate the role and effects of gravity on gas-liquid flow through porous media.
• Outcome will be the development of design and operational guidelines for gas-liquid Packed Bed Reactors in partial and microgravity conditions.
• Directly aligns with high priorities from the NRC Decadal survey on Biological and Physical Sciences and crosses over to other technologies.
• AP-2: Provides a study of a critical multiphase flowcomponent for life support systems.
• TSES-6: Provides a fundamental study in porous media under microgravity conditions.
• Porous media are critical components in life support systems; thermal control devices; fuel cells; and biological and chemical reactors.
• Completed extensive (but time-limited) low-G aircraft tests.
• Engineering model hardware and Proto-flight unit.
• Video and data down-linked to the ground for evaluation.
• Develop on-orbit replaceable test section to extend experiment capabilities. Enables flexibility for future development of porous media components/devices.
Contacts at NASA Glenn Research
Project Manager: Nang Pham, NASA, GRC
Project Scientist: Dr. Enrique Ramé, NCSER-NASA GRC
Principal Investigator: Dr. Brian Motil, NASA GRC
Co-Investigator: Prof. Vemuri Balakotaiah, University of Houston &
Julie L Mitchell (JSC)
Engineering Team: ZIN Technologies, Inc.