NASA SBIR 02-1 Solicitation


PROPOSAL NUMBER:02- B1.01-9762 (For NASA Use Only - Chron: 022237 )
SUBTOPIC TITLE: Exploiting Gravitational Effects for Combustion, Fluids, Synthesis, and Vibration Technology
PROPOSAL TITLE: Void Fraction Sensor for Packed-Bed Reactors in Microgravity

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Creare Inc
P.O. Box 71
Hanover , NH   03755 - 0071
(603 ) 643 - 3800

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Christopher J. Crowley
P.O. Box 71
Hanover , NH   03755 - 0071
(603 ) 643 - 3800

The innovative product resulting from this project is an instrument to measure void fraction in packed-bed reactors. As NASA pursues long-duration crewed missions, it will be necessary to adapt packed-bed chemical processing methods to reduced gravity to minimize the mass and volume of consumables carried from earth. Accurate measurement of void fraction is critical to (1) identify the flow regimes, and (2) quantify the liquid holdup for design and performance calculations. At present, there is no simple, easy-to-use instrument for microgravity. Capacitance-based sensors have several advantages including the potential to be very sensitive to liquid held up in the reactor, not intrude into the flow, and provide high rates of data sampling. With the conductive fluids used in reactors, a new signal-conditioning scheme is needed for capacitance-based measurements of void fraction. We will develop the new signal-conditioning scheme with an adapted version of a unique capacitance sensor previously developed at Creare. During Phase I we will prove the feasibility of the new signal-conditioning electronics using a multiphase flow facility. During Phase II we will develop the electronics package, adapt the sensor mechanical design to the configuration of packed-bed reactors, and demonstrate the prototype under packed-bed flow conditions.

A void fraction instrument capable of being used with conductive fluids has numerous industrial and research applications in many areas including chemical processing facilities, biotechnology, and pharmaceutical manufacturing. Our innovative electronics will also optimize the performance of the void fraction instrument for use with cryogenic fluids where the relative permittivity of the liquid is low. There are a host of industrial and aerospace applications where this capability is needed.

Crewed space activities depend upon the development of packed-bed reactors for regenerative life support systems for extraction, absorption, humidification, leaching, etc. In addition to this primary application, the same innovative electronics approach that will enable operation with conductive fluids will also optimize the sensor performance with cryogenic fluids. NASA has many obvious potential applications for this technology in propellant transfer applications and in the operation of systems that use these fluids.

Form Printed on 09-05-02 10:10