External Catalyst Breakup Phenomena
Abstract
The overall objective of the work in the program was to investigate the external breakup mechanisms of shell 405 catalyst so as to establish an understanding of the phenomenon in order to provide monopropellant hydrazine thruster designers with a fundamental technology base which they can use to achieve long life mission requirements. Following a review of the literature and other available information, twenty (20) different mechanisms or factors potentially significant to catalyst breakup were investigated either experimentally or analytically or by use of both techniques. Slightly more than half of the mechanisms investigated were found to have a significant influence on the complex phenomena involved in overall catalyst breakup. The significant primary catalyst breakup mechanisms were in general, associated with either pressure crushing forces or with various effects resulting from the presence of liquid hydrazine. A major secondary breakup mechanism is particle to particle abrasion which can occur if the catalyst in a voided bed experiences rapid motion. Another important factor in catalyst breakup is the deterioration as a result of thruster exposure of the ability of a fresh catalyst to resist the various breakup mechanisms. Results also indicate that the effect of the various mechanisms on the magnitude of breakup can be controlled by adjusting reactor operating variables such as liquid injection velocities, bed temperature, bed gas linear velocity and pressure drop, bed preload and catalyst selection for the various sections of a thruster and point to a number of variables or factors involved in thruster operation where operating envelopes or procedures could be developed to enhance catalyst life.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1976
- Accession Number
- ADA027217
Entities
People
- John D. Kuenzly
- Robert L. Sackheim
- William F. Taylor
- William T. Webber