Apparatus and methods for detecting propellant degradation in solid propellant fuel

• US 8,590,404 B2
• Filed: 02/27/2012
• Issued: 11/26/2013
• Est. Priority Date: 02/27/2012
• Status: Expired due to Fees

• Current Assignee: US Department of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Brantley, Christina L., Edwards, Eugene, Ruffin, Paul B., Luo, Fang
• Primary Examiner(s): Wallenhorst, Maureen M
• Assistant Examiner(s): NGUYEN, HOANG T
• Application Number:
  US13/405,469
• Publication Number:
  US 20130224872A1
• Time in Patent Office: 638 Days
• Field of Search: 738/632.3, 738/635.1, 738/638.1, 738/638.3, 738/643.4
• US Class Current: 73/863.23
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 1/22 in the gaseous state specially adapted for biological material G01N33/497; measuring breath flow A61B5/087
• CPC Class Codes: G01N 1/2202 involving separation of sample components during sampling
• CPC Class Codes: G01N 1/2205 with filters
• CPC Class Codes: G01N 1/24 Suction devices G01N1/22 - G01N1/2294 take precedence
• CPC Class Codes: G01N 2021/3155 Measuring in two spectral ranges, e.g. UV and visible
• CPC Class Codes: G01N 2021/3595 using FTIR
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 33/222 Solid fuels, e.g. coal
• CPC Class Codes: Y10T 436/177692 Oxides of nitrogen
• CPC Class Codes: Y10T 436/178459 Only nitrogen dioxide
• CPC Class Codes: Y10T 436/204998 Inorganic carbon compounds
• CPC Class Codes: Y10T 436/205831 Carbon monoxide only

Abstract

The present disclosure relates to a gas sensor, including: a gas collecting chamber including: (a) a nanoporous wall including alumina, on a portion of the gas collecting chamber in the near vicinity of the solid propellant fuel; a micro pump attached to the gas collecting chamber; and a gas analysis device connected to the gas collecting chamber. The gas analysis device measures both type and concentration of gases collected in the gas collecting chamber via the nanoporous wall, the gases measured being selected from the group consisting of CO, CO₂, NO, N₂O, NO₂ and combinations thereof. The present disclosure also relates to a method of sensing propellant degradation in solid fuel and a method of using a gas collecting chamber to sense such degradation.

Claims

1. A gas sensor, comprising:

a gas collecting chamber including;

a nanoporous wall including alumina, on a portion of the gas collecting chamber in a near vicinity of the solid propellant fuel;

a micro pump attached to the gas collecting chamber between the nanoporous wall and a gas analysis device, the micro pump being both for sucking ambient air out of the gas collecting chamber thereby forcibly bringing gas out of the gas collecting chamber through the pores in the nanoporous wall and also for blowing inert gas selected from the group consisting of argon, helium, neon, krypton, xenon, radon, sulfur hexafluoride, nitrogen and combinations thereof into the gas collecting chamber and out through the nanoporous wall thereby to rid the nanoporous wall of accumulated particles;

a baffle located in the gas collecting chamber near an area of the gas collecting chamber where the micro pump is connected, the baffle being for channeling the gas sucked by the micro pump from the solid propellant fuel to the gas analysis device; and

the gas analysis device connected to the gas collecting chamber, the gas analysis device measuring both type and concentration of gases collected in the gas collecting chamber via the nanoporous wall, the gases measured being selected from the group consisting of CO, CO₂, NO, N₂O, NO₂ and combinations thereof.

2. The gas sensor according to claim 1, wherein there are pores in nanoporous material in the nanoporous wall, the pores having an average diameter of from 0.2×

10<sup>−

9</sup> m to 5.0×

10<sup>−

4</sup> m.

3. The gas sensor according to claim 2, wherein there are pores in nanoporous material in the nanoporous wall, the pores having an average diameter in a range from 200 nm to 300 nm.

4. The gas sensor according to claim 1, wherein the gas collecting chamber has an internal pressure varying from 0 to 5,000,000 pounds per square inch.

5. The gas sensor according to claim 4, further comprising a control valve to at least partially regulate the pressure in the gas collecting chamber, the control valve either opening or closing the gas collecting chamber to incoming outside gas.

6. The gas sensor according to claim 1, wherein the gas analysis device is selected from the group consisting of a ultraviolet absorption measuring device, a visible absorption measuring device, an infrared absorption measuring device, a Raman effect measuring device, a chemical reductions measuring device, an electrochemical effects measuring device, and combinations thereof.

7. The gas sensor according to claim 1, wherein the nanoporous wall further comprises nanoporous material selected from the group consisting of ceramics, polymers, glasses, crystals and combinations thereof.

8. The gas sensor according to claim 1, wherein the gas collecting chamber is from 100 nm to 1,000 mm in internal diameter.