Relationship Between The Minex And The Helium-Driven Modified Coker In The Measurement Of Jet Fuel Thermal Stability
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Report Number: AFAPL TR 67-17
Author(s): Lander, Herbert R., Jr., Zengel, Alan E.
Corporate Author(s): Air Force Aero Propulsion Lab Wright-Patterson AFB OH
Date of Publication: 1967-02
Pages: 54
DoD Task:
Identifier: AD0653188
Abstract:
Six different jet fuels were tested for their resistance to thermal deposition by two versions of the CRC modified coker and the Minex heat exchanger. The test results are compared by plotting the coker deposit code rating versus coker-preheater-tube wall temperature. The temperature of the tube wall, where large quantities of deposits form, is compared with the temperature of the Minex fuel-out, where tube fouling due to deposits occurs. Fouling is indicated by a change in measured heat transfer coefficient. The relative ranking of the six fuels was the same on the Minex as on the helium-driven modified coker. The pump-driven modified coker, however, gave a relative ranking that correlated with neither the Minex nor the gas-driven coker. It was concluded that the pump-driven modified coker was not a satisfactory test tool for fuels with a resistance to thermal degradation above 500F. It was also apparent that the pump on the coker was affecting the test results when fuels of high thermal stability were tested. The most obvious reason for this effect is that the fuels with thermal stability above 500F were treated to remove trace materials, and that these trace materials provide a degree of boundary lubrication. Without this degree of boundary lubrication, the coker pump may wear and release wear products that affect the test results.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Lander, Herbert R., Jr., Zengel, Alan E.
Corporate Author(s): Air Force Aero Propulsion Lab Wright-Patterson AFB OH
Date of Publication: 1967-02
Pages: 54
DoD Task:
Identifier: AD0653188
Abstract:
Six different jet fuels were tested for their resistance to thermal deposition by two versions of the CRC modified coker and the Minex heat exchanger. The test results are compared by plotting the coker deposit code rating versus coker-preheater-tube wall temperature. The temperature of the tube wall, where large quantities of deposits form, is compared with the temperature of the Minex fuel-out, where tube fouling due to deposits occurs. Fouling is indicated by a change in measured heat transfer coefficient. The relative ranking of the six fuels was the same on the Minex as on the helium-driven modified coker. The pump-driven modified coker, however, gave a relative ranking that correlated with neither the Minex nor the gas-driven coker. It was concluded that the pump-driven modified coker was not a satisfactory test tool for fuels with a resistance to thermal degradation above 500F. It was also apparent that the pump on the coker was affecting the test results when fuels of high thermal stability were tested. The most obvious reason for this effect is that the fuels with thermal stability above 500F were treated to remove trace materials, and that these trace materials provide a degree of boundary lubrication. Without this degree of boundary lubrication, the coker pump may wear and release wear products that affect the test results.
Provenance: Lockheed Martin Missiles & Fire Control