Bubble point pressures of binary methanol/water mixtures in fine‐mesh screens

Abstract

Binary methanol/water mixture bubble point tests involving three samples of fine-mesh, stainless steel screens as porous liquid acquisition devices are presented in this article. Contact angles are measured as a function of methanol mass fraction using the Sessile Drop technique. Pretest predictions are based on a Langmuir isotherm fit. Predictions and data match for methanol mole fractions greater than 50% when pore diameters are based on pure liquid tests. For all three screens, bubble point is shown to be a maximum at a methanol mole fraction of 50%. Model and data are in disagreement for mole fractions less than 50%, which is attributed to variations between surface and bulk fluid properties. A critical Zisman surface tension value of 23.2 mN/m is estimated, below which contact angles can be assumed to be zero. Solid/vapor and solid/liquid interfacial tensions are also estimated using the equation of state analysis from Neumann and Good.

Warm Pressurant Gas Effects on the Static Bubble Point Pressure for Cryogenic LADs

“…The second finest 450x2750 mesh produced the highest bubble points, for both GHe and GH 2 . The 510x3600 mesh outperformed the 325x2300 mesh at LH 2 temperatures, but the 325x2300 yielded higher pressures in room temperature liquids [11,12]. The reason for this crossover in performance is due to the temperature dependence of the screen pore diameter, as mentioned previously.…”

“…The bubble point is defined as the differential pressure across a LAD screen pore that overcomes the surface tension forces at that pore. Bubble point pressure is proportional to the surface tension of the liquid and inversely proportional to the effective screen pore diameter, as derived in Hartwig and Mann [11,12] and shown in Eq. 1:…”

“…Pore sizes for 325x2300 (12795 warp and 90551 shute wires per meter), 450x2750 (17716 warp and 108268 shute wires per m), and 510x3600 (20079 warp and 141732 shute wires per meter) Dutch Twill were determined in room temperature tests [11,12]. The exact same samples were used here for heated pressurant gas tests in cryogenic liquids.…”

Warm Pressurization Gas Effects on the Liquid Hydrogen Bubble Point

“…The bubble point is defined as the differential pressure across a LAD screen pore that overcomes the surface tension forces at that pore. Bubble point pressure, P BP , is proportional to the surface tension of the liquid and inversely proportional to the effective screen pore diameter, as derived in [11,12] and shown in Equation 1:…”

Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

“…Based on previously reported cryogenic bubble points from McQuillen (2011 and2012a), the model is only valid for normally saturated liquids. Hartwig and Mann (2013b) showed that Equation (1) simplifies to…”