Measurement of the gradient of viscosity with composition of mixtures for non-ideal gases

Hdl Handle:
http://hdl.handle.net/10149/58342
Title:
Measurement of the gradient of viscosity with composition of mixtures for non-ideal gases
Authors:
Russell, P. A. (Paul); Buffham, B. A. (Bryan); Mason, G. (Geoffrey); Hellgardt, K. (Klaus)
Affiliation:
Loughborough University. Department of Chemical Engineering; University of Teesside. School of Science and Technology; Imperial College. Department of Chemical Engineering and Chemical Technology. London.
Citation:
Russell, P. A. et al. (2006) 'Measurement of the gradient of viscosity with composition of mixtures for non-ideal gases', Chemical Engineering Science, 61 (19), pp.6604-6615.
Publisher:
Elsevier
Journal:
Chemical Engineering Science
Issue Date:
Oct-2006
URI:
http://hdl.handle.net/10149/58342
DOI:
10.1016/j.ces.2006.06.016
Abstract:
A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity–composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures. The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity–composition profiles from the results. The apparatus has been tested using helium–HFC-125 mixtures and two new viscosity–composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.
Type:
Article
Keywords:
experimental; gases; helium–HFC-125; viscosity
ISSN:
0009-2509
Rights:
Author can archive post-print (ie final draft post-refereeing). For full details see http://www.sherpa.ac.uk/romeo/ [Accessed 06/01/2010]
Citation Count:
0 [Web of Science and Scopus, 06/01/2010]

Full metadata record

DC FieldValue Language
dc.contributor.authorRussell, P. A. (Paul)-
dc.contributor.authorBuffham, B. A. (Bryan)-
dc.contributor.authorMason, G. (Geoffrey)-
dc.contributor.authorHellgardt, K. (Klaus)-
dc.date.accessioned2009-04-01T10:49:33Z-
dc.date.available2009-04-01T10:49:33Z-
dc.date.issued2006-10-
dc.identifier.citationChemical Engineering Science; 61 (19): 6604-6615-
dc.identifier.issn0009-2509-
dc.identifier.doi10.1016/j.ces.2006.06.016-
dc.identifier.urihttp://hdl.handle.net/10149/58342-
dc.description.abstractA perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity–composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures. The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity–composition profiles from the results. The apparatus has been tested using helium–HFC-125 mixtures and two new viscosity–composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.-
dc.publisherElsevier-
dc.rightsAuthor can archive post-print (ie final draft post-refereeing). For full details see http://www.sherpa.ac.uk/romeo/ [Accessed 06/01/2010]-
dc.subjectexperimental-
dc.subjectgases-
dc.subjecthelium–HFC-125-
dc.subjectviscosity-
dc.titleMeasurement of the gradient of viscosity with composition of mixtures for non-ideal gases-
dc.typeArticle-
dc.contributor.departmentLoughborough University. Department of Chemical Engineering; University of Teesside. School of Science and Technology; Imperial College. Department of Chemical Engineering and Chemical Technology. London.-
dc.identifier.journalChemical Engineering Science-
ref.assessmentRAE 2008-
ref.citationcount0 [Web of Science and Scopus, 06/01/2010]-
or.citation.harvardRussell, P. A. et al. (2006) 'Measurement of the gradient of viscosity with composition of mixtures for non-ideal gases', Chemical Engineering Science, 61 (19), pp.6604-6615.-
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