Hostname: page-component-788cddb947-nxk7g Total loading time: 0 Render date: 2024-10-14T23:48:04.634Z Has data issue: false hasContentIssue false

The preparation of water for surface-clean fluid mechanics

Published online by Cambridge University Press:  29 March 2006

John C. Scott
Affiliation:
Fluid Mechanics Research Institute, University of Essex, Colchester, England

Abstract

This paper describes the development of a new technique for removing surface-active contaminants from water so that it may be used for surface-clean experiments in fluid mechanics. The removal of contamination from concentrated aqueous solutions of non-surface-active materials is also possible, allowing considerable variation of density and viscosity in these experiments. Instead of using the conventional distillation processes necessary for most work involving surface chemical phenomena, surface-active substances are removed by adsorption onto a dense current of small nitrogen gas bubbles rising in a long vertical column of the water. The efficiency of the technique was found to increase to a great extent when common salt was dissolved in the water, up to concentrations around 40 g/l, and experiments are described which allow the identification of several physical processes which aid the operation of the method. The adequate performance of the cleaning technique in the removal both of an ionic surface-active material and also of Gentian Violet dye is demonstrated. The method should permit the design of surface-clean experiments using much larger volumes of water than are possible when the water has to be distilled using conventional surface chemical techniques. A simple apparatus for the measurement of surface tension is also described.

Type
Research Article
Copyright
© 1975 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Davies, J. T. & Vose, R. W. 1965 Proc. Roy. Soc A 286, 218234.
Gleim, V. G., Shelomov, I. K. & Shidlovskii, B. R. 1959 J. Appl. Chem. U.S.S.R. 32, 10691072.
Kitchener, J. A. 1964 In Recent Progress in Surface Science, vol. 1, pp. 5193. Academic.
Lamb, H. 1932 Hydrodynamics, 6th edn, pp. 631632. Cambridge University Press.
Lemlich, R. 1972 Adsorptive Bubble Separation Techniques, pp. 15, 133143. Academic.
LUCASSEN-REYNDERS, E. H. & Lucassen, J. 1969 Adv. Colloid Int. Sci. 2, 347395.
Marrucci, G., Nicodemo, L. & Acierno, D. 1969 In Co-Current Gas Liquid Flow, pp. 95108. Plenum.
Monahan, E. C. & Zeitlow, C. R. 1969 J. Geophys. Res. 74, 69616966.
Padday, J. F. 1957 In Proc. 2nd Int. Cong. Surface Activity, vol. 1, pp. 16. Butterworths.
Padday, J. F. 1969 Surface Colloid Sci. 1, 101149.
Sebba, F. 1960 Nature, 188, 736737.