Helium contamination through polymeric walls

Gabal Lanau, Miguel ; Lozano Bernal, Maria Pilar (Universidad de Zaragoza) ; Oca, Arancha ; Pina Iritia, Maria Pilar (Universidad de Zaragoza) ; Sesé Monclús, Javier (Universidad de Zaragoza) ; Rillo Millán, Conrado

Resumen: The concentration of impurities in helium gas is an important parameter for a recovery and liquefaction plant. A low level of impurities is necessary to maintain an optimum liquefaction rate in any kind of liquefier. The main origin of the impurities is the air contamination that enters into the helium mainstream at some point in the recovery cycle. In this work we have: i) identified the main sources for impurities in an experimental helium recovery plant, ii) quantified the contamination rate and iii) proposed a mitigation strategy. An analysis of the He impurities composition reveals a nitrogen/oxygen ratio different to the one existing in air. This observation is in accordance with the permeability values for nitrogen and oxygen through the polymer materials used in the plant. Experimental on line measurements for oxygen content in the He mainstream with sensitivity below 1 ppm, have been performed after recirculation through metal and polymeric pipelines, respectively, to validate our hypothesis. In addition, the dependence of the impurities concentration with the He retention time in the recovery gas bag has been evaluated. Finally some operational recommendations are given for practical applications.

Idioma: Inglés

DOI: 10.1016/j.phpro.2015.06.025

Año: 2015

Publicado en: Physics procedia 67 (2015), 141-146
ISSN: 1875-3892

Factor impacto SCIMAGO: 0.262 - Physics and Astronomy (miscellaneous)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/IPT-2012-0442-420000

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)
Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)