000048103 001__ 48103 000048103 005__ 20210121114517.0 000048103 0247_ $$2doi$$a10.1016/j.phpro.2015.06.025 000048103 0248_ $$2sideral$$a88346 000048103 037__ $$aART-2015-88346 000048103 041__ $$aeng 000048103 100__ $$0(orcid)0000-0002-5022-5094$$aGabal Lanau, Miguel 000048103 245__ $$aHelium contamination through polymeric walls 000048103 260__ $$c2015 000048103 5060_ $$aAccess copy available to the general public$$fUnrestricted 000048103 5203_ $$aThe concentration of impurities in helium gas is an important parameter for a recovery and liquefaction plant. A low level of impurities is necessary to maintain an optimum liquefaction rate in any kind of liquefier. The main origin of the impurities is the air contamination that enters into the helium mainstream at some point in the recovery cycle. In this work we have: i) identified the main sources for impurities in an experimental helium recovery plant, ii) quantified the contamination rate and iii) proposed a mitigation strategy. An analysis of the He impurities composition reveals a nitrogen/oxygen ratio different to the one existing in air. This observation is in accordance with the permeability values for nitrogen and oxygen through the polymer materials used in the plant. Experimental on line measurements for oxygen content in the He mainstream with sensitivity below 1 ppm, have been performed after recirculation through metal and polymeric pipelines, respectively, to validate our hypothesis. In addition, the dependence of the impurities concentration with the He retention time in the recovery gas bag has been evaluated. Finally some operational recommendations are given for practical applications. 000048103 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/IPT-2012-0442-420000 000048103 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000048103 592__ $$a0.262$$b2015 000048103 593__ $$aPhysics and Astronomy (miscellaneous)$$c2015 000048103 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000048103 700__ $$0(orcid)0000-0001-7659-3963$$aLozano Bernal, Maria Pilar$$uUniversidad de Zaragoza 000048103 700__ $$aOca, Arancha 000048103 700__ $$0(orcid)0000-0001-9897-6527$$aPina Iritia, Maria Pilar$$uUniversidad de Zaragoza 000048103 700__ $$0(orcid)0000-0002-7742-9329$$aSesé Monclús, Javier$$uUniversidad de Zaragoza 000048103 700__ $$aRillo Millán, Conrado 000048103 7102_ $$15005$$2555$$aUniversidad de Zaragoza$$bDpto. Ing.Quím.Tecnol.Med.Amb.$$cÁrea Ingeniería Química 000048103 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDpto. Física Materia Condensa.$$cÁrea Física Materia Condensada 000048103 773__ $$g67 (2015), 141-146$$tPhysics procedia$$x1875-3892 000048103 8564_ $$s679122$$uhttps://zaguan.unizar.es/record/48103/files/texto_completo.pdf$$yVersión publicada 000048103 8564_ $$s7019$$uhttps://zaguan.unizar.es/record/48103/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000048103 909CO $$ooai:zaguan.unizar.es:48103$$particulos$$pdriver 000048103 951__ $$a2021-01-21-11:00:23 000048103 980__ $$aARTICLE