2562 KB29 KB199920252014Asaff, YesidDe Negri, Victor J.Murrenhoff, HubertusTheissen, Heinrichštevilka:6letnik:60str. 417-424, SI 80ISSN:0039-2480COBISSID:13511195URN:URN:NBN:SI:doc-3IG9TVQ4enZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikbiorazgradljive hidravlične tekočinebiorazgradljivosthidravlične tekočine na osnovi estrovhidrolizakontaminacijaoksidacijaAnalysis of the influence of contaminants on the biodegradability characteristics and ageing of biodegradable hydraulic fluids|Ongoing concerns regarding environmental protection encourage further research aimed at the development of environmentally-friendly products. Certain research activities and industrial applications have broken the paradigm of using mineral oil for hydraulic systems by providing solutions with biodegradable hydraulic fluids. Petroleum-based hydraulic fluids are not able to meet this demand due to their often toxic properties and their environmental effects. Therefore, ecologically-acceptable fluids based on natural and synthetic esters are increasingly used as pressure fluids. Knowledge of the influence of contaminants on the biodegradability characteristics and ageing of biodegradable hydraulic fluids is a prerequisite for the successful application of these fluids in hydraulic systems. Accordingly, in this study, new information obtained from commercial biodegradable fluids (hydraulic oil environmental ester synthetics (HEES)) under the influence of common contaminants (water, mineral oil, copper solid particles, and oxygen) present in current hydraulic systems has been investigated. Based on oxidation and hydrolytic stability tests, the biodegradability characteristics and ageing of biodegradable fluids are analysed, and the influence of contaminants is described. A comparison between fluid samples with different contaminants has shown that both the total acid number (TAN) and viscosity change significantly as a consequence of ageing in the presence of water and solid particles of copper, while the biodegradability characteristic was modified mainly by contamination with mineral oilČlanek preučuje vpliv onesnaževal, kot so voda, mineralna olja, delci bakra in kisik, na biorazgradljivost in staranje biorazgradljivih tekočin v hidravličnih sistemih. Kljub temu, da so mineralna olja tradicionalno najbolj razširjena vrsta hidravličnih tekočin v fluidni tehniki, pa so ta olja danes podvržena vse večjemu nadzoru, zlasti zaradi vse strožjih vladnih predpisov za preprečevanje posledic razlitja hidravličnih tekočin in iztekanja tekočin v okolje. Večja moč hidravličnih sistemov se poleg tega dosega s povečevanjem delovnega tlaka, kar pa pomeni tudi večje tveganje netesnosti. Tovrstne nezgode lahko resno škodujejo okolju pri aplikacijah kot so npr. hidroelektrarne, kmetijski stroji in stroji v pomorstvu. Opisana situacija je privedla do globalnih poskusov identifikacije hidravličnih tekočin, ki imajo manjši okoljski in toksični vpliv pri nenamernem stiku z okoljem. Poznavanje vpliva onesnaževal na biorazgradljivost in staranje biorazgradljivih hidravličnih tekočin je pogoj za uspešno uporabo teh tekočin v hidravličnih sistemih. Predstavljena študija obravnava nove podatke o komercialnih biorazgradljivih tekočinah (okoljsko sprejemljiva hidravlična olja na osnovi sintetičnih estrov oz. HEES) pod vplivom splošnih onesnaževal (voda, mineralno olje, delci bakra in kisik), ki so prisotna v današnjih hidravličnih sistemihTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo