Laser welding of micro-VLE-measurement device and its practical application

Marika Hirvimäki*, Heidi Piili, Arttu Jussila, Tuomas Purtonen, Matti Manninen, Petri Uusi-Kyyny, Aarne Sundberg, Ville Alopaeus, Antti Salminen

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

1 Citation (Scopus)


The knowledge of phase equilibrium is critical for the modeling and operation of reactors and separation units. The use of incorrect vapor-liquid equilibrium (VLE) data for distillation leads to tower malfunction with varying end results. The only reliable method for obtaining valid VLE data for a non-ideal system is to measure it. When studying components that are either very expensive or hazardous the amount of chemicals used is preferably minimized. Typical volume of chemicals used in a VLE-measurement is 100 cm3 or above. In a VLE-measurement the temperature, pressure and composition of both phases are determined for a range of concentrations. The laser micro/fine processing is one of the fastest spreading and developing areas of all laser processes in the world. The wide field of applications makes laser a novel tool for micro processing and gives lots of new ideas, solutions, opportunities and applications for designing these milli and micro scale process devices for chemical industry. In this study an exceptionally small VLE-measurement device was designed and manufactured by utilization of laser processing. Even though the application itself is in micro scale the laser processing used in fine processing scale gave opportunity to reach the minimum volume. Laser welding has unique possibilities for this kind of welding when heat input can be controlled and only small heat affected zone and thereby minor distortions are caused. Laser welding also enables welding of demanding structures, like this micro-VLE-device. The volume of the measurement cell of micro-VLE-device was approximately 2.5 cm3, which was made possible by using the pressure transducer cavity as the equilibrium cell. The chemical consumption is therefore reduced by up to a factor of 50. The valves were also welded to the structure. The welding would not have been possible with conventional methods due to overheating of the transducer electronics. The cell was initially tested by measuring pure component vapor pressures of alkanes.

Original languageEnglish
Title of host publication29th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2010 - Congress Proceedings
Number of pages8
Publication statusPublished - 27 Dec 2010
MoE publication typeA4 Article in a conference publication
EventInternational Congress on Applications of Lasers and Electro-Optics - Anaheim, United States
Duration: 26 Sep 201030 Sep 2010
Conference number: 29


ConferenceInternational Congress on Applications of Lasers and Electro-Optics
Abbreviated titleICALEO
CountryUnited States

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