Raoul-Pierre Pictet (4 April 1846 – 27 July 1929) was a Swissphysicist. Pictet is co-credited with French scientist Louis-Paul Cailletet as the first to produce liquid oxygen in 1877.[1]
Biography
Pictet was born in Geneva. He served as professor in the university of that city. He devoted himself largely to problems involving the production of low temperatures and the liquefaction and solidification of gases.[2]
On December 22, 1877, the Academy of Sciences in Paris received a telegram from Pictet in Geneva reading as follows: Oxygen liquefied to-day under 320 atmospheres and 140 degrees of cold by combined use of sulfurous and carbonic acid. This announcement was almost simultaneous with that of Cailletet who had liquefied oxygen by a completely different process.[3]
Two pre-cooling refrigeration cycles: 1. SO2(-10 °C) 2. CO2 (-78 °C) oxygen flow is pre–cooled by the means of heat exchangers and expands to atmosphere via a hand valve