Pictet

NAME:

Pictet, Raoul-Pierre

ACHIEVEMENTS:

Pioneer of refrigeration

NICKNAME/ALIAS:

None

DATE AND PLACE OF BIRTH:

4 April 1846, Geneva, Switzerland

DATE AND PLACE OF DEATH AND AGE AT DEATH:

27 July 1929, Paris, France. Aged 83

DISCIPLINE:

Experimental physicist

FIELD:

Refrigeration

PARENTS:

Father: August Pictet-de Bock

Mother: ???

SIBLINGS:

???

SPOUSE:

???

CHILDREN:

???

EDUCATION:

Geneva

Paris

MAJOR WORK:

LIFE AND TIMES:

Pictet studied chemistry and physics in Paris and on his return to Geneva began investigating the physics of low temperatures with a view to making money in the refrigeration industry. Building on <furthered work of> Faraday’s* work on the liquefaction of gases earlier in century, Pictet developed a vapor compression refrigeration system that used sulphur dioxide as a coolant and put it on the market in 1874. It operated at a lower pressure than did rival systems but was liable to corrosion if the sulphur dioxide came into contact with water. Nevertheless, Pictet marketed his system with a degree of success.

In 1875, the first methyl chloride was made by <work related to>  JBA Dumas* but was not used as a refrigerant for another three years. Meanwhile, Pictet carried on with his investigations and in December 1877 announced his successful liquefaction of oxygen to the Paris Academy of Sciences.

He had achieved this by liquefying three different gases in succession, each of which acted as a coolant to the next gas. He used sulphur dioxide in the first cycle, carbon dioxide in the second, and oxygen in the third and last cycle.

Working separately and employing a different method, <co-creator of liquid oxygen with> Cailletet* had also liquefied oxygen a few weeks earlier,  but had failed to announce the fact. Pictet’s success in liquefying small amount of oxygen and nitrogen provided a base for further developments in cryogenics by the Scots physicist <influenced> Dewar* and the Dutch physicist <influenced> Onnes*.

In 1879 Pictet was appointed professor of industrial physics at Geneva University. He resigned in 1886 to establish an industrial research laboratory in Berlin and to market his inventions. He patented a new coolant, called Pictet liquid, which was a mixture of sulphur dioxide and carbon dioxide. Pictet liquid was used in several refrigeration systems but his machines were still liable to corrosion if the coolant became contaminated with water.

ASSESSMENT: Pictet’s achievement in liquefying oxygen paved the way for the development of refrigeration.

EXTRA CONNECTIONS: He traveled in France with the British textile manufacturer <a pal of> Robert Owen*

Was assistant to <assistant to> Saussure*

ONELINER: R-P Pictet,  refrigeration pioneer

BIBLIOGRAPHY:

Cooper, Alan J, The World Below Zero, ACR Today & Battlepress Ltd., Aylesbury, Buckinghamshire, 1997