The Linde plant is a large cooling system where oxygen and nitrogen are separated by fractional distillation and liquid air is produced. Air consists of about 20 per cent nitrogen and 80 per cent oxygen. Put in a nutshell the process consists of compressing the air and then allowing it to expand. This produces a drop in temperature. The process is repeated, and can be used to achieve very low temperatures. At a certain point the air becomes liquid. The oxygen is distilled and the nitrogen remains. To produce calcium cyanamide, one must have calcium carbide and nitrogen gas.
The air intake was not far from the school, some distance from the factory. The Linde plant was installed right alongside the calcium cyanamide factory, because the nitrogen from the Linde Building was needed in the cyanamide kilns. Crushed carbide was combined with other substance in cylinder-shaped kilns, into which nitrogen from the Linde plant was conveyed through pipes in the ground below the hall housing the kilns.
The first building permit for the Linde plant was issued on 25 May 1908. It concerned the cyanamide factory and its pure nitrogen production plant. The processing plant was set up when production was started in 1907/08. A new plant was built in 1912, when the production capacity of the smelting plant was increased. In 1915 the daily production was 100 tonnes liquid air, which was distilled to make 77 tonnes nitrogen. After World War II the plant was obsolete and unreliable, and a new nitrogen plant with new compressors was bought and installed in 1949. This is the plant which remains in the building today. The last compressors, which were replaced in the Nineties, have been removed and sold.
The most important method for producing liquid air is the one invented by Linde in Munich in 1895. Not long after Hampson invented a similar method in London, independently of Linde. The Linde plant is based on the so-called Joule-Thomson effect. The first manager of the Smelting Plant, Dr. Albert Petersson, wrote his PhD thesis on the Thomson effect in Zürich in 1895. Von Linde is recognized as the inventor of the commercial LNG process which turns dry gas into a liquid by means of a combination of increased pressure and cooling. The process was discovered in 1897, when Von Linde managed to make oxygen, nitrogen and air liquid in one and the same operation. His LNG freezing technology patent has played a very important role for the international commerce of natural gas, and his research has been crucial for all cooling technology.
The demand for nitrogen has been great in our age, because of the use of chemical fertilizers in farming, to increase the harvest.
In the article “Harnessing the Hottest Heat and the Coldest Cold”, a story about the Odda factories from 1918, nitrogen is described as ”the World`s Friend”.
The Linde Building was in a state of bad disrepair when the NVIM museum, national heritage institutions and the local municipality together made it possible to restore a large part of the façade. The architecture reflects the styles adopted in industrial buildings in the late 19th and early 20th century, when modernism was gaining ground, but classicist elements still prevailed.
When the production at the Odda Smelting plant was discontinued, the Linde Building was put to use for cultural events as theatre productions, concerts and the annual literature festival. The house bears witness to a new way to use industrial buildings for cultural purposes, and symbolizes a changing Odda.
