Nexans leads the world market in cable cryostats with more than three decades of expertise. Our first cryostats for low-temperature superconducting cables were manufactured in the 1970s. To date, we have shipped more than 2,000 transfer lines for liquefied gas and Nexans cryogenic systems are applied, among others, at the European nuclear research center CERN and the European Space Agency’s test rig for the Ariane 5 carrier rocket.
Today, Nexans’ core competencies comprise the industrial production of transfer lines for cryogens such as liquid nitrogen, which are also deployed in our superconducting cables. At Nexans, cable cryostats are manufactured in a continuous process and technically available in any length according to customer specifications. In addition, we supply cryostats for cable joints and terminations made of stainless steel which are produced and installed by Nexans. All products are helium leak tested and we guarantee the vacuum integrity of our transfer lines for two years. As a rule, however, our transfer lines are in operation without maintenance requirements for periods of more than 10 years.
Liquid nitrogen is employed as a cryogen in many industrial processes, but also in food deep freezing and for medical purposes. It is universally available, easy to handle, transportable without problems, and non-toxic.
Nexans offers superconducting cables with open and closed cooling systems based on liquid nitrogen. Superconducting cables require stations for recooling the cryogen at suitable intervals depending on the cables’ dimension and load. The dimensions of cooling stations are similar to those of a standard garage.
Losses of liquid nitrogen from open cooling systems are compensated by reservoir tanks. These tanks are equipped with a level monitoring system and will generate electronic requisition notes automatically while a close-meshed logistic infrastructure ensures refilling from tanker trucks within a narrow time frame.
Closed liquid nitrogen cooling systems include electrically powered cryocoolers and operate free of nitrogen loss.
The potential environmental impact of liquid nitrogen is marginal. A leak in a cryostat would entail only a local ground freezing.