Commissariat a L'energie Atomique

Areva Nc

Compagnie Generale Des Matieres Nucleaires

Patrice Brun

Jacques Lacombe

Christian Ladirat

Francis Bousquet

Geoffroy Berard

Valerie Petitjean

Antony Prod'Homme

Jean-Francois Hollebecque

Thierry Flament

Eric Chauvin

Angular sectors of a cylindrical wall of a crucible for vitrification of waste, built in steel and subject to high temperatures, are coated with a mixture of mainly glass and ceramic, the coating being subject to a heat treatment comprising a step between 650&#xb0; C. and 850&#xb0; C. so as to perform surface melting of the mixture filling the open porosity, improving dielectric strength and the cohesion of the coating, but without producing any excessive thermal expansion or oxidation of the substrate which would lead to fast flaking of the coating.

Method for coating a metal crucible element with a mixture of glass and ceramic

A temperature measurement tube is composite and comprises a rigid shaft (), which is cooled so as to shield it from corrosion and from the melt, and an end-fitting () housing a thermocouple () on the end of the tube and constructed from a noble metal, which is resistant to corrosion and to the high melting point. An alumina coating () is placed between the two metals in order to prevent any corrosion-inducing electrochemical exchange between them.

Temperature measurement tube

The electricity transmission device comprises prolonged rigid conductors made of copper, and also a connector comprising a network of flexible elements, such as brazed tubes with cooling channels for the conductors, that enables angular displacements between the successive segments and therefore gives a flexibility absorbing small displacements of the device. A lifting manoeuvre system is associated with the segments. The segments may be joined to other elements of the device through connections with jaws enabling slipping.

Electricity transmission device at high current and high frequency

Vertical segments of a side wall of a crucible for an induction furnace are assembled at an adjustable, invariable position by screws screwed into tapped holes of a flange common to all segments. A precise assembly is thus obtained producing no deformation and no internal stresses. The segments are coated with a ceramic coating for their protection and to prevent formation of electric arcs. Junction edges of faces are rounded to achieve the same effect. Water cooling boxes of the lower furnace hearth are similarly constructed. The apparatus can, as an example, be applied to vitrification techniques.

Core-type furnace

Growing community of inventors

Saint Michel d'Euzet, France

Patrice Brun