F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
F27B5/00—Muffle furnaces; Retort furnaces; Other furnaces in which the charge is held completely isolated
F27B5/04—Muffle furnaces; Retort furnaces; Other furnaces in which the charge is held completely isolated adapted for treating the charge in vacuum or special atmosphere
Procédé de traitement pour améliorer la perméabilité des fonds de récipients métallurgiques pourvus d'éléments réfractaires perméables, et matériaux pour sa mise en oeuvre