Glazed surfaces on facade panels for buildings - obtd. using large plasma burner to melt surface of panel

Surface melting of solid materials or objects, esp. building elements, using an arc as a source of heat, the novelty being that a gas is fed through the arc so that the resulting directed plasma ensures the prodn. of the required heat. The arc is pref. generated using a low voltage direct current, the plasma source being located 2-80 mm from the surface being fused and the axis of the plasma jet is pref. at an angle of 10-90 degrees to the surface. The gas employed is pref. Ar, N2, air, a hydrocarbon, H2 or a mixt. thereof, and the surface may contain an inorganic pigment, esp. metal oxide. Several burners may be used in an automatic program, and a pref. burner design is claimed. Used e.g. for producing a glazed but porous surface on panels 12 m2 in 15 mins., the panels being used as facades in domestic or large industrial buildings using mass prodn. and pre-fabricated building elements. Using a value of 1 for the cost of facades produced by the invention, the use of coloured grey cement with limestone chips is 2.5. times more expensive, and the use of coloured plastics 4-6 times more expensive. L'INVENTION CONCERNE UN PROCEDE DE FUSION DE MATERIAUX.ON DECRIT ICI UN PROCEDE DE FUSION PARTIELLE DE LA SURFACE DE MATERIAUX OU CORPS SOLIDES, EN PARTICULIER D'ELEMENTS DE CONSTRUCTION, UTILISANT UN ARC ELECTRIQUE COMME SOURCE DE CHALEUR ET CARACTERISE PAR LE FAIT QUE L'ON FAIT PASSER UN GAZ A TRAVERS L'ARC ELECTRIQUE ET QUE L'ON ASSURE L'ACTION THERMIQUE AU MOYEN DU PLASMA DIRIGE AINSI ENGENDRE.APPLICATION AUX MATERIAUX DE CONSTRUCTION.