Fosbel International Limited

Glaverbel

Stephen D Cherico

Pierre Robyn

Alexandre Zivkovic

Charles M Zvosec

Leon P Mottet

Guy Van Marcke De Lummen

Jean Moreau

Naiping D Zhu

Valentin S Nemkov

John Bacon

A self-fusing alloy thermal spray coating or a vitreous ceramic coating is fused to a complicated metal shape or convoluted metal surface, such as a waterwall panel having a plurality of tubes interconnected by a plurality of membranes, without significant warpage or adverse change in the microstructure of the material forming the panel. The coating is first applied to the panel and then is heated to a liquidus temperature (typically between about 1000.degree.-2200.degree. F.), by induction at a frequency of greater than about 25 kHz, so as to effect fusing. An inductive coil assembly for this purpose comprises a copper tubular combined electrical current conductor and conduit for circulating cooling water having a first closed end and a second end connectable to a source of cooling fluid and a source of electricity. At least one, and preferably a plurality, of copper noses extend outwardly from the combined conductor and conduit and both conduct electricity and circulate cooling fluid. The noses extend substantially perpendicularly to the combined conductor and conduit and are configured so as to effect proper induction heating of the panel. A magnetic flux concentrator is preferably provided over at least some of the noses. Preheating noses (e.g. solid copper blocks) may be connected to a leading portion of the combined conductor and conduit.

High frequency induction fusing

Process for forming a refractory repair mass

In ceramic welding processes, oxidizing gas and a mixture of refractory and fuel powders are projected against a surface and the fuel is burnt to generate sufficient heat that the refractory powder becomes at least partially melted or softened and a cohesive refractory weld mass is progressively built up against that surface. In order to reduce any tendency for the weld mass to include a low-grade refractory phase and thus promote the refractoriness of that weld mass, the fuel powder is present in a proportion of not more than 15% by weight of the total mixture and includes at least two metals selected from aluminum, magnesium, chromium and zirconium, in that at least the major part by weight of the refractory powder consists of one or more of magnesia, alumina and chromic oxide, and in that the molar proportions of silica and calcium oxide present in the refractory powder (if any) satisfy the following expression:

Ceramic welding powder mixture

In ceramic welding processes, oxidising gas and a mixture of refractory and fuel powders are projected against a surface and the fuel is burnt to generate sufficient heat that the refractory powder becomes at least partially melted or softened and a cohesive refractory mass is progressively built up against that surface. In order to reduce any tendency for the weld mass to include a low-grade refractory phase and thus promote the refractoriness of that weld mass, the fuel powder is present in a proportion of not more than 15% by weight of the total mixture and includes at least two metals selected from aluminium, magnesium, chromium and zirconium, and in that at least the major part by weight of the refractory powder consists of one or more of magnesia, alumina and chromic oxide, and in that the molar proportions of silica and calcium oxide present in the refractory powder (if any) satisfy the following expression: molar concentration of SiO.sub.2 in % .ltoreq.0.2+molar concentration of CaO in %

Ceramic welding process

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North Royalton, OH, United States of America

Stephen D Cherico