Nitrogen Bubbles From Azs Refractories

At the production of many technical glasses in melting tanks there is a certain basic level of bubbles which is between 0-10%. The gas content of these bubbles is mainly nitrogen. One source of the bubbles is the refractory material of the melting tanks, e.g. the fused cast AZS blocks which form bubbles, stones and knots at the refractory-melt interface during the start-up period as well as during the normal furnace campaign.