Glass Industry Refractories with Special Reference to Tank Furnaces

JSGT 1917 V01 T137-T139

The following remarks apply to the refractories used in tank furnaces. The comparatively low temperatures employed are favourable to long life" and there is an abundance of siliceous material available sufficiently refractory, so far as resistance to fusion is concerned. A high fusion point is, however, only one of the factors to be considered. Fusibility depends on the character of the atmosphere to which the material is subjected while highly heated. The nature of the charge in glass tank furnaces is such that at the temperatures employed, alkaline dust or vapours are a significant constituent of the furnace gases. It is therefore not merely a question of a reducing or oxidising atmosphere, but of one charged with vapours or particles with a distinct corrosive action on acid materials. The effect would be most marked at the exit ports, where the products of combustion were being swept away at a high velocity through narrow openings but, as the furnaces are reversible, the port blocks would each in turn be subjected to the corroding effect of the furnace gases. The obvious remedy would be to employ, in the portion of the furnace attacked, materials that would not suffer corrosion or the rate of corrosion of which would be such that the efficient life of the furnace would not be affected. But the first requisite for the selection of materials with the required properties would be an accurate knowledge of the composition of the furnace gases and the temperature, at which they are brought into contact with the ports of the furnace under discussion.

Cosmo Johns