Notes on some Fireclays and Refractory Stone Used in the Glass Industry

JSGT 1917 V01 T126-T129

 The particular type of refractory material used in the construction of a furnace for glass--making depends largely upon the conditions under which it is likely to be heated. Thus, for the crown of a furnace where the refractory material is required to withstand a high temperature, but is not subjected to the chemical action of the glass during the process of manufacture, or to the mechanical action of the slowly moving fluid, silica bricks are usually regarded as most suitable. For the sides and bottom of a tank furnace the conditions are different and the type of refractory material must be altered to suit the changed conditions. Not only must the material used be refractory in the sense that it offers a high resistance to deformation through the action of heat alone, but it must also resist chemical attack both by the batch materials and the glass, and must also possess sufficient mechanical strength to resist the abrasive action due to the "washing" effect of heavy weights of fused materials. For the construction of the sides and bottoms of tank furnaces, large blocks are used in preference to bricks. Such blocks are sometimes made from fireclay and sometimes from a particular " firestone" obtained almost exclusively from

Durham. Opinions differ considerably, even amongst men with considerable practical experience of both types of blocks, as to their relative merits, but the balance of opinion appears to be that for floor blocks and side blocks below the actual level of the glass in the tank under average working conditions, stone blocks are preferable, whereas at the actual surface level, where they are subjected. to the mechanical action of the fluid glass, fireclay blocks are more efficient.

Notes on some Fireclays and Refractory Stone Used in the Glass Industry

J. H. Davidson