ABSTRACT
An intermittent two-chamber glass tank furnace with a common flame apace has been designed and constructed for simultaneous experimental dual melting of both flint and coloured glass, fusing under the same atmospheric conditions. This was precipitated by the determination to give a new outlook with a view to solving some deficiencies identified, acknowledged and generally experienced with the conventional single-compartment construction of periodic tank furnaces employed for studio glass melting in general, and that used in Glass Technology Section of Industrial Design Department in particular. The constructional materials used were exclusively imported standard refractory materials obtained from three Nigerian glass industries, and metal materials, locally obtained. In the three separate experimental test melting of pairs of glasses carried out, most associated short-comings of the single-chamber construction were overcome. For example, it became possible to melt both coloured and flint glass simultaneously - an impossible and uncommon operation with tank furnaces, both continuous and periodic; provision of more working space for simultaneous studio glass practice with accompanying increased productivity; and reduction in fuel consumption. The reduced height of the two-chamber unit and its longitudinal mode of firing ensured that the heat generated was brought closer to the glass melts and sufficient space provided for flame propagation. The strategic location of the port made it multi-purpose; it served as an inlet for fuel and combustion air, a view hole for both chambers, and acted as an avenue for sample taking of molten glass without materially tempering with the doors during firing operations. Closed packing of the furnace refractory bricks and judicious application of external backing insulation guaranteed uniformity of temperature distribution in both chambers; 1300�C remained the maximum temperature attained in all the three firing operations. Regulation of atmospheric conditions of the furnace space was aided by an adjustable