JPS5692126A - Direct electroheating melting furnace of glass and melting method - Google Patents

Abstract

PURPOSE:To considerably expand the fluctuation range of the pulling amount of glass by inserting plural electrodes of different heights into the molten glass in a melting furnace so as to avoid superposing in a vertical direction, and controlling the electric energy to be supplied to these electrodes. CONSTITUTION:Barlike electrodes 3, 3' of a low level inserted perpendicularly from a hearth 2, and barlike electrodes 4, 4' of a high level inserted perpendicularly from the hearth 2 are provided in a melting vessel 9 which melts and clarifies glass raw material batch. The electrode parts l1 of the electrodes 4, 4' corresponding to the electrodes 3, 3' are coated with a refractory material insulator 8 to avoid superposing the electrode parts in a vertical direction. In follow up to the pulling amount of molten glass 6, the glass raw material batch is supplied from the top opening of the vessel 9 to form a raw material batch layer 7. When the pulling amount of the glass 6 is the mean optimum amount of the melting capcity of the vessel 9, approximately equal electric power is supplied to the electrodes 3, 3', 4, 4', and when the pulling amount of the glass 6 decreases, the supply electric energy to the electrodes 4, 4' is decreased. When the pulling amount of the glass 6 increases, the supply electric power to the electrodes 4, 4' is increased.