| 摘要 |
<p>1,180,443. Control of electric furnaces. DEMAG-ELEKTROMETALLURGIE G.m.b.H. 23 Feb., 1967 [7 March, 1966], No. 8759/67. Heading H2H. A method of controlling an electric melting furnace comprises estimating or measuring the weight of the furnace charge, calculating the electrical energy required to effect a determined stage of a melting process, supplying a digital or analogue first signal representative of the calculated value to one part of a -comparator, feeding a second signal representative of the energy absorbed directly to another part of the comparator and obtaining a third signal which disconnects the furnace or initiates a further process stage when the first and second signals are equal. Where a changing operation is subdivided, the first signal is divided unequally so that the second part of the charge is added before the first part has fully melted. The furnace voltage may be set for each stage by hand or a punched tape system which is provided with a voltage indicator. Sensors may be provided for local temperature measurement and lining wear. A fourth signal may be added to the first for stages involving molten metal processes.</p> |
