OCR Text |
Show bottom of the ladle is about 30K, which is less than half that with the conventional burner. Effects of Introducing the Regenerative Burner Ladle Heating System Energy-saving effects The flow of heat in the ladle heating system before and after the application of the regenerative burner is illustrated in Fig. 8. (The heat flow of the regenerative burner is that in the state for which the amount of gas is a minimum, and the heat loss from the ladle due to radiation is the value when the temperature inside the ladle is 1270K and in the state of equilibrium.) In the conventional system, the exhaust gas, which is produced at temperatures as high as 1270K after heating the ladle, was released through the flue, because no exhaust heat recovery system was installed. As a result, only 3 0 % of the input fuel was used to maintain the ladle temperature, and the remainder was lost as exhaust gas. With the conventional burner, only about 3 0 % of the combustion heat of the input fuel was used to maintain the ladle temperature. However, with the regenerative burner, the exhaust heat can be recovered with high efficiency, and as a result, more than 7 0 % of the combustion heat of the input fuel can be used to maintain the ladle temperature. As shown in Table 2, the fuel usage, which was previously constant at 200 Nm3/h, is reduced to 120 Nm3/h during the heating period, and the introduction of automatic furnace temperature control reduces the fuel usage during the homogeneous-heating period even further, to 70 to 80 Nm3/h. Operation records indicate that a 5 6 % reduction in fuel consumption is achieved. This figure is equivalent to a reduction in monthly fuel usage of 2.4 x 1 o6 MJ. Because the introduction of the regenerative burner causes the temperature of exhaust gas to decrease, w e installed an IDF. W e also installed a controller. The use of these accessories results in an increase in power consumption. We 7 |