OCR Text |
Show atmosphere. The amounts of both coke oven gas (COG) and heating air are manually controlled by operators, and accurate control of heating temperatures is difficult. In general, the temperature inside the ladle is not continuously measured. When we measured the temperature inside the ladle continuously by means of thermocouples, w e found that the atmospheric temperature inside the ladle reached a state of equilibrium at approximately 1270K. W e suspected that variations may occur in the temperature distribution inside the ladle due to the off-center placement of the burner. In order to eliminate these concerns, w e decided to use a regenerative burner. Advantages of using a regenerative burner are as follows: (1) It is possible to reduce energy consumption by recovering the high-temperature exhaust gas with high efficiency to enable energy conservation. (2) It is possible to increase the life of the refractory material by homogenizing the temperature distribution inside the ladle and by uniformly heating the refractory material on the inner wall of the ladle using the alternate combustion method. For the above reasons, a regenerative burner was adopted for the first time for a vertically-placed ladle heating system. The resulting system has been operating since December 1996. Outline of the regenerative burner A schematic diagram of the regenerative burner is shown in Fig. 2, and its specifications are given in Table 1. The regenerative burner uses a cordierite honeycomb regenerator, and two burners are turned on alternately every 30 seconds. Using a four-way selector valve (Cross Exchange Mechanism C E M ), air is supplied to the active burner, and the other (inactive) burner functions as the flue for exhaust gas. The high-temperature exhaust gas that passes through the regenerator of the inactive burner is heat-exchanged, and discharged as low-temperature exhaust gas. The active regenerative burner functions as a heat exchanger, which generates low-temperature exhaust gas 3 |