| 摘要 |
PURPOSE:To improve energy saving feature, operability of a furnace, and temp. distribution in the furnace by switching operation to a proportional control in a high burning and to an on-off control in a low burning range. CONSTITUTION:During a high burning time, the burning amount is continuously changed using such an advantage of a proportional control that fuel to air ratio is kept at a constant level and energy saving and temp. distribution properties are excellent as wee. On the other hand, during a low burning time, an on-off operation is carried out under the condition which throttles the amount of fuel and air together. Without stopping some of the burners and introducing excess air, the temp. range between the upper and lower limits is kept small as compared with an conventional on-off operation with improved temp. distribution during this operation. Switching temp. from the proportional to the on-off operation is determined by measuring the furnace inside temp. distribution. And, operation may be switched over automatically at an appropriate switching temp. |
