| 摘要 |
PURPOSE:To adjust easily the amt. of the molten additive to be added to a molten iron and to add a required amt. thereof with good accuracy in the stage of feeding under pressure the molten additive in a hermetic vessel through a suspended tubular body into the molten iron by controlling the amt. of the additive to be added with a target value and feeding pressurized gas into the tubular body. CONSTITUTION:An additive of the amt. larger than the target value W to be added is put into a hermetic vessel 1 which is then hermetically sealed. The value W and the value (w) slightly smaller than the same are set in a control device 11 and when a detector 10 for the amt. of the additive to be added and the device 11 are operated, a shutter 12 is opened by a driving device 13 and the additive in the vessel 1 flows downward through the inside of a tubular body 3. When pressurized gas is fed into the vessel 1 by a means 5, the additive is forcibly fed into a molten iron 2. When the amt. of the additive value to be added attains the value (w), the shutter 12 is driven and opened to a prescribed opening degree by the devices 11, 13 in accordance with the input from the device 10, by which the speed of addition is decelerated. When the amt. of the additive to be added attains further the value W, the shutter 12 is closed and the downflow of the additive is stopped; at the same time, gas is fed into the body 3 through a means 14 and the additive in the body 3 is forcibly fed fully into the iron 2. |
