1. Low material line. When the blast furnace cannot be loaded on time, the top material surface of the furnace will gradually drop, so that the probe rule is lower than the normal specified material line by more than 0.5 m, which is called the low material line. When a low material line occurs, the wind should generally be reduced.
2. Suspended material. When the blast furnace charge stops falling for more than 1 to 2 batches, it is suspended. When the material is suspended, the air permeability deteriorates due to the suspension of the material column, and the amount of air blown into the hearth is reduced, and the air pressure becomes higher and higher, which will cause the fan to surge in severe cases. If it is not handled in time, the pressure difference between the hearth and the top of the furnace will become larger and larger, and the feeding will become more difficult, and the suspension will become more and more serious. When material suspension occurs, the vent valve is often opened, and the air is quickly reduced by 10% to 15%, or other operational measures are taken to reduce the charge.
3. Seating materials. The purpose is to make the suspended charge collapse. That is, artificially quickly open the air release valve on the cold air pipe to release air, so that the air pressure drops rapidly until it drops to 0.01 MPa～0.005 MPa, and maintains it for 3 min～5 min, so that the charge loses the floating force of the gas in the furnace and collapses. . The air pressure of 0.01 MPa～0.005 MPa must be left when the material is seated to prevent the gas in the furnace from flowing back into the air pipe and causing an explosion.
When the material is seated, the air pressure of the blower decreases rapidly and the air volume increases due to the sudden air release, resulting in abnormal situations. Therefore, the blower station should be notified in advance to reduce the load of the blower before the material is seated.
4. Shut the wind. During the production process of the blast furnace, due to temporary maintenance, the short-term suspension of air supply to the furnace is called a break air. Wind break for more than 6 h to 8 h is called long-term wind break. The blower can be stopped at this time. Generally, short-term wind breaks are used to release air to stop the air supply to the blast furnace. At this time, the blower needs to take corresponding measures to adjust the air volume.
