Blast Furnace Level Measurement Solutions

Level measurement in blast furnaces is a critical process that employs advanced technologies such as radar sensors and robust mechanical systems to monitor both the burden level at the top of the furnace and the liquid metal level tapping into the torpedo car or iron ladle, ensuring optimal furnace operation despite challenging conditions of high temperatures, dust, and pressure.

 

Blast furnaces are the core equipment in the steel industry that produces pig iron from iron ore. In this continuous ironmaking process, iron ore, coke, and limestone are charged at the top of the furnace and react with hot air (900-1,250degC) pumped in from the bottom. In the furnace, the descending materials react efficiently with the ascending gas due to the countercurrent principle, and the iron oxide in the iron ore is reduced at a high temperature of about 1,600degC to produce molten pig iron.

 

• Once "blowing" begins, it runs continuously until the firebricks need repair or the demand for steel falls.
• The main chemical reaction taking place in the furnace is Fe₂O₃ + 3C → 2Fe + 3CO₂.
• The molten pig iron and slag collect at the bottom of the furnace and are periodically drained.
• Blast Furnaces are the traditional method of steel production and are essential for producing high-quality steel products, are a challenge to decarbonize.

Two main technologies are used to measure the burden level (stockline) in blast furnaces, which are radar and mechanical stockline indicators.

 

• Non-contact measurement is unaffected by operating temperature or changing gas compositions.
• It transmits a high-frequency radar pulse and calculates the distance from the round-trip time of the reflected wave from the surface of the charge. (FMCW radar principle system is aslo applicable.)
• Small sensor unit allows for maintenance-free operation.
• Housed in a nitrogen purged dust-proof and cooled protective enclosure.

 

• Using a cable drum in a gas-tight casing and measuring weights.
• Operates at an ascent speed of 60m/min and a descent speed of 42m/min.
• Powered by electric motor with VVVF drive and manual brake release lever.
• Matsushima Measure Tech is offering unique torque control system (slipping clutch mechanism) which provides headacheless adjustment and free from troubles by electrical noise.

 

 

Both systems are essential for controlling the burden distribution in the blast furnace and by monitoring the burden surface profile, contribute to more stable and efficient blast furnace operation.

Torpedo cars are horizontal cylindrical containers used to transport molten iron tapped from a blast furnace at high temperatures of over 1,400degC. Accurate level measurement is essential for the safe and efficient loading of this molten iron.

 

• FMCW Radar Level Transmitters are widely used since 50 years.
• It is installed on the casting floor and transmits microwaves through the antenna to the molten iron surface in the torpedo car. The reflected waves are then received to continuously measure the level.
• Accurate understanding of the filling status improves safety and enables efficient operation (productivity improvement) of torpedo cars.