Blast Furnace: Equipment

Equipment
Combustion Technology
Energy Consumption
Process Description
R&D Trends

Blast furnaces are large intricate systems that are constructed from a combination of off-the-shelf equipment and custom constructed components. The largest components of the blast furnace proper include the furnace shell, the furnace internal refractory lining, and the crucible-like hearth. Most of the stand-alone equipment such as motors, burners, etc., are associated with the following:

• Raw material assembly and transport
• Hot metal and slag transfer
• Off-gas cleaning
• Hot-blast stoves

While all of the equipment used in the above operations may be of interest, the focus here is placed on the equipment and components specific to the blast furnace.

Skip Car (conveyors) – The skip cars, and in some installations conveyors, are used to deliver the blast furnace charge to the top of the furnace.

Bosh – The bosh is an inverted conical section in which the melting starts.

Receiving Hopper – The blast furnace charge is loaded into the receiving hopper, which in turn delivers the charge to the rotating distributor. The rotating distributor helps assure a uniform distribution of the charge in the furnace stack.

Hearth – The hearth is an intricately constructed crucible-like vessel upon which the vertical shaft portion of the furnace sits. All the molten metal and slag collect in the hearth before being drained.
Bells (large and small) – the large and small bells are conically shaped devices that form a gas-tight lock hopper. The hopper prevents gas from escaping from the furnace while it is being charged.

Bustle Pipe – The bustle encircles the blast furnace and delivers the hot blast air from the hot-blast line to the furnace.
Stack – The stack is the upper portion of the furnace where the burden is pre-heated.

Injection Lance – The injection lance is inserted into the blowpipe that leads up to the tuyeres. The supplemental fuel is delivered to the furnace through the injection lance.

Iron and Slag Notches- The molten metal is removed from the hearth through the iron notches. The metal is placed into transfer ladles, while the slag may be transferred to slag pots, drawn off into dry pits for solidification, or granulated with a stream of water and flushed into a well pit.

Tuyeres – The hot blast air is delivered to the furnace through water-cooled openings called tuyeres. The tuyeres are located at the top of the hearth.

The Making, Shaping, and Treating of Steel, 10th Edition, Association of Iron and Steel Engineers, 1985.