The tapping of a Basic Oxygen Furnace is a rapid, high-volume event where hundreds of tons of molten steel are discharged in a matter of minutes. Bringing control and precision to this intense process is the job of the slide gate system, and the very first component to face the molten steel is the Inner Nozzle. This highly engineered refractory nozzle acts as the gatekeeper of the entire tapping operation, and its performance directly impacts steel quality, safety, and process efficiency.

The BOF Inner Nozzle is a pre-formed, durable refractory component that is set into the tap hole of the converter, positioned directly above the moving plates of the slide gate. It is designed to perform several crucial functions from the moment tapping begins.

The Critical Functions of the Inner Nozzle

• Shaping the Steel Stream: Its primary and most important job is to gather the molten steel and form it into a coherent, stable, and non-turbulent stream before it passes through the slide gate. A well-defined stream minimizes air entrainment and splashing in the ladle below, which is crucial for producing clean steel with low gas content.
• Providing Erosion Resistance: The Inner Nozzle bears the full, initial impact of the molten steel rushing from the furnace. It must be made from highly erosion-resistant materials to maintain its internal bore diameter and prevent it from wearing away, which would lead to an uncontrolled and erratic flow.
• Protecting the Slide Gate: By conditioning the steel flow, the Inner Nozzle provides a less turbulent stream to the slide gate plates, reducing wear on these critical moving parts. It also provides a clean, stable upper surface for the slide gate to seal against.

Material Requirements for Extreme Duty

To survive this demanding environment, BOF Inner Nozzles are manufactured from high-performance refractory compositions, such as high-purity alumina, alumina-spinel, or advanced magnesia-carbon composites. These materials are chosen to deliver:

• Extreme thermal shock resistance to withstand instantaneous contact with steel at over 1600°C.
• Excellent resistance to erosion and chemical corrosion from the specific steel grades being produced.
• Precise and consistent dimensions to ensure a perfect, leak-free fit within the tap hole assembly.

The Inner Nozzle may be a relatively small component in the grand scale of a BOF, but its performance is absolutely critical. A failure or poor performance can lead to tapping problems, compromised steel quality, and significant operational and safety risks.

A Complete Solution for Your Tapping Needs

At Pennekamp Middle East, we provide a full range of high-quality consumables for BOF tapping systems. Our portfolio includes high-performance Inner Nozzles engineered for durability and reliability, designed to work seamlessly with our other slide gate components.

Contact us today to ensure your tapping operations are safe, clean, and efficient with our advanced refractory solutions.