Ladle Nozzle / Tundish Nozzle Liners
Ladle Nozzle Liners and Tundish Nozzle Liners (often referred to generically as metering nozzles or shrouds) are high-performance refractory tubes or sleeves installed in the bottom of the steel teeming ladle and the tundish in a continuous casting operation. Their primary function is flow control, specifically to meter and guide the molten steel flow from the vessel into the next stage (ladle to tundish, or tundish to mold).
These liners are subject to some of the harshest conditions in the steelmaking process, including extreme thermal shock, high-velocity metal erosion, and chemical corrosion by both the molten steel and the protective slag covering.
Main Function and Characteristics
The liners control the flow rate of molten steel and protect the metal stream from atmospheric re-oxidation, ensuring consistent casting speed and high metal quality.
| CHARACTERISTIC | VALUE RANGE | PRIMARY REFRACTORY FUNCTION |
|---|---|---|
| Material | Alumina-Carbon (Al₂O₃-C), Zirconia (ZrO₂) | Provides high wear resistance and thermal stability. |
| Purpose | METERING & SHROUDING | Controls liquid flow rate and protects the metal stream. |
| Design | PRECISION SHAPE | Optimized internal geometry for uniform, non-turbulent flow. |
CLASSIFICATION
- Engineering Focus: Consumable Flow Control
- Primary Application Focus: Erosion resistance and anti-clogging; Continuous Casting of Steel (Ladle-to-Tundish, Tundish-to-Mold).
Key Performance Metrics
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
|---|---|---|
| Erosion Resistance | CRITICAL | Resists wear from high-velocity, turbulent molten steel flow. |
| Thermal Shock | HIGH | Must withstand rapid heating from ambient to ~1600°C. |
| Anti-Clogging | HIGH | Composition must resist the build-up of non-metallic inclusions (e.g., alumina) that can choke the bore. |
- Material Composition
The choice of refractory material is dictated by the level of wear and the need to prevent clogging:
- Alumina-Carbon (Al₂O₃-C): Used for standard, high-performance metering nozzles. The carbon content provides excellent thermal shock resistance, while the high Al₂O₃ aggregate provides wear resistance.
- Zirconia (ZrO₂): Used in the most critical areas, such as the slag line or a seating block, due to its extremely high refractoriness, chemical inertness, and resistance to erosion by aggressive steel grades. Zirconia is also used for the insert in some nozzles to specifically combat alumina clogging.
- Fused Silica/Alumina: Used for specialized shrouding tubes that are prone to thermal shock.
- Specialized Flow Control Systems
The liners are often integrated into complex flow control mechanisms:
- Slide Gate Nozzles (Ladle): The liner is housed within the slide gate mechanism, which uses refractory plates (often Al₂O₃-C) to open and close the bore, providing precise control over the teeming process.
- Submerged Entry Nozzles (SEN) (Tundish-to-Mold): These are long, complex liners that plunge beneath the molten metal in the continuous casting mold. Their primary functions include:
- Shrouding: Protecting the metal stream from air to prevent re-oxidation.
- Flow Shaping: Utilizing specific exit port designs to optimize the fluid dynamics within the mold, which is crucial for surface quality.
- The Clogging Problem
A major challenge is the tendency for high-alumina steel to deposit solid Al₂O₃ inclusions on the nozzle bore, rapidly reducing the flow rate—a phenomenon known as nozzle clogging.
Solution: Nozzles are often treated or manufactured with stabilized Zirconia or CaO injection systems to chemically alter the inclusions at the bore surface, preventing them from adhering.
✨ Customization Services
We offer product customization services, allowing you to tailor the appearance, dimensions, or specific markings of items like refractory shapes or bricks. This includes options for incorporating specific geometric requirements to ensure seamless integration into your process systems.
🔬 Sampling for Testing & Validation
Free product samples are available for thorough testing and validation. This allows you to confirm the quality, compatibility, and performance of our materials—such as specific bricks, castables, or raw materials—before committing to a full order.
💡 Expertise in Refractory Solutions
Leverage our deep expertise to receive detailed, application-specific refractory solutions. We move beyond just selling products by providing comprehensive plans that encompass material selection, installation guidance, and performance optimization to maximize the lifespan and efficiency of your high-temperature processes.
Rabatec products are exclusively manufactured in facilities that have achieved rigorous ISO certifications across Quality (ISO 9001), Environmental Management, and Occupational Health & Safety. This commitment ensures every product, from refractory bricks to specialized equipment, meets the highest global benchmarks for performance, sustainability, and workplace safety.
📦 Logistics Excellence: Shipping, Packaging, and Marking
Minimizing Risk: We manage all logistics to minimize handling touchpoints and transit shock. Our carriers are pre-vetted for their experience in transporting heavy, fragile, and sensitive industrial materials.
Traceability: Every shipment includes comprehensive documentation and tracking information, providing end-to-end visibility and ensuring precise delivery coordination for your site.
Protection is Paramount: Our packaging strictly follows industry standards to prevent damage, corner chipping, and moisture absorption—especially critical for materials like Basic Refractory Bricks and Refractory Mortars & Mixes.
Robust Palletization: Products are secured on fumigated, high-strength export pallets (e.g., 1100x950mm or similar sturdy dimensions) using heavy-duty strapping and durable protective wrapping (polyethylene sheeting, cardboard, etc.) to withstand long-distance travel and multiple loadings.
Moisture Control: Sensitive materials are protected with appropriate sealing and, where necessary, desiccants or moisture-vapor proof enclosures to maintain the product's integrity until installation.
Clear Identification: All outer packaging is clearly marked on multiple sides with large, legible text for immediate identification and safe handling.
Full Traceability: Markings include all essential data points: Product Name, Quality Grade, Batch Number, Quantity, Net/Gross Weight, Order Number, and the Final Destination/Construction Area. This ensures every pallet can be accounted for and correctly staged upon arrival.
Safety & Compliance: We adhere to all regulatory requirements for marking, labeling, and placarding—especially for any items classified as Dangerous Goods—to ensure full compliance with international and domestic transport regulations.
❓ Frequently Asked Questions (FAQ)
Question | Elaborated Answer |
Q: What is the Refractoriness Under Load (RUL) of your refractories? | A: Refractoriness Under Load (RUL) is a critical property that defines the maximum temperature our materials can withstand while under compressive stress before deforming (softening). Since we offer a wide range of materials—from Alumina-Silicate Bricks to high-performance Silicon Carbide Bricks—the RUL varies significantly. For specific product data, please refer to the product data sheet or submit a quote request for the material you are interested in. |
Q: Where are the Rabatec refractories and materials produced? | A: Our products are primarily sourced from specialized manufacturing plants in China. Crucially, these facilities have all undergone rigorous audits and achieved comprehensive ISO certifications (Quality, Environment, and Safety), ensuring that production adheres to the highest global standards for consistency and performance. |
Q: What refractory materials does the company offer? | A: We supply a comprehensive portfolio of advanced refractory solutions, including: Shaped Products: Alumina & Silica Bricks, Basic & Specialized Bricks (e.g., Magnesia), SiC & Structural Ceramics, and Precast Shapes. Monolithic Products: Refractory Castables, Mixes & Mortars. Insulation: Insulation Fibre and High-Performance Insulation Products. |
Q: How should I choose the appropriate refractory material for my application? | A: Selecting the correct refractory is paramount to process efficiency. The choice depends on three key factors: 1. Operating Environment: Maximum process temperature and thermal cycling (shock). 2. Chemical Attack: Type of slag, molten metal, or corrosive gas being handled (acidic, neutral, or basic). 3. Mechanical Stress: Abrasion, erosion, and static load requirements. We recommend utilizing our detailed refractory solutions service to consult with our engineers for an optimized, application-specific recommendation. |
Q: Which monolithic material should I choose when patching an existing lining? | A: For patching and minor repairs, the ideal monolithic material depends on the parent lining material, the patching depth, and the need for a rapid return to service. Common choices include: Refractory Mortars & Mixes (for minor joints/surfaces) or Plastic Refractories (for areas requiring physical compaction). Always choose a patch material chemically compatible with the existing lining to ensure proper bonding and service life. |
Q: Can I receive product samples before placing a major order? | A: Yes. We gladly provide product samples for your internal testing and validation purposes. This ensures you can confirm the quality, composition, and fit of the material—such as our Refractory Castables or Alumina-Silicate Bricks—in your specific operational environment before committing to a bulk purchase. |
Q: Do you provide certifications to verify material quality? | A: Absolutely. We provide product-related inspection certificates and quality assurance documentation upon request. This verifies that your order has passed all internal quality control checks and meets the required material specifications and industry standards. |
Q: What measures are taken for product protection during transport? | A: We ensure quick, reliable transport by using robust, industrial packaging that strictly follows industry standards. This includes high-strength palletization, heavy-duty strapping, and weather-resistant wrapping to protect fragile items like bricks and mixes from corner chipping, mechanical damage, and moisture during transit. |
