R9m 4-Strand Continuous Caster
1. Equipment Overview
This equipment is an R9m 4-Strand Continuous Caster, adopting a full-arc casting configuration with a casting radius of R9000mm. The system consists of four casting machines and four strands, allowing four-strand continuous casting operations.
The caster is designed for processing steel grades including Q195, Q215, Q235 and Q355B, with MS as the main product. It supports two billet section sizes: 180×500mm and 180×550mm, with an annual designed production capacity of 1.4 million tons.
Different casting speeds are configured according to billet section sizes. The casting speed is 1.1–1.15m/min for 180×500mm billets and 1.0–1.1m/min for 180×550mm billets.
The complete caster system consists of a ladle turret, tundish, tundish car, mold, secondary cooling system, secondary cooling guide section, withdrawal and straightening machine, dummy bar, flame cutting equipment and billet discharge roller tables.
These systems work together to complete the continuous casting process, including steel pouring, initial solidification, secondary cooling, billet withdrawal, straightening, cutting to length and billet discharge.
2. Main Technical Specifications
| Item | Technical Specifications |
|---|---|
| Equipment Name | R9m 4-Strand Continuous Caster |
| Caster Type | Full-arc |
| Steel Grades | Q195, Q215, Q235, Q355B |
| Annual Capacity | 1.4 million tons/year |
| Main Products | MS |
| Billet Sections | 180×500 mm; 180×550 mm |
| Number of Strands | 4-machine 4-strand |
| Casting Radius | R9000 mm |
| Strand Spacing | 1750 mm |
| Maximum Fixed Length | 8 m |
| Casting Speed for 180×500mm | 1.1–1.15 m/min |
| Casting Speed for 180×550mm | 1.0–1.1 m/min |
| Metallurgical Length | Approx. 20m from mold meniscus to flame cutting machine; approx. 15.6m to the last pair of withdrawal-straightening rolls |
| Dummy Bar Type | Flexible Dummy Bar |
| Cutting Method | Flame Cutting |
3. Main Caster Structure and Process Configuration
(1) Ladle Turret
The equipment adopts a butterfly-type elevating ladle turret, which is designed to support, lift and rotate the ladle during continuous casting operations.
As an important load-bearing and ladle transfer component of the caster, the ladle turret supports ladle positioning and transfer, helping maintain the steel supply required for continuous casting production.
(2) Tundish
The tundish adopts a T-shaped configuration, with a working liquid level of 700mm and an approximate capacity of 35 tons.
Located between the ladle and the mold, the tundish receives molten steel from the ladle and distributes it to the individual casting strands, providing an intermediate steel distribution system for multi-strand continuous casting.
| Item | Technical Specifications |
|---|---|
| Tundish Type | T-shaped |
| Working Liquid Level | 700 mm |
| Capacity | Approx. 35 t |
(3) Tundish Car
The tundish car adopts a portal frame with a semi-cantilever structure, featuring an approximate load capacity of 70 tons.
It is designed to support and transport the tundish, providing assistance for tundish installation, positioning and operational handling.
| Item | Technical Specifications |
|---|---|
| Structure | Portal Frame, Semi-cantilever Type |
| Load Capacity | Approx. 70 t |
4. Mold System
The mold is one of the core components of the continuous caster. It is primarily responsible for the initial solidification of molten steel and the formation of the initial billet shell.
The equipment features a mold copper tube length of 900mm and is equipped with two rows of four-sided foot rolls, each with a diameter of Φ80mm.
The mold adopts a mechanical oscillation system consisting of a four-bar linkage and half-leaf-spring mechanism. It also uses a split-type submerged entry nozzle casting method to support stable steel pouring and initial solidification inside the mold.
Main Mold Specifications:
| Item | Technical Specifications |
|---|---|
| Mold Copper Tube Length | 900 mm |
| Foot Roll Configuration | 2 rows of four-sided foot rolls |
| Foot Roll Diameter | Φ80 mm |
| Mold Oscillation | Four-bar linkage + half-leaf-spring mechanical oscillation |
| Casting Method | Split-type submerged entry nozzle casting |
| Mold Level Control | Eddy-current + stopper rod control |
Mold Level Control
The equipment adopts an eddy-current detection system combined with stopper rod control.
The system is used to monitor and regulate the molten steel level inside the mold. The eddy-current detection system provides liquid level signals, while the stopper rod controls the molten steel flow into the mold, supporting stable mold level control during casting operations.
5. Secondary Cooling System
The equipment adopts a four-zone secondary cooling control system, consisting of full-water cooling in the foot-roll zone and air-mist cooling in Zones 2 to 4.
The secondary cooling system provides further cooling and solidification after the molten steel leaves the mold. Through different cooling zones, the system performs staged cooling of the billet to meet the cooling requirements of the continuous casting process.
Secondary Cooling Configuration:
| Cooling Zone | Cooling Method |
|---|---|
| Foot-roll Zone | Full-water cooling |
| Zone 2 | Air-mist cooling |
| Zone 3 | Air-mist cooling |
| Zone 4 | Air-mist cooling |
6. Secondary Cooling Guide Section
The secondary cooling guide section adopts a fan-shaped configuration consisting of three sections with different clamping roll specifications.
The inner and outer arc clamping rolls provide support and guidance for the billet during secondary cooling.
Guide Section Configuration:
| Section | Clamping Roll Configuration | Roll Diameter |
|---|---|---|
| Section 1 | 10 pairs of inner/outer arc clamping rolls | Φ140 mm |
| Section 2 | 14 pairs of inner/outer arc clamping rolls | Φ200 mm |
| Section 3 | 4 pairs of inner/outer arc clamping rolls | Φ250 mm |
The three-section arrangement uses different roll diameters to accommodate the guidance and support requirements of the billet throughout the continuous casting process.
7. Withdrawal and Straightening System
The equipment adopts a five-roll withdrawal straightener, which is primarily used for continuous billet withdrawal and straightening operations.
The machine consists of five rolls. The first pair of rolls is driven by both the upper and lower rolls, while the third pair is driven by the upper roll.
Through the coordinated operation of the withdrawal and straightening rolls, the billet is continuously transported from the curved casting section toward the subsequent production area while undergoing the required straightening process.
Withdrawal and Straightening Configuration:
| Item | Configuration |
|---|---|
| Machine Type | Five-roll Withdrawal Straightener |
| First Pair of Rolls | Upper and lower rolls driven |
| Third Pair of Rolls | Upper roll driven |
8. Dummy Bar System
The equipment adopts a flexible dummy bar, which is used during the initial startup and casting operation.
After connecting with the initial billet, the dummy bar works together with the withdrawal system to guide the initial billet through the various working sections of the caster, supporting the establishment of continuous casting operations.
| Item | Technical Specifications |
|---|---|
| Dummy Bar Type | Flexible Dummy Bar |
9. Cutting System
The equipment adopts flame cutting for cutting continuously cast billets to the required length.
The maximum fixed billet length is 8m. The cutting system performs billet cutting according to production requirements and works together with the downstream discharge roller tables to complete billet transportation after cutting.
| Item | Technical Specifications |
|---|---|
| Cutting Method | Flame Cutting |
| Maximum Fixed Length | 8 m |
10. Billet Discharge System
The billet discharge roller table system is divided into three sections: the pre-cut guide, cutting chamber guide and post-cut guide.
Different roller configurations and driving methods are adopted in each section to meet the billet transportation and discharge requirements.
Billet Discharge Configuration:
| Section | Roller Configuration per Strand | Driving Method |
|---|---|---|
| Pre-cut Guide | 4 rolls | One group driven by a power-frequency drive per strand |
| Cutting Chamber Guide | 2 rolls | Hydraulic drive discontinued |
| Post-cut Guide | 6 rolls | One VFD for every two rolls |
The pre-cut guide transports billets toward the cutting area. The cutting chamber guide supports billet handling during cutting operations, while the post-cut guide transports the billets after cutting.
11. Metallurgical Length and Production Parameters
The metallurgical length of the equipment is defined according to different positions along the casting line:
Approximately 20m from the mold meniscus to the flame cutting machine.
Approximately 15.6m from the mold meniscus to the last pair of withdrawal-straightening rolls.
Different casting speeds are configured according to billet section sizes:
| Billet Section | Casting Speed |
|---|---|
| 180×500 mm | 1.1–1.15 m/min |
| 180×550 mm | 1.0–1.1 m/min |
12. Key Equipment Features
Four-Machine Four-Strand Configuration: Adopts a 4-machine 4-strand design, allowing four strands of continuous casting simultaneously, with an annual designed capacity of 1.4 million tons, suitable for large-scale billet production.
Wide Range of Steel Grades: Suitable for Q195, Q215, Q235 and Q355B steel grades, meeting the production requirements of different steel products.
Two Billet Section Specifications: Supports 180×500mm and 180×550mm billet sections, with corresponding casting speed configurations.
Full-Arc Caster Design: Adopts a full-arc configuration with a casting radius of R9000mm, equipped with complete mold, secondary cooling and withdrawal-straightening systems.
Four-Zone Secondary Cooling: Features a four-zone cooling control system, combining full-water cooling in the foot-roll zone with air-mist cooling in the subsequent zones.
Mold Level Control Configuration: Uses eddy-current detection combined with stopper rod control to support molten steel level regulation during casting.
Five-Roll Withdrawal Straightener: Equipped with a five-roll withdrawal straightening machine featuring different roll driving configurations to meet billet withdrawal and straightening requirements.
Complete Billet Discharge System: Includes pre-cut guide, cutting chamber guide and post-cut guide roller tables to support continuous billet transportation before and after cutting.