2. Definition and Uses

Metallurgical ladle cranes are machines that operate by longitudinal movement along factory tracks, lateral movement of the trolley, and lifting/lowering of the hook. They are primarily used in steelmaking continuous casting processes to lift molten metal (such as iron and steel), specifically including adding molten iron to the converter and transporting molten steel to the refining furnace or continuous casting ladle turret. Their working environment is harsh, characterized by high temperatures and high dust levels, requiring high operating levels (A7, A8) and extremely high equipment safety standards. Metallurgical casting cranes are specialized cranes conforming to standards such as JB/T7688.1-95 and JB/T7688.15-95 for lifting molten metal. Generally applicable to ambient temperatures from -10℃ to +50℃, with relative humidity not exceeding 50% at 40℃, and the radiant temperature of the molten metal being hoisted on the forging hook or plate hook not exceeding 300℃.

According to the safety regulations of the "Safety Technical Regulations for Lifting Machinery," the hoisting of molten metal must be carried out using a dedicated metallurgical casting crane (such as a fixed gantry hook casting crane). The use of ordinary cranes is strictly prohibited to prevent major safety accidents such as the overturning of molten steel ladles.

3. Structural Form and Technical Parameters

3.1 Structural Form

The main structural forms of casting cranes hand ladle handling include: four-beam four-rail double trolley, four-beam six-rail double trolley, double-beam single trolley, and double-beam mother-daughter trolley. For large casting cranes (over 300 tons), the main hoisting mechanism mainly has the following structural forms: integral large reducer type, three reducer type, and double reducer type. Among them, the integral large reducer type can improve the stress state of the main trolley and improve safety and reliability.

Due to the harsh working environment, its key components must meet special requirements. The lifting hooks are usually special metallurgical plate hooks. The wire rope and hook assembly must be high-temperature resistant. The wheels use composite rolled forged steel wheels, and cast iron pulleys are not used. The main beam body uses high-temperature resistant protective materials. The electrical parts (motor, cable) must also meet high-temperature resistance requirements.

Four-beam four-rail double-trolley casting crane

3.2 Technical Parameter

3.3 Technical characteristics of 450t four-beam four-rail casting crane

4. Differences From General Cranes and Metallurgical Casting Cranes

Comparison Dimensions	Casting crane	ordinary crane
Job duties	Casting cranes are specifically used in smelting workshops to lift molten steel ladles, molten iron, and other high-temperature molten metals. The working environment is characterized by high temperatures and heavy dust.	Ordinary cranes are used in general warehouses and workshops to lift goods at normal temperatures, where the environment is relatively mild.
Security Configuration	Casting cranes must be equipped with dual brakes (working brake + safety brake) and dual limit switches (heavy hammer type + rotary type). The hoisting mechanism must have overspeed protection and forward and reverse contactor fault protection.	A single brake and a single limit switch are sufficient to meet the basic requirements of a regular crane.
High temperature resistant design	The lower flange of the main beam of the casting crane must be reinforced with a heat insulation layer. The motor insulation class must be H (temperature resistance ≥180℃). The wire rope must have a high-temperature resistant metal core or asbestos core. Cast iron is strictly prohibited for pulleys.	Ordinary cranes can use conventional carbon steel and Class B insulated motors.

Comparison Dimensions	Casting crane	General metallurgical cranes
Hoisting Object	Liquid metal	Solid metal
Security Configuration	Equipped with dual or even triple brakes, anti-molten steel splash guards, and professional heat shields.	Standard brakes only, with simple heat insulation panels added as needed.
Speed	Run smoothly and slowly (to prevent liquid sloshing).	The lifting and moving speeds are relatively fast.
Working Class	The highest level is A8 (24-hour operation).	A6-A7 level (no need for 24-hour full load)
Structure	The steel structure is thicker and has stronger resistance to high-temperature deformation.	Conventional steel structure
Detection	All vehicles must undergo a special overload test before leaving the factory, and a special inspection must be carried out annually.	Testing was conducted according to standard procedures.
Personnel Qualifications	A special operation certificate for molten metal hoisting is required.	A general metallurgical crane operator's certificate is sufficient.

5. Security Guarantee System

Metallurgical ladle cranes are machines that operate by longitudinal movement along factory tracks, lateral movement of the trolley, and lifting/lowering of the hook. Their working environment is harsh, characterized by high temperatures and high dust levels, requiring a high level of operational capability and extremely high equipment safety standards.

• The equipment strictly adheres to relevant standards and specifications for metallurgical cranes. It is equipped with multiple safety devices, including lifting height limits, travel limits, overload protection, demagnetization protection, emergency braking, and high-temperature protection. Key components utilize highly reliable configurations and reinforced redundancy design. Combined with a real-time safety monitoring system, it forms a quadruple protection system of "structural safety + mechanism safety + control safety + monitoring safety," ensuring the equipment operates flawlessly under high-temperature, heavy-load, and continuous operation.

• Multiple protection measures are implemented. It features interlocking, overload protection, zero-position protection, and limit protection to guarantee the crane's safe and reliable operation. The lifting drum is made of steel with a small wire rope deflection angle, effectively preventing wear. The lifting motor has an independent air-cooling system with thermal protection. It also has an independent braking system with automatic wear compensation.

• Safety monitoring system. It features an advanced PLC automatic detection system, combining the PLC with a touchscreen. Utilizing the touchscreen's powerful human-machine interface, it measures and calculates the crane's performance, safety, and operational status, monitors the crane's real-time operation, displays faults, and promptly shows the crane's status.

6. Typical Application Scenarios

• Converter Charging Bridge (Hot Iron Bridge): Used to hoist and pour high-temperature molten iron from the blast furnace into the converter for pre-smelting charging. This operation is characterized by high temperature, heavy load, frequent start-ups, and harsh environment.

• Refining Bridge (LF/VD furnace, etc.): Responsible for safely and smoothly hoisting huge ladles containing hundreds of tons of molten steel into the refining furnace for composition adjustment and temperature control.

• Casting Bridge / Continuous Casting Rotary Table: Precisely hoisting and placing the refined molten steel ladle onto the rotary table of the continuous casting machine for subsequent continuous casting.

• High-Temperature Molten Metal Emergency Handling: In the event of a metallurgical emergency, safely transfer and handle ultra-large volumes of liquid high-temperature metal to ensure the overall production safety of the smelting workshop.

7.Development Trend

The technological development trends of metallurgical casting crane include standardized structural types, internationalized production models, generalized crane models, and specialized lifting tools. Basic transmission and control are developing towards higher reliability and precision, adopting a structure of industrial PC + PLC + basic transmission (such as frequency conversion speed regulation) to achieve fault self-diagnosis, automatic control, and networking with the factory management system. The use of star-shaped reducers in the main transmission of casting cranes is becoming a development trend, replacing traditional ratchet and pawl drives. Modernization demands are driving the development of metallurgical cranes towards larger sizes, higher speeds, and higher quality. The speed regulation system of the running mechanism has been improved from the traditional eddy current braking + steering stator voltage regulation to frequency conversion speed regulation. Detection and sensing technologies such as fault display printing, 3D positioning, and collision avoidance devices are being applied. Ergonomics are being optimized, and the operating environment is becoming more comfortable, such as adding air conditioning to the driver's cab and using inclined ladders. Safety requirements are constantly increasing. Digital technology is being used to enable intelligent control, automatic cruise, and ultra-precise positioning, providing key equipment for building "intelligent factories."

8. Major manufacturers of casting cranes

Konecranes and Demag are long-established global industry giants from Europe; Tehnoros represents the heavy lifting equipment manufacturing industry in the Russian market; and AFE Crane is a well-known supplier of lifting and material handling equipment.

Henan Mine Crane, Weihua Group, Taiyuan Heavy Industry Group, and Dalian Huarui Heavy Industry are backbone enterprises and industry representatives in China's lifting and heavy equipment manufacturing sector.

9. Conclusion

Henan Mine Crane will continue to leverage its core advantages in new-type productivity, innovate and develop high-quality, high-performance, and cost-effective cranes, and provide customers with better services, empowering the high-quality development of the manufacturing industry through high-quality intelligent manufacturing.