QC Manget Overhead Crane

What is a QC Magnet Overhead Crane?

It is typically a double-girder overhead crane where the entire system-the structure, electrical feeds, and controls-is engineered to integrate seamlessly with a powerful electromagnet. It is the premier solution for efficiently moving steel, iron, and scrap.

Advantages of a QC Magnet Overhead Crane

Extreme Efficiency: Eliminates the need for slings, hooks, or chains. The magnet attaches and releases from the load instantly, drastically reducing cycle times.

Handles Difficult Loads: Ideal for moving a single steel plate from a stack, loose scrap metal, or other items that are hard to sling.

Reduced Labor Costs: One operator can manage the entire loading/unloading/stockpiling process without a ground crew.

Minimal Load Damage: The magnetic field applies even pressure, avoiding the scratches and distortions caused by mechanical grapples or hooks.

Versatility: While designed for a magnet, it can often be fitted with a hook block for occasional conventional lifts.

Is a QC Magnet Overhead Crane Right for You?

Consider this crane if your operation:

Handles primarily carbon steel or iron (not aluminum, stainless, etc.).

Requires high-speed cycling of materials.

Seeks to reduce labor costs and improve safety.

Handles materials that are difficult to sling (like sheets or loose scrap).

Is concerned about product damage from mechanical hooks.

Core Components：Bearing, Gearbox, Motor, Pump

Place of Origin：Henan, China

Warranty：1 Year

Weight (KG)：2000 kg

Video outgoing-inspection：Provided

Machinery Test Report：Provided

Design：Double beam

Effectiveness：high efficiency

Operating speed：High speed operation

Stability：Anti-swing function

Color：Optional

Power Source：110V/220V/230V/380V/440V,customized

Span：7.5-31.5m

The components of a QC Magnet Overhead Crane form a highly integrated system where the crane structure, electrical systems, and the magnet itself are designed to work in unison for safe and efficient handling of ferrous materials.

Here is a detailed breakdown of its key components.

1. Overhead Crane Structure

This is the robust framework designed for severe-duty cycles.

Double Main Girders: The primary horizontal beams. The double-girder design provides the strength, rigidity, and most importantly, the hook height required to lift large stacks of material with the magnet.

End Trucks: The structures at each end of the bridge that house the wheels and drive mechanisms for moving the entire crane along the runway rails.

Long Travel Drives: The motors, gearboxes, and wheels mounted on the end trucks that enable the crane to travel the length of the bay.

Hoist Unit: A heavy-duty hoist designed for precise control, responsible for raising and lowering the magnet. It must provide smooth operation to prevent load swing.

Trolley Assembly: The frame that carries the hoist and travels along the rails on top of the main girders, allowing for cross-wise movement.

2. Magnetic Lifting System

This is the specialized heart of the crane that differentiates it from a standard overhead crane.

Electromagnet (The Lifter):

Construction: A massive, durable steel shell housing one or more cores of soft iron wrapped with heavy copper windings.

Function: When Direct Current (DC) electricity passes through the windings, it creates a powerful magnetic field that magnetizes the core and the outer shell, inducing a magnetic field in the ferrous load below.

DC Power Supply System:

Thyristor Rectifier / Generator Set: The electromagnet requires DC power. This unit, mounted on the crane's bridge, converts the facility's standard Alternating Current (AC) into the controlled DC needed. Modern systems use thyristor rectifiers for their efficiency and control.

Cable Reel:

A motor-driven or spring-driven reel that manages the heavy, flexible power cable connecting the crane to the magnet. It pays out cable when the magnet is lowered and retracts it when raised, preventing damage, tangling, and wear.

3. Control & Safety Systems

These systems ensure precise operation and, most critically, safety.

Control Panel & Magnet Controller:

Houses the programmable logic controller (PLC), contactors, and the specialized magnet controller. This controller doesn't just turn the magnet on/off; it often includes a "de-magnetizing" cycle that applies a reverse current pulse to counteract residual magnetism, ensuring a clean load release.

Battery Backup Unit (BBU):

This is a non-negotiable safety component. In the event of a total power failure on the crane, the BBU instantly and automatically provides DC power to the electromagnet. This prevents a catastrophic load drop, allowing the operator to safely lower the load to the ground. Its charge and health are constantly monitored.

Operator Control:

Radio Remote Control: This is the standard. It allows the operator to move freely on the floor for optimal visibility of the load and surroundings, which is crucial for safety and efficiency when handling obscured loads like scrap.

Safety Devices:

Load Moment Indicator (LMI): Monitors the weight of the load to prevent overloading the crane.

Limit Switches: Prevents the hoist, trolley, and bridge from over-traveling.

Thermal Protection: Sensors on the magnet and rectifier to prevent overheating.

Sketch

Main technical

Advantages of a QC Magnet Overhead Crane

This crane offers transformative benefits in speed, cost-efficiency, and safety for specific material handling tasks.

1. Unmatched Operational Efficiency

Instantaneous Cycling: The magnet attaches and releases loads in seconds, eliminating the time required to rig slings, hooks, or chains. This dramatically increases the number of cycles per hour.

Automated Handling: The process of picking up and dropping materials is seamless and requires no physical intervention from ground personnel.

2. Significant Cost Savings

Drastic Labor Reduction: A single operator can manage the entire loading, unloading, and stacking process, eliminating the need for a rigging crew.

Reduced Product Damage: The magnetic field applies even, non-marking pressure. This avoids the scratches, crimps, and distortions caused by chains, grapples, or mechanical clamps, preserving the value of the material (especially important for finished sheets or plates).

3. Enhanced Safety

Operator Distance: With standard radio remote control, the operator can position themselves for the best view, away from the load path, falling hazards, and the magnet itself.

Fail-Safe Design: The integrated Battery Backup Unit (BBU) is a critical safety feature that prevents catastrophic load drops in the event of a power failure.

Eliminates Rigging Hazards: Removes the dangers associated with workers being under or near loads to attach and detach rigging.

4. Material Handling Versatility

Handles Difficult Loads: Excels at tasks that are challenging for hooks, such as lifting a single steel plate from the top of a stack, handling loose scrap, or moving large, unwieldy coils.

Adaptable to Various Shapes: Effectively lifts a wide range of ferrous items, from structured beams to irregular scrap chunks, without needing to change attachments.

5. Minimal Load Damage

Non-Contact Lifting: Since the magnet does not need to grip the load mechanically, there is no physical abrasion or point-loading that can damage the product surface.

Applications of a QC Magnet Overhead Crane

This crane is an indispensable asset in any industry that deals with large volumes of iron and steel.

1. Scrap Metal Recycling Yards

Primary Application: This is the quintessential environment for a magnet crane.

Use Cases:

Unloading ferrous scrap from trucks and railcars.

Sorting and moving scrap within the yard.

Charging scrap into shredders, balers, and shears.

Loading processed scrap for shipment.

2. Steel Service Centers and Warehouses

Use Cases:

Handling and stacking steel plates, sheets, and coils.

Loading and unloading trucks and railcars.

Feeding processing lines (e.g., laser cutters, press brakes).

Moving structural steel like I-beams and channels.

3. Foundries and Steel Mills

Use Cases:

Charging Crane: Loading scrap metal, pig iron, and other ferrous raw materials into melting furnaces.

Transfer Crane: Moving hot materials (using special high-temperature magnets) between processes.

4. Ports and Terminal Operations

Use Cases:

Unloading steel products (coils, plates, structurals) from ships.

Loading steel for export.

Handling bulk ferrous scrap in port-side recycling facilities.

5. Heavy Fabrication and Shipbuilding

Use Cases:

Moving large steel plates for cutting and welding.

Handling fabricated sections during the assembly process.

The production procedure for a Factory Casting Shop Bridge Crane is a complex, multi-stage process that combines heavy steel fabrication, precise mechanical assembly, and rigorous electrical installation and testing. It must adhere to strict quality and safety standards like ISO, CMAA, FEM, or ASME.

Here is a detailed breakdown of the production procedure.

Stage 1: Design & Engineering

This is the foundational stage where the crane is conceived and specified.

Customer Requirements Analysis: Reviewing capacity, span, lifting height, duty cycle (M7/M8), and specific foundry conditions (heat, dust).

Conceptual & Detailed Design:

Structural Analysis: Using Finite Element Analysis (FEA) to model the bridge girders and end trucks for stress, deflection, and fatigue under full load.

Mechanical Design: Selecting and designing the hoist units, trolley, travel drives, wheels, and shafts.

Electrical Design: Creating schematics for power supply, motor controls, safety circuits, and operator interfaces.

Special Features: Designing heat shields, insulated cab, and other foundry-specific protections.

Bill of Materials (BOM) Creation: A complete list of all raw materials, purchased components (motors, brakes, wire rope), and standard parts.

Stage 2: Material Procurement & Preparation

Procurement: Sourcing raw materials (steel plates, beams, etc.) and purchased components from certified suppliers. Critical items like hoists, motors, and brakes are often from specialized manufacturers.

Material Preparation: Steel plates are shot-blasted and primed for corrosion protection. They are then cut to size using CNC plasma or flame cutting machines for precision.

Stage 3: Structural Fabrication & Assembly

This is the core of the manufacturing process.

Girder Fabrication:

CNC Cutting: Steel plates are cut into the required web and flange profiles.

Sub-Assembly: Components are fit together using jigs to ensure straightness and squareness.

Welding: Automated Submerged Arc Welding (SAW) is used for long, critical welds to ensure deep penetration and high strength. Manual welding is used for smaller, complex areas.

Stress Relieving: The completed girders are heated in a large furnace to relieve internal stresses from welding, preventing future distortion.

Machining: The girder ends and trolley rail mounting surfaces are machined to ensure a perfect fit with the end trucks and smooth trolley travel.

End Truck Fabrication: A similar process of cutting, welding, and machining is used to create the rigid end truck structures that house the wheels and drives.

Stage 4: Mechanical Assembly

Bridge Assembly: The two main girders are bolted or welded to the end trucks to form the complete bridge.

Trolley Assembly: The trolley frame is built, and the main and auxiliary hoist units are mounted onto it. The hoist drums, gearboxes, and motors are aligned with precision.

Drive Unit Installation: The long travel drive assemblies (motor, gearbox, wheel) are installed onto the end trucks. The trolley travel drive is installed on the trolley frame.

Wheel & Rail Installation: All wheels are installed, and the crane rails are mounted on top of the girders for the trolley.

Stage 5: Electrical & Control System Installation

Cab Wiring: The operator's cab is fully wired with control pendants, joysticks, and instrumentation.

Bridge Wiring: Main control panels, Variable Frequency Drives (VFDs), and the conductor bar system are installed along the bridge.

Cable Reels & Trailing Cables: The cable reel for the magnet or hoist and all power and control cables are installed and connected.

Safety Devices: All limit switches, the Load Moment Indicator (LMI) system, anti-collision sensors, and emergency stop buttons are installed and wired.

Stage 6: Works Testing & Inspection (FAT - Factory Acceptance Test)

Before disassembly for shipment, the fully assembled crane undergoes rigorous testing in the factory.

Visual Inspection: Checking for workmanship, proper welding, and assembly.

Dimensional Verification: Ensuring all critical dimensions (span, wheelbase, etc.) match the drawings.

No-Load Test: Running all motions (hoist, trolley, bridge) without a load to check for smooth operation, noise, and alignment.

Load Testing:

Static Load Test: Lifting a test load of 125% of the rated capacity and holding it to check for structural integrity and brake holding capacity.

Dynamic Load Test: Lifting a test load of 110% of the rated capacity and running it through all motions to verify performance under dynamic conditions.

Safety Function Test: Verifying the operation of all limit switches, brakes, E-stops, and the LMI system.

Stage 7: Dismantling, Painting & Packaging

Dismantling: The crane is carefully disassembled into transportable pieces (girders, end trucks, trolley, etc.), with all components clearly marked.

Surface Preparation & Painting: All components are thoroughly cleaned, abrasive-blasted, and painted with a high-performance industrial coating system (often an epoxy primer and polyurethane topcoat) for corrosion protection.

Packaging: Components are packaged with protective covers on machined surfaces to prevent damage during transit.

Stage 8: Site Installation & Commissioning (SAT - Site Acceptance Test)

Site Preparation: Verifying the runway is complete, level, and correctly aligned.

Erection: Using mobile cranes to reassemble the bridge, trolley, and all components on the customer's runway.

Final Connections: Connecting electrical power, finalizing wiring, and checking alignments.

Site Commissioning & SAT: Repeating key functional and safety tests (often with the customer present) to ensure the crane performs perfectly in its final location. Operator training is also provided.

Workshop view:

The company has installed an intelligent equipment management platform, and has installed 310 sets (sets) of handling and welding robots. After the completion of the plan, there will be more than 500 sets (sets), and the equipment networking rate will reach 95%. 32 welding lines have been put into use, 50 are planned to be installed, and the automation rate of the entire product line has reached 85%.