Overhead Crane With Grab QZ Type

Description

The Weihua QZ grab bucket bridge crane is a specialized heavy-duty lifting equipment launched by Weihua Group for the bulk material handling market. Using a grab bucket as its primary lifting device, it is an ideal choice for loading and unloading bulk materials in power plants, freight yards, workshops, docks, and other similar locations. This product represents a functional extension and professional upgrade of the traditional hook bridge crane, specifically designed for the grabbing, handling, and loading/unloading of bulk materials in their natural stacking state, such as coal, coke, ore, sand, fertilizer, and grain.

In terms of technical positioning, the QZ grab bucket bridge crane complements the QD hook bridge crane—the QD type primarily uses a hook to lift packaged goods, while the QZ type's core function is grabbing bulk materials. Together, they form a complete product matrix of general-purpose bridge cranes, widely used in industries such as machinery, metallurgy, mining, power, railway, ports, petroleum, and chemicals.

Structurally, the QZ-type grab bucket bridge crane mainly consists of five parts: the bridge frame, the trolley traveling mechanism, the gantry traveling mechanism (including the hoisting mechanism and opening/closing mechanism), the grab bucket lifting device, and the electrical control system. The bridge frame adopts a double-main-girder box-shaped welded structure, characterized by high rigidity, minimal deformation, and strong load-bearing capacity. The lifting device is a double-drum, four-rope grab bucket, simple in structure, reliable in operation, and the grab bucket can be opened and closed at any height.

In terms of technical parameters, the Weihua QZ-type grab bucket bridge crane covers lifting capacities from 5 tons to 20 tons (rated lifting capacity includes the grab bucket's own weight), spans from 10.5 meters to 31.5 meters (commonly 13.5m, 16.5m, 19.5m, 22.5m, 25.5m, 28.5m, and 31.5m), and maximum lifting heights from 18 meters to 28 meters. This crane is designed for heavy-duty operation, with a duty class of A6, suitable for continuous operation conditions with frequent work and high load rates.

In terms of intelligent configuration, the QZ grab bucket bridge crane is designed and manufactured in accordance with international and general standards such as GB, FEM, and IEC. The electrical control system adopts an advanced system of "PLC + touch screen + frequency converter," realizing comprehensive monitoring, control, and high-precision speed regulation of the entire machine. The product has three control modes: manual, semi-automatic, and fully automatic, which can be freely switched. Manual priority is available in any automatic mode. Furthermore, the system also features real-time dynamic metering of materials, crane fault diagnosis and alarm functions, and remote fault diagnosis capabilities.

Parameter

Feature&Advantages

1. Professional Grab Bucket Lifting Device – Four-Rope Structure, Opening and Closing at Any Height

The core competitiveness of the QZ grab bucket bridge crane lies in its professional grab bucket lifting device:

Double-Drum Four-Rope Grab Bucket, Reliable Structure: The lifting device is a double-drum four-rope grab bucket, using two sets of steel wire ropes to control the lifting and opening/closing actions of the grab bucket. The lifting mechanism is responsible for the overall lifting and lowering of the grab bucket, while the opening/closing mechanism is responsible for the opening and closing of the grab bucket jaws. The two mechanisms work together to achieve efficient control of the entire material grabbing process.

Opening and Closing at Any Height, Flexible Operation: The grab bucket can open and close at any height, without being limited by the lifting height. Whether grabbing materials directly from a stockpile or unloading in mid-air, it can be completed flexibly.

Multiple Structural Configurations Available: Depending on user needs and material characteristics, the lifting mechanism of the QZ grab bucket bridge crane can be configured with single-layer or double-layer frames, single drums or double drum assemblies, and other different options.

Two Opening Directions: The grab bucket can open in two directions: parallel to the main beam and perpendicular to the main beam. Users can choose the most suitable configuration based on site conditions such as silo layout and unloading port location.

Material Adaptability: The grab bucket is only suitable for bulk materials in a naturally stacked state. When grabbing underwater materials or special materials, this must be specifically specified when ordering so that targeted design and configuration can be carried out.

2. Heavy Duty System – High-Frequency Operation, Durable

The QZ grab bucket bridge crane is positioned as a professional bulk material handling equipment, and its design fully considers the special requirements of high-frequency operation conditions:

A6 Working Class, Heavy-Duty Continuous Operation: This crane is designed for heavy-duty operation with a working class of A6. This means that the equipment is designed for heavy-duty operation scenarios with high frequency and high load utilization, and can meet the requirements of long-term continuous operation every day.

High-Strength Structural Design: The bridge frame adopts a double main beam box-shaped welded structure. All mechanisms have been checked for fatigue strength according to the heavy-duty system. Key components are made of high-quality materials to ensure long-term reliability under frequent start-stop and high-load conditions.

High-speed operation and efficient work: Lifting speed reaches 39.2–45.7 m/min, trolley travel speed 43.2–45.9 m/min, and main trolley travel speed 87.3–113.6 m/min. High-speed operation significantly increases material handling capacity per unit time, meeting the operational needs of high-throughput locations such as power plants and docks.

Typical efficiency data: According to actual operating data from a large coastal port, the Weihua QZ grab bucket bridge crane achieves a lifting speed of up to 12 m/min (grab bucket opening and closing speed), a 30% improvement over existing equipment, significantly reducing cargo loading and unloading time; the equipment failure rate is extremely low, with less than 20 hours of downtime per year, far below the industry average.

3. Intelligent Control System – PLC + Touch Screen + Frequency Conversion, Three Modes Available

The Weihua QZ grab bucket bridge crane adopts industry-leading technology in electrical control:

Independent PLC Control: Each crane is equipped with an independent PLC control system for individual crane control. The control room allows for centralized control of all crane operations, including material handling, loading, and mixing.

Variable Frequency Speed ​​Control: All mechanisms of the crane utilize digital variable frequency speed control devices, and the entire machine is controlled by a PLC. Variable frequency speed control not only achieves smooth starting and braking and precise speed control but also significantly reduces mechanical shock and extends equipment lifespan.

Three Control Modes with Free Switching: The product offers three control modes: manual, semi-automatic, and fully automatic, which can be freely switched. In any automatic mode, a manual priority function is provided, allowing operators to intervene at any time to ensure operational safety.

Human-Machine Interface: The electrical control system adopts a "PLC + Touch Screen + Variable Frequency Speed ​​Control Device" architecture, enabling comprehensive monitoring, control, and high-precision speed adjustment of the entire machine. Operators can intuitively understand the equipment's operating status, parameter settings, and fault information through the touch screen.

4. Intelligent Management Functions – Real-time Metering and Fault Diagnosis

The Weihua QZ grab bucket bridge crane boasts significant advantages in intelligent management:

Real-time Dynamic Material Metering: The system features real-time dynamic material metering with a comprehensive accuracy of ≤±1%. Material weighing is completed during grabbing and handling, eliminating the need for additional metering steps and significantly improving operational efficiency and data accuracy. This function is particularly important for scenarios requiring precise control of feed volume, such as waste incineration power plants.

Fault Diagnosis and Remote Alarm: The system features crane fault diagnosis alarms and remote fault diagnosis functions. When equipment malfunctions, the control system automatically identifies the fault type and issues an alarm, while also supporting remote engineer intervention for diagnosis, quickly locating problems and minimizing downtime.

Operating Parameter Recording and Traceability: The PLC system records equipment operating parameters and operational data, facilitating efficiency analysis, maintenance planning, and fault traceability.

5. Comprehensive Mechanism Configuration – Adaptable to Multiple Working Conditions

The QZ grab bucket bridge crane exhibits high adaptability to various scenarios in its mechanism configuration:

Universal Indoor/Outdoor Design: This crane can be used both indoors and outdoors. For outdoor use, a rain cover is added to protect electrical equipment and mechanisms from rainwater corrosion.

Flexible operator's cab configuration: All mechanisms are operated from the operator's cab. There are three access methods to the operator's cab: end entry, side entry, and top entry. Users can choose the most suitable solution based on the site layout. The operator's cab is available in open and closed types; the closed operator's cab can be equipped with air conditioning as needed.

Multiple power supply methods: The crane's power supply can be configured with safety sliding contact lines or angle steel sliding lines according to user requirements, adapting to the power supply conditions of different workshops.

High-efficiency hoisting mechanism: The hoisting mechanism adopts a dual-drive scheme (hoisting motor + opening/closing motor). The two motors work together to achieve high-speed lifting and rapid opening and closing of the grab bucket.

Application

1. Waste-to-Energy Plants

Waste-to-energy incineration is the most mature application area for QZ-type grab bucket bridge cranes. In waste-to-energy plants, this equipment undertakes key operational tasks such as feeding, turning, mixing, and transferring municipal solid waste from the waste pit.

Typical Operations:

Feeding Operation: Grabbing municipal solid waste from the waste pit and feeding it into the incinerator's feed hopper, ensuring a continuous and stable supply to the incinerator.

Turning and Mixing: Turning and mixing the materials in the waste pit to promote fermentation and homogenization, improving combustion efficiency.

Transfer Operation: Transferring and stacking materials between the new waste entry area, fermentation area, and feeding area.

Emergency Backup: Managing backup materials during incinerator maintenance or malfunctions.

Configuration Advantages:

Waste-to-energy plants have special requirements for lifting equipment—the equipment must be able to withstand the high humidity and highly corrosive environment of the waste pit, while also achieving accurate metering of the feed. The Weihua QZ grab bucket bridge crane is equipped with real-time dynamic material metering, with a comprehensive accuracy of ≤±1%, allowing for precise control of the feeding amount. The product is widely used in various scales of waste incineration plants with daily processing capacities of 4800t/d, 3000t/d, 2400t/d, 1000t/d, 800t/d, and less than 600t/d.

For waste incineration applications, the QZ grab bucket bridge crane can be configured with the following functions:

Fully automatic/semi-automatic control modes, with preset feeding programs, achieving automated operation with "unattended operation and manned inspection."

Anti-sway function ensures accurate landing point for rapid, high-altitude material feeding.

Corrosion-resistant treatment adapts to the harsh environment of waste pits.

2. Bulk Cargo Loading and Unloading at Ports and Terminals

Ports and terminals are a traditional strength of the QZ grab bucket bridge crane. This equipment is widely used for loading and unloading bulk materials such as coal, ore, sand, gravel, and grain from ships, transferring materials in storage yards, and loading onto trucks.

Typical Operations:

Ship-to-shore loading and unloading: Grabbing materials from bulk carriers and unloading them into dock hoppers, or vice versa.

Storage yard management: Stacking, transferring, and organizing materials in open storage yards.

Loading operations: Grabbing bulk materials and loading them into train cars or trucks.

Booth feeding: Feeding materials to rear hoppers or belt conveyors.

Configuration advantages:

Port operations are complex (waterfront, high salt spray, windy), requiring equipment with excellent corrosion resistance and wind resistance. The Weihua QZ grab bucket bridge crane can be used outdoors; the outdoor version includes a rain cover. With the addition of windproof anchoring devices and rail clamps, it meets the wind resistance and safety requirements of coastal ports.

According to feedback from a large coastal port, the Weihua QZ grab bucket bridge crane has a lifting/opening/closing speed of up to 12m/min, improving operational efficiency by 30% compared to existing equipment. Annual downtime due to malfunctions is less than 20 hours, and its loading capacity and stability meet the high-intensity operational requirements of ports.

3. Thermal Power Plants

The coal yard of a thermal power plant is a key application scenario for the QZ-type grab bucket bridge crane. This equipment undertakes critical operations such as unloading, stockpiling, retrieving, and loading raw coal into silos.

Typical Operations:

Unloading: Unloading coal transported by train or truck into the coal yard.

Stockpiling: Stockpiling and retrieving coal in the coal yard.

Loading: Grabbing coal and feeding it into the conveyor belt system to supply coal to the boiler.

Coal Blending: Blending different types of coal to meet boiler combustion requirements.

Configuration Advantages:

Thermal power plants have extremely high requirements for coal yard inventory management and continuous coal supply. The QZ-type grab bucket bridge crane is equipped with a PLC control system and variable frequency speed regulation, enabling precise material handling control and efficient material transfer operations.

Technical Features:

Working class A6, meeting the high-intensity continuous operation requirements of coal yards in thermal power plants.

Rapid operation performance (lifting speed above 45m/min) ensures timely coal supply.

Optional semi-automatic/fully automatic control enables intelligent management of the coal yard.

4. Metallurgy and Mining

Raw material storage yards and finished product yards in the metallurgical and mining industries are typical application scenarios for QZ-type grab bucket bridge cranes.

Typical Operations:

Ore grabbing: Loading, unloading, and transferring of metal ores such as iron ore and copper ore.

Coke handling: Loading, unloading, storage, and feeding of coke in coking plants.

Auxiliary material management: Handling of metallurgical auxiliary materials such as limestone and dolomite.

Intra-plant transfer: Short-distance transport of various bulk materials within the plant area.

Configuration Advantages:

The metallurgical and mining industries produce a wide variety of materials with large particle size differences, placing special requirements on the grab bucket type. Weihua can customize the grab bucket's capacity, jaw plate shape, and wear-resistant treatment scheme according to material characteristics (bulk density, particle size, moisture content, etc.).

The A6 working class configuration meets the characteristics of heavy-duty, high-frequency operations. For highly abrasive materials (such as iron ore), high-wear-resistant grab buckets and key component reinforcement treatments can be configured to extend the equipment's service life.

5. Workshops and Yards

Raw material warehouses, semi-finished product warehouses, and finished product yards in various industrial and mining enterprises require frequent loading, unloading, transfer, and stacking of bulk materials.

Typical Operations:

Raw Material Loading and Unloading: Inbound and outbound of bagged or bulk materials such as fertilizers, soda ash, grains, and feed.

Yard Management: Stacking, transferring, and sorting of various bulk materials.

Loading Operations: Loading bulk materials onto trucks or trains.

Configuration Advantages:

Workshop and yard spaces are relatively compact. The QZ-type bridge crane fully utilizes the roof space of the factory building, without occupying ground operating area. The driver's cab entrance direction can be selected from end entry, side entry, or top entry, flexibly adapting to the workshop layout. The grab bucket can be opened parallel to or perpendicular to the main beam to adapt to the location requirements of the silo and discharge port.

6. Special Material Handling

In addition to handling conventional materials such as coal, ore, and sand, the QZ grab bucket bridge crane can also be customized according to specific user needs.

Special Material Customization Requirements:

Underwater Material Handling: When handling underwater materials, this must be specifically requested when ordering, requiring a waterproof grab bucket and a special sealing structure.

High-Temperature Material Handling: High-temperature resistant grab buckets and heat insulation protection can be configured.

Lightweight Material Handling: Dedicated grab buckets with large capacity and lightweight jaw plates can be configured.

Sticky Material Handling: Anti-stick coating and special jaw plate design can be configured.

Company Strength

1. Company Overview and Industry Position

Henan Weihua Heavy Machinery Co., Ltd., founded in 1988, is a core holding subsidiary of Weihua Group. Headquartered at No. 18 Shanhai Avenue, Changyuan City, Henan Province, known as the "Capital of Lifting Machinery in China," the company boasts a registered capital of RMB 1.066 billion. It is a leading enterprise in China's crane manufacturing industry and one of the world's largest industrial crane manufacturers. As a national manufacturing single-item champion enterprise, Henan Weihua holds a significant position in the domestic and international lifting machinery industry.

2. Main Business and Product System

The company focuses on the research, development, manufacturing, and sales of bridge cranes, gantry cranes, electric hoists, and new intelligent lifting equipment. Product types cover multiple series including general-purpose bridge cranes, European-style cranes, metallurgical cranes, explosion-proof cranes, and port gantry cranes, meeting the complex operational needs of various industries. With its modular, lightweight, and intelligent design concepts, Henan Weihua's products are at the forefront of the industry in terms of structural performance, safety, reliability, and service life.

3. Application Areas and Market Coverage

Henan Weihua's products are widely used in many key sectors of the national economy, including machinery manufacturing, metallurgy, power energy, port logistics, railway transportation, petrochemicals, and construction engineering. The company's products not only sell well in all provinces, municipalities, and autonomous regions of China, but are also exported to more than 100 countries and regions in Southeast Asia, the Middle East, Africa, Europe, and the Americas, serving numerous Fortune 500 companies and key national engineering projects, earning a good international reputation.

4. Technology R&D and Quality Assurance

The company highly values ​​technological innovation and has established several high-end R&D platforms, including a national-level enterprise technology center, a postdoctoral research station, and the Henan Provincial Lifting Machinery Engineering Technology Research Center. In recent years, Henan Weihua has actively promoted intelligent and digital manufacturing transformation, accumulating over a thousand national authorized patents and participating in the formulation of multiple national and industry standards. In terms of quality management, the company has passed ISO9001, ISO14001, and ISO45001 international system certifications and has successively won numerous honors such as "China Famous Brand Product," "National Quality Benchmark," and "National Technological Innovation Demonstration Enterprise," establishing a comprehensive quality control system from raw materials to finished products.