QZ grab overhead crane

QZ Grab Bridge Crane, also known as a “waste handling crane,” is a type of heavy-duty lifting equipment specifically designed for waste transfer stations, incineration plants, landfills, recycling centers, and similar facilities. It is primarily used for grabbing, handling, stacking, and sorting various types of solid waste, including municipal solid waste, industrial waste, and construction waste.

Main Functions

• Waste Grabbing and Handling: The grab bridge crane is equipped with a hydraulic or electric grab, enabling it to effectively grab loose materials such as waste, scrap metal, and waste plastic.

• Sorting and Stacking: Used in waste sorting lines, potentially equipped with magnetic separators or manual sorting stations, to separate recyclables from waste. Feeding and Landfill: In incineration plants or landfills, waste is fed into processing equipment or compacted in layers for landfill.

Advantages & Features

Working Principle

       The QZ Grab Bridge Crane is a type of overhead crane specifically designed for handling bulk materials. Its core function is to grab, lift, transport, and discharge materials using an electrically or mechanically driven grab. Its working principle can be broken down into the following key stages:

Structural Components

The grab crane mainly consists of the bridge, electric trolley, electrical equipment, and the grab itself. The bridge provides a stable support structure for the entire crane, bearing the weight of each component and the load during lifting.

• Bridge: Spans the working area, allowing the trolley to travel horizontally along the rails.
• Hoisting Trolley: The trolley travels along the bridge for horizontal movement and is equipped with a hoisting mechanism and a closing mechanism.
• Grab: Typically adopts a double-shell or multi-shell clamshell structure. Its opening and closing are controlled by wire ropes or chains, suitable for bulk materials like coal, ore, grain, etc.

Working Process

• Grabbing Material: The grab is lowered onto the material pile via the closing mechanism. When closing, it relies on its own weight or hydraulic/electric drive to clamp the material.
• Lifting and Transporting: The hoisting mechanism lifts the loaded grab to the required height. The main and cross travel mechanisms coordinate to transport the material horizontally to the target location.
• Unloading: The grab opens again at the unloading point, releasing the material and completing one cycle.

Grab Selection

     Waste handling cranes can be equipped with different types of grabs based on material characteristics, such as light-duty grabs (for grain), medium-duty grabs (for coal), heavy-duty grabs (for ore), and special grabs (for waste, scrap steel, etc.). Common types of grabs include the following two:

1. Orange Peel Grab

• Structural Features: Composed of 4-6 curved jaws, resembling an “orange peel,” forming a closed space when closed.
• Suitable Materials: Scrap steel, waste, irregular bulk materials (e.g., metal scrap, construction waste).
• Advantages: Wide grabbing range, adapts to materials with complex shapes, good leakage prevention.

2. Clamshell Grab

• Structural Features: Composed of two symmetrical shells, resembling a “clamshell,” controlled by wire ropes or hydraulic cylinders for opening and closing.
• Suitable Materials: Bulk materials with good flowability such as coal, ore, gravel, grain.
• Advantages: Simple structure, easy maintenance, uniform gripping force.

Applications

       Waste handling cranes are widely used across various bulk material handling industries. With their efficient loading and unloading capabilities, they are key equipment in sectors such as ports, power generation, metallurgy, construction materials, chemicals, grain, and waste treatment. As the characteristics of materials handled differ across industries, matching grabs of the corresponding type is essential to ensure operational efficiency and safety.