Screening machine

A vibrating screen operates by using a motor to drive an eccentric shaft, creating vibration and forming elliptical or linear motion paths. The screen box is inclined at 15-25 degrees, allowing materials to move and be classified along the screen surface.

The screen apertures range from 0.074mm to 100mm, capable of separating 2-5 sizes simultaneously. Amplitude typically ranges from 2-10mm, with frequencies between 900-3600 rpm. Smaller particles pass through the screen, while larger particles are conveyed to the discharge port.
Multi-layer screens enhance efficiency, with handling capacities reaching 300-500 tons/hour.

Vibration parameters can be adjusted according to material characteristics to optimize screening. Screening efficiency is generally between 85-95%, with some high-efficiency screens reaching up to 98%. Vibrating screens are widely used in industries like ore, coal, sand, and chemicals, serving as crucial material classification equipment.

Vibrating screens are mainly divided into circular vibrating screens and linear vibrating screens. Circular vibrating screens create circular or elliptical motion paths, suitable for most materials, with capacities up to 500 tons/hour.

Linear vibrating screens produce linear motion, ideal for difficult-to-screen materials, such as wet and sticky substances. Additionally, there are high-frequency vibrating screens (1800-3600 rpm) for fine powder screening; heavy-duty vibrating screens for large particle screening in mining; and multi-layer vibrating screens for separating multiple sizes simultaneously. Different types are suited to various working conditions and material characteristics.

Choosing a vibrating screen requires consideration of material characteristics (size, moisture, density), capacity, screening precision, and work environment. Fine powders (<0.1mm) are best suited for high-frequency vibrating screens (1800-3600 rpm).

Large particles (>10mm) should use low-frequency, large amplitude screens. Capacities over 300 tons/hour may require large circular vibrating screens. Wet sticky materials are better suited for linear vibrating screens.

Considerations also include screen type, number of layers (typically 2-5), and screen box inclination (15-25 degrees). For example, for processing 100 tons/hour of 1-10mm sand and gravel, a medium circular vibrating screen with 3 layers, 20-degree inclination, 5-7mm amplitude, and 1200-1500 rpm frequency may be chosen.

Common screens include wire mesh, perforated plates, polyurethane screens, and rubber screens. Wire mesh offers good wear resistance and high precision, with minimum apertures down to 37 microns.

Perforated plates have high strength, suitable for large particle screening. Polyurethane screens offer strong wear resistance, lasting 3-5 times longer than wire mesh. Rubber screens have excellent anti-blocking properties, lasting 50-100% longer than metal screens.

Different materials require different screens, such as wire mesh for ores and polyurethane screens for chemical powders. Screen replacement cycles range from 3 months to 2 years, depending on material and usage conditions.

The processing capacity of a vibrating screen depends on the model, size, and material characteristics. Small screens handle 10-50 tons/hour, medium screens 100-300 tons/hour, and large screens up to 300-500 tons/hour.

Screen area ranges from 1 to 10 square meters, directly affecting capacity. Amplitude (2-10mm) and frequency (900-3600 rpm) are also key factors. For example, a circular vibrating screen with a 5-square-meter surface can process up to 200 tons/hour of dry sand but may drop to 50 tons/hour with wet clay.

Characteristics like material size, moisture content, and density affect actual capacity, so choosing the appropriate model based on specific conditions is essential. Multi-layer screens can improve overall efficiency, but single-layer capacity may decrease accordingly. Some high-efficiency screens use special designs, like curved screens or multi-point excitation, to further enhance capacity.

Foundation Stability: Ensure the foundation is solid and level to prevent excessive vibration or movement during operation. A stable foundation minimizes wear and tear on the machine.
Proper Alignment: Align the vibrating screen accurately with the feed and discharge points. Incorrect alignment can lead to uneven loading, reducing efficiency and potentially causing damage.
Safety Measures: Install safety guards and barriers to prevent accidental contact with moving parts. Ensure emergency stop buttons are accessible and functioning.
Vibration Isolation: Use rubber pads or springs to isolate vibrations and reduce noise. This also protects the surrounding equipment and structures from vibration-related damage.
By considering these factors, you can ensure efficient and safe operation of the vibrating screen.