Vibrating screen exciters are mechanical devices that generate the vibration necessary for screening materials in industries such as mining, metallurgy, and construction. There are several types of vibrating screen exciters, each with its unique design and method of operation.

Vibrating Screen Exciters Types

1. Electromagnetic Exciters:

Operation: Electromagnetic exciters use an electromagnetic field to create a vibrating motion. The alternating current passed through a coil creates a magnetic field that moves the screen.

Usage: These are often used for fine material screening, where high-frequency vibrations are required.

2. Unbalanced Motor (or Rotary) Exciters:

Operation: These consist of a motor with unbalanced weights attached to either end of the rotor shaft. As the motor spins, the unbalanced weights generate centrifugal forces, causing the screen to vibrate.

Usage: Common in both circular and linear motion screens, these exciters are versatile and used in many screening applications.

3. Gearbox Exciters:

Operation: These exciters use a gearbox that drives the screen’s vibratory motion. The gearbox typically contains gears that generate a consistent vibratory motion when powered by an electric motor.

Usage: Often used in heavy-duty applications where significant vibration forces are needed, such as in mining screens.

4. Direct Drive Exciters:

Operation: In direct drive exciters, the vibration is generated directly by an electric motor without any intermediate gearbox or mechanical linkage. The motor is typically mounted directly on the screen.

Usage: Used in high-frequency and fine material screening, they provide precise control over the vibration frequency.

5. Hydraulic Exciters:

Operation: Hydraulic exciters use hydraulic fluid to drive a piston or actuator, which creates the vibratory motion. The system can be precisely controlled to vary the frequency and amplitude of the vibration.

Usage: Common in applications requiring variable control over vibration and often used in heavy-duty or specialized screening operations.

6. Eccentric Shaft Exciters:

Operation: Eccentric shaft exciters consist of a rotating shaft with an offset mass (eccentric weight) that generates a circular motion as the shaft rotates.

Usage: Widely used in circular motion screens, they are reliable and effective in handling large materials.

7. Twin-Shaft Exciters:

Operation: Twin-shaft exciters use two shafts synchronized with gears. These shafts rotate in opposite directions, generating a linear motion in the vibrating screen.

Usage: Ideal for linear motion screens, often found in heavy-duty applications such as mining and aggregates processing.

Each type of exciter is suited to specific applications depending on the material being processed, the desired screening efficiency, and the operational requirements.

Selecting the right linear vibrating screen for your application involves considering several key factors to ensure the screen meets your specific needs. Here’s a guide to help you make the right choice:

Linear Vibrating Screen Selection Guide

1. Material Characteristics

Particle Size and Distribution: The screen mesh size should match the particle size of the material. Fine materials require a finer mesh, while coarser materials need a coarser mesh.

Moisture Content: Materials with high moisture content may require special screens designed to handle wet or sticky materials, or additional features like a dewatering system.

Bulk Density: The density of the material will affect the screening efficiency. Denser materials require more robust screens.

Material Abrasiveness and Corrosiveness: If the material is abrasive or corrosive, select screens made from wear-resistant or corrosion-resistant materials.

2. Screening Capacity and Efficiency

Throughput Requirements: Determine the amount of material that needs to be processed per hour. The screen size, deck number, and vibration amplitude should align with your throughput needs.

Efficiency: Consider the efficiency of separation required. High-efficiency screens are essential when a high level of precision is needed.

3. Screen Size and Deck Configuration

Screen Dimensions: The length and width of the screen should be appropriate for the space available and the material to be processed. Larger screens generally handle more material but require more space.

Number of Decks: Multiple decks allow for the separation of materials into different size fractions in a single pass. Determine how many separations are needed.

Mesh Size: The mesh size should be chosen based on the smallest particle you need to retain.

4. Vibration Characteristics

Amplitude and Frequency: The amplitude (height of the vibration) and frequency (speed of the vibration) should be chosen based on the material properties. Higher amplitudes and lower frequencies are better for larger particles and heavier materials, while smaller particles and lighter materials benefit from higher frequencies and lower amplitudes.

Vibration Pattern: Linear vibrating screens typically have a straight-line vibration, but the pattern can be adjusted based on the specific needs of the material.

5. Power Requirements

Motor Type and Power: Ensure the motor is powerful enough to generate the required vibration force. It should also be energy-efficient to minimize operating costs.

Adjustability: Some screens allow you to adjust the motor speed and vibration amplitude, which can be beneficial for handling different materials or changing operating conditions.

6. Screen Surface Material

Material Type: The screen surface can be made from various materials, such as woven wire mesh, perforated plate, or polyurethane. The choice depends on the material being screened, with wire mesh being common for most applications, and polyurethane or rubber being preferred for abrasive materials.

Durability: Consider the expected lifespan of the screen material, particularly if you are dealing with abrasive or heavy materials.

7. Ease of Maintenance

Access and Cleaning: The screen should be easy to access for maintenance, including cleaning and replacing screen media. Consider screens with quick-release clamps or modular designs that simplify maintenance tasks.

Durability and Wear Parts: Select a screen with readily available wear parts, and consider the ease of replacement to minimize downtime.

8. Environmental Considerations

Dust and Noise Control: If the material being processed generates dust or if noise levels are a concern, look for screens with dust covers, enclosures, or noise-reducing features.

Vibration Isolation: Consider whether the screen will need vibration isolation to prevent the transmission of vibrations to surrounding structures.

9. Cost and Budget

Initial Investment: Consider the cost of the screen in relation to its features and your budget. Don’t just focus on the cheapest option; consider long-term efficiency and durability.

Operating Costs: Evaluate energy consumption, maintenance costs, and the expected lifespan of the screen.

10. Vendor Support and Customization

Customization Options: Some vendors offer customization options to tailor the vibrating screen to your specific needs. This could include adjustments to the vibration frequency, deck configuration, or screen material.

After-Sales Support: Ensure that the manufacturer provides good after-sales support, including parts availability, technical support, and service.

By carefully considering these factors, you can select a linear vibrating screen that is well-suited to your material, processing requirements, and operational environment, ensuring efficient and reliable performance.