Eight Key Tips for Selecting a Vibrating Screen Model

The vibrational force generated by the vibrating source of a circular vibrating screen is an inertial force that rotates around a fixed axis with a normal change in direction. Its essence is the centrifugal force formed by an eccentric mass rotating around a fixed axis. The working principle of a circular vibrating screen is that after the screen is started, the vibrating screen exciter drives the vibrating screen box to perform directed jumping motion. Simultaneously, materials smaller than the screen aperture pass through the apertures and fall into the lower layer, becoming the material beneath the screen apertures. Materials larger than the screen aperture diameter are continuously bounced and discharged through the outlet, ultimately completing the screening process.

The primary factors influencing the selection of a screening machine type include:

Characteristics of the screening material (particle content of the screening material, content of difficult-to-screen particles, moisture and clay content in the material, material shape, material proportion, etc.);

Screener structure (screen area, number of screen layers, screen aperture size and shape, screen aperture area ratio, screener movement mode, amplitude, and frequency, etc.);

Mining process requirements (processing capacity, screening efficiency, screening method, screener inclination angle, etc.).

In addition to considering the above factors, the following basic principles should be followed:

(1) After determining the screening area, the width of the screen surface should be at least 2.5 to 3 times the maximum material size to prevent the screen from being blocked by large materials.  

(2) To ensure the screen operates under good conditions, the ratio of screen length to width should be selected within the range of 2 to 3.  

(3) Appropriate screen surface materials and structures should be selected based on the operating conditions.  

(4) For fine screens, curved screens, and linear vibrating screens, the screen aperture size should be 2 to 2.2 times the separation particle size, with a maximum of 3 times; for vibrating screens used for medium-sized screens, the screen aperture size should be 1.2 times the separation particle size; for coarse screens, the screen aperture size should be 1.05 times the separation particle size; for probability screens, the screen aperture size is generally 2 to 2.5 times the actual separation particle size.

(5) Determining whether to use a double-layer or multi-layer screen. When the particle size range of the material to be screened is wide, using a double-layer screen instead of a single-layer screen can increase the screening machine's processing capacity, protect the lower layer screen, and extend its service life. The selection of upper layer screen aperture size for a double-layer screen should generally be determined based on the feed particle size characteristics. The screen aperture size should be selected such that the undersize fraction of the upper layer screen accounts for 55–65% of the original feed material.

Note that when the content of undersize particles in the raw material exceeds 50%, there are many difficult-to-screen particles, the material contains a high proportion of sticky clay, or the moisture content is high, it is advisable to avoid selecting a double-layer screen as a single-layer screen.

(6) Determine the effective working area of the screen. The screening area calculated according to production process requirements is the effective area of the screen, while the screen specification represents the nominal area. For vibrating screens handling medium-sized materials, the effective screening area should be 0.8 to 0.85 times the nominal area of the screen. Of course, this is closely related to the open area ratio of the screen openings on the screen surface.

(7) Materials larger than 200 mm are typically processed using heavy-duty vibrating screens; materials larger than 10 mm are typically processed using circular motion screens; linear vibrating screens and high-frequency vibrating screens are primarily used for de-silting, dewatering, and grading.

(8) When conditions permit, seat screens should be prioritised for ease of maintenance. When suspended screens must be selected, the suspension height should be minimised to reduce the vibrating screen's oscillation range, facilitating production and operation.

When selecting screening equipment, one should not consider a single factor but should comprehensively evaluate various factors to ensure the selection of equipment suitable for specific working conditions. For more details, please click on the website customer service, available 24/7 online.