Vibrating Screen for Feed Mills

What Does a Vibrating Screen Do?

Material is fed onto the screen surface and moved by controlled vibration. Particles smaller than the screen opening pass through the screen, while oversized particles continue across the surface toward a separate outlet.

In animal feed production, a vibrating screener can be used for:

• separating fines and dust from feed pellets
• removing oversized particles
• grading crumbled feed
• separating large particles before downstream processing
• final screening before storage or packing

The required screening duty should therefore be defined before selecting the machine.

How Does a Vibrating Screen Work?

Product enters through the inlet and spreads across the screening surface. Vibration keeps the material moving while allowing smaller particles to work their way through the product layer and reach the screen openings.

Screening performance depends on maintaining the correct material movement. If the product travels too quickly, there may not be enough screening time. If it moves too slowly, material can accumulate on the screen.

The objective is not maximum vibration. It is to achieve stable product flow and efficient particle separation for the material being processed.

Vibrating Screen Applications in Feed Mills

One of the most common applications is pellet screening after the cooler.

Pellets can generate fines and broken particles during pelletizing, cooling and conveying. Screening separates these particles before the finished pellets are transferred to finished-product bins, bulk loading or packing.

A typical pellet line arrangement is:

Pellet Mill → Pellet Cooler → Vibrating Screen → Finished Product Bin / Packing

For crumble feed, the screen is normally installed after the crumbler. The product may contain fines, correctly sized particles and oversized pieces. Screening helps separate these fractions and obtain the required particle size range.

Pellet Mill → Cooler → Crumbler → Vibrating Screen → Finished Product Bin / Packing

Vibrating screens can also be used in raw material handling to prevent particles larger than the selected screen opening from entering downstream equipment.

Screen Opening and Screening Area Selection

Selecting a vibrating screen based only on tons per hour can lead to poor screening performance.

The design should also consider:

• product type
• bulk density
• incoming particle size distribution
• required finished particle size
• screen opening
• percentage of fines
• moisture and flow characteristics
• required screening area
• number of screen decks
• number of product outlets

Insufficient screening area may allow material to leave the machine before the required separation is completed.

Moist, oily or sticky materials create another challenge. Material can gradually block screen openings, reducing the effective open area even though the physical dimensions of the screen remain unchanged.

For this reason, the actual capacity of the same vibrating screen can vary considerably between different products.

Factors Affecting Vibrating Screen Performance

Feed Rate

Excessive feed creates a thicker material bed on the screen. Fine particles may then leave with the oversize fraction before reaching the screen openings.

Moisture and Flowability

Dry, free-flowing feed behaves differently from moist or oily material. Increased moisture can promote adhesion and screen blinding.

Particle Size Distribution

A product containing a high percentage of particles close to the screen opening is generally more difficult to separate than a product with clearly different coarse and fine fractions.

Vibration and Screen Inclination

Vibration characteristics and screen inclination influence material velocity and retention time on the screening surface.

Screen Condition

Screen surfaces should be inspected for wear, loose sections, damaged openings and local blockage. Changes in operating noise or vibration can also indicate that bearings, springs, connections or screen tension require inspection.

Where Is a Vibrating Screen Installed in a Feed Production Line?

There is no single installation point for every application.

For finished feed pellets:

Pellet Mill → Cooler → Vibrating Screen → Finished Product Bin / Packing

For crumble production:

Pellet Mill → Cooler → Crumbler → Vibrating Screen → Finished Product Bin / Packing

For raw material screening:

Raw Material Intake → Pre-Screening → Grinding → Dosing & Mixing

The final position should be selected according to the purpose of screening, product characteristics, fines return system and overall feed mill layout.

Custom Vibrating Screen Solutions from KARDEV

KARDEV Makina designs and manufactures vibrating screening solutions according to the requirements of each feed mill project.

Screening capacity is not evaluated as an isolated number. Product type, bulk density, particle size distribution, moisture, required separation, screen area, number of decks, outlets and installation layout are considered together.

Depending on the process, the machine can be configured for pellet fines separation, crumble grading or removal of oversized material before downstream equipment.

For vibrating screen selection, share your product type, required capacity and target particle size with KARDEV so that the appropriate screening configuration can be evaluated for your feed mill.

Frequently Asked Questions

What products can be processed with a vibrating screen?

Vibrating screens can be used for feed pellets, crumbled feed, grains and other free-flowing bulk materials. The screen type and opening must be selected according to the properties of the product and the required separation.

What is the difference between single-deck and multi-deck vibrating screens?

A single-deck screen normally separates the product into two fractions. Additional screen decks can be used when three or more particle size fractions are required.

Why is a vibrating screen used after a pellet cooler?

It separates fines and broken particles generated during pellet production, cooling and conveying before the finished feed is transferred to storage or packing.

How is vibrating screen capacity determined?

Capacity depends on several factors including screening area, screen opening, bulk density, particle size distribution, moisture, feed rate and the required separation efficiency. It should therefore be evaluated for the specific product and process.