01Grading · cleaning
Vibrating screen
A perforated deck, single or double. Sizes the product, removes coarse trash, drains wash water, or works with an aspiration unit for light foreign material.
Read about vibrating screens
Technical reference
Vibrating screenconveyors.
Machines that move, grade and clean product with vibration: how a vibrating screen, a vibratory conveyor and a vibrating feeder work, and how they are specified for food and dried-fruit lines.
Inclined screen · two decksFeed at the high end, oversize at the low end, undersize through the deck.
Definition
What a vibrating screen conveyor is
A vibrating screen conveyor is a trough or deck that is set into a controlled vibration by one or two vibration motors. Each vibration cycle throws the product a short distance forward, so the product travels along the machine without a belt. If the deck is perforated, material smaller than the opening falls through while it travels: the same motion conveys and screens at once. Depending on what the deck is made of and what sits above or below it, the machine is called a screen, a conveyor or a feeder.
Types
Three machines, one motion
The three groups differ in what the deck does with the product. All are built in stainless steel for food contact and driven by vibration motors.
02Transport
Vibratory conveyor
A closed trough that moves the product to the next station in an even flow. Internal agitators can separate clumped fruit into single pieces on the way.
Read about vibratory conveyors03Dosing
Vibrating feeder
A short tray under a hopper. Turns a batch dumped by hand or by a tipper into a steady, controllable stream for the machine downstream.
Read about vibrating feedersHow it works
From vibration to product flow
Step 1
Vibration motors drive the deck
Unbalanced weights on the motor shafts produce a directed vibration. Two motors running in opposite directions give a linear stroke along the deck.
Step 2
The product is thrown forward
Each stroke lifts the product and sets it down a little further along. Stroke, frequency and deck angle together set how fast the product travels and how thick the layer is.
Step 3
The deck separates or conveys
On a perforated deck, undersize falls through as the product travels. On a closed trough, the product simply moves to the discharge in an even stream.
Selection depends on the product and the line.
Deck opening, number of decks, trough width, angle and drive are chosen from the product group and the required throughput, not from a catalogue size.
Articles
Recent articles
Dewatering screens after product washing
How a vibrating dewatering screen separates wash water from fruit, where the water goes, and why the collection tray matters for the drain.
Read the articleDouble-deck screens: sizing and trash removal in one pass
Why a double-deck vibrating screen can grade a product into sizes and remove coarse trash in one pass, and how the outlets are arranged.
Read the articleRemoving light foreign material with aspiration
How an aspiration unit on a vibrating screen pulls out leaves, stalks and dust while the screen removes stones and soil.
Read the articleTerms
Terms used on this site
- Deck
- The screening surface of a vibrating screen. A machine can have one deck or two stacked decks with different openings.
- Oversize / undersize
- What stays on the deck versus what passes through it. Which of the two is the product depends on the task.
- Stroke
- The distance the deck travels in one vibration cycle. Together with frequency it sets conveying speed and how strongly the product is agitated.
- Aspiration
- An air stream drawn across the product that lifts light material (leaves, stalks, dust) out of the flow.
- Dewatering
- Separating free water from product after washing; the water passes the deck and is collected in a tray.
- Agitator
- A fixed element inside a vibratory conveyor trough that helps break clumped fruit into single pieces while it travels.