A linear vibrating screen is driven by two vibration motors rotating in opposite directions. Their combined forces cancel sideways movement and produce a straight-line throwing motion, so seeds hop forward along the deck in one direction. A circular vibrating screen uses a single eccentric shaft or unbalanced weight, which makes the whole screen body move in a circular or elliptical path.
The practical result: on a linear deck, material travels quickly and predictably from inlet to outlet. On a circular deck, seeds tumble and re-orient as they move, spending more time over the mesh openings. Both designs are standard options within the vibrating screen category used ahead of oilseed pressing.
Linear motion typically wins on throughput per square metre of deck. Because material moves in a straight line at a relatively shallow throw angle, large volumes of peanuts, soybeans, sunflower or sesame can be pre-cleaned quickly, removing stones, stalks, dust and oversize trash. Linear screens also accept multiple decks easily, so one machine can split a stream into several fractions in a single pass.
Circular motion typically wins on separation sharpness. The rotating throw keeps seeds turning over the mesh, so near-size particles get more chances to pass through, and the deck tends to self-clean as blinding particles are flung free. For grading seeds into tight size bands — for example, sizing peanut kernels before dehulling — circular screens generally deliver a cleaner cut at the cost of somewhat lower capacity.
For most oil mills, the first screening stage is about volume, not perfection: pull out the gross impurities before they reach the dehuller or screw press. That role suits a linear screen, often paired with an air aspirator and magnet in a dedicated seed cleaning machine. Removing sand and stones early matters because abrasive contaminants accelerate wear on press worms and barrels downstream.
Choose a circular screen when the job is grading rather than rough cleaning — uniform kernel size improves the performance of a seed dehulling machine, since shellers and dehullers are typically adjusted for one size band at a time. Many medium and large plants simply use both: linear for pre-cleaning, circular for sizing.
A vibrating screen rarely works alone. In a typical flow, seeds pass through cleaning, screening, dehulling and roasting before pressing — each stage protecting the next and raising final oil yield. The full equipment range for this stage is covered under seed preparation equipment, including the vibrating screen options in both linear and circular configurations.
SinoOil Machinery has manufactured factory-direct oil processing equipment since 2009, supplying mills in over 80 countries with ISO9001, CE and SGS certification. If you are unsure which screen type and deck configuration fits your raw material and daily capacity, contact our engineers for a line-specific recommendation.
A multi-deck linear screen can remove oversize trash and fines in one pass, which is enough for many small mills. But if you need tight size grading before dehulling, a separate circular screen typically gives a sharper cut than asking one machine to do both jobs.
Stones, sand and metal accelerate abrasive wear on screw press components, and trash absorbs oil and contaminates cake. Cleaning and screening early protects downstream dehulling, roasting and pressing equipment while supporting higher, more consistent oil yield.
Circular motion tends to self-clean better because the rotating throw flings near-size particles off the mesh. For sticky or high-oil materials, ball-tray or bouncing-ball cleaning systems are also commonly fitted under the deck on either screen type.
Yes. Dehullers and shellers are adjusted for a specific clearance, so a uniform size band shells more cleanly with less kernel breakage. Feeding mixed sizes typically means small seeds pass unshelled while large kernels break.
SinoOil engineers size the right pretreatment equipment for your capacity — free plant design included.
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