Square Gyratory Screen

What the square gyratory screen solves

A square gyratory screen separates dry bulk solids into controlled particle-size fractions. Use it when a packing line receives too much fine dust, oversize particles enter a finished product, or one feed needs several saleable grades. Rectangular screen decks and separate outlet paths let each fraction be collected, stored or returned for reprocessing.

• Off-size material in finished bags: remove oversize and fines before the packing hopper.
• Mixed sand grades: assign each mesh cut to its own silo or bagging route.
• Unnecessary disposal: keep oversize and undersize streams separate so the process can return suitable material to crushing or granulation.
• Frequent mesh blockage: use the specified bouncing-ball cleaning arrangement, with feed moisture and loading controlled.

Where it fits in a production line

• Dry silica sand: dryer and cooler → controlled feeder → square gyratory screen → graded silos → packing. Dust extraction and wear inspection are important at the inlet and discharge.
• Fertilizer: granulator and cooler → screen → finished-product bin, fines return and oversize rework. Check breakage with the actual granules.
• Chemical crystals: drying or storage → screening → mixer or bagging machine. Select seals and contact materials for the chemical and its moisture sensitivity.
• Plastic pellets: pellet cooling → fines and oversize separation → storage or packaging. Provide cleanout access when changing resin or color.

Working principle

An eccentric drive moves the suspended rectangular screen box in a horizontal gyratory motion. Feed spreads over the mesh; particles smaller than the opening pass through, while larger particles travel to their discharge. Successive meshes produce additional size cuts. Bouncing balls beneath the mesh help dislodge particles caught in the openings.

A dual-stack arrangement divides the feed between parallel screening paths. Ten screen decks in a dual five-deck arrangement do not automatically mean eleven finished grades: the discharge arrangement determines which fractions are combined or kept separate.

Selection factors that affect separation

• Particle-size distribution: provide the percentage close to every target cut, not only the largest particle.
• Feed rate and bulk density: specify normal and peak t/h, kg/m³ and feeder control. A stable, distributed feed prevents local overloading.
• Moisture and temperature: damp or sticky feed can blind the mesh; drying, cooling or another separation process may be required.
• Mesh and cleaning balls: select aperture, wire diameter and ball material together. Ball wear must not contaminate the product.
• Installation: allow screen-frame removal clearance, flexible inlet/outlet connections and access around the suspension. Size the support structure for operating loads.

FY-2040 dual five-deck configuration

The attached LIYOU drawing specifies a suspended FY-2040 (Dual 5) with Q235 construction, a 7.5 kW motor and 1950 × 4000 mm screen frames. Its screening-area notation is 7.8 m² × 10 decks, with 480 cleaning balls × 10 decks. These are configuration details, not a guaranteed throughput.

The illustrated outlet grades are >5 mm, 1.5–5 mm, 1.0–1.5 mm, 0.5–1.0 mm, 0.15–0.5 mm and <0.15 mm. They describe this drawing only; specify your own cut sizes when ordering.

Drawing dimensions include 5300 mm overall plan length, 2650 mm width, a Ø245 mm feed inlet and Ø159 mm outlets. The views show 3250 mm and 3226 mm vertical dimensions; use the final approved installation drawing for height and civil works.

View the FY-2040 dimensional drawing ↗

Operating checks and maintenance

• Fine material in the coarse outlet: inspect blocked mesh, feed surges and excessive bed depth.
• Coarse particles in the fine outlet: stop and check torn mesh, frame seating and bypass at seals.
• Unequal discharge from parallel stacks: check feed splitting and individual mesh condition.
• Abnormal noise or movement: inspect suspension joints, fasteners, flexible connections and lubrication against the maintenance instructions.
• Before restarting after a product change: clean the decks, ball trays and discharge paths, then verify each outlet with a sample.