A scraper flight chain conveyor uses evenly spaced transverse flight blades attached to one or two roller chains running inside a U-trough or enclosed rectangular casing — scraping and pushing bulk solid along the casing floor to the discharge point. Processing 0.5-100 t/h horizontally or inclined up to 30 degrees at chain speeds of 0.1-0.5 m/s, it handles cohesive, sticky, or wet materials (10-70% moisture) that en-masse conveyors cannot process — the standard conveyor for wet filter cake, moist granules, sludge, and sticky food by-products.
Flights (steel, rubber, or polyurethane-tipped) attached to the chain at fixed pitch scrape material forward along the casing floor with each chain revolution. The material between flights is positively displaced — independent of material flowability or cohesion. Discharge occurs at one or more floor openings along the casing; a head scraper deflects remaining material at the end of the run. Twin-chain designs distribute force symmetrically — required for heavy or sticky materials above 1 t/h. Rubber-tipped flights prevent metal-floor contact in stainless GMP designs — protecting pharmaceutical-grade casing finish.
Challenges
Flight Wear and Rubber Tip Deformation on Abrasive Material
Hard mineral excipients and abrasive chemical granules erode rubber flight tips within 500-2,000 hours.
Material Build-Up Behind Flights on Sticky or Wet Product
Adhesive material bridges between adjacent flights -- chain tension rises; potential jams.
Chain Sag Between Flights Allowing Material Pass-Through
Chain sag in long unsupported spans allows material to pass under the flight -- loss of conveying.
Dust Emission at Flight-to-Casing Clearance (3-8 mm)
Standard flight-to-casing side clearance allows fine powder escape in pharmaceutical areas
Inclined Conveying Performance Drop Above 25 degrees
Material slides back between flights above 25 degrees inclination -- conveying efficiency falls sharply.
Solutions
- Polyurethane or UHMWPE Flight Tips (Replaceable Inserts): Replaceable polymer tips extend service life 3-5x vs. standard rubber; field-replaceable without chain removal.
- Self-Cleaning Anti-Stick PTFE Coating on Flight Face: PTFE coating on flight contact face reduces adhesion -- prevents bridging of sticky or wet materials.
- UHMWPE Wear Strips on Casing Floor (Full-Length Runners): Full-length polymer runners support chain against sag -- zero pass-through gap at all points.
- Dust Skirt Seals at Flight Edges (Rubber Wiper, Full Length): Continuous rubber wiper seals flight-to-casing side clearance -- dust emission <1 mg/m3.
- Closed-Pitch (Shorter Flight Spacing) for Inclined Runs: Reducing flight pitch doubles material support points -- maintains performance to 30 degrees inclination.
Applications
- Chemical: Wet filter cake from filter press, sticky pigment cake, sludge and moist chemical by-product transfer.
- Food & Beverage: Wet food by-product, moist bakery waste, sticky confectionery trim, sugar paste transfer.
- Pharmaceutical: Wet granulation discharge transfer to dryer -- moist granule handling at LOD up to 30%.
- Wastewater / Environmental: Sewage sludge, biosolid cake, and wet waste transfer from dewatering to disposal.
- Mining & Minerals: Wet ore, mineral concentrate, and sticky tailings cake horizontal transfer.
Product Catalogue & Technical Datasheet
| Model | Casing W (mm) | Length (m) | Capacity (t/h) | Inclination Max (dig) | Chain Speed (m/s) | Motor (kW) | Flight Material | Bulk Density Max (kg/m3) | L x W x H (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|---|---|---|---|
| SFC-200 | 200 | 1-15 | 0.5-5 | 30 | 0.1-0.5 | 0.18-0.55 | PU tip | 1,500 | Custom x 350×500 | 22 |
| SFC-300 | 300 | 1-25 | 1-12 | 30 | 0.1-0.5 | 0.37-1.1 | PU tip | 1,800 | Custom x 480×620 | 35 |
| SFC-400 | 400 | 2-40 | 3-25 | 30 | 0.1-0.5 | 0.55-2.2 | PU/UHMWPE | 2,000 | Custom x 620×750 | 55 |
| SFC-500 | 500 | 2-50 | 6-40 | 30 | 0.1-0.5 | 1.1-4.0 | PU/UHMWPE | 2,000 | Custom x 750×880 | 80 |
| SFC-650 | 650 | 3-60 | 12-65 | 25 | 0.1-0.4 | 2.2-7.5 | Steel/PU tip | 2,000 | Custom x 950×1,050 | 120 |
| SFC-800 | 800 | 3-80 | 25-100 | 25 | 0.1-0.4 | 4.0-11 | Steel/PU tip | 2,000 | Custom x 1,150×1,250 | 175 |
| SFC-1000 | 1,000 | 5-100 | 50-150 | 20 | 0.1-0.3 | 7.5-18.5 | Steel | 2,000 | Custom x 1,400×1,500 | 250 |