Dryer Lifting Flights

Function

Dryer flights govern heat-transfer efficiency directly: a complete, correctly profiled flight set moves more aggregate mass through the gas stream per unit time, reducing specific fuel consumption and enabling rated throughput. They also provide mechanical agitation that breaks up clumped, fine, or moist aggregate. Because they operate in an abrasive environment — cold, sharp, freshly crushed rock at the feed end — they wear progressively and must be inspected and replaced on a planned schedule. Reduction of flight height by more than 20–25% typically produces a measurable increase in stack moisture readings and fuel consumption per tonne of mix.

Construction & quality

Fabricated from abrasion-resistant steel plate — HARDOX 400 or equivalent AR steel, 10–16 mm thick — giving a nominal hardness of 370–430 BHN at the working surface. Flight profiles are laser-cut or plasma-cut to the engineered geometry (L-profile, radial-lip, or bucket profile depending on drum size and aggregate grading), then bent on a press-brake to the design angle. Flights are supplied with pre-drilled attachment holes for bolt-on installation (M20/M24 hex bolts) or as weld-on vanes with a prepared fillet weld land. For hot-zone boundary flights a ceramic-faced wear insert option is available. All flights are supplied in matched, balanced sets per drum zone to maintain rotational equilibrium.

When to replace

• Flight height eroded to less than 70% of original radial dimension
• Bent, cracked, or missing individual flights breaking the aggregate curtain pattern
• Increased stack exhaust moisture or reduced aggregate discharge temperature at constant feed rate
• Higher fuel consumption per tonne at equivalent throughput
• Loose or fractured attachment bolts from fatigue cracking at the flight root weld zone