Drum Lifting Flight Set

Function

The flight curtain is the primary mechanism of heat and mass transfer inside the drying drum. By dividing aggregate into a continuously renewed veil of particles, flights expose maximum aggregate surface area to the hot gas stream — cutting drying time, improving fuel efficiency and ensuring uniform temperature distribution across all aggregate gradations. Worn or collapsed flights reduce curtain density, extending drying time, raising fuel burn and increasing the risk of insufficiently dried aggregate entering the mixing unit. Replacement of a full flight set on schedule is among the highest-leverage maintenance actions for sustained plant efficiency.

Construction & quality

Flights are fabricated from abrasion-resistant AR400 steel (Brinell hardness 370–430 HBW). Each flight is press-formed in a purpose-built die and laser-trimmed to tolerance before being pre-assembled into bolted segments (bolt-on designs) or supplied as weld-in blanks with pre-drilled reference holes. Lifting edges are reinforced with a 6 mm tungsten-carbide hard-face weld overlay on grades specified for highly abrasive aggregates such as granite or quartzite. Bolt-hole spacing and radius dimensions are matched to the drum shell directly to the Avelta OEM pattern. Full sets are supplied as matched kits including all fasteners and installation hardware.

When to replace

• Blade leading-edge thickness reduced to 3 mm or less — measure through drum inspection hatch at shutdown.
• Bent, detached or missing flight segments visible during internal drum inspection.
• Aggregate outlet moisture persistently above 0.5 % at normal feed rate, indicating degraded curtain density.
• Fuel consumption rising 10 % or more above baseline at constant feed rate and aggregate type.
• Uneven or intermittent curtain pattern observed through the drum sight glass during operation.