Metal Super Raschig Ring Structure & Pressure Drop Explained

Engineer's Brief: A metal super Raschig ring is a high-performance random packing built from a thin-walled cylinder with alternating sinusoidal webs instead of plain walls. The wave webs create several thin liquid films, promote interface renewal, and keep free volume at 96–98%. Compared with a plain metal Raschig ring it avoids nesting; compared with standard metal Pall rings it typically gives lower pressure drop at equal throughput and higher flooding capacity in retrofits. FXSINO supplies super raschig-style rings in carbon steel, SS304/304L and SS316L/316L.

• • Multiple films: Sinusoidal webs split the liquid into several thin films; recurrent contact points remix the films and renew the gas-liquid interface.[4](@ref)
• • High open area: Free volume 96–98% depending on size, so gas passes with little contraction and dry ΔP stays low.[5](@ref)
• • Anti-nesting: Alternating wave frequency/amplitude reduces entanglement during dumping and makes removal easier.[4](@ref)
• • Low bulk weight: Thin stamped sheet gives high surface area per unit mass; support grid load is lower than ceramic and often lower than solid-wall metal rings.[4](@ref)
• • Fouling tolerance: Open structure suits liquids with minor solids; fewer dead zones than closed-window geometries in dirty service.[5](@ref)

• Dry ΔP: Very open geometry — published metal super-ring dry pressure drop is already lower than a 50mm metal Pall ring at the same F-factor.[4](@ref)
• Wet ΔP at low L: Air/water tests on No.0.3–0.5 sizes show dry ΔP around 20Pa/m at zero liquid and roughly 50–80Pa/m at L=1–2m³/m²h in small-column references; values scale with size, F-factor and tower diameter.[1](@ref)
• Wet ΔP at high L: Gap vs Pall grows with liquid load because films and windows stay open; super-ring wet ΔP can be substantially below comparable high-performance rings.[4](@ref)
• Loading/flooding: In 50mm-class comparisons, super raschig flooding capacity was about 25–33% higher than 50mm Pall and 10–15% higher than some high-performance rings; exact margin depends on system and distributor quality.[2](@ref)
• Vs plain Raschig: Plain metal Raschig has much higher packing factor and channeling; super raschig is not a fair 1:1 swap — re-rate bed height, support open area and distributor density.

• Size vs diameter: Keep nominal size ≤ D/30 for even distribution; 50mm for 1.5m ID, 76mm for ≥2.3m, 25–38mm only in small/high-efficiency columns.
• Support open area: Use a camel hump support grid or punched support plate with ≥80% open area; super raschig low ΔP is wasted if the support restricts flow.
• Distributor density: Small 25mm needs more drip points/m² than 76mm; pair with a liquid distributor/redistributor for beds >6m.
• Hold-down: Light stamped metal at high F or vacuum needs a bed limiter/hold-down plate; size bar gap to retained element, not to nominal OD.
• Entrainment: For high gas velocity add a wire mesh demister above the top bed.

• • Vacuum distillation: Low ΔP per stage protects vacuum system; 50–76mm super raschig or structured packing depending on HETP target.
• • Atmospheric distillation/refinery: High flooding capacity supports debottleneck without larger shell.
• • Absorption/scrubbing: SO₂, HCl, NH₃, CO₂ — open web handles variable liquid load; 316L for corrosive scrub liquor.
• • Stripping/regeneration: Steam stripping of VOC or amine regeneration where low ΔP reduces reboiler/compressor cost.
• • Dirty/once-through liquors: Super raschig open structure tolerates fines better than small-window Pall; still less tolerant than hollow-ball media.

Q: How much lower is pressure drop than a metal Pall ring?

A: Published 50mm-class tests report super raschig wet ΔP roughly 60% lower than Pall in one cyclohexane/n-heptane dataset and clearly lower than Pall under air/water at equal F; ammonia/water retrofits show smaller ΔP reductions at equal throughput (e.g., No.1 vs 1.5" Pall about −21 to −33%). Always re-run with your fluid properties.[2,15](@ref)

Q: Can I replace plain Raschig or Pall 1:1 by volume?

A: No. Super raschig has higher free volume and different HETP, so 1:1 volume usually over-designs or changes separation duty. Send existing bed height, throughput, pressure budget and HETP; FXSINO proposes size, bed height and internals as a package.

Q: Is super raschig better than structured packing for vacuum?

A: Structured packing gives the lowest ΔP/HETP in clean vacuum service; super raschig is preferable when you need random-packing flexibility, dirty feed, easy reload, or retrofit inside an existing support/distributor layout. For deepest vacuum and tight HETP, compare both with wire mesh structured packing.

Get a Metal Super Raschig Quote

FXSINO is a manufacturer of metal random packing & tower internals — super raschig rings, metal Pall rings, support grids, distributors and demisters. Custom sizes in carbon steel/SS304/316L, fabricated to drawing, shipped worldwide.

Send tower ID, service fluid, pressure, temperature, gas/liquid rates, target HETP or ΔP budget. We return size recommendation, bulk volume, support open area, distributor density and a same-day budget quote. FXSINO supplies the full package — support grids, bed limiters, redistributors and demisters.

Contact FXSINO: jackieqiu9202@gmail.com | +86 18507999558