Pall ring media is a random packing used in degassing, stripping and aeration towers. It developed from the Raschig ring: the cylinder is the same, but the wall carries two rows of punched-out holes with the displaced material turned inward as fingers. Those fingers open up the interior of the ring, so gas and liquid reach surface that a plain Raschig ring keeps sealed behind its wall.
The result is more usable surface area per cubic metre, a higher void fraction and a lower pressure drop across the bed. In a degassing tower that means more contact area for CO2 to leave the water without adding fan duty. Rings are moulded in polypropylene (PP) and are supplied loose for random dumping into the packed section.
Key Features
- Two rows of punched holes with inward-turned fingers, opening the ring interior to flow
- Void volume of 0.89 to 0.94 m³/m³ across the range, so pressure drop stays low
- Specific surface area from 52.8 to 188 m²/m³, rising as ring size drops
- Uniform gas-liquid contact and a high flooding point
- Low mass-transfer unit height
- Moulded in polypropylene (PP)
- Six sizes from DG16 to DG100, supplied loose for random packing
- Sold by the cubic metre; bulk number and packing density per size are listed below so bed volume converts straight to ring count and weight
Technical Details
| Size | D x H x wall (mm) | Specific area (m²/m³) | Void volume (m³/m³) | Bulk number (per m³) | Packing density (kg/m³) | F factor (m-1) |
|---|---|---|---|---|---|---|
| DG16 | 16 x 16 x 1 | 188 | 0.91 | 112,000 | 141 | 275 |
| DG25 | 25 x 25 x 1.2 | 175 | 0.90 | 53,500 | 64 | 239 |
| DG38 | 38 x 38 x 1.4 | 115 | 0.89 | 15,800 | 54 | 220 |
| DG50 | 50 x 50 x 1.5 | 93 | 0.90 | 6,500 | 42.5 | 127 |
| DG76 | 76 x 76 x 2.6 | 73.2 | 0.92 | 1,927 | 52 | 94 |
| DG100 | 100 x 100 x 3.0 | 52.8 | 0.94 | 1,000 | 50 | 82 |
Smaller rings carry more surface area per cubic metre but pack more densely and cost more pressure drop; larger rings do the reverse. We stock DG25 and DG50, which cover the great majority of degassing and stripping duties. The other sizes in the table are available on request.
Sold by the cubic metre. Use the packing density column to convert a bed volume to shipping weight, and the bulk number column to convert it to ring count.
