In chemical industrial, we always design various type of chemical column for treatment of waste water and tail gas . The main chemical column including cooling tower/column, washing tower/column, distillation tower/column, desulfurizing tower/column and so on.
We will design different types of random packing rings and structured packing according to different type of chemical column and working temperature. The main materials are ceramic, metal and plastic depending on the temperature, corrosive characteristics.
The normal random packing includes Pall ring, Cascade mini ring, Saddle ring, super Saddle ring, Bio ball,Q-pack, plastic floating ball, Teller Rosette ring, Raschig ring,Polyhedral hollow ball,Snow flake, Tri-pack and many other types.
The most common used random packing is Pall ring.Pall ring is the improved product of Raschig ring. It has great improvement of surface area compared with Raschig ring so its treatment capability increase 50% and the pressure drop decrease 50% than Raschig ring.
There are three type of material normally for Pall ring. They are plastic, ceramic and metal. Different material can resist different working temperature,acidity, alkalinity and corrosivity. Plastic pall ring is slight. If temperature is within 100 degree and low corrosivity, plastic pall ring is the best choice for low cost. Ceramic pall ring is heavy but can resist high temperature, high acidity, high alkalinity and high corrosivity. The cost of ceramic pall ring is also acceptable. Metal pall ring has very high cost but it is much lighter than ceramic pall ring and can resist much higher temperature than plastic pall ring. The resistance of high temperature, high acidity, high alkalinity and high corrosivity is also much higher than plastic pall ring.
Ceramic pall ring pictures
Plastic pall ring pictures
Metal pall ring pictures
I will introduce these three type of material pall ring separately.
1.Ceramic pall ring
There are three types of ceramic pall ring including common alumina ceramic pall ring, media alumina ceramic pall ring and high alumina ceramic pall ring. The standard sizes are dia25mm, 38mm, dia50mm, dia 75mm. As a common chemical packing, the ceramic pall ring alumina content is normally 23%. We can also produce higher alumina content pall ring such as 65%, 90% and other types. Following data is based on common ceramic pall ring 23%
Technical Data of 23% ceramic pall ring
| Spec | D*H*T(mm) | Surface area (m²/m³) | Free volume (%) | Number per m³ | Bulk density (Kg/m³) | Dry Packing Factor(m-1) |
| Ø 25 | 25*25*3 | 220 | 73 | 54000 | 620 | 565 |
| Ø 38 | 38*38*4 | 150 | 75 | 13400 | 570 | 356 |
| Ø 50 | 50*50*5 | 120 | 78 | 6800 | 550 | 252 |
| Ø 80 | 80*80*8 | 75 | 80 | 1950 | 520 | 146 |
Physical properties of 23% ceramic pall ring
| Index | Value |
| Specific gravity(g/cm3) | 2.25-2.35 |
| Water absorption (%) | <0.5 |
| Acid-resisting strength, %Wt. Loss (ASTMc279) | <4 |
| Firing temperature(Degree C) | 1280-1320 |
| Softening point( Degree C) | >1400 |
| Density(kg/m3) | 2350 |
2.Plastic pall ring
Plastic pall rings are widely used in chemical tower with high treatment efficient. The normal plastic materials are PP, PE, PVC, CPVC, PVDF, PTFE,PFA and so on based on different requirement. Plastic pall ring are widely used in washing column,cooling column, distillation column etc. The standard sizes are dia 25mm, dia38mm, dia 50mm, dia76mm. PP plastic pall ring is the most common type because of its large production capacity and low cost.
Specification
| Product | Material | Model | Size | Number per volume | Surface area | Void Volume | Dry packing factor |
| Pall ring | PVC | D×H×δ mm | n/m3 | m2/m3 | % | m-1 | |
| PP | Φ16 | 16×16×1 | 180000 | 188 | 91.1 | 275 | |
| PE | Φ25 | 25×25×1.2 | 49000 | 175 | 90 | 239 | |
| CPVC | Φ38 | 38×38×1.4 | 13600 | 155 | 89 | 220 | |
| RPP | Φ50 | 50×50×1.5 | 6300 | 93 | 90 | 127 | |
| Φ76 | 76×76×2.6 | 1830 | 73.2 | 92 | 94 |
Materials Physical Property
| Performance/Material | PE | PP | RPP | PVC | CPVC | PVDF |
| Density (g/cm3) | 0.94-0.96 | 0.89-0.91 | 0.93-0.94 | 1.32-1.44 | 1.50-1.54 | 1.75-1.78 |
| Operation Temp (Centigrade) | 90 | >100 | >120 | >60 | >90 | >150 |
| Chemical corrosion resistance | Good | Good | Good | Good | Good | Good |
| Compression Strength (Mpa) | >6.0 | >6.5 | >7.0 | >6.0 | >8.0 | >10.0 |
3.Metal ceramic pall ring
Metal ceramic pall ring has high cost but due to its high temperature resistance , low weight and many other advantage compared with plastic pall ring and ceramic pall ring, it is also widely used in various chemical tower. The materials are SUS304, SUS316, SUS316L, SUS321,carbon steel, Ally etc. The standard sizes are dia 16mm, dia 25mm, dia38mm, dia 50mm, dia76mm.
Specification Data:
| Specification | Number per volume | Surface-area | Void Volume | Dry packing factor |
| D×H×δ mm | n/m3 | m2/m3 | % | |
| 16×16×0.4 | 185000 | 239 | 0.928 | 299 |
| 25×25×0.6 | 51900 | 219 | 0.934 | 269 |
| 38×38×0.8 | 13800 | 129 | 0.945 | 153 |
| 50×50×1 | 6500 | 112.3 | 0.949 | 131 |
All above sizes and materials are the most common ones. We could also do customized products according to the special requirement.
