Types and Applications of Metal Tower Packings

Metal tower packing is the core component of gas-liquid mass transfer equipment in chemical, petroleum, environmental protection and other fields. Its material is mostly stainless steel, carbon steel, titanium alloy, with high strength, corrosion resistance, high temperature resistance and other characteristics, widely used in distillation, absorption, extraction and other processes. The following are several common and highly used metal tower fillers and their application fields.

1. Pall Ring

Structural Features: Modified from Raschig rings with side-wall windows and inward-curved tongues, increasing surface area and reducing gas resistance.

Advantages: High capacity, low pressure drop, and uniform liquid distribution.

Applications:

Petrochemicals: Crude oil fractionation columns.

Environmental Engineering: Absorption towers for flue gas desulfurization (FGD).

Pharmaceuticals: Solvent recovery and purification of fine chemicals.

2. Cascade Ring

Structural Features: Half the height of Pall Rings with a conical flange, shortening gas paths and enhancing liquid surface renewal.

Advantages: 30% higher mass transfer efficiency than Pall Rings, lower resistance, and anti-clogging capability.

Applications:

Vacuum Distillation: Separation of heat-sensitive materials (e.g., fragrances).

High-Pressure Absorption: Natural gas sweetening (CO₂/H₂S removal).

Large-Diameter Tower Retrofits: Replacing trays to improve capacity.

3. Metal Ring Saddle Packing

Structural Features: Hybrid of ring and saddle shapes with surface perforations for enhanced liquid distribution.

Advantages: High corrosion resistance, moderate pressure drop, and large capacity.

Applications:

Strong Acid Environments: Absorption towers in sulfuric/nitric acid production.

High-Temperature Reactions: Gas-liquid mass transfer in ammonia/methanol synthesis.

Wastewater Treatment: Extraction of heavy metal ions.

4. Metal Wire Gauze Structured Packing

Structural Features: Corrugated metal gauze plates with 30°–45° angles, offering ultra-high surface area (up to 700 m²/m³).

Advantages: Extremely high separation efficiency (10 theoretical plates per meter).

Applications:

Precision Distillation: Isotope separation and ultra-pure solvent production.

Pharmaceuticals & Electronics: Purification of high-purity chemicals (e.g., semiconductor-grade acids).

Cryogenic Air Separation: Oxygen/nitrogen separation.

5. Metal Sheet Perforated Packing

Structural Features: Perforated corrugated metal sheets (5mm holes) balancing efficiency and anti-clogging performance.

Advantages: Cost-effective, resistant to fouling, and suitable for dirty feeds.

Applications:

Atmospheric Distillation: Crude oil desalting and dehydration.

Waste Gas Treatment: Scrubbing of dust-laden gases.

Food Industry: Energy-saving retrofits in ethanol distillation.

Conclusion

The selection of metal tower packings depends on medium properties, operating conditions (temperature, pressure), cost, and maintenance. Random packings (e.g., Pall Rings) suit general purposes, while structured packings (e.g., corrugated types) excel in high-precision separations. With advancements in materials and engineering, metal packings will continue to evolve, broadening their industrial applications.