Selection Guide for Industrial Packing Materials

Industrial random packing is a core internal component of gas-liquid or liquid-liquid mass transfer equipment (such as towers). The combination of its material and structure directly determines the separation efficiency, throughput, pressure drop, and operational reliability of the equipment. This article briefly introduces the core characteristics, applications, and selection logic of random packing based on three main material systems: metal, ceramic, and plastic.

Core Characteristics by Material

The selection of packing material is primarily determined by process conditions. The key characteristics of metal, ceramic, and plastic packings are compared below.

Metal Packing

Materials: Stainless steel, carbon steel, titanium, special alloys.

Key Properties: High mechanical strength, excellent temperature resistance (up to 600°C+), variable corrosion resistance based on alloy, high density.

Typical Types: Pall rings, cascade rings, saddle rings, conjugate rings.

Ceramic Packing

Materials: Alumina, silicon carbide, porcelain.

Key Properties: Superior corrosion resistance (except to HF), excellent high-temperature resistance (up to 1000°C+), hydrophilic surface, high wettability, brittle nature.

Typical Types: Saddle rings, raschig rings, berl saddles.

Plastic Packing

Materials: PP, PE, PVDF, PTFE.

Key Properties: Excellent corrosion resistance, low cost and density, poor to moderate temperature limits (PP ≤ 100°C, PTFE ≤ 260°C), hydrophobic surface.

Typical Types: Pall rings, cascade rings, snowflake rings, multi-faceted balls.

Typical Application Areas

Metal Packing is used in high-temperature/pressure distillation, high-vacuum operation, and highly corrosive services with compatible alloys.

Ceramic Packing is standard for high-temperature corrosive gas absorption (e.g., sulfuric acid plants), gas scrubbing, and services requiring excellent surface wettability.

Plastic Packing is dominant in environmental engineering (scrubbers, biofilters), low-pressure-drop gas treatment, and handling corrosive chemicals at moderate temperatures.

Systematic Selection Guidelines

Selection follows a three-step process: Material First, Structure Second, Final Verification.

Step 1: Material Selection

The decision is driven by temperature and corrosivity.

Check Temperature: For temperatures >250°C, eliminate plastics. Choose between metals and ceramics.

Assess Corrosivity:

For strongly corrosive media at high temperatures, select special alloys or silicon carbide ceramics. At moderate temperatures, choose fluoroplastics (PTFE/PVDF) or ceramics.

For weakly corrosive media, all materials are viable. Plastics (PP/PE) are typically the most cost-effective choice.

Verify Other Requirements: Consider mechanical strength, thermal shock resistance, cleanliness, and fire safety.

Step 2: Structure Selection

Once material is chosen, select the packing type based on process goals.

Step 3: Final Verification

Perform a techno-economic analysis comparing initial investment and lifecycle costs. Conduct a final safety review for chemical compatibility and operational risks. 

Conclusion

The optimal packing results from matching material compatibility with structural efficiency. Metal handles extreme conditions, ceramic excels in high-temperature corrosion, and plastic offers economical performance for common chemical and environmental processes.For more information, please contact us via email at annayu@169chem.net or WhatsApp at +8618909016373.