Packing Equipment | Structured Packing | Random Packing

Working Principle Gas enters at the bottom of the tower, and liquid is sprayed down from the top, so the two meet countercurrently on the packing surface. Structured packing channels guide the gas and liquid along set paths, giving even liquid film distribution and a large contact area. Random packing relies on the gaps between pieces to form irregular channels, where gas and liquid keep contacting each other. Mass transfer takes place at the interface between the liquid film and the gas—easily dissolved components move from gas into liquid, while less soluble ones go the other way. A taller packing bed means longer contact time and better separation, but resistance rises along with it. Application Fields 1.Chemical distillation: separating liquid mixtures and purifying products. 2.Gas absorption: removing acidic gases or harmful components from exhaust. 3.Environmental scrubbing: purifying acid mist, ammonia, and similar emissions. 4.Petroleum refining: gas-liquid mass transfer in fractionation and extraction towers. FAQ Q1: How do you choose between structured and random packing? A: It depends on mass transfer requirements and what the material is like. Structured packing is efficient and low-resistance, making it a good fit for vacuum distillation and heat-sensitive materials—but it costs more and demands careful installation. Random packing is cheaper, handles high throughput, and resists fouling, so it suits materials with high solids content or strong corrosiveness. If separation precision isn't a big concern, random packing is the more economical pick. Q2: What materials are packing equipment usually made of? A: Metal, plastic, and ceramic are all common. Metal packing is strong and handles heat well, usually stainless or carbon steel. Plastic packing resists corrosion and is lightweight, usually polypropylene or PVC, but its temperature limit is lower. Ceramic packing handles acids, bases, and high temperatures, but it's brittle and breaks easily. Q3: How is the height of a packing bed determined? A: It mainly comes down to the number of transfer units and the height of a transfer unit. The number of transfer units comes from the separation requirements, while the height of a transfer unit depends on packing type, gas and liquid flow rates, and physical properties. In actual design, you also need room for liquid distributors and redistributors, and the tower diameter has to be checked to avoid flooding. If the bed gets too tall, it's usually split into several sections with redistributors in between.