Category of Packing in Tower Packing
Tower packing refers to the small fluid resistance, which is suitable for the process of treating large gas volume and small liquid volume. The liquid flows from top to bottom along the packing surface, and the gas and liquid flow meet in countercurrent or co-current, depending on the specific reaction. The amount of liquid in the packing tower is small. Regardless of the gas or liquid phase, its flow pattern in the tower is close to plug flow. If the solid phase is formed during the reaction, tower packing is unsuitable.
The packing tower is filled with various shapes of packing materials so that the liquid flows along the surface of the packing to form a liquid film, which is dispersed in the continuous flow of gas. The gas-liquid two-phase contact surface is on the liquid film surface of the packing, which is film-like contact equipment. Tower packing is generally divided into ceramic tower packing, metal tower packing, and plastic tower packing.
Ⅰ. Ceramic tower packing
Ceramic tower packing has excellent acid and heat resistance and can withstand the corrosion of various inorganic acids, organic acids, and organic solvents except for hydrofluoric acid. It can be used on various high and low-temperature occasions and has a wide range of applications. Ceramic tower packing can be used in drying towers, absorption towers, cooling towers, washing towers, rectification towers, atmospheric towers, synthesis towers, catalytic towers, regeneration towers, etc. of the chemical, metallurgical, gas, and oxygen production industries.
Ⅱ. Metal tower packing
The metal tower packing can be made of various materials and should be specifically analyzed when selecting. Carbon steel fillers are low in cost and have good surface wetting properties. They are prior to being used for non-corrosive or low-corrosive material systems. Stainless steel fillers have strong corrosion resistance and can withstand the corrosion of standard material systems (except Cl-), but the cost is relatively high and the surface wetting performance is poor. In some unique processes (such as the vacuum distillation under very low spray density), the surface needs to be treated to obtain good utilization effects. Fillers made of titanium materials, special alloy steel, and other materials are expensive, which is generally used only in certain highly corrosive materials.
Ⅲ. Plastic tower packing
Plastic tower packing includes tower packing made of PP, PE, RPP, PVC, CPVC, PVDF and other materials. Plastic tower packing has the characteristics of a large void ratio, pressure drop and low height of mass transfer unit, high flooding point, sufficient vapor-liquid contact and high mass transfer efficiency. The operating temperature in various media is 60-280℃. Plastic tower packing is widely used in packing towers in petroleum, chemical, chlor-alkali, gas, environmental protection, and other industries.