Structured packing is a type of packing arranged in a tower according to a uniform geometric shape and neatly stacked. It has the characteristics of large specific surface area, low pressure drop, uniform fluid distribution, high mass and heat transfer rate and has been applied widely. Metal structured packing were developed early and later plastic structured packing, ceramic structured packing and carbon fiber structured packing were developed successively.
The most widely used structured packing is vertical corrugated packing. Vertical corrugated packing can be divided into plate corrugated type and mesh corrugated type. In the representation of the specifications and models of corrugated packing, numbers generally represent their specific surface area values and the letters X and Y respectively represent their ripple inclination angle of 30 ℃. For example, 400X indicates that this type of corrugated filler has a specific surface area of 400m2/m3 and a ripple inclination angle of 30 ℃. The pressure drop of X-shaped packing is small; The Y-shaped packing has good mass transfer performance.
1.Metal structured packing
Metal structured packing include perforated plate corrugated packing, wire gauze corrugated packing and annular corrugated packing.
Perforated plate corrugated packing is a structured packing formed by assembling large corrugated holes on the surface of metal sheets. It has the characteristics of low resistance, uniform gas-liquid distribution, high efficiency, high flux and unclear amplification effect. It is applied in negative pressure, atmospheric pressure, and pressurized operations.
Wire gauze corrugated packing is an important milestone in the development of regular packing. This type of packing is composed of corrugated wire mesh arranged in a pressed manner, with an inclination angle of 30 ° or 50 °. The adjacent two corrugated plates have opposite directions. When filling in the tower, the upper and lower plates of packing are staggered and stacked 90 °. It has the advantages of high efficiency, pressure reduction, and high flux. The products include BX and CY types, which are commonly used in vacuum distillation, atmospheric distillation, and absorption processes for difficult to separate and thermosensitive systems.
2.Plastic structured packing
Plastic structured packing include honeycomb inclined pipes, straight pipes, plastic sheet corrugated packing and plastic wire mesh corrugated packing.
- Honeycomb inclined pipe: This product is mainly used for water purification, sand removal and accelerated sedimentation of domestic sewage, oil separation, and tailings concentration, and is an excellent water purification filler.
- Honeycomb straight pipe: This product is mainly used as a microbial carrier in contact oxidation tanks, biofilters, and biological turntables, for biochemical treatment of industrial organic wastewater or urban domestic sewage. It can also be used as a filling material for chemical towers, cooling tower fillers, etc.
- Plastic sheet corrugated and screen corrugated packing: This product is mainly used in various industries such as gas purification, environmental protection, and separation and purification. It has the advantages of light weight, large capacity, low pressure drop, high specific surface area and easy replacement.
3.Ceramic structured packing
Ceramic structured packing, also known as ceramic corrugated packing, is also called Kelapak packing. Due to the separation efficiency of corrugated packing being several to ten times higher than that of bulk packing, corrugated packing is also known as high-efficiency packing. Compared with bulk packings, it has a series of advantages such as high efficiency, low pressure drop, large processing capacity, small liquid holding capacity, unclear amplification effect, and large operating flexibility.
Ceramic corrugated packing is a new type of structured packing, which is composed of many packing units with the same geometric shape. Due to the unique structure of ceramics and their excellent hydrophilicity, their surface can form an extremely thin liquid film. The turbulence and inclined and tortuous channels of the airflow can promote the airflow without blocking it, making ceramic packings comparable to metal packings. However, their corrosion and high temperature resistance cannot be compared to metal packings. The surface structure has good wetting performance, which can accelerate the flow of liquid and reduce the liquid retention of packings to a low level. This reduces the chances of overheating, polymerization, and coking.
Ceramic structured packings are mainly used to replace old-fashioned bulk fillers in towers, solving prominent problems such as high resistance, small specific surface area, poor mass transfer efficiency, and easy breakage. It can be widely used in gas washing towers, coking benzene washing, naphthalene washing, ammonia washing towers, fertilizer hot gas saturation towers, desulfurization, and desulfurization towers.
Post time: Jul-05-2024