A Select Guide to Types of Structured Packing

A Select Guide to Types of Structured Packing

Structured packing means it is neatly stacked in a tower and arranged according to a uniform geometric figure. It is widely used due to its advantages of large specific surface area, small pressure drop, uniform fluid distribution, and high mass transfer and heat transfer efficiency. Metal structured packing was first developed, followed by plastic structured packing, ceramic structured packing, and carbon fiber structured packing.

Types of Structured Packing

1. According to its structural characteristics

Structured packing can be divided into two categories: corrugated and non-corrugated. The former is divided into the vertical corrugated type and horizontal corrugated type; the latter is divided into grid type and plate type.

The most widely used structured packing is vertical corrugated packing. Vertical corrugated packing is divided into plate corrugated type and mesh corrugated type. In the specification and model representation of corrugated packing, the numbers generally represent the value of its specific surface area, and the letters X and Y represent the corrugated inclination angle of 30°C and 45°C respectively. For example, 400X means that the corrugated packing has a specific surface area of 400m2/m3 and a corrugated inclination of 30°C. The pressure drop of the X-type packing is small; the mass transfer performance of the Y-type packing is better.

2. According to the material type

Structured packing can be divided into metal structured packing, ceramic structured packing, and plastic structured packing.

Metal structured packing

Metal structured packing can be made of various metal materials, such as low carbon steel, stainless steel, Monel alloy, titanium alloy, etc. Stainless steel structured packing is the most popular because of its excellent corrosion resistance, rust resistance, and durability. Metal structured packing has different packing types, which can be divided into wire mesh structured packing and perforated plate structured packing.

Wire mesh structured packing has low pressure and high separation efficiency, and is the most widely used of all metal structured packings. Suitable for precision distillation and vacuum distillation units.

Porous plate structured packing is perforated to form a series of 5mm holes, which are then corrugated. This design allows for even distribution of the liquid. In addition, it can improve the surface wettability of structured packing. Porous plate structured packing provides high strength, excellent corrosion, and rust resistance for large diameter columns and high liquid load applications.

Ceramic structured packing

Ceramic structured packing consists of many packing elements of similar geometric design. The geometric design is a series of corrugated sheets placed in parallel. Ceramic structured packing has high filtration and separation efficiency to suit complex applications. It also features low-pressure drop, increased operating flexibility, minimal amplification, and maximum liquid handling. Ceramic structured packings are available in round or rectangular shapes to suit different applications.

Plastic structured packing

Plastic structured packing can be divided into wire mesh packing and plate packing. Wire mesh packing is made of PP and PE material, and board packing is made of PP or PVDF material. Openings can be added to the plate to improve mass transfer efficiency. Similar to ceramic structured packing and metal structured packing, plastic structured packing can also be made in a round or rectangular shape. Special shapes can be customized.

Advantages of Structured Packing

Low-pressure drop: Compared to other packing options, structured packing, especially gauze packing, offers very low-pressure drop and is a better choice for more volatile chemicals.

Large surface area: In the column packing, there needs to be a lot of opportunity for liquid and vapor contact. The best way to do this is to spread the liquid into a thin film, which structured packing does better than any other packing method.

High Efficiency: Structured packing has excellent separation and filtration efficiency compared to trays and random packing. This means more filtration can be achieved with shorter columns.

High Capacity: The tightly organized internal structure of structured packing enables columns to be more efficient and pack more volume than other packing types. This increased capacity also increases operating costs and rates.

Maximize liquid and gas flow: Structured packing is designed to handle larger flow rates than bulk packing, making it more suitable for high flow rates.

In addition to these advantages, structured packing tends to be more resistant to corrosion and temperature than another packing.

However, structured packing is not the best choice for every application. It tends to be more expensive than another packing due to the quality of materials and manufacturing. This makes it a less cost-effective option for some applications. In addition, structured packaging techniques are more susceptible to problems associated with misallocation.

What is Structured Packing Used For?

Structured packing is used in distillation and absorption processes and is best suited for low pressure and low irrigation applications. Some common applications for structured packing include:

1. Offshore drilling

Structured packing is commonly used in offshore applications such as offshore drilling. This is because it increases liquid dispersion which can help to counteract the effects of constant tilt and motion.

2. Dehydration of natural gas

Natural gas must be dehydrated before passing through the pipeline, or water vapor can freeze at low temperatures and damage the pipeline. Structured packing is 50% more efficient than tray technology and can be used to reduce the diameter of absorption towers, resulting in significant cost savings.

3. Styrene manufacturing

Styrene is a chemical used to make latex, disposable cups, plastic packaging, and many other commonly used products. Styrene is typically produced using distillation columns with structured packing. This is because styrene polymerizes rapidly at high temperatures, while structured packing provides low bottom temperatures and low-pressure drop, which help prevent polymerization during manufacturing and produce purer styrene.

Structured Packing From Naike Chemical

Structured packing is a valuable packing method for a range of applications in processing facilities. If you want to learn more about structured packing, its benefits, and how to choose the right packing material for your application, Naike Chemical can help.