Rschig Ring
It has a smooth surface without holes, grooves & other textural elements. It features low capacity, low efficiency and high corrosion resistance.
Random packing, also known as dumped packing, is different from structured packing. It has irregular shapes with special surface structures and high porosity. By increasing gas/liquid contact surface area, it enhances separation efficiency. It is commonly used in adsorption columns, drying columns, cooling columns, and desulfurization columns to achieve separation, adsorption, drying, cooling, reaction and other operations. Additionally, it is widely used in chemical, petroleum, refining, metallurgy, environmental protection, and other industrial fields.
It is the earliest random packing made of ceramic material. It is a ring whose height is equal to its diameter. Later, it can also be made of metallic and non-metallic materials. In order to improve its performance, a series of random packing such as Lessing ring, cross ring, inner spiral ring, short Rashig ring have been derived from Rashig ring.
Rschig Ring
It has a smooth surface without holes, grooves & other textural elements. It features low capacity, low efficiency and high corrosion resistance.
Lessing Ring
Usually made of ceramic materials, it adds an internal spacer based on the Rashig ring to increase the surface area and enhance the efficiency.
Cross Ring
It adds a cross spacer based on the Rashig ring and is generally made of ceramic materials. Currently, it is mostly used.
Its basic feature is to open holes in the ring wall of the ring-type packing, so that the opened slot forms an inwardly curved tongue piece pointing to the center of the ring. It improves gas-liquid two-phase flow through the packing layer, making the liquid distribution more uniform and enhancing the mass transfer efficiency of the packing layer.
Pall Ring
It is a hollow ring packing whose hose height is equal to its diameter. Two layers of window openings with inwardly extending tongue pieces are opened on the wall of Rschig ring. It greatly improves the gas-liquid two-phase flow inside the packing, and enhances the hydrodynamic and mass-transfer performance of the packing.
Cascade Mini Ring
It has the features of Rschig ring, but reduce the ring height and the pressure drop of the gas through the packing layer. The side end adds a turning edge design and enhances its mechanical strength and the mass transfer efficiency of the packing.
Flat Ring
It has a small height-diameter ratio. The ring wall opening is continuous inflexed arced fins without turning edge design. It is a new packing suitable for liquid-liquid extraction process.
Super Mini Ring
It is improved based on the flat ring to make the fluid resistance smaller, expand the contact between liquid and gas, and enhance the hydrodynamic and mass-transfer performance of the packing.
Also known as Berl saddle ring packing, its shape is similar to a saddle and can reduce the liquid wall flow and enhance the gas mobility. But it is easy to overlap.
Berl Saddle Ring Packing
Initially, it is made of ceramic materials and processed by punch or casting molds. But, it is easy to overlap and produce voids, so it is currently rarely used in industrial processes.
Rectangular Saddle Ring Packing
Both ends are rectangular, not arc-shaped. It adopts continuous extrusion process to overcome the shortcomings of the Berl saddle type packing easy to overlap and produce voids.
It is a combination of the ring and the saddle, which benefits the advantages of the two. It improves the flux and pressure drop of the random packing as well as its mass transfer efficiency.
Metal Intalox Rectangular Saddle Ring
It combines the structural characteristics of hollow ring and Intalox saddle ring. Its open structure makes the packing flux increase and pressure drop decrease, which contributes to the distribution of liquid and improves the mass transfer efficiency.
Nutter Ring
The surface utilization of the packing layer is improved by lateral liquid diffusion and surface renewal of the liquid film, which is conducive to mass and heat transfer in the packing layer.
Conjugated Ring
Inside each semicircular member has a semi-circular rib in the middle to increase the surface area of mass transfer and improve the performance of mass transfer.
In addition to the main types of packing, because of the good plasticity of plastic material, in recent years, some other structures, shapes of random packing have been developed including polyhedral hollow ball packing, rosette ring packing, Haier packing, etc.
Polyhedral Hollow Ball Packing
Made of plastic, two hemispheres consisting of a number of semi-fan blades are combined together to form a spherical shape, which increases its surface area and facilitates the distribution of gases and liquids.
TRI Pack
It consists of many grid-like branches. It has high porosity and small structural anisotropy. Its surface can be well wetted and maintain a uniform liquid distribution, which is favorable to the mass transfer between the gas-liquid two phases.
Mella Ring
Also known as VSP ring, it is a kind of random packing stamped with metal materials into a rosette-like shape. The ring wall has a large open area and features large flux, low resistance and high mass transfer efficiency.
Rosette Ring
Also known as Teller rosette ring, it is usually made of plastic or metal materials and consists of many circles around the knot. Its shape looks like an ellipsoid. It can increase the contact time of the gas-liquid two-phase, and improve the mass transfer efficiency.
Super Raschig Ring
It employs improved geometry and structural design with larger surface area and higher porosity. It can provide more gas-liquid contact points, thus improving mass and heat transfer efficiency.
Haier Ring
It features unique modeling, large flux, low pressure drop, good corrosion resistance and impact resistance. It has small wall flow effect and uniform gas-liquid distribution, the packing will not be nested.
Dixon Ring
Also known as θ mesh ring packing, it is a ring packing made of metal mesh. Its height and diameter are equal, and it is an efficient packing for small particles mainly used in laboratories.
Random packing is widely used in absorption columns, distillation columns, degasification columns and stripping columns, aiming to achieve gas-liquid mass transfer. The following is an example of the working principle of random packing in stripping columns.
Stripping is a process of recovering the solute absorbed from the fluid and separating liquid from solute. First, differing from the orderly distribution of structured packing, random packing is randomly distributed on the packed bed, strippant (gas) enters from the bottom and moves upward. Dirty water sprays downward from tray distributors. During the process, the solute molecules are transferred into gases through an endothermic process. Gases and liquids contact each other in a form of counter-flow in the column. The irregular distribution of random packing increases the surface area and enhances the mass transfer between two fluids. The solute turns into gas and mixes with strippant. Droplets are removed through the mist eliminator at the top of the tower and flows out from the top of the column. Clean liquid moves downward due to gravity and flows out at the bottom of the column.
It is often used in chemical, petroleum, refining, metallurgy and other industrial fields for separation, absorption, drying, cooling, desulfurization and other process operations, providing efficient and reliable solutions for engineering.
