Commonly used standard wire mesh demister types, models and standards

Commonly used standard wire mesh demister types and models and standard introduction - Anping County Maoqun Wire Mesh Manufacturing Co., Ltd.
⒈ HG5-1404 (1405, 1406) -81
standard divided into ascending pipe type (1404), reduced diameter type (1405) and full diameter type (1406). The diameter of the demister ranges from 300mm to 6400mm, with two heights of 100mm and 150mm. When ordering, only the drawing number and the material used need to be provided. Marking example: HG5-1406-81-11, 304/Q235A
means that the wire mesh is made of 304 stainless steel, the grille is made of Q235A, the full diameter type top-mounted, the diameter is 1600mm, and the height is 100mm.
⒉ The new standard HG/T21618-1998
combines the three installation forms of riser type, reduced diameter type and full diameter type; proposes four mesh types of SP, HP, DP and HR and expands the types of materials; and increases the interval density of the setting specifications.
Marking example: HG/T21618 Wire mesh demister S1600-100 SP 304/304
means that the grille and wire mesh are both made of 304 stainless steel, top-mounted, with a diameter of 1600mm, a height of 100mm, and a mesh type of SP.
3. HG/T21586-98 (Drawer-type wire mesh demister)
This standard is mainly applicable to occasions where the demister elements need to be cleaned or replaced, such as the drying tower and absorption tower of the sulfuric acid device. The nominal diameter range of the selected is DN300mm~DN5000mm, a total of 56 types. When ordering, you only need to provide the drawing number and the selected material (316L, NS-80 and RS-2 are the wire mesh materials selected for sulfuric acid devices).
Marking example: HG/T21586.11-98 WME-1600-100 NS-80/Q235A
means that the wire mesh is NS-80, the grille is Q235A, the diameter is 1600mm, and the height is 100mm.
4. Wave (guide type) wire mesh demister
The corrugated wire mesh demister has the following characteristics:
it realizes the gas-to-gas path and the liquid-to-liquid path, basically eliminates the secondary entrainment phenomenon, and significantly improves the defoaming effect.
Due to the tilt of the mesh block, the actual defoaming area is increased by 15%, which is convenient for adjusting the airflow, speed, resistance and defoaming effect during design.
Using one layer of corrugated wire mesh demister can achieve the defoaming effect of two layers of wire mesh demisters, saving installation space and reducing the cost of a single tower demister.


Introduction to the types and characteristics of commonly used metal wire mesh corrugated packing-Anping County Maoqun Wire Mesh Manufacturing Co., Ltd.
Metal wire mesh corrugated packing is also known as stainless steel wire mesh packing, regular wire mesh packing, etc.
Metal wire mesh corrugated packing is an important milestone in the development of structured packing. It is a disc-shaped packing composed of several parallel and straight metal corrugated mesh sheets. First, small holes with a small density of 0.4-0.5mm in diameter are pressed out on the metal plate, and then the multi-perforated plate is pressed into corrugated sheets to assemble into structured packing. Due to the special puncture structure on the surface, the wetting performance of the packing is improved, and the performance of the metal wire mesh corrugated packing can be maintained. Stainless steel corrugated packing includes perforated plate corrugated packing, plate mesh corrugated packing, calendered perforated plate corrugated packing, wire mesh corrugated packing and ring-shaped corrugated packing.

Characteristics of wire mesh corrugated packing:
The corrugated top angle of wire mesh corrugated packing is about 90 degrees, and the channel formed by the corrugation is 45 degrees or 30 degrees to the vertical direction. The flow channels of two adjacent corrugated sheets are 90 degrees, and the upper and lower plates of corrugated packing are rotated 90 degrees and stacked. In the tower with a smaller diameter connected by flanges, the corrugated packing is made into a whole disc with a diameter slightly smaller than the inner diameter of the tower. In the tower with a larger diameter, each plate of corrugated packing is divided into several pieces, put into the tower through the manhole, and assembled into complete discs in the tower. The corrugated sheets of the upper and lower plates of packing are rotated 90 degrees to install, so that the fluid is fully mixed in the tower. It has the characteristics of thin wall, large porosity, large flux, light weight, small resistance, small gas phase passage inclination angle, regularity, sufficient gas contact, good separation effect, high efficiency, and low pressure drop.

The application of wire mesh corrugated packing:
Metal mesh corrugated packing (stainless steel corrugated packing) is a highly efficient packing widely used in countries around the world, especially suitable for vacuum distillation towers. It is mainly used in petrochemical industry, fertilizer industry, natural gas purification, smelting, etc. Such as coal chemical industry (benzene washing tower for recovering crude benzene in coking plant), ethylbenzene separation, high-purity oxygen preparation, propylene oxide separation, debutanizer, cyclohexane recovery, gasoline fractionation, atmospheric and vacuum refining, etc. It is used as a packing in a three-phase separator or two-phase separator in the process of crude oil degassing and dehydration. It is especially suitable for treating heat-sensitive, easy to decompose, easy to polymerize, and easy to carbonize materials.

Metal mesh corrugated packing is composed of vertically arranged corrugated wire mesh strips to form a disc-shaped regular packing. The height of each packing is 40-300mm, and the inclination angle of the corrugation direction to the tower axis is 30° or 45%. The adjacent two corrugations are in opposite directions. The diameter of the packing plate is a few millimeters smaller than the tower diameter, depending on the tower diameter. The packing plate accurately fills the tower section. Each packing plate can have a flange on the outer hoop to prevent wall flow, and the two adjacent plates above and below are rotated 90° for packing. For small tower diameters, the packing is filled in a whole plate. For large towers with a diameter of more than 1.5m or towers without flange structures, the packing can be loaded into the tower from the manhole in the form of blocks and then assembled. The main materials used to make wire mesh corrugated packing are stainless steel, copper, aluminum, iron, nickel, etc.

The mass transfer performance of metal wire mesh corrugated packing is directly determined by the specific surface area of the packing. According to the specific surface area, the metal wire mesh packing can be divided into 250 type, 500 type, and 700 type. Since the metal wire mesh packing belongs to the liquid film mass transfer type, holes are opened on the corrugated packing sheet or double-layer wire mesh packing is made to strengthen the uniform distribution of liquid on the wire mesh corrugated sheet. Especially at low spray density, whether the liquid can be evenly distributed on the wire mesh sheet to form a film is the key to maintaining high separation efficiency.

There are small holes on the metal wire mesh corrugated sheet to strengthen the uniform distribution of liquid and liquid film renewal, reduce dead corners in the packing (especially in small towers), and improve separation efficiency. In order to enhance the lateral mixing of gas and liquid, the diameter of the small holes on the corrugated sheet should be 4-5mm.

In view of the geometric structure of the wire mesh corrugated packing, the following characteristics are formed:
1. Large specific surface area, high porosity, light weight. The specific surface area of 500 type packing is equivalent to 4.5 times that of Dg50mm metal ball ring (ball ring specific surface area 110m2/m3, density 80kg/m3), while the density is only 40% of the ball ring. The porosity is high, and the wire mesh has a strong capillary effect, which makes it have excellent wetting performance. Even if the spray density is 0.2m3/(m2?h), it can achieve complete wetting, so the packing efficiency is high.
2. The gas phase passage has a small inclination angle, a regular gas phase passage, less pressure loss, and low packing pressure drop.
3. Good radial diffusion and sufficient gas-liquid contact.
4. Avoid clogging, corrosion, and difficulty in cleaning, and can only be cleaned by chemical methods.
5. The unit volume packing has a high cost, which limits its scope of use.