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Demister

Demister

The principle of wire-mesh demister

The diameter of the separated drops in the gas which comes out in the ordinary chemical industry operation is about 0.1~5000μm. The separation of drops which have the diameter of above 100μm can be solved easily, for the sedimentation speed of such drops is relatively high. The drops which have the diameter above 50μm can be separated by gravitational settling method, the ones which have the diameter above 5μm can be separated by inertial impaction and centrifuge method; the smaller ones should be congregated to become lager, or be separated by using fiber filter and static demister.

wire-mesh demister(or mist eliminator)is mainly used to separate drops of the diameter between 3μm to 5μm, the operating principle is showed in the fig at the right side. When the gas with liquid drops rises at a certain speed, passing through the wire mesh on the grid bar, the inertia of the rising drops make them collide with the wire and then adhere to the surface of the wire. The drops on the wire will diffuse and subside. It makes the drops form bigger ones and then flow along the wire to the intertexture of the wire. Because the wire can be humidified, and because of the surface tension of liquid and the capillarity effect of the wire, the drops will become bigger and bigger. They will be separated and fall when their own weight exceed the resultant force of buoyancy of the rising gas and surface tension of liquid. They will flow to the device of the container in the backward position. As long as the speed of the gas is properly controlled and with other proper condition, the efficiency of foam remove will be as high as 97% after the gas pass through wire-mesh demister. The purpose of removing foam will be achieved completely.


The characteristic of wire-mesh demister

  • Structure simple, weight light.
  • High factor of porosity, low head loss.
  • Great contact surface area, high removing foam ratio.
  • Convenience of installing, operating and repairing.
  • Long service life.

China standard of wire-mesh demister

⒈ HG5-1404(1405、1406)-81

The new standard units includes three installing modalities: ascension pipe type, reduction diameter type and full diameter type. The diameters of the wire mash demisters are ranging from about 300mm to 6400mm, and the height of the wire-mesh has two alternates: 100mm or 150mm. Only type number and required material are requested when ordering.

standard number demonstration: HG5-1406-81-11, 304/304

it expresses wire-mesh demister: both the grille and the wire-mesh are used stainless 304,full diameter type and up-stalling,diameter is 1600mm,height is 100mm.

⒉ HG/T21618-1998

The new standard unites the three installing modalities of ascension pipe type, reduction diameter type and full diameter type, puts forward four types of meshwork, namely SP、HP、DP and HR, expands the variety of the material to be used . It increases more types in size.

standard number demonstration:HG/T21618 wire-mesh demister S1600-100 SP 304/304

it express wire-mesh demister: both the grille and the wire-mesh are used stainless 304, up-stalling,diameter is 1600mm,height is 100mm,and the mesh type is SP.

3. HG/T21586-98 (drawer wire-mesh demister)

This standard is mainly applied in the situation in which the components of demister need clean and replace frequently. For example, the drying tower and the absorbing tower of vitriol devices. There are totally 56 types of general diameters to choose, ranging from DN300mm to DN5000mm. Only type number and material are requested when ordering. (Among these, 316L, NS-80 as well as RS-2 are materials for mesh on vitriol devices.

standard number demonstration:HG/T21586.11-98 WME-1600-100 NS-80/Q235-A

it represents drawer wire-mesh demister: Material of the wire-mesh is NS-80, grille is carbon steel bar of which diameter is 1600mm, height is 100mm.


Other non-standard wire-mesh demister

Our company can also make a great variety of special shape wire-mesh demisters according to the clients' requirement, such as wave type, embedding type, outside-loaded type, SWD1 type, square type, rectangle type and abnormal type, etc. The height and interval of the wire-mesh demister can be altered according to the clients' demand.

Our factory will provide charts of bearing hardware and the installation charts of wire-mesh demisters to every client who choose china standard.


Material of Wire-mesh demister

Wire-mesh demisters produced in our company have three kinds according to material: metal, nonmetal and metal knitting with nonmetal.
材质
国标代号 国外代号 标准号
Q235-A Q235-A GB343
20 20 GB3206
0Cr19Ni9 304 GB4240
00Cr19Ni11 304L
0Cr17Ni12Mo2 316
0Cr17Ni14Mo2 316L
0Cr19Ni10Ti 321
0Cr19Ni13Mo3 317
0Cr25Ni20 310
1Cr25Ni20Si2 310S
00Cr20Ni25Mo4.5Cu(N08904) 904L
0Cr23Ni13 309S
NS-80(1Cr18Ni11Si4AlTi) 厂商代号
RS-2
黄铜丝 H68、H65、H62 GB3110
锡青铜 Qsn GB3128
镍丝 N4、N6、N7、N8 GB3120
钛丝及钛合金丝 TA2、TA3、TC3、TC4 GB3623
聚氯乙烯 PVC
聚乙烯 PE
聚丙烯/丙纶 PP
聚四氟乙烯(F4) PTFE
四氟乙烯与六氟丙烯共聚物(F46) PE
其他氟材料系列 PFA、ETFE、PVCF etc.
哈氏合金(20合金) Hastelloy alloy
因科镍 Inconel
蒙乃尔 (蒙耐尔) Monel
四氟乙烯与六氟丙烯共聚物(F46) PE
金属与玻璃纤维(无、中碱线)交/混织 S.S & Fiberglas.
金属与非金属丝交/混织 S.S & PP.PVC.F46.etc.

Unit demonstration