Standard Wire Mesh Demister Pad, 304 wire mesh demister pad
What is a Demister?
DEMISTERs are essential in many process operations for the removal of
entrained material in vapour flow. Demister ASIA’s Demisters and mist eliminators provide a wide range of
solutions suitable for any application.
The principle of a Demister operation is based on having a large number of obstacles
intercepting entrained droplets in a vapour flow. These obstacles
must provide minimum drop in pressure over the removal system.
How a Demister Works:
Mist eliminators/ Demisters are fabricated from knitted materials
with interlocking asymmetrical loops of metal or plastic with
typical diameters of 0.1 – 0.3mm. By careful choice of wire
diameter, DemisterASIA has produced demisters with extremely high
free volumes (typically 98 – 99%) along with very high removal
efficiency and low pressure drop.
Along with wire diameter and mesh density, another important
parameter in design and operation of a demisters is the vapour
velocity. This can be controlled by careful selection of the
eliminator area. Optimal area will depend on operating temperature,
pressure and pressure drop. Under normal operating conditions more
than 99% removal efficiency can be achieved with a pressure drop of
less than 250 Pascals.
Different Types Of Demisters:
DEMISTERs can come in different forms and designs, a general guideline as
follows:
| Standard DEMISTER Types | Surface Area m²/m³ | Free Volume % | Density kg/m³ | Typical Applications |
| Type 1 | 1650 | 95 | 450 | Very high efficiency |
| Type 2 | 1300 | 95.5 | 350 | High efficiency |
| Type 3 | 600 | 97.5 | 195 | Very high efficiency & clean service |
| Type 4 | 400 | 97.5 | 195 | Heavy duty |
| Type 5 | 350 | 97.75 | 170 | Heavy duty |
| Type 6 | 300 | 98 | 145 | General purpose |
| Type 7 | 250 | 98.5 | 125 | High velocity |
| Type 8 | 200 | 98.75 | 100 | High velocity, dirty service |
| Type 9 | 200 | 98.75 | 100 | High velocity, clean service |
| Type 10 | 150 | 99 | 75 | Dirty service, least pressure drop |
| Type 11 | 445 | 98 | 145 | High efficiency, fine entrainment |
| Type 12 | 400 | 98.5 | 120 | Fine entrainment |
| Type 13 | 1200 | 93 | 600 | High efficiency, fine entrainment |
Stock Materials commonly used:
Stainless Steel: Grades 302, 304, 316, 316L, 321, 309, 310S
Super Alloys: Inconel 601, Incoloy DS, Hastaloy, Carpenter 20
Fibrous Filament: ‘E’ Glass, ‘S’ Glass, ‘A’ Glass, Basalt, Ceramic,
Silica, Kevlar
Others: Aluminium, Monel, Copper, and Brass, Mild Steel (plain and
galvanised), Polypropylene, Polyethylene
Why Demisters from DemisterASIA?
Elimination of DA demisters are dependent on droplet sizes:
5 – 9 micron 99%
> 10 micron 99.5%
Most of the weight of entrained mist tends to be associated with
the larger mist particles (larger than 5 – 10μm) thus providing
greater than 99.99% weight removal.
