Division 1.7.1 Dust emissions
United Kingdom
| Measure/Technique | Description | |
|---|---|---|
| a | Electrostatic precipitators (ESPs) | A general description of ESPs is provided in Section 1.5.1 |
| b | Fabric filters | A general description of fabric filters is provided in Section 1.5.1 Fabric filters receive high particle retention, typically over 98 % and up to 99 % depending on the particle size. This technique offers the best efficiency on particle collection in comparison to other dust abatement measures/techniques used in the magnesia industry. However, because of the high temperatures of the kiln flue-gases, special filter materials which can tolerate high temperatures have to be used. In DBM manufacturing, filter materials operating with temperatures of up to 250 °C are used, such as PTFE (Teflon) filter material. This filter material shows good resistance to acids or alkalis and a lot of corrosion problems have been solved |
| c | Cyclones (centrifugal separator) | A general description of cyclones is provided in Section 1.6.1. They are robust equipment and they have a wide operational temperature range with a low energy requirement. Because of the system-dependent limited degree of separation, cyclones are mainly used as preliminary separators for coarse dust and flue-gases |
| d | Wet dust separators | General description of wet dust separators (also called wet scrubbers) is provided in Section 1.6.1 Wet dust separators can be divided into various types according to their design and working principles, such as the venturi type. This type of wet dust separator has a number of applications in the magnesia industry, including when gas is directed through the narrowest section of the venturi tube, the ‘venturi neck’, and gas velocities of between 60 and 120 m/s can be achieved. The washing fluids which are fed into the venturi tube neck are diffused into a mist of very fine droplets and are intensively mixed with the gas. The particles separated onto the water droplets become heavier and can be readily drawn off using a drop separator installed in this venturi wet dust separator |