Filtration device like an electrostatic precipitator is removes particles like dirt and smoke from gas. Because the name indicates, it uses the electrostatic charge to prevent the flow of gases. This allows the clean air to flow out of the electrostatic precipitator. Any gas that is generated after burning fuel pollutes the air much less after being processed through an electrostatic precipitator.
An electrostatic precipitator’s performance depends on its dust layer resistance and something called resistivity, which helps to determine how easily it removes the dust particles. Normal resistivity in an electrostatic precipitator works well in normal operating voltage and current levels and has high collection performance. What this means is that it collects dust sufficiently well.
Types of Electrostatic Precipitators
Electrostatic precipitators are mostly used for controlling industrial particulate emissions, and comply with pollution norms in various places, called pollutant emission standards. They also help in collecting particles necessary for other processes, like catalyst collection in oil refineries. They can also be used in consumer-settings, commonly sold as air purifiers. They can also act as replacements for furnace filters and are appropriate for removing many harmful forms of bacteria.
There are basically two types of electrostatic precipitators:
- Wet: These remove wet particles like oils, acids, resins, and tar. These are mostly independent of resistivity and work well in most voltage scenarios and current levels. They are best suited for situations where the potential for explosion is high. The collectors of the particles, or the electrodes, are sprayed with a liquid like water and the particles are collected from a sludge.
- Dry: These remove dry particles like dust, smoke, cement, and ash. The dust particles are later collected by hammering the electrodes. They are not as efficient as wet precipitators.
Irrespective of the type, both are usually corrosive in nature, and it is difficult to clean them. However, they can be used for extended periods easily, and do not have any issues with equipment reliability, since they have very high efficiency in normal circumstances. Under normal situations, the efficiency of dust particle removal can go as high as 99% of the particulate matter, which makes them a highly reliable choice for their purpose.
Advantages of Electrostatic Precipitator
Electrostatic Precipitators have several advantages which make them an attractive option, despite the fact that they are essential for bringing intact emissions from industrial settings:
- High Efficiency of Particulate Removal: As mentioned earlier, under usual settings, these devices have high removal of dust particles by up to 99%. They also have relatively high collection efficiencies (about 99-100%), and an extensive range of particle sizes (ranging from 0.05-5 μm), so they can capture a good range of particulates.
- Dry as well as Wet Particulate Collection: Both wet and dry precipitators can be used, depending on what kind of particulates are to be collected. Wet ESPs are used to remove particles that are not dry in the conventional sense. Therefore, the wide range of particulate types available for collection makes it useful.
- Low Operating Costs: The costs of operating an Electrostatic Precipitator are low, and in the long run scenario, they prove to be economically feasible also.
Regardless of the advantages, there is a need for such devices to improve manufacturing efficiency and allow government support to promote their installation. While they are commonly used in air conditioning systems, they are also found in thermal or steam plants, and chemical processing plants, where corrosiveness is a question mark. They are also used for recovery of valuable products such as oxides of copper and lead. They also help to clean blast furnace gases in thermal power plants.