Wet scrubbing techniques are designed to collect dust particles by imposing forces onto the water droplets which then collide with or come to contact with the dust or polluted gas. This is a device handling harmful gas and dust at the same time.
A device designed to filter out dust particles from the exhaust gas and cleaning out the collected dust.
As techniques to remove sulfur oxides (SOx) from the exhaust gas, there are wet, dry and semi-dry desulfurization processes. In the wet desulfurization, lime and limestone slurries are injected into a reaction tower for sulfur oxides collection, and the lime sludge produced in the course of this process is collected as a form of plaster (CaSO4). In the semi-dry desulfurization, the limestone slurries are sprayed into the reaction tower from the top. In this process, sulfur oxides are absorbed and dried; then they are removed via the bag filter placed in the post treatment process.
As techniques to remove nitrogenous compounds (NOx) from the exhaust gas, there are selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). In SCR, a reducing agent (NH3) is injected with various catalysts (V2O5, TiO2, etc.) to turn nitrogenous compounds into harmless nitrogen and water. In SNCR, a reducing agent is injected directly into the exhaust gas at high temperature to reduce the concentration of the nitrogenous compounds.