Selective Catalytic Reduction Dosing Systems
The purpose of the dosing system is to inject the correct quantity of a reductant into the flue gas, depending on the amount of NOx present and the flue gas temperature.
The reductant is normally based on ammonia and may be ammonia gas, ammonia solution or urea solution. Where the reductant is in liquid form it is normally injected at high pressure through a nozzle so that it turns into a fine mist. The pressure for this may be provided by a powerful electric pump or by compressed air.
The dosing system needs to incorporate various sensors so that the reductant quantity can be accurately metered, and also a control panel so that it can be set up and maintained. The control panel also needs to allow various diagnostic functions which may include a log of the NOx levels before and after the SCR catalyst. Remote connection to the control panel via telemetry is often a useful feature.
Whitebeam can design and supply reductant dosing systems for a wide range of SCR applications.