Dry Ice Blasting for Cleaning Selective Catalytic Reduction (SCR) Systems
Attached to equipment that includes gas turbines and boilers, selective catalytic reduction (SCR) systems can significantly reduce the amount of toxic nitrogen oxide (NOx) created by power plants – removing 90% to 100% of NOx emissions at peak capacity.
But such efficacy depends on diligent maintenance and cleaning processes – a task made challenging by the intricate composition of the units.
A handful of cleaning options exist, but most are slow and leave some mess behind. One solution, however, leaves SCR units thoroughly clean – and can do so in record time: dry ice blasting.
The Mess: Honeycombs Packed with Ash
SCR systems are large, multi-level, multi-chamber units composed of waffle or honeycomb shaped compartments filled with a catalyst. Flue gas passes through the system’s reactor, is funneled through an ammonia chamber, and is finally forced into the honeycomb compartments.
Those compartments get plugged with fly ash – the toxic byproduct of combusted coal that settles into the small crevices and hardens.
Improperly cleaned, the plugged chambers act like a dirty air filter and SCRs cannot process NOx emissions thoroughly.
Options for Cleaning SCR Technology
Keeping SCR systems clean is no small feat. The layers of the unit must first be unpacked so the technician can access all of the plugged honeycomb components. The fly ash caked into them is hard and difficult to extract, but the units must be handled delicately.
Abrasive cleaning methods are powerful, but they leave behind debris and pose a risk of damage to the SCR. Vacuum and manual cleaning are safe but laborious and time consuming. Neither are recommended for SCR cleaning.
Sponge blasting uses tiny bits of synthetic sponge soaked with abrasive media and is more effective when used by highly trained technicians. The method creates 90% less dust than other abrasive blasting methods.
However, sponge blasting has drawbacks: the method introduces foreign material, so some amount of vacuum and hand cleaning are still required.
Dry Ice Blasting SCR Units
The method best suited for SCR technology cleaning is dry ice blasting, which uses tiny pellets of frozen CO2 to blast away grime and cleans more quickly and effectively than vacuuming, hand cleaning, and sponge blasting.
Because dry ice sublimates on contact, no foreign material is introduced, and no secondary cleanup is required. That makes the method faster and safer than other options.
Best yet: the powerful blast of a dry ice machine can reach even the tiniest corners of plugged honeycombs, resulting in being almost clean as new.
Additional benefits of dry ice blasting include:
- Safe to use around electrical equipment
- Chemical-free and water-free
- Reduced exposure to hazardous cleaning chemicals for enhanced worker safety
- Reduced water and sanitation costs
- Non-flammable and non-conductive
Partner with Polar Clean for Squeaky Clean Power Plant Equipment
Since being founded in 2011, Polar Clean has cleaned up some of the toughest messes at power plants. Because dry ice blasting works without water and introduces no foreign material, it is the preferred solution for power plant applications, from turbines to heat recovery steam generator (HRSG) tubes.
To learn more about dry ice cleaning for SCR systems and the method’s other applications at power plants, contact our team for an assessment.