Power Plant Silo Management

Power plants use silos for multiple material types throughout the production chain. Coal silos store fuel before crushing and pulverisation. Biomass silos handle wood chips, pellets or straw. Ash silos collect residual ash from combustion. Each material type presents unique challenges. Coal is self-igniting and explosive as dust. Biomass is hygroscopic and biologically active. Fly ash is very fine-grained and cohesive.

Self-ignition in coal and biomass silos is a serious and persistent risk. Biological decomposition in biomass and oxidation in coal generate heat. If heat is not dissipated quickly enough, temperature can rise to ignition point. CO monitoring is the most important detection method. Prevention includes limited storage time, good ventilation, temperature monitoring and regular stock rotation.

Fly ash is one of the most problematic materials for silo storage. Particle size is typically 1-100 micrometres, and the material is extremely cohesive. Fly ash absorbs moisture easily and can harden into concrete-like masses. Bridging is the most common problem in ash silos. Fluidisation is a common flow aid technique but requires dry air to function optimally.

Biomass such as wood chips, pellets and straw presents unique silo challenges. The material irregular shape creates bridges more easily than spherical particles. Wood swells with moisture uptake, increasing wall friction. Biological activity in moist biomass can generate significant heat. Mould and fungal growth reduces energy content.

Cleaning of silos in power plants requires special expertise due to the unique risks: explosive dust, self-igniting material and potentially toxic gases. Mechanical cleaning is the preferred method for ash silos with hardened deposits. Powerful rotating tools can break loose even concrete-hard ash deposits without anyone needing to enter the silo.

Blue Power has extensive experience cleaning silos for power plants and combustion facilities throughout Scandinavia. We understand the special safety requirements and have equipment sized for the most difficult materials. Contact us for an assessment of your cleaning needs.