In certain parts of the world, bulk material storages operate under extreme and cold climatic conditions. This can create challenges in reclaiming the necessary capacities or lump sizes from pre-stacked piles that have been exposed to freezing over longer periods of time.
The time it takes for a pile front to freeze up naturally depends on a number of factors; for example the lump size distribution and moisture content of the material and the weather conditions at the given site.
As a rule of thumb the frost crust on the pile front grows between 5-10 cm every 24 hours until it reaches a depth of approximately 60 cm. If piles are exposed to frost and no reclaiming takes place for some time, challenges may arise in terms of insufficient capacity or oversized lumps, which can cause problems downstream along the production line.
Pile front seen from the top.
Maximising availability in cold climate
Workers covering the hoses with the insulation blanket.
To cope with these challenges, different measures can be taken. FLSmidth has introduced a simple thawing system for its bucket excavator storage to avoid the cost-intensive solution of insulating and heating the entire storage building. Anti-freezing liquid is heated by a heat station and pumped through rubber hoses covering the pile front. The rubber hoses are placed as a curtain on top of the pile front(s) by means of retainers that keep the hoses in place during installation and operation. An insulating blanket is placed on top of the hoses while operating the storage to reduce heat loss to the atmosphere.
The system is intended for planned production stops to ensure smooth and reliable start-up, but can also be used when unexpected shutdowns occur.
About the Author
Anders.Olsen@FLSmidth.comMore Content by Anders Olsen