10. 7. 2023
Separation of iron particles from coal dust in a thermal power plant (case study)
Initial status
Despite the rapid transition to renewable sources in the energy sector, affordable fossil fuels (such as brown coal dust) are still widely used even in the Western European energy sector. However, this input material is often contaminated with iron objects (e. g., broken pieces of mining or processing machinery), which can damage the expensive technological equipment of power plants. Therefore, it is necessary to remove ferromagnetic particles from the coal dust. However, the high explosiveness of coal dust complicates the removal of the tramp ferrous material, making it necessary to use equipment approved for application in explosive atmospheres (according to the ATEX directive).
Problem
Our client, the German energy company RWE, was using an older type of magnetic drum in one of their brown coal power plants. However, this drum no longer complied with the updated regulations of the Mining Authority for equipment used in potentially explosive atmospheres. Besides, the drum was not only constructed with ferrite magnets, but also significantly obsolete and worn out, and that is why no longer able to protect in a reliable way the subsequent technological equipment.
Solution
On the processing line in this particular brown coal power plant, the dried lignite is transported vertically by a conveyor and afterwards it falls into a crusher. The pulverized coal dust is then conveyed by a trough chain conveyor for further processing (and in the end, the crushed coal dust is injected into the boiler for combustion). To protect the valuable grinding equipment, we installed our extremely powerful neodymium drum MBZ 304 N 1000 in front of the mill (certified for use in the most hazardous Zone 20, according to the ATEX 99/92/EC Directive).
Benefits of our solution for the client
The new magnetic separator enabled the client to meet the authorities' requirements for the safe operation of the magnetic separation system in a highly explosive environment. Another positive effect is that the new magnetic separator not only performs much better than the original separator (it can separate ferrous particles from 0,5 mm), but it is also significantly more efficient (in total it captures much more ferrous particles and provides a higher level of protection for the subsequent processing equipment).
Applied equipment MBZ 304 N 1000