Modern technical solutions for new and reconstructed sinter plants. Report 3. Charge the mix onto sinter machines

The technological operations and equipment for charging a sinter bed and mix onto sintering machines have been analyzed in their historical development from the mid-20th century to the present. Modern requirements for the technology and components of the mix charging unit have been reviewed, refined, and expanded. It is confirmed that the system of equipment for charging concentrate-based mixes at Russian sintering plants is rational. For such mixes, installing a mix bin in front of sintering machines instead of a loading hopper into which the mix is fed from a pelletizing drum located at ground level (as at AF-5 MMK) is unacceptable. Pelletizing drums must be installed in the sintering chamber upstream of the loading hopper. For new sintering machines, a shuttle-type mix distributor perpen-dicular to the loading hopper is recommended. It is demonstrated that the use of a 10–20 mm sinter fraction bed (up to 50 mm thick) at AF-5 MMK increases the free area of the grate by 20% (gap between bars increased from 2.5 to 3.0 mm) and enables the effective use of heavy-duty grate bars. The mix charging unit should also include a mix flow stabilizer, with the drum feeder’s rotational speed maximized to the point just before mix slippage occurs. The working length of the loading chute should be ~1200 mm, with an adjustable inclination angle of 55–60°, and its lower edge positioned above the bed surface. Studies indicate that the nine-roller mix distributor installed on AF-5 MMK sintering machines achieves separation efficiency by size and carbon content comparable to a two-layer charging system, without enlarging the sintering machine’s footprint or complicating the process flow sheet. The mix bed profile on the sintering strand (and thus on the drum feeder) must ensure uniform advancement of the fuel combustion zone toward the protective bed layer across the entire width of the sintering machine.