A TEC has installed an alternative fuel system for kiln riser duct firing at CRH's Turna Nad Bodvou cement plant in Slovakia.
The cement plant already operated a solid alternative fuel (SAF) system for the main burner, which consists mainly of a double truck-docking station and a dosing system.
The riser duct itself has a gas residence time of approximately three seconds, so a thermal substitution rate of up to 25 per cent at the riser duct is possible by limiting the material to a maximum size of 50mm (2D). The SAF is now injected above the bypass take-off point (in the location of the current meal inlet).
To limit CO emissions, a hot ignition zone has been created at the SAF injection. This was realised by moving the existing meal inlets to the riser duct of about 8-10m.
As the kiln is equipped with an extended kiln riser duct (without tertiary air) it is possible to fire a significant amount of fuel in this kiln riser duct. Now about 20 per cent of the total fuel as SAF with main burner quality can be fired.
