CRH, Turna nad Bodvou (SK)
In 2017 A TEC has engineered an alternative fuel system for kiln riser duct firing in Slovakia. The Turna cement plant has already operated a 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 approx. 3 sec, so 20 % TSR at the riser duct are possible by limitation of the material to max. 50 mm (2D) size. The SAF is now injected above the bypass take-off point (in the location of the current meal inlet). To limit the 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 – 10 m.
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 % of the total fuel as SAF with main burner quality can be fired.
Additionally the current bypass system has been equipped with a cyclone where only the fine dust is extracted while the coarse dust is returned to the kiln inlet. To increase Cl extraction the dust outlet duct of the cyclone has been modified to a pneumatic transport to the clinker cooler vent air system or to the bypass dust silo.