While this year marks Fives FCB’s 80th anniversary in the cement industry, the company also has 35 years of precalcining experience. Its latest precalciner with combustion chamber, the ‘Zero-NOx precalciner’, incorporates a design with direct flows which minimises NOx emissions while allowing the use of a wide range of fuels, from gas or fuel oil to anthracite or alternative solid fuels (ASF). In this article, Fives FCB shares some case studies of projects undertaken at different cement plants across the world, namely three Holcim cement facilities in Mexico, Costa Rica and Brazil, as well as results from Vietnam and Qatar. By S Jorget, Fives FCB, France.
The FCB Zero-NOx precalciner has been designed as an efficient burning system. With its multichannel Fives PILLARD burner and direct flow configuration, it allows stable fuel ignition and the creation of a centred flame.
In addition, the burner has a hub with a large central tube for alternative fuels feed. These features, combined with the vertical position of the burner, are ideal for the use of coarse alternative fuels (Figure 1). Solid fuels can be fed through the burner by simple gravity and are ignited when arriving into the hot core of the flame. As a result, they achieve a high combustion rate before leaving the combustion chamber.
