FCT Combustion develops Turbu-Flex burner

The fundamentals are:

• Switching between different fuels can make it harder to manage quality
• Fuel savings can be lost with lower production
• It is difficult to maintain low rates of NOx emissions.

To address these challenges FCT Combustion developed the Turbu-Flex burner, which is based on the successful Turbu-Jet burner, a technology that has delivered exceptional value for many years across hundreds of global installations.

The new Turbu-Flex burner has the flexibility to fire both 100% conventional solid fuel and very high levels of varying AF, while maintaining production output, quality and low NOx emissions under all circumstances, to truly realize the value of fuel cost reduction. 

In short – realize the profitability of AF, without compromising on plant operations.

Features and benefits

• No moving parts in the burner or on the faceplate – to ensure trouble-free operation and ensure primary air injection is known precisely.
• AF Boost valve at the rear of the burner controls split to axial primary air for control of secondary air entrainment and flame temperature.
• Swirl valve is used to control the swirl number.
• Blower speed is used to control total primary air and, hence, burner impulse.

The new Turbu-Flex burner has demonstrated in the field its ability to optimize the profitability of alternative fuels, with lowest possible fuel costs and optimal kiln performance. The first deployment has been firing on very high levels of Refuse Derived Fuels (RDF) in a cement processing plant since August 2017 and delivering exceptional results.

Burner design based on proven and scientifically validated techniques.

FCT Combustion has been employing a variety of modeling techniques to develop burner designs since its inception in 1984. In particular, FCT Combustion uses Computational Fluid Dynamics (CFD) to compare the performance of different burner designs in rotary kilns. In order to develop the Turbu-Flex burner, they conducted an extensive CFD investigation that assessed the effect of the number, distribution and arrangement of axial and swirl primary air holes. These are the key design variables that control axial and swirl momentum and hence burner impulse, secondary air entrainment, mixing and flame shape.

This identified that grouping holes close together changes the secondary air entrainment and, hence, flame temperature and NOx. In particular, halving the number of axial air holes results in an ~7% increase in peak radiation and NOx and a further ~7% (peak radiation & NOx) when the holes are grouped together.

A burner with the flexibility for adjustment of axial air configuration can hence optimize combustion, depending on fuel and emissions requirements – i.e. a high number of axial holes can help suppress NOx formation, while a small number of holes grouped together is ideal for co-firing AF.

A world first. Effortlessly adapt to different fuels with one burner.

FCT Combustion’s solution is the Turbu-Flex burner in which the axial holes are in two groups, each with a separate air supply. With the turn of a single valve the burner changes from operating with many evenly distributed holes all at the same pressure to operating with a small number of holes grouped together and at high pressure. In other words, the burner changes from Standard mode to AF Boost mode of operation simply with a turn of a single valve.

The benefits to plant managers are clear – with the flexibility to effortlessly switch between fuels, the new Turbu-Flex burner ensures lowest fuel costs and highest kiln performance.

With the Turbu-Flex burner changes in fuel can be made easily and with certainty about the outcome – as expressed in fuel use, NOx and product quality – all from the one burner.

Author: Roger Hassold, General Manager, FCT Combustion APAC

Read the article online at: https://www.worldcement.com/special-reports/05042018/fct-combustion-develops-turbu-flex-burner/