With increasing pressure to conform to the 2020 Air Quality Act, industrial equipment supplier Heaton Valves Africa have introduced Zeeco Combustion equipment’s GB single-jet burner into the Southern African Market in order to minimise oxides of nitrogen (NOx) emissions.
During fuel combustion, nitrogen and oxygen atoms combine to create nitric oxide (NO). This further combines with oxygen to create nitrogen dioxide (NO2). Together, NO and NO2 are referred to as NOx.
Heaton’s product manager Grant Douglas explains that, according to the Act, combustion installations will have new targets to meet for example. Furnaces with a design capacity equal to or greater than 50 MW heat input for new plants must amount to 400 mg/Nm3 under normal conditions of 10% O2 and 1 700 mg/Nm3 under normal conditions of 10% O2 for existing plants. In a South African context, replacing all furnaces to conventional ultra-low NOx burners will be too expensive to achieve.
Therefore, Heaton Valves Africa’s GB single-jet low NOx gas-fired burner is designed by combustion systems manufacturers Zeeco. The burner unit reduces NOx emissions through its internal flue gas recirculation, which mixes gas fired from the gas port with the products of combustion, which lowers thermal NOx production. It comprises staged fuel and staged air.
The unit is easily retrofitted, with slotted holes used for adjustments, enabling the burner retrofit kit to be installed with the existing burner tile and wind box in place. Besides ultra-low NOx emissions, the burners also includes low maintenance and a simple design.
“By implementing the low NOx burner technology, we are ‘futureproofing’ the furnaces by ensuring that less NOx is emitted, in line with current and future emissions stipulations. A 50 MW unit would consist of about four burners, which means that the unit needs to be at 400 mg/Nm3. With our NOx burner technology, the units will be at 120 mg/Nm3, which is a big difference.”
Douglas explains that, “the Zeeco GB single jet burner's non-symmetrical design uses internal flue gas recirculation and staged air to achieve NOx emissions reduction in one simple burner design with only one fuel gas tip and/or one fuel gas riser.”
When it comes to unique burner technology, staged fuel is a priority because it ensures that NOx emissions are reduced from combustion. Staged air and staged fuel, both involved in the staged combustion process, can reduce NOx emissions by up to 75%.
He mentions that Zeeco’s low NOx burner units were developed in 2014 and have been on the market since 2015. However, staged fueling and low NOx burner technology is not a new concept – it has been around since 1986. “Global pressure and air-quality standards have resulted in low NOx burner technology becoming increasingly sustainable,” he adds.
Douglas adds that the company aims to inspect combustion units to assess how the company could implement more efficient and cost-effective technology such as that used in a GB single fuel jet burner.