The use of air staging as a technique for reducing NOX emissions from process industry burners has been employed for many years but lower levels of NOX and high thermal efficiencies can be achieved using a partial premixed combustion mode. The development of partial premixed burners has only gradually increased because of the increased risk of flash back and the difficulties of control. The current study presents both an experimental and a numerical investigation on a laboratory-scale counter-flow combustion system of the partial premixed mode. The system aims to duplicate the mixing process observed within an industrial burner, which produces a double flame structure. Results have shown that the nozzle configuration has a direct influence on NOX emissions.