A multi-burner flameless oxidation furnace equipped with regenerative FLOX(TM) burners. This rig consists of three pairs of regenerative FLOX(TM) burners, each with a rated thermal power of 100 kWth, thus 300 kWth in total. The burners were manufactured by WS Wärmeprozesstechnik GmbH. They are of the REGEMAT CD 200 B type. Each burner has four combustion air/flue gas nozzles
(ϕ=20 mm) around a central fuel nozzle (ϕ=12 mm). The furnace has inner dimensions of 1500 x 1500 x 1850 mm (length x width x height) and is optically accessible. The insulation consists of three layers of ceramic bricks, together 300 mm thick. During the experiments the temperature in the furnace is measured at various locations with S-type thermocouples. Also, the temperature of the preheated air is measured in two burners (one burner pair). The fuel and combustion air flowrates are measured by orifice plate differential pressure meters. The combustion air flowrate is controlled by a manual valve, allowing the variation of the excess air ratio. Eighty percent of the flue gas is sucked by a induction fan via the air nozzles over these honeycombs for regeneration of the heat, while the remaining twenty percent leaves the furnace via the central stack at the roof.
During regeneration the sucked flue gas traverses ceramic honeycomb heat exchangers situated inside the burners. The inlet temperature is around 950oC and the outlet temperature is approximately 150 oC, under steady state conditions. Thermal load is simulated by a cooling system which consists of eight single ended concentric tubes, four placed at the bottom of the furnace and four at the top. Air enters the inner tube, turns at the end and flows back through the outer tube. This design was made to minimize the temperature gradients along the length of the outer tube, thus, creating an as uniform as possible heat extraction distribution.
The furnace is equipped with standard on-line analysers (CO, NO, CO2,O2) and FTIR with heated gas cell can also be used for gas quantification. Non-intrusive velocimetry is also available for this furnace: PIV (particle image velocimetry) for local flow characterization in specific burner area’s. Along with the measurements modeling activities are ongoing using Fluent(TM) and Numeca software (CFD).