A small porous-plug burner for studies of combustion chemistry and soot formation

Abstract

We have developed and built a small porous-plug burner based on the original McKenna burner design. The new burner generates a laminar premixed flat flame for use in studies of combustion chemistry and soot formation. The size is particularly relevant for space-constrained, synchrotron-based X-ray diagnostics. In this paper, we present details of the design, construction, operation, and supporting infrastructure for this burner, including engineering attributes that enable its small size. We also present data for charactering the flames produced by this burner. These data include temperature profiles for three premixed sooting ethylene/air flames (equivalence ratios of 1.5, 1.8, and 2.1); temperatures were recorded using direct one-dimensional coherent Raman imaging. We include calculated temperature profiles, and, for one of these ethylene/air flames, we show the carbon and hydrogen content of heavy hydrocarbon species measured using an aerosol mass spectrometer coupled with vacuum ultraviolet photoionization (VUV-AMS) and soot-volume-fraction measurements obtained using laser-induced incandescence. In addition, we provide calculated mole-fraction profiles of selected gas-phase species and characteristic profiles for seven mass peaks from AMS measurements. Using these experimental and calculated results, we discuss the differences between standard McKenna burners and the new miniature porous-plug burner introduced here.

The Identity and Chemistry of C7H7 Radicals Observed during Soot Formation

“…Temperature profiles for premixed flames as a function of HAB. (a) Simulated profiles are compared with experimental measurements of temperature for an ethylene flame with the stabilization plate at 13.6 mm above the burner surface . (b) Simulated temperature profiles from the LLNL mechanism are compared with those from the Jin–Farooq mechanism for the butane, methane, and ethylene flames with the stabilization plate at 21 mm above the burner.…”

“…The premixed flames were generated at atmospheric pressure by a porous-plug burner, also known as a “mini-McKenna burner”, described previously . A mixture of fuel and oxygen flows through a 38.1 mm sintered-brass plug, and an inert shroud gas flows through a sintered-brass ring surrounding the central plug.…”

“…The premixed flames were generated at atmospheric pressure by a porous-plug burner, also known as a "mini-McKenna burner", described previously. 80 A mixture of fuel and oxygen flows through a 38.1 mm sintered-brass plug, and an inert shroud gas flows through a sintered-brass ring surrounding the central plug. The flames were stabilized with a water-cooled stainless-steel cylinder with a diameter of 38.1 mm, mounted 21 mm above the burner surface, and maintained at a temperature of approximately 60 °C.…”