Flame burner experiments measuring

The present work involves measurement of k in a 0.1 atmosphere, stoichiometric CH -Air flame. All experiments were conducted using 3 inch diameter water-cooled sintered copper burners. Data obtained in our study include (a) temperature profiles obtained by coated miniature thermocouples calibrated by sodium line reversal, (b) NO and composition profiles obtained using molecular beam sampling mass spectrometry and microprobe sampling with chemiluminescent analysis and (c) OH profiles obtained by absorption spectroscopy using an OH resonance lamp. Several flame studies (4) have demonstrated the applicability of partial equilibrium in the post reaction zone of low pressure flames and therefore the (OH) profile can be used to obtain the (0) profile with high accuracy. 

Among other new methods, tunable laser absorption spectroscopy using infrared diode lasers offers prospects for improved accuracy and specificity in concentration measurements, when a line-of-sight technique is appropriate. The present paper discusses diode laser techniques as applied to a flat flame burner and to a room temperature absorption cell. The cell experiments are used to determine the absorption band strength which is needed to properly interpret high temperature experiments. Preliminary results are reported for CO concentration measurements in a flame, the fundamental band strength of CO at STP, collision halfwidths of CO under flame conditions, and the temperature dependence of CO and NO collision halfwidths in combustion gases. 

Experiments are currently in progress to measure CO and NO concentrations in a flat flame burner by diode laser spectroscopy. Comparative measurements are also being made using microprobe sampling with subsequent analysis by non-dispersive infrared and chemiluminescent techniques. Some preliminary laser absorption results for CO are reported here initial results for NO have been published separately (4). Also reported are initial data for collision halfwidths in combustion gases. 

The numerical model for n-butane oxidation, by Pitz et al. [228], was used also by Carlier et al. [21] to simulate experimental studies of the two-stage combustion of n-butane at 0.18 MPa on a flat-flame burner and, following this validation, to simulate the ignition delays of n-butane in a rapid compression machine. The numerical studies of the burner experiments were extended by Corre et al. [233]. For simulations of the behaviour on a flat-flame burner the chemical model was computed in an isothermal mode, the experimental one-dimensional temperature profile being introduced as an input parameter. Among the important aims of the tests by Corre et al. [233] was the rationalization of the predicted extent of n-butane consumption throughout the development of the first (cool-flame) and second stages of combustion, with that observed experimentally. The experimental study by Minetti et al. [22, 116] included the detection and measurement of RO2 and HO2 radicals by esr, the one-dimensional spatial profiles of which were simulated by Corre et al. [233],... 

It is impossible, however, from a mere inspection oi the flame produced by these burners, without accurately measuring the amount of gas consumed by each, to arrive at any conclusion as to which form is the most economical or generally desirable. TJntil, as Richardson and Ronalds justly remark, impartial comparative experiments have been instituted with them all, decldod preforenco cannot be awarded to any one in particular. 

The following results were obtained from an experiment carried out to measure the enthalpy of combustion (heat of combustion) of ethanol. The experiment involved heating a known volume of water with the flame from an ethanol burner. 

The burner of Case 1 uses a swirled injector (Fig. 9.1) where swirl is produced by tangential injection downstream of a plenum. A central hub contributes to flame stabilization. In the experiment methane is injected through holes located in the swirler but mixing is fast so that perfect premixing is assumed for computations. Experiments include LDV (Laser Doppler Velocimetry) measurements for the cold flow as well as a study of various combustion regimes. The dimensions of the combustion chamber are 86 mm X 86 mm x 110 mm. 

Figure 6- Measured time profiles of pressure, gas temperature, relative humidity with respect to ice, back-scattered laser light intensity, as well as ice particle number concentration for two expansion cooling experiments with different flame soot aerosol samples from the CAST burner as seed aerosol (Mdhler et al, 2004b). See text for details.

One of the key issues in the porous media burner is where flame stabilization occurs. Numerical modeling, backed up by atmospheric pressure laboratory experiments, suggests that when stabilization is obtained at the interface between the media, operating flexibility and heat release is optimal. The numerical model results from the University of Texas (Prof. J. L. Ellzey) have been used to guide the positioning of thermocouples in the HP rig wall that will measure the rapid temperature rise adjacent to the interface, both axially and circumferentially. This is an important issue in the excess enthalpy concept on which this type... 

Directions Perform this experiment in the hood. Measure out into an evaporating dish 8 c.c. of water and add to it 10 c.c. of concentrated sulphuric acid. (Do not add the water to the acid.) While the solution is cooling set up an apparatus like the one for the preparation of chlorine, Experiment 21. Put 10 grams of sodium chloride into the test tube and pour the acid down the thistle tube. When the salt has become thoroughly moistened with the acid, heat the test tube with a low flame, holding the burner in your hand. To determine when the bottle has been filled, hold a piece of wet blue litmus paper at its mouth. Do not consider the bottle full when the first test is obtained but continue generating the gas until it overflows in some quantity. Collect four bottles full and cover them with glass plates. 

Three of the burner settings were varied in the experiments air distribution between primary and secondary ducts (air ratio, AR, expressed as frachon of secondary air over the total air flow rate) and the swirl numbers of both air streams (SI and S2, respectively both reported here as a percentage with respect to maximum swirl level). Detailed in-flame measurements revealed significant changes in the distribution of species and temperatures inside the flame when AR, SI, or S2 were varied... 

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