The motion of a manifold of finely dispersed liquid droplets in the counterflow of high-temperature gases

Abstract.Regularities of physical and chemical processes occurring during the heating of the coal dust particles by low-temperature air flow are investigated by means of thermogravimetric analyzer TA SDT Q600 and experimental setup of optical diagnostics of multiphase flows based on PIV method. Qualitative and quantitative characteristics were established for the processes of the coal particle inert heating, moisture evaporation, thermal decomposition, combustible gas mixture formation, oxidation of volatiles and carbon. It was revealed that the temperature of the oxidizer required for the coal particle ignition is higher than 500• C. The experimental data can be used to develop predictive mathematical models of technological processes fire hazard in pulverized coal systems of thermal power plants.

Section: Experimental Studies and Resultsmentioning

confidence: 99%

Ignition of a coal particle at the low temperature of gas flow

Glushkov

Шарыпов

2015

“…The setup is similar to that one which are applied at investigation carrying out of water droplet evaporation in high-temperature (more than 1000 K) gas area [10][11][12] with using of "Particle Image Velocimetry" (PIV) and "Interferometric Particle Imaging" (IPI) [13][14][15] methods. The main elements of the stand are similar to applied in [10][11][12]. The digital camera 1 (with format -1024 × 1024 pixels, the frame frequency -100 000 per second) was used for droplets registration in the experiments opposite to techniques [10][11][12].…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

Experimental determination of water droplet “strain cycles” characteristic in the gas area

Кузнецов

Стрижак

Забелин

2015

Abstract. Experimental investigation of deformation regularities of widely used in industry liquid (water, kerosene, ethanol) droplets during the motion through the gas area under the action of gravitational forces has been conducted. Droplet characteristic sizes were varied in the range from 3 mm to 6 mm. Droplet motion velocities were come up to 5 m/s. Cross-correlation video recording system with optical methods of droplet size and velocity measurement was used. More than 10 characteristic droplets "strain cycles" have been established during they pass the distances up to 1 m through the gas area. The characteristic droplet forms, times, extents and amplitudes have been determined for each "strain cycle". The expression has been formulated which describes the characteristic "strain cycles" time dependencies on droplet velocities and sizes, also on the fundamental properties (viscosity, density, surface tension) of liquid and gas area in a first approximation. The conditions of droplet deformation intensification and this process in industry gas-vapordroplet setups stabilization have been determined.

“…Completeness and the rate of evaporation of atomized liquids in these technologies is largely determined by the characteristic dimensions of the droplets [4]. However, it was presented in the work [5] that if the value of the typical size of atomized liquid flow droplets was less than 100 μm, it was possible the deceleration, turning and taking away a liquid by the flow of gas medium moving in the opposite direction, from whence the intensity and completeness of evaporation were decreased.…”

Section: Introductionmentioning

confidence: 98%

Experimental Investigation of Droplet Evaporation of Water with Ground Admixtures while Motion in a Flame of Liquid Fuel

Dmitriyenko

Nyashina

Жданова

et al. 2016

Abstract. The evaporation features for the atomized flow of suspension on the base of water with ground admixtures in an area of high-temperature combustion products of liquid flammable substance (acetone) were investigated experimentally by the optical methods of gas flow diagnostic and the high-speed video recording. The scales of influence of clay and silt concentration in droplets of atomized flow on the intensity of its evaporation were determined. The approximation dependences describing a decrease in typical size of suspension droplets at various values of ground admixtures were obtained.