scholarly journals Experimental Study on Internal Mixing Sonic Flow Air Assist Atomizer for Heavy Oils

1990 ◽  
Author(s):  
Ju Shan Chin ◽  
Li Xing Wang
Keyword(s):  
Experimental Study ◽  
Flame Length ◽  
Chamber Pressure ◽  
Heavy Oils ◽  
Air Supply ◽  
Air Stream ◽  
Internal Mixing ◽  
Mixing Chamber ◽  
Fine Spray ◽  
Sonic Flow

Based on the experiences previously obtained from the experimental study of plain jet atomization under cross flowing air stream and under supersonic air flow, the authors designed and studied a serious of internal mixing sonic flow air assist atomizers for heavy oil application. The contradiction between the requirements for fine spray (for high combustion completeness) and for long flame (for flame rigidity) often existing in industrial furnace has been solved. Good data were obtained which can be used for the design of such kind atomizers. By properly choosing the configuration and geometrical dimensions of the atomizer, also by choosing suitable values for mixing chamber pressure, air–liquid ratio, it is possible to have very fine spray and desirable flame length. The results showed that the ratio of mixing chamber pressure to air supply pressure should be in the range of 0.6 to 0.7. For atmospheric pressure combustion furnace, such air assist atomizer needs 0.4 MPa compressed air to have sonic flow at nozzle exit. This type of air assist atomizer has already been put into industrial operation.

scholarly journals Unsteady Behaviour of the Effervescent Atomizer

2020 ◽  
Vol 328 ◽  
pp. 01008
Author(s):  
Marek Mlkvik
Keyword(s):  
Plug Flow ◽  
Liquid Fuels ◽  
Viscous Liquids ◽  
Internal Mixing ◽  
Viscosity Increase ◽  
Mixing Chamber ◽  
Effervescent Atomizer ◽  
Fine Spray ◽  
Gas Consumption ◽  
Working Parameters

The effervescent atomizer is a well-established type of the twin-fluid nozzle with internal mixing of fluids. It is popular for the ability to process highly viscous liquids, such as liquid fuels, into a fine spray with low gas consumption. This study aims to investigate the performance of the effervescent nozzle when spraying the liquids with a viscosity up to 308 mPa·s. The working parameters of the nozzle were defined by the mass flows ratio of the gas to the liquid (GLR =2.5 to 20 %) and the gas pressure at the nozzle inlet (Δp = 0.14 MPa). The spray quality was investigated by the laser diffraction system, measuring the spray drop sizes. The investigated nozzle was able to atomize all of the model liquids. However, the liquid viscosity increase led to the need to operate the nozzle with the larger gas consumption. The minimum GLR for the spraying of the liquid with the viscosity 308 mPa·s was 10 %, while the less viscous liquid (60 mPa·s) was processed with the GLR = 2.5 %. It was observed that the spray quality was, at the low GLRs, lowered by unstable nozzle work, caused by the presence of the plug flow in the mixing chamber of the atomizer.

Effects of Air Temperature on Combustion Characteristics of LPG Diffusion Flame

2020 ◽  
Vol 1008 ◽  
pp. 128-138
Author(s):  
Ahmed M. Salman ◽  
Ibrahim A. Ibrahim ◽  
Hamada M. Gad ◽  
Tharwat M. Farag
Keyword(s):  
Air Temperature ◽  
Diffusion Flame ◽  
Nitrogen Addition ◽  
Flame Length ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Low Oxygen ◽  
Air Temperatures ◽  
Air Stream ◽  
Wide Range

In the present study, the combustion characteristics of LPG gaseous fuel diffusion flame at elevated air temperatures were experimentally investigated. An experimental test rig was manufactured to examine a wide range of operating conditions. The investigated parameters are the air temperatures of 300, 350, 400, 450, and 500 K with constant percentage of nitrogen addition in combustion air stream of 5 % to give low oxygen concentration of 18.3 % by mass at constant air swirl number, air to fuel mass ratio, and thermal load of 1.5, 30, and 23 kW, respectively. The gaseous combustion characteristics were represented as axial and radial temperatures distributions, temperatures gradient, visible flame length and species concentrations. The results indicated that as the air temperature increased, the chemical reaction rate increased and flame volume decreased, the combustion time reduced leading to a reduction in flame length. The NO concentration reaches its maximum values near the location of the maximum centerline axial temperature. Increasing the combustion air temperature by 200 K, the NO consequently O2 concentrations are increased by about % 355 and 20 % respectively, while CO2 and CO concentrations are decreased by about % 21 and 99 % respectively, at the combustor end.

Intelligent simulation experimental study on influence of air velocity of air supply hood and exhaust hood with vertical push-pull ventilation

2019 ◽  
Vol 37 (4) ◽  
pp. 4819-4826 ◽  
Author(s):  
Lindong Liu ◽  
Jingwen Dai ◽  
Junwei Yang ◽  
Miao Jin ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Exhaust Hood ◽  
Air Velocity ◽  
Air Supply ◽  
Intelligent Simulation

Experimental study of a heterogeneous plasma flow in a reactor with a multijet mixing chamber

1997 ◽  
Vol 70 (4) ◽  
pp. 559-566
Author(s):  
V. D. Shimanovich ◽  
A. L. Mossé ◽  
L. E. Krat'ko ◽  
N. I. Chubrik ◽  
E. A. Ershov-Pavlov ◽  
...  
Keyword(s):  
Experimental Study ◽  
Plasma Flow ◽  
Mixing Chamber

scholarly journals Spraying of Viscous Liquids: Influence of Fluid-Mixing Mechanism on the Performance of Internal-Mixing Twin-Fluid Atomizers

2020 ◽  
Vol 10 (15) ◽  
pp. 5249
Author(s):  
Marek Mlkvik ◽  
Jan Jedelsky ◽  
Heike P. Karbstein ◽  
Volker Gaukel
Keyword(s):  
Optical Diffraction ◽  
Liquid Fuels ◽  
Liquid Viscosity ◽  
Two Phase ◽  
Internal Mixing ◽  
Mixing Chamber ◽  
Wide Range ◽  
Effervescent Atomizer ◽  
The Common ◽  
Jet Nozzle

The thermal usage of liquid fuels implies their combustion, which is a process strongly influenced by the performance of the atomizer, which disrupts the fuel into drops of the required sizes. The spray quality of the twin-fluid atomizers with internal mixing (IM-TFA) is primarily influenced by the two-phase flow pattern inside the mixing chamber. We studied the performance of the four types of the IM-TFA nozzles by the optical diffraction system (Malvern Spraytec) to answer the question of how the mixing chamber design influences the spray quality at low atomizing gas consumption. We tested the effervescent atomizer in outside-in-liquid (OIL) and outside-in-gas (OIG) configurations, the Y-jet nozzle and new nozzle design, and the CFT atomizer when spraying model liquids with the viscosities comparable to the common fuels (μ=60and143 mPa· s). We found that the effervescent atomizer performance was strongly influenced by the configuration of the inlet ports. Although the OIL configuration provided the best spray quality (D32 = 72 μm), with the highest efficiency (0.16%), the OIG nozzle was characterized by unstable work and poor spray quality. Both the devices were sensitive to liquid viscosity. The Y-jet nozzle provided a stable performance over the liquid viscosity spectrum, but the spray quality and efficiency were lower than for the OIL nozzle. Our findings can be used to improve the performance of the common IM-TFA types or to design new atomizers. The results also provide an overview of the tested atomizers’ performances over the wide range of working conditions and, thus, help to define the application potential of the tested nozzle designs.

INFLUENCE OF SOME GEOMETRICAL PARAMETERS ON THE CHARACTERISTICS OF PREFILMING TWIN-FLUID ATOMIZATION

2014 ◽  
Vol 38 (3) ◽  
pp. 391-404
Author(s):  
Jiafeng Yao ◽  
Shinji Furusawa ◽  
Akimaro Kawahara ◽  
Michio Sadatomi
Keyword(s):  
Great Influence ◽  
Geometrical Parameters ◽  
Porous Fiber ◽  
Spray Characteristics ◽  
Fiber Ring ◽  
Practical Applications ◽  
Internal Mixing ◽  
Mixing Chamber ◽  
Liquid Atomization ◽  
Different Shapes

Geometries are considered to have a great influence on the spray characteristics of atomizers. In the present study, we studied a prefilming twin-fluid atomizer patented by Sadatomi and Kawahara (2012), in which liquid atomization is implemented by supplying compressed air alone into an internal mixing chamber, and water is automatically sucked by the negative pressure induced by an orifice. In the experiments, we studied spray characteristics influenced by the geometrical parameters, such as orifices in different opening area ratios and different shapes, porous rings with different porous diameters, and different atomizer sizes. Higher spray performance can be obtained by a small sized atomizer with a circular orifice in opening area ratio of 0.429 and a porous fiber ring with porosity of 25 μm. The present results provide a significant guidance for practical applications with different requirements of spray characteristics.

Experimental Study of Effects of Axi-asymmetric Combustion Air Supply in Horizontally Oil-fired Burner and Furnace

2009 ◽  
Vol 23 (8) ◽  
pp. 3899-3908 ◽  
Author(s):  
Young Gun Go ◽  
Sangmin Choi ◽  
Won Yang
Keyword(s):  
Experimental Study ◽  
Air Supply

Experimental Study of Flow Field of Large Air-Cooled Turbine Generator for Multi-Ventilation Ducts of Stator

2014 ◽  
Vol 644-650 ◽  
pp. 377-380
Author(s):  
Yi Ping Lu ◽  
Qing Hui Pan ◽  
Hui Lan Li ◽  
Jia De Han
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Axial Symmetry ◽  
Ventilation System ◽  
Hot Wire ◽  
Turbine Generator ◽  
Turbine Generators ◽  
Air Supply ◽  
Ventilation Ducts ◽  
Machine Configuration

To study rotational air flow field of rotor and complicated flow distinction owing to multi-ventilation ducts of stator in a large air-cooled turbine generator, considering axial symmetry of air supply, an experiment setup of ventilation system of semi-machine configuration was built in this paper. At condition of rotating, ventilation is measured by hot-wire anemometer. Firstly, ventilation in 16 different semi-circle radius is got. Measurement shows that ventilation in different radius varies much. Then ventilation of outlet of stator ducts is measured. The result shows that ventilation which is affected by flow back and jet less is higher. The conclusion will provide theoretical references for ventilation cooling of rotor ducts in large air-cooled turbine generators.

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