scholarly journals Application of Deswirl Device in Cyclone Dust Separator

2017 ◽  
Vol 20 (3&4) ◽  
pp. 203-216 ◽  
Author(s):  
M. Z. Abdullah ◽  
Z. Husain ◽  
S. M. Fraser
Keyword(s):  
Vortex Flow ◽  
Flow Instability ◽  
Laser Doppler Anemometry ◽  
Experimental Investigations ◽  
Reduced Pressure ◽  
Constant Flow Rate ◽  
Visualization Experiment ◽  
Vortex Finder ◽  
Dust Separator ◽  
Main Components

The experimental investigations of the vortex flow inside the vortex finder (outlet duct) of the cyclone dust separator have been carried out.  Preliminary study from the visualization experiment has been performed and discovered vortex instability inside the conventional vortex finder.  In order to minimize the instabilities, the streamlined entry shape was inserted at the vortex finder entrance and the results showed remarkable improvement of the vortex flow instability inside the vortex finder.  The velocity measurements of two main components of velocity were performed using a laser-Doppler anemometry at the cyclone vortex finder outlet.  The experiments were conducted at a constant flow rate of 0.0246m3/s with the vortex finder diameter of 64mm and with several types of entrance configuration in order to improve the cyclone performance and to reduce the losses.  The use of deswirl devices inside the vortex finder significantly reduced pressure drop and energy losses.

Computational and experimental investigations in a cyclone dust separator

1997 ◽  
Vol 211 (4) ◽  
pp. 247-257 ◽  
Author(s):  
S M Fraser ◽  
A M Abdel-Razek ◽  
M Z Abdullah
Keyword(s):  
Flow Field ◽  
Richardson Number ◽  
Swirling Flow ◽  
Laser Doppler Anemometry ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Cyclone Chamber ◽  
Dust Separator

Three-dimensional turbulent flow in a model cyclone has been simulated using PHOENICS code and experimental studies carried out using a laser Doppler anemometry (LDA) system. The experimental results were used to validate the computed velocity distributions based on the standard and a modified k-∊ model. The standard k-∊ model was found to be unsatisfactory for the prediction of the flow field inside the cyclone chamber. By considering the strong swirling flow and the streamlined curvature, a k-∊ model, modified to take account of the Richardson number, provided better velocity distributions and better agreement with the experimental results.

Investigations into the Precessing Vortex Core Phenomenon in Cyclone Dust Separators

1994 ◽  
Vol 208 (2) ◽  
pp. 147-154 ◽  
Author(s):  
P Yazdabadi ◽  
A J Griffiths ◽  
N Syred
Keyword(s):  
Vortex Core ◽  
Reynolds Numbers ◽  
Frequency Parameter ◽  
Experimental Investigations ◽  
Swirl Number ◽  
Significant Drop ◽  
Precessing Vortex Core ◽  
Dust Separator ◽  
The Relationship

Experimental investigations have been carried out to examine the effect of downstream pipework configurations on the precessing vortex core (PVC) generated within the exhaust region of a cyclone dust separator. Characterization of the PVC using a non-dimensionalized frequency parameter (NDFP) was used to determine the relationship between Reynolds number and geometrical swirl number of the cyclone. The results show that the NDFP tends towards an asymptotic value for Reynolds numbers of about 50 000 and high swirl numbers (> 3.043). This value is reached earlier with lower swirl numbers. It was concluded that any exhaust pipework configuration produced a significant drop in the PVC frequency, and certain configurations either delayed or promoted the development of the PVC.

Leakage Flow Investigations on a Through-Wall Crack Related to Thermal Fatigue of Nuclear Power Plant Piping

2017 ◽  
Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien
Keyword(s):  
Experimental Data ◽  
Nuclear Power ◽  
Numerical Models ◽  
Measurement Techniques ◽  
Experimental Investigations ◽  
Leakage Flow ◽  
Test Rig ◽  
Reduced Pressure ◽  
Flow Rates ◽  
Set Up

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.

Slit Aspect Ratio Effect on Flow Instability and Heat Transfer Characteristics of Wavy Vortex Flow

2019 ◽  
Vol 44 (9) ◽  
pp. 7767-7777 ◽  
Author(s):  
Dong Liu ◽  
Siliang Sun ◽  
Shicheng Ding ◽  
Nana Kofi Amponsah-Gyenin ◽  
Hyoung-Bum Kim
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Vortex Flow ◽  
Flow Instability ◽  
Heat Transfer Characteristics ◽  
Ratio Effect ◽  
Transfer Characteristics

Study on the Configuration Effect of a Vortex Finder for a Gas-Solid Cyclone Separator Using Eulerian-Eulerian Approach

2013 ◽  
Author(s):  
Moonho Choi ◽  
Sungwon Lee ◽  
Jin-Ki Ham
Keyword(s):  
Pressure Loss ◽  
Erosion Rate ◽  
Separation Efficiency ◽  
Solid Particles ◽  
Least Square ◽  
Design Parameters ◽  
Reduced Pressure ◽  
Eulerian Approach ◽  
Method Of Least Square ◽  
Vortex Finder

Granular model, a part of Eulerian-Eulerian approach is implemented to improve a gas-solid cyclone separator’s performances which are largely determined by dimensions of a vortex finder. Design-Of-Experiments method analyzes the performances such as pressure loss, separation efficiency, and erosion rate of each variation model due to the change of design parameters of the vortex finder. Separation efficiencies due to the motion of solid particles are predicted according to the classical efficiency model by using the method of least square. The numerical results are validated by comparing with previously reported experimental data. The standard Stairmand design cyclone is improved judging from the reduced pressure loss by 43%, the reduced cut size by 63% and the reduced erosion rate by 2% by changing the position and the diameter of the vortex finder.

Flow Instability at the Inlet of a Centrifugal Compressor

1981 ◽  
Vol 103 (2) ◽  
pp. 451-456
Author(s):  
G. Flueckiger ◽  
A. Melling
Keyword(s):  
Centrifugal Compressor ◽  
Flow Instability ◽  
Laser Doppler Anemometry ◽  
Suction Side ◽  
Operating Conditions ◽  
Gas Velocity ◽  
Unstable Flow ◽  
Flow Angle ◽  
Compressor Impeller ◽  
Service Conditions

Using laser Doppler anemometry, two components of the gas velocity have been measured at the inlet of a centrifugal compressor impeller, operated at speeds typical of service conditions for a medium-sized turbocharger. The flow was found to be unstable, especially adjacent to the suction side of the blades, such that two predominant conditions existed in the flow. The unstable flow is illustrated in the paper by distributions of relative velocity and relative flow angle, and the effects of different operating conditions on these distributions are examined. The instability is believed to be caused by a pre-stall condition as the compressor operating point approaches a fully stalled condition which occurs during surge.

Experimental Investigations of the Surface Groove Effect in Taylor-Couette-Poiseuille Flow

2020 ◽  
Author(s):  
Lamia Gaied ◽  
Fethi Aloui ◽  
Marc Lippert ◽  
Emna Berrich
Keyword(s):  
Couette Flow ◽  
Vortex Flow ◽  
Axial Flow ◽  
Vortex Structures ◽  
Base Flow ◽  
Taylor Vortex ◽  
Experimental Investigations ◽  
Surface Groove ◽  
Taylor Couette ◽  
The Impact

Abstract In this paper, we investigate the effects of an imposed axial flow on hydrodynamic instabilities’ Couette-Taylor flow in the case where the wall of the inner cylinder of the system is grouved. Without imposed axial flow, the basic flow of a fluid between two coaxial cylinders known by Couette flow, which is characterized by several temporal and spatial symmetries. The increase in the rotation causes the breaking of these symmetries. In both cases where the surface of the inner cylinder is smooth and grooved, five different flow regimes can be determined: Taylor vortex flow (TVF), wavy vortex flow (WVF), and Modulated Wavy vortex flow (MWVF). Each time the flow passes from one hydrodynamic regime to another until it enters a state of turbulence, which is characterized by the destruction of all the symmetries that existed at the beginning. In addition, when an axial flow is imposed on a Taylor-Couette flow, new helical vortex structures are observed in both cases (with and without surface groove). The influence of surface structures (grooves) on the shear stress of the wall is discussed with and without axial base flow. A spatio-temporal description of several flow models was obtained using firstly, a visualization’s qualitative study using kalliroscope particles. Secondly, a quantitative study by polarography using simple probes have been used to characterize the impact of vortex structures on the Couette-Taylor flows without and with an axial flow on the transfer.

Combustor Configuration Influence on Combusion Instabilities Performance

2010 ◽  
Author(s):  
Georgy K. Vedeshkin ◽  
Evgeniy D. Sverdlov ◽  
Alexey N. Doubovitsky
Keyword(s):  
Gas Flow ◽  
Flow Instability ◽  
Combustion Instability ◽  
Low Frequency ◽  
Experimental Investigations ◽  
Flow Recirculation ◽  
Instability Modes ◽  
Conical Diffuser ◽  
Recirculation Zones ◽  
The Given

The paper describes the results of calculations and experimental investigations of combustor configurations. It is shown that combustor configuration effects high frequency and low frequency combustor instabilities, gas dynamics of the flow, recirculation zones dimensions and lean flame out limits. Combustion instability modes had been investigated in two versions of combustor configurations: with the abrupt divergence of the channel and with an inlet conical diffuser. Gas flow instabilities had been investigated in the central recirculation zone without any chemical reactions. As a result the combustion instability model in which a role of a feed back mechanism is performed by hydrodynamic gas flow instability in the combustor is suggested. Modification of the combustor with a conical diffuser with the suggested model of the hydrodynamic combustion instability taken into account made it possible to settle the instability problem for the given combustor.

Flow Field Investigations on the Effect of Rib Placement in a Cooling Channel With Film-Cooling

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Martin Kunze ◽  
Konrad Vogeler
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Film Cooling ◽  
Laser Doppler Anemometry ◽  
Measurement Techniques ◽  
Experimental Investigations ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Field Investigations ◽  
Small Influence

This paper presents experimental investigations on flat plate film-cooling in combination with a ribbed cooling channel. The effect of rib placement on the film-cooling injection and the flow in the cooling channel was studied. The velocity fields were measured using optical laser measurement techniques including LDA (laser doppler anemometry) and PIV (particle image velocimetry). A row of three cylindrical film holes is placed in the center rib segment of the cooling channel. The dimensionless rib-to-hole position s/D is varied from 4.5 to 10.5. The investigations are conducted at isothermal conditions for a variation of the coolant Reynolds number Rec,Dh from 10,000 up to 60,000 and for three blowing rates M = 0.5, 0.75, and 1.00. The flow field results for the film-cooling injection showed only a small influence of the rib placement. Due to different coolant-to-main flow pressure ratios across the row, a slight nonuniform share of coolant flow occurs. Intense streamwise mixing and decay of the turbulence in the film jet was observed within the first 10 hole diameters. Enhancement of the turbulence intensity inside the jet core was found with increasing coolant Reynolds numbers. Inside the internal cooling channel, the flow field showed significant influence of the rib position which is most pronounced at low Reynolds number (Rec,Dh = 10,000) and high blowing ratios (M = 1.0). The effect becomes significantly smaller when the Reynolds number is increased. This is mainly attributed to the strongly increasing channel mass flow which equals to a decreasing suction ratio SR = uh/uc of the holes. The experimental results are compared to comprehensive numerical simulations.

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