An experimental investigation of the oil film distribution in an oil–gas cyclone separator

Author(s):  
Lingzi Wang ◽  
Jianmei Feng ◽  
Shijing Xu ◽  
Xiang Gao ◽  
Xueyuan Peng

The film flow behavior in an oil–gas cyclone separator was experimentally studied to improve the separation efficiency in terms of the effect of the oil film on the cylinder wall. The oil film flow pattern was captured using a high-speed camera, and the cylinder wall was divided into seven regions to analyze according to the different oil film flow patterns. Along the cyclone cylinder height, the central part of the cylinder was the main flow area, in which droplet–wall collisions and oil film splashing were severe. Additionally, the oil film’s distribution characteristics under inlet velocities of 14.0, 16.0, and 18.0 m/s were compared, and the results showed that more splashing oil droplets were generated under higher inlet velocity. Moreover, changing the structure of the central channel and outer cylinder slightly changed the oil film’s area and flow pattern but exhibited a weak effect on the oil film thickness and re-entrainment. Then, an improved structure was proposed by adding a porous cylinder to the outer cyclone to avoid the generation of small splashing droplets from the oil film. The performance of the modified separator was measured in a real oil-injected compressor system, which demonstrated higher separation efficiency with no increase in static pressure loss. The separation efficiency increased by up to 2.7%, while the pressure loss decreased by up to 10%. Thus, the improved structure can improve the performance of oil–gas separators by changing the distribution and thickness of the oil film on the cylinder wall.

2013 ◽  
Author(s):  
Junpeng Shao ◽  
◽  
Chunxi Dai ◽  
Yanqin Zhang ◽  
Xiaodong Yu ◽  
...  

2011 ◽  
Vol 383-390 ◽  
pp. 6436-6442
Author(s):  
Xin Yang ◽  
Jian Mei Feng ◽  
Yun Feng Chang ◽  
Xue Yuan Peng

Experimental study of the separation efficiency of oil-gas cyclone separator for oil-injection compressor system was conducted with the aim of understanding the separation process and identifying the main parameters affecting the separation efficiency. Malvern Particle Size analyzer was applied to analyze the separators’ performance. By simultaneously measuring the oil droplet size distribution and oil concentration upstream and downstream of the separators, the separation performance was assessed. The results of the study contribute to an optimized cyclone separator design.


2000 ◽  
Vol 78 (8) ◽  
pp. 779-801 ◽  
Author(s):  
J Legrand ◽  
P Legentilhomme ◽  
G Lefèbvre

This work is dedicated to an experimental study of the wall shear stress in a turbulent swirling decaying flow induced by means of a tangential inlet in an annular cell. The flow pattern near both cylinders of the annulus is analyzed by means of measurements of wall velocity gradients using an electrochemical method involving micro-electrodes working in inert wall. The analysis of the axial and circumferential evolutions of the mean wall velocity gradient and of its power spectral density emphasizes the complexity and highly three-dimensional nature of the flow pattern of the annular swirling decaying flow induced by means of a single tangential inlet. Near the inner wall of the annulus, a recirculating zone, consisting of several pairs of contra-rotating cells, develops following the main helical motion of the fluid along the flow path. Near the external wall of the annular cell, high local velocities and energetic turbulent structures are detected in the vicinity of the tangential inlet. These eddies rapidly decay along the flow path because of the decrease of the swirl intensity. The setup of a recirculation bubble near the inner wall induces a quasi-axisymmetric flow behavior at the outer cylinder of the annulus. Near both walls, the power spectral densities of the velocity gradient reveal a superposition of small turbulent eddies having a low energetic level in the high-frequency domain.


2013 ◽  
Author(s):  
Junpeng Shao ◽  
◽  
Chunxi Dai ◽  
Yanqin Zhang ◽  
Xiaodong Yu ◽  
...  

2011 ◽  
Vol 339 ◽  
pp. 630-633
Author(s):  
Wen Bin Cai ◽  
Yuan Gang Xu ◽  
Qi Zhang

The cyclone plays an important role in the downhole oil-water separator during artificial lift for high water cut oil well, the processes of oil-water separation is completing in the cyclone. The oil-water cyclone separator was designed based on the oil and water density contrast and the cyclone separation theory; the laboratory experiment of cyclone separator was carried out and the relationship of the cyclone oil cut of apex and split ratio, oil-water separation efficiency and the velocity , the pressure loss of the cyclone and the velocity were also studied. When the reinjectivity is within 70% of the produced volume, cyclone separator has good water-oil separation ability, split ratio increased with the increase of the vecolity, when the flow vecolity reached 0.25m/s, the split ratio over 30%. But with the increase of the velocity, the increased rate of the split ratio is reduced. The relationship of the flow rate and cyclone intrinsic pressure loss is nonlinear exponential curve.


1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.


Author(s):  
Shinji Honami ◽  
Wataru Tsuboi ◽  
Takaaki Shizawa

This paper presents the effect of flame dome depth on the total pressure performance and flow behavior in a sudden expansion region of the combustor diffuser without flow entering the dome head. The mean velocity and turbulent Reynolds stress profiles in the sudden expansion region were measured by a Laser Doppler Velocitmetry (LDV) system. The experiments show that total pressure loss is increased, when flame dome depth is increased. Installation of an inclined combuster wall in the sudden expansion region is suggested from the viewpoint of a control of the reattaching flow. The inclined combustor wall is found to be effective in improvement of the diffuser performance. Better characteristics of the flow rate distribution into the branched channels are obtained in the inclined wall configuration, even if the distorted velocity profile is provided at the diffuser inlet.


Author(s):  
W. A. Woods

This paper presents the results of an experimental investigation of steady flow through a pair of exhaust poppet valves. An account is given of the gas exchange process on engines which use poppet valves and the reason why pressure losses should be kept to a minimum is explained. Tests carried out on the cylinder head of a uniflow two-stroke cycle engine are described following a brief description of the apparatus used. The results of a simple analysis of incompressible flow are also given. It is shown that the two previous models of flow through a valve, namely the sudden enlargement and constant static pressure, both give unrealistic pressure losses for large area ratios, i.e. at high valve lifts. A new model is introduced which leads to realistic pressure losses at small and large area ratios, i.e. at low and high valve lifts. Effective areas for the present tests are calculated on the basis of the constant pressure model, and details of calculation of pressure losses are outlined. The blockage effect caused by placing the exhaust valves near the cylinder wall is given in the discussion of the test results. This is zero for 0 < l/d < 0·08, but reaches a maximum blockage of 10 per cent at l/d = 0·28. With unrestricted twin valves the effective area is about twice that of a single valve up to l/d = 0·18 with a progressively larger effective area at lifts up to 13 per cent higher at l/d = 0·4. A comparison is also made with other data readily available. The pressure losses determined from the tests were analysed using a parameter derived in the simple theory. The parameter used is found to be almost independent of pressure ratio and the results are presented by means of this pressure loss parameter as a function of valve lift. The representation provides a quantitative method of comparing the performance of a given configuration of valve and port. On this basis the twin poppet valves are shown to give a slightly higher pressure loss than a single valve.


2005 ◽  
Vol 2005 (1) ◽  
pp. 77-89 ◽  
Author(s):  
W. Chon ◽  
R. S. Amano

When the airflow patterns inside a lawn mower deck are understood, the deck can be redesigned to be efficient and have an increased cutting ability. To learn more, a combination of computational and experimental studies was performed to investigate the effects of blade and housing designs on a flow pattern inside a1.1mwide corotating double-spindle lawn mower deck with side discharge. For the experimental portion of the study, air velocities inside the deck were measured using a laser Doppler velocimetry (LDV) system. A high-speed video camera was used to observe the flow pattern. Furthermore, noise levels were measured using a sound level meter. For the computational fluid dynamics (CFD) work, several arbitrary radial sections of a two-dimensional blade were selected to study flow computations. A three-dimensional, full deck model was also developed for realistic flow analysis. The computational results were then compared with the experimental results.


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