Group Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Title: 15.3.4 - A Simultaneous Upward/Downward Two Phase Flow (Viscous Liquid-Gas) Variable Inclination Test Loop
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Permanent Link: http://ufdc.ufl.edu/UF00102023/00375
 Material Information
Title: 15.3.4 - A Simultaneous Upward/Downward Two Phase Flow (Viscous Liquid-Gas) Variable Inclination Test Loop Experimental Methods for Multiphase Flows
Series Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Physical Description: Conference Papers
Creator: Asuaje, M.
Kenyery, F.
Massi, A.
Maestu, A.
Arias, L.
Aguillón, O.
Tremante, A.
Pérez, C.
Publisher: International Conference on Multiphase Flow (ICMF)
Publication Date: June 4, 2010
 Subjects
Subject: two-phase flow
experimental loop
horizontal flow
vertical flow
inclined flow
upward/downward simultaneous flow
viscous fluid
flow pattern visualization
pressure drop measurement
hold-up measurement
 Notes
Abstract: The available data of two-phase flow with high viscous liquid is scarce. The importance of reliable experimental data is crucial to enhance mechanistic models for two-phase flow, mainly for mixtures containing high viscous liquid. A test loop capable to visualize and measure simultaneously upward/downward flow phenomenon phenomena was designed and built, as a result the system saves time related with data acquisition. Translucent PVC pipes of 25.40 mm internal diameter (ID) have been mounted over a pivoting and balanced pyramidal shaped truss, which can be moved easily turned from the horizontal (0°) to the vertical position (90°), where ° represented the inclination angle. The test loop has for both pipelines in either branch (side): a developing section of 60 diameters, a testing section of 162 diameters and an exit section of 50 diameters. The results of the calibration of the facility were compared with the experimental data (Barnea et al. 1986) for an air-water mixture. The next experiments will attempt to work with mixtures of air and high viscous liquid, and water and high viscous liquid. Mineral oils with dynamic viscosities of 92 and 311 cp will be use as high liquid viscous.
General Note: The International Conference on Multiphase Flow (ICMF) first was held in Tsukuba, Japan in 1991 and the second ICMF took place in Kyoto, Japan in 1995. During this conference, it was decided to establish an International Governing Board which oversees the major aspects of the conference and makes decisions about future conference locations. Due to the great importance of the field, it was furthermore decided to hold the conference every three years successively in Asia including Australia, Europe including Africa, Russia and the Near East and America. Hence, ICMF 1998 was held in Lyon, France, ICMF 2001 in New Orleans, USA, ICMF 2004 in Yokohama, Japan, and ICMF 2007 in Leipzig, Germany. ICMF-2010 is devoted to all aspects of Multiphase Flow. Researchers from all over the world gathered in order to introduce their recent advances in the field and thereby promote the exchange of new ideas, results and techniques. The conference is a key event in Multiphase Flow and supports the advancement of science in this very important field. The major research topics relevant for the conference are as follows: Bio-Fluid Dynamics; Boiling; Bubbly Flows; Cavitation; Colloidal and Suspension Dynamics; Collision, Agglomeration and Breakup; Computational Techniques for Multiphase Flows; Droplet Flows; Environmental and Geophysical Flows; Experimental Methods for Multiphase Flows; Fluidized and Circulating Fluidized Beds; Fluid Structure Interactions; Granular Media; Industrial Applications; Instabilities; Interfacial Flows; Micro and Nano-Scale Multiphase Flows; Microgravity in Two-Phase Flow; Multiphase Flows with Heat and Mass Transfer; Non-Newtonian Multiphase Flows; Particle-Laden Flows; Particle, Bubble and Drop Dynamics; Reactive Multiphase Flows
 Record Information
Bibliographic ID: UF00102023
Volume ID: VID00375
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: 1534-Asuaje-ICMF2010.pdf

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7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010



A Simultaneous Upward/Downward Two Phase Flow (Viscous Liquid-Gas) Variable
Inclination Test Loop


M. Asuaje, F. Kenyery, A. Massi, A. Maestu, L. Arias, O. Aguill6n A. Tremante, C. P~rez

Universidad Simbn Bolivar, Departamento de Conversibn y Transporte de Energia, Laboratorio de Conversibn de Energia
Mecanica, Valle de Sartenejas, Caracas, 1080, Venezuela
asuajem~usb.ve, tremante~fiu.edu, cperez~,newfield.com, fk~enyery~usb.ve, aguillon~usb.ve


Keywords: Two-phase Flow, Experimental loop, Horizontal Flow, Vertical Flow, Inclined Flow, Upward/Downward
Simultaneous Flow, Viscous fluid, Flow pattern visualization, Pressure drop measurement, Hold-up measurement


Abstract

The available data of two-phase flow with high viscous liquid is scarce. The importance of reliable experimental data is crucial
to enhance mechanistic models for two-phase flow, mainly for mixtures containing high viscous liquid. A test loop capable to
visualize and measure simultaneously upward/downward flow phenomenon phenomena was designed and built, as a result the
system saves time related with data acquisition. Translucent PVC pipes of 25.40 mm internal diameter (ID) have been mounted
over a pivoting and balanced pyramidal shaped truss, which can be moved easily turned from the horizontal (00) to the vertical
position (900), where [o] represented the inclination angle. The test loop has for both pipelines in either branch (side): a
developing section of 60 diameters, a testing section of 162 diameters and an exit section of 50 diameters. The results of the
calibration of the facility were compared with the experimental data (Barnea et al. 1986) for an air-water mixture. The next
experiments will attempt to work with mixtures of air and high viscous liquid, and water and high viscous liquid. 1Vineral oils
with dynamic viscosities of 92 and 311 cp will be use as high liquid viscous.


Introduction

"The state of the art in the oil industry implies the use of
both modeling and experimental approaches to enhance
prediction models for two-phase flow" (Shoham, 2000).
Research throughout experimentation is necessary to
improve two-phase flow models, specially for mixtures
containing high viscous liquid. A closed loop facility, where
the phenomenon is accurately reproduced will ensure a
proper experimental setup, giving the margins that
encapsulate the arms of the research. In the two-phase
literature is very hard to find specific experiments dealing
with simultaneous upward and downward flow. An
exception of this was the work made by Lau and Rezkallah
(1992), studied the pressure drop for upward and downward
flow in vertical pipes (9.53 mm of ID) for an air-water
mixture being the mavor contribution of this research
project to prove that it is possible to take simultaneous data
for vertical pipes.
But what would be the next frontier? How can we answer
the new challenges? The innovation definitely will lie on the
base of a new kind of testing loop that allows a simultaneouS
study for upward and downward flow comprised in a global
study that includes several inclinations and high viscosity
working fluids, such as mineral oils with viscosities higher
that 90 cp. The facility presented attempts this goal and the
first results conducted with air-water mixtures proved that
the results are on a good direction.
In order to measure pressure drops, two pressure taps were
made at the beginning and at the end of the visualization
section. For the holdup measurements, two quick


simultaneously closing valves were used to capture the
average liquid holdup in the visualization section.

Nomenclature

Re= Reynolds number.
VM= IVixture velocity [m/s]
VSG= Superficial gas velocity [m/s]
VSL= Superficial liquid velocity [m/s]
h = No Slip Liquid Holdup
4,M = IVixture viscosity [Pa.s]
RLL = Liquid Viscosity [Pa. s]
RLG = Gas Viscosity [Pa.s]
p,= 1Vixture density [kg/m3]
pL= Liquid density [kg/m3]
pG= Gas density [kg/m3]
AP = Total pressure gradient [psig]
APt- Frictional pressure gradient [psig]
AP,= Gravitational pressure gradient [psig]
f = Friction factor is the Swamee-Jain friction factor [7]
E/d= Relative roughness
1 = Length of the testing section [mm]


1 Configuration of the two-phase flow variable
inclination loop

The two-phase flow loop is made up of translucent pipes
where the phenomena will be studied. The visualization
section is mounted on an aluminium pyramidal shaped
truss. This structure has 16 pipe hangers, distributed along






























gr 1250 m 4050 mm 1500 mm


7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010



In order to avoid the siphon effect the upward and
downward pipes were connected using a 50.80 mm x
2590.00 mm long PVC pipe working as a flow damper.
Additionally, there is a 50.80 mm drainage pipe. Each line
has three sections (Figure 2):
A flow development section of 60 diameters (1524.00 mm).
An observation and testing section of 162 diameters
(4114.80 mm).
An exit section of 50 diameters (1270.00 mm).
The holdup capture valves are triggered by
electro-pneumatic pilot valves.


the circuit allowing the alignment of the individual pipe
sections. The truss can be rotated around its middle point in
order to study the two-phase flow phenomena for a wide
range of inclinations (from 00 to 900). Because of its
centered pivoting axis, the structure is well balanced and
can be easily rotated without the need of a motor or wire
winch.

1.1 Variable Inclination System

An easy and simple positioning system has been developed
in order to set a specific inclination for the test loop. The
system consists of a positioning bar controlling the loop
inclination (Figure 1). The bar is attached to the platform by
means of a planar joint and slides between two calibrated
rails anchored to the ground. These rails have different
marks to set the whole range of inclinations (00; 20; 100.
30; 450; 600; 700; 80; 900)


Downward testing section ( =1")


e


2" Draina


IOutlet

Iet 1500 mmi 4050 mm 1250 mm
t 2" Flux Damper
Upward testing section (#=1")
Upward Flow
Downward Flow


Figure 2. Testing loop


1.3 Fluid feeding system

The fluid feeding system consists in two lines, one for liquid
line and one for gas. A pump is used to transfer the liquid
from a ground level tank in the case of water or an
atmospheric vessel for high viscous liquids. A reciprocating
compressor is used to supply the air.
These two lines have their metering and controlling
instrumentation in order to check and control their
properties [4,5,6].

1.4 Liquid holdup and pressure drop

The study the two-phase flow phenomenon is based on the
visual identification of the flow pattern, then the pressure
drop is taken and finally the average liquid holdup is
captured and measured.
The pressure drop is sensed through two pressure taps
located at the beginning and at the end of the testing section,
both pressure intakes are located between the two holdup
capture valves


Figure 1. Multiple-position system.


1.2 Visualization section

The loop's visualization section consists of two arms of
25.40 mm (ID) translucent PVC pipes (for upward and
downward flow) with two holdup trap valves and two
pressure taps per line (f 2.76 kPa). The upward flow line
has two quick closing valves: one is a three way valve and
the other is a two way valve. Downward flow has two
two-way valves to capture the flow. The reason for this
arrangement is to avoid damages to the system caused by
the sudden closure of the quick closing valves. This will
also help to save time allowing the system to operate
continuously.






7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010


2 -d


APg = phl -g g--sin 8


0.252
8[E 5.74

3.71d


eq. (7)


eq. (8)





eq. (9)


Figure 3. Deflections on the truss


Re, ""d


V, = Vs + VG




VsL VSG


eq. (1)


eq. (2)




eq. (3)


eq. (4)


eq. (5)


eq. (6)


Ph = Ph Z+Pl.1 Z


rUM = IU1 j U .1 Z


2.1 Comparison methodology


In general, in order to validate the procedure and the data,
the experimental results were analyzed as follows:
The flow pattern transition was compared with the unified
transition model of [1].
The hiquid holdup was compared with the non-slip hiquid
holdup (eq. 3)
The pressure drop was calculated with eq. 6 and compared
with the pressure drop measured.
A relative error characterizing each of the properties studied
during the commissioning tests is defined as:




%error = prprep-poe ho 100 e.(0
proper exp


3 Results


The comparison of the flow pattern transition is shown on
Figures 4, 5 and 6.



Dispersed Bubble Flow Region






Intermittent Flow Region


0.1
0.1 Vsgl(m/s) 1


I Dispersed Bubble fow - -EXP 1-DB
i Interminentflow --Bamea

Figure 4. Experimental and theoretical "I-DB"
transition for water-air and 9 = 00 pipe.


-- = ,f


1.5 Structural analysis of the pyramidal shaped
truss

To guarantee the alignment of the pipes a structural analysis
simulation was carried out to determine the maximum edge
deflection of the truss (Figure 3). The deflection analysis
was made with NastramTM considering the weight of the
truss, accessories, instrumentation and the pipeline weight
filled with water.

As a result, the maximum deflection at the edge of the
structure was 0.198 mm. This value is quite small compared
with the horizontal reference that was set by means of a
water lever and adjusted with the pipe hangers to ensure the
00 reference. The vertical reference was ensured using a
plumb line. The tests sections inclination angles can be
easily modified by changing the fixing point of the
positioning bar over the ground rails.

2 Commissioning tests of the loop

The commissioning tests of loop were made for 00, +900
(upward) and -900 (downward). The flow pattern transition,
average liquid holdup and pressure drop across the test
section were measured for air-water mixtures and
compared with experimental data available on the literature
[1].
The experimental data were compared with the
homogeneous flow model. This method takes into account
the mixture average velocity and physical properties as
follows:































I Dispersed Bubbleflow - EP 1-D -D
SChurn flow
Sinterminent flow Barnea


Figure 5. Experimental and theoretical "A-I-DB"
transition for water-air and 9 = + 900 pipe
10


1 rmttnt


SDispersed Bubble flow - EXP Al
o Annular flow -j=P .DB
x Intermittent flow- Barnea


Figure 6. Experimental and theoretical "A-I-DB"
transition for water-air and 9 = -900 pipe


Dashed lines show the experimental data boundaries
whereas solid lines represent the Barnea' s prediction model,
for intermittent to dispersed bubble transitions. In general,
the intermittent-dispersed bubble superficial liquid velocity
for the transition increases as the superficial gas velocity
increases in its whole range. In a general ivay, this behavior
can be seen for all inclinations studied, both flow directions
on the laboratory experiences. The experimental transition
was reached at lower superficial velocities of liquid, for
both horizontal (15%) and vertical pipes (10%).

The comparisons of the pressure drop and liquid hold-up for
all data points identified as dispersed bubble flow were
calculated by means of the homogeneous model [8]. The
results are shown on figures 7, 8 and 9. The maximum
relative errors found were 15% for the pressure drop and
12% for the liquid holdup.


7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010


+15 o


5 1.0 1.5


4.5
4.0
3 5





1.5


0.5
0.


10
Dispersed Bubble



3 88, B
1 I~~


P H i ~
o.i a a


Intermittent Flow


Churn Flow
Region


2.0 2.5 3.0
AP HOMOGENEOUS (PSi)


3.5 4.0


Vsg~l~ms)


Figure 7. Experimental Pressure Drop vs.
Homogeneous Model, water-air. 9 = 00 pipe.


+ 15%



. o **co.* .&* .5


0.1


4.0 5.0 6.0 7.0 8.0 9.0 10.0
AP HOMOGENEOUS (PSi)


Figure 8. Experimental Pressure Drop vs.
Homogeneous Model, for water-air and 9 = + 900 pipe.


Anular Flow Region


Vsgl(m/s)


+ 15 %


^ 3.0

a.
< 2.0


_ 49


AP HOMOGENEOUS (PSI)


Figure 9. Experimental Pressure Drop vs.
Homogeneous Model, for water-air and 9 = 900 pipe.


Each graph displays on the vertical axis the experimental
values against the theoretical values on the horizontal axis.
A 450 slope line was included in each graph to give an idea
of how close are the two data sets. Also each graph presents
the above stated relative error bands.

The comparisons of the experimental hiquid holdup and the
homogeneous hiquid holdup are presented on Figures 10, 11
and 12. These graphs were completed with the
corresponding 450 slope lines representing the
homogeneous [8] model for the liquid holdup.






7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010

4 Conclusions


A test loop was built and tested with air-water mixtures with
the following results:
The test loop can used to study two-phase phenomena with
a confident degree of reliability (15% or less with the
unified model of Barnea).
The results show good agreement with the Bamnea unified
model for the intermittent-dispersed bubble transitions and
with the homogenous model for the pressure drop and liquid
holdup.


The figures also show the relative error bands (f12%) for
horizontal (Figure 10) pipe and the upward/downward
vertical pipes (Figure 11,12).


-- o The intermittent-dispersed bubble flow transition, for both
horizontal and, vertical pipes were 110% of the transition
0.5 0.6 0.7 0.8 0.9 1.0 liquid superficial velocity theoretical values.


The pressure drop errors were estimated around f15% for
horizontal and vertical pipes.
Finally, the liquid holdup errors are around 12% and the
best performances observed during the tests were for the
vertical pipes (their data points has a lower dispersion
compared with the horizontal ones).
Given the fact that the results for horizontal and vertical
pipes are satisfactory we can expect a good agreement for
inclined pipes.


Acknowledgements


The authors wish to thank all the collaboration provided by
Dr. Ovadia Shoham and the University of Tulsa

References


Figure 10. Experimental liquid holdup vs. h0 for
water-air and 9 = 00 pipe
For the horizontal position, the majority of the points lie
between the error bands (f12%) and they are closely
gathered to the homogeneous model line.
Looking at the vertical positions (Figures 11 & 12), most of
the data points lie between the homogeneous model and the
upper relative error band (+12%).


1.0

0. +12 % .

S0.8


0.7


0.6




Figu


1.0


0.9






0.6


[1] Bamnea, D., A Unified Model for Predicting Flow

Inclination, Int. J. 1Multiphase Flow, 13, No. 1, pp.
o 1-12, 1986.
[2] Shoham, O., 2000. Two Phase Flow Modeling Course,
0.6 .7 08 0. 1.0The University of Tulsa
[3] Lau, Jiang and Rezkallah, K.S., Pressure Drop During
Upward and Downward Two-Phases Gas-Liquid
re 11. Experimental liquid holdup vs. h Ofor Flow in a Vertical Tube, ASIME, Vol 144, pp.81-87,
water-air and 9 = + 900 pipe 1992.
[4] Arias, L., 2003. Estudio Experimental de Flujo Bifasico
(Liquido Viscoso Gas) en Tuberias Verticales y
on Altamente Inclinadas. IM.Sc. Thesis, Universidad
+ 12 . ..'0 o Simon Bolivar, Caracas, Venezuela, 2003.
'.. o [5] Massi, A., Estudio Experimental de Flujo Bifasico
-- a (Liquido Viscoso Gas en Tuberias Horizontales
..~' .~'~y Ligeramente Inclinadas. IM.Sc. Thesis,
.* .. -12 % Universidad Simon Bolivar, Caracas, Venezuela,
2003.
[6] Maestu, A., Patrones de Flujo, Caida de Presibn y
Fraccibn de Liquido en Mezclas Bifasicas
j/, (Liquido Viscoso-Gas). IM.Sc. Thesis,
0.6 0.7 0.8 0.9 1.0 Universidad Simon Bolivar, Caracas, Venezuela,
h 2003.
[7] Mendez, M.V, Tuberias a Presibn en los sistemas de
ore 2. xpermenal lqui holup s. hforAbastecimiento de Agua. Publicaciones UCAB,
ure 2. xpermenal lqui holup s. AforVenezuela, 1995.


water-air and 9= -90 pipe


Fig






7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010

[8] Wallis, G.B,. One-Dimensional Two-Phase Flow.
1Mccraw-Hill Book Co. Inc., New York City. USA,
1969.




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