What Is the Leak Rate for a Liquid Slug Flowing Past a Side Branch?

2020 ◽  
Author(s):  
C. Hartloper ◽  
E. Clavelle ◽  
K. Leong ◽  
M. Fitz ◽  
S. Epur
Keyword(s):  
Critical Velocity ◽  
Liquid Velocity ◽  
Branch Pipe ◽  
Branch Length ◽  
Side Branch ◽  
Leak Rate ◽  
Flow Loop ◽  
Chemical Cleaning ◽  
Set Up ◽  
Pipe Size

Abstract Chemical cleaning is used in gas pipelines to remove debris that was resistant to mechanical cleaning. The cleaner is a liquid mixture of a hydrocarbon-based solvent and a surfactant. It is transported down the pipeline either batched between two cleaning tools or pushed by a single tool. During a chemical cleaning run, liquid will leak into any side branch it passes. Consequently, gas quality problems may arise when the pipeline returns to regular operations as the leaked liquid hydrocarbons evaporate into the gas stream. Furthermore, operational problems such as flooded separators can occur if a large volume of liquid is lost. Currently, there is no understanding of what factors influence the liquid’s leak rate into side branches. This paper aspires to address this knowledge gap. A water flow loop was set up to investigate the effect on leak rate of mainline pipe size, side branch pipe size, side branch length, and mainline liquid velocity. The leak rate is found to increase with the side branch pipe size, while remaining unaffected by the mainline pipe size and side branch length. At mainline velocities below the critical velocity, gravitational effects such as the downstream back pressure significantly affect the leak rate. At mainline velocities above the critical velocity these effects disappear, and the leak rate decreases as the mainline liquid velocity increases.

Performance of Corrosion Inhibitors at High CO2 Pressures

2008 ◽  
Author(s):  
Patchareeporn Sintoorahat ◽  
Aree Wairatpanich ◽  
Suchada Chimam ◽  
Dayin Mongkholkhajornsilp ◽  
Cheolho Kang
Keyword(s):  
Corrosion Inhibitors ◽  
Liquid Velocity ◽  
Flow Characteristics ◽  
Stratified Flow ◽  
Inhibitor Concentration ◽  
Flow Loop ◽  
Corrosion Rates ◽  
Offshore Pipeline ◽  
Carbon Dioxide Pressure ◽  
Corrosion Rate Measurement

The objective of this study was to evaluate the performance of two corrosion inhibitors (CI-A and CI-B) under conditions similar to the second PTT’s offshore pipeline. The experiments were carried out in flow-loop system, 36 m long, 10.16 cm diameter at 10.5 and 14 bar of carbon dioxide pressure, a temperature at 50°C. The performances of corrosion inhibitors were examined under conditions of superficial liquid velocity of 0.03 m/s and gas velocities of 6, 8 and 10 m/s in 0 and 3 degree inclinations using the ER probe and X65 weight-loss coupons for corrosion rate measurement at the top and bottom of pipe. According to flow characteristics, it was found that the smooth and wavy stratified flow occurred in 0 degree. For 3 degree inclination, wavy stratified flow with big waves was dominantly presented for all conditions. Corrosion inhibitor B showed a better performance than inhibitor A in all cases. For inhibitor B, the target corrosion rates of less than 0.1 mm/yr were achieved in all conditions with 50 ppm of inhibitor concentration whereas the amount of 75 ppm inhibitor concentration was required for CI-A. The color, turbidity, and emulsion tendency with corrosion inhibitors will be also discussed in this paper.

scholarly journals Thermal-hydraulic behavior of physical quantities at critical velocities in a nuclear research reactor core channel using plate type fuel

2012 ◽  
Vol 27 (3) ◽  
pp. 229-238
Author(s):  
Ali Sidi ◽  
Zaki Boudali ◽  
Rachid Salhi
Keyword(s):  
Heat Flux ◽  
Critical Velocity ◽  
Nuclear Reactor ◽  
Reactor Core ◽  
Thermal Characteristics ◽  
Nuclear Research ◽  
Coolant Fluid ◽  
Critical Velocities ◽  
Set Up ◽  
Physical Quantities

The thermal-hydraulic study presented here relates to a channel of a nuclear reactor core. This channel is defined as being the space between two fuel plates where a coolant fluid flows. The flow velocity of this coolant should not generate vibrations in fuel plates. The aim of this study is to know the distribution of the temperature in the fuel plates, in the cladding and in the coolant fluid at the critical velocities of Miller, of Wambsganss, and of Cekirge and Ural. The velocity expressions given by these authors are function of the geometry of the fuel plate, the mechanical characteristics of the fuel plate?s material and the thermal characteristics of the coolant fluid. The thermal-hydraulic study is made under steady-state; the equation set-up of the thermal problem is made according to El Wakil and to Delhaye. Once the equation set-up is validated, the three critical velocities are calculated and then used in the calculations of the different temperature profiles. The average heat flux and the critical heat flux are evaluated for each critical velocity and their ratio reported. The recommended critical velocity to be used in nuclear channel calculations is that of Wambsganss. The mathematical model used is more precise and all the physical quantities, when using this critical velocity, stay in safe margins.

A laboratory set up for the measurement of wellbore instability due to erosion of unconsolidated formations

2015 ◽  
Vol 55 (1) ◽  
pp. 329
Author(s):  
Ghazal Avijegon ◽  
Joel Sarout
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Ct Scanning ◽  
High Flow ◽  
Annular Space ◽  
Chemical Additives ◽  
Flow Loop ◽  
Coiled Tubing ◽  
Early Results ◽  
Set Up

Borehole instability is a recurring issue encountered during drilling operations in the oil and gas, and mining industries. In exploration drilling using coiled tubing technology, boreholes are slim and the annular space is usually tight. Similar situations are also encountered around the drill-collar section in standard drilling where the annular space can be tight; therefore, the drilling fluid has a high flow velocity and a turbulent flow regime is dominant. The flow conditions are the governing conditions for borehole erosion, which can lead to borehole instability. Erosion of the borehole introduces more cuttings into the annulus space, which is detrimental to the efficiency of cuttings transport and brings contamination to samples being retrieved at the surface for geochemistry and mineral analyses. In this peer-reviewed paper a new laboratory set-up aimed at estimating borehole erosion in pre-drilled rock samples is reported. A flow loop unit is used, which allows the injection of high flow-rates of any type of fluid composed of chemical additives and simulated cuttings. Early results of an exploratory study are reported in terms of changes in the internal borehole diameter (ID) of the sample before and after the erosion experiment. These were recorded using X-ray CT scanning. This change in ID acts as a measure of the formation’s erodibility, from which shear stress is estimated.

Design and Performance of Slug Damper

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Antonio Reinoso ◽  
Luis E. Gomez ◽  
Shoubo Wang ◽  
Ram S. Mohan ◽  
Ovadia Shoham ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Liquid Velocity ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
Gas Velocity ◽  
Flow Loop ◽  
Two Phase ◽  
Superficial Gas Velocity

This study investigates theoretically and experimentally the slug damper as a novel flow conditioning device, which can be used upstream of compact separation systems. In the experimental part, a 3 in. ID slug damper facility has been installed in an existing 2 in. diameter two-phase flow loop. This flow loop includes an upstream slug generator, a gas-liquid cylindrical cyclone (GLCC©, ©The University of Tulsa, 1994) attached to the slug damper downstream and a set of conductance probes for measuring the propagation of the dissipated slug along the damper. Over 200 experimental runs were conducted with artificially generated inlet slugs of 50 ft length (Ls/d=300) that were dumped into the loop upstream of the slug damper, varying the superficial liquid velocity between 0.5 ft/s and 2.5 ft/s and superficial gas velocity between 10 ft/s and 40 ft/s (in the 2 in. inlet pipe) and utilizing segmented orifice opening heights of 1 in., 1.5 in., 2 in., and 3 in. For each experimental run, the measured data included propagation of the liquid slug front in the damper, differential pressure across the segmented orifice, GLCC liquid level, GLCC outlet liquid flow, and static pressure in the GLCC. The data show that the slug damper/GLCC system is capable of dissipating long slugs, narrowing the range of liquid flow rate from the downstream GLCC. Also, the damper capacity to process large slugs is a strong function of the superficial gas velocity (and mixture velocity). The theoretical part includes the development of a mechanistic model for the prediction of the hydrodynamic flow behavior in the slug damper. The model enables the predictions of the outlet liquid flow rate and the available damping time, and in turn the prediction of the slug damper capacity. Comparison between the model predictions and the acquired data reveals an accuracy of ±30% with respect to the available damping time and outlet liquid flow rate. The developed model can be used for design of slug damper units.

Experimental Evaluation of Wire Type Leak Detector Layout for Prototype Fast Breeder Reactor (PFBR)

2009 ◽  
Author(s):  
K. K. Rajan ◽  
G. Vijayakumar ◽  
S. Chandramouli ◽  
K. Madhusoodhanan ◽  
P. Kalyanasundaram ◽  
...  
Keyword(s):  
Test Section ◽  
Detection System ◽  
Leak Rate ◽  
Test Facility ◽  
Fast Breeder Reactor ◽  
Leak Detector ◽  
Secondary Circuit ◽  
Flow Area ◽  
Annular Gap ◽  
Set Up

Wire type leak detectors working on conductivity principle are used for detecting sodium leak in the secondary sodium circuits of FBRs. It is required to assess the performance of these detectors and confirm that they are meeting the requirements. A test facility by name LEENA was constructed at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam to test the wire type leak detector lay out by simulating sodium leaks of different rates. This test facility consists of a sodium dump tank, a test vessel, interconnecting pipelines with valves, micro filter and test section with leak simulators. There are three different test sections in the test set up of length 1000 mm each. These test sections simulate piping of Prototype Fast Breeder Reactor (PFBR) secondary circuit and the leak detector layout in full scale. All test sections are provided with leak simulator. A leak simulator consists of a hole of size one mm drilled in the test section and closed with a tapered pin. The pin position is adjusted by a screw mechanism and there by the annular gap of flow area is varied for getting different leak rates. Test facility was commissioned and 20 experiments were attempted at 350°C to 550°C. Out of 20 experiments 11 experiments were successfully completed and 9 experiments were terminated in between due to the choke in the simulator hole. From the experimental data it is found that sodium leak rate of 200 g/h and above can be detected within 6 hours. A relationship between leak rate and detection time was established from the experimental results and found that sodium leak rate of 100g/h is likely to be detected in 11.4 hours. This paper deals with the details of wire type leak detector layout for the secondary sodium circuit of PFBR, performance requirement of leak detection system as per codes, description of test facility, experimental procedure and test results. Paper also reviews the experiment conducted in CEA, Cadrache and compares with results of present experimental study.

Numerical Simulation of Acoustic Resonance in Closed Side Branch With Different Cross-Section Shapes

2018 ◽  
Author(s):  
Jiang LiuYi ◽  
Zhang Hong ◽  
Duan QingQuan
Keyword(s):  
Cross Section ◽  
Research Work ◽  
Branch Pipe ◽  
Acoustic Resonance ◽  
Side Branch ◽  
Pipeline System ◽  
Detached Eddy Simulation ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross

There are many closed side branches in the gas conveying pipeline system. When the gas passes through the closed side branch, the shear layer will arouse the acoustic resonance in the closed side branch, which is harmful to the safe operation of the pipeline. The research work is insufficient about the influence of the cross-section shape of the closed side branch on acoustic resonance. Using the Detached-Eddy Simulation (DES) model, the acoustic resonance characteristics caused by the side branch pipe with different square cross-sections are simulated at the inlet boundary conditions of 25 m/s, 30 m/s and 35 m/s. The results show that in the center axis of the side branch, a 1/4 wavelength standing wave was formed, and the acoustic resonance occurs at a higher Strouhal number in circular branch. The cross-section shape of the side branch does not affect the acoustic resonance frequency, but it has a certain influence on the amplitude of pressure fluctuation and has a significant influence on the high-order frequency components.

Screening of fast biofilm formation on stainless steel by thermophilic sporeformers originated from dairy powder and their resistance against CIP

2020 ◽  
Author(s):  
Louis Delaunay ◽  
Florence Postollec ◽  
Ivan Leguerinel ◽  
Anne-Gabrielle Mathot
Keyword(s):  
Stainless Steel ◽  
Image Analysis ◽  
Nitric Acid ◽  
Caustic Soda ◽  
Early Stage ◽  
Raw Milk ◽  
Chemical Cleaning ◽  
The Matrix ◽  
Positive Threshold ◽  
Set Up

<p><strong>Introduction: </strong></p> <p>Thermophilic sporeformers are present in raw milk at very low concentration and resist to pasteurisation applicated to destruct vegetative and pathogenic cells. Those spores can adhere to stainless steel due to their hydrophobicity and can form biofilms. Early stage biofilms are important because it can increase the matrix and the adhesion of other cells. Because of those biofilms, the three main species: Geobacillus stearothermophilus, Anoxybacillus flavithermus and Bacillus licheniformis can resists to Cleaning In Place (CIP) procedure, and contaminate a new process.</p> <p> </p> <p><strong>Material and Methods: </strong></p> <p>Early stage adhesion was conducted on stainless steel submerged by milk inoculated with a fresh culture of bacteria (G. stearothermophilus (N=15), A. flavithermus (N=32) and B. licheniformis (N=15)) for 6h of growth at 55°C under agitation. The ability of sporeformers to form biofilms under those conditions were measured by image analysis after a fluorescent coloration (acridine orange) and random photography. A coverage percentage was calculated by ImageJ ; and a positive threshold was set up at 5% of covering.</p> <p>The efficiency of CIP procedures were obtained after a caustic soda and nitric acid treatment during different duration and temperature of treatment. Tested biofilms were formed in milk during 12h at 55°C, in stainless steel microplates (96 wells) on the same species (3 strains for each) under agitation. Surviving spores were enumerated by the microcolony method.</p> <p> </p> <p><strong>Results:</strong></p> <p>Early stage adhesion shows that 62.5 % (N=20) of A. flavithermus strains can form biofilm within 6h, whereas only 6.7% (N=1) of G. stearothermophilus and 0% (N=0) of B. licheniformis biofilm in 6h at 55°C on submerged stainless steel. However, the maximum covering % on A. flavithermus was 35%; while on the only biofilm forming strain of G. stearothermophilus, this percentage reach 75%. Image analysis also shows biofilm structure from 2D to 3D.</p> <p>The presence and the resistance of spores to chemical cleaning was highly variable within strains. Nitric acid appears to be more effective than caustic soda against biofilms formed by vegetative cells and spores from these strains.</p> <p> </p> <p><strong>Significance: </strong></p> <p>Those results shows that strong biofilms are mainly composed of spore and are very resistant to CIP used in dairy industries. That is why a better understanding of control methods can lead to a finer and suitableness use of cleaning products.</p>

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