scholarly journals Hydraulic transients for a pipe line network of treated effluent rising main using SAP 2R

2021 ◽  
Author(s):  
Ajmal Hussain ◽  
Muhammad Mustafa ◽  
Hazi Mohammad Azamathullah ◽  
M. R. Sadique
Keyword(s):  
Direct Result ◽  
Hydraulic Transients ◽  
Pressure Drops ◽  
Treated Effluent ◽  
Pipe Line ◽  
Safe Limit ◽  
Protection Devices ◽  
Pressure Changes ◽  
Line Network ◽  
Simulated Scenario

Abstract Hydraulic transients occur as a direct result of rapid variations of flow field in pressurized systems. The change in velocity from valve closures or pump operations causes pressure surges that are propagated away from the source throughout the pipeline. The associated pressure changes during a transient period are quite large and occur quickly (within a few seconds). It should also be noted that when the maximum pressures exceed the bar ratings (mechanical strength) of the piping material, failure can occur. Similarly, if the minimum pressure drops below the vapour pressure of the fluid, cavitation can occur. The purpose of the present study is to model and simulate the hydraulic transients in a pipeline network system of treated effluent rising main of Mpophomeni sanitation scheme using SAP 2R. A total of five scenarios were simulated using different combinations. The simulation results show that the transient pressures in the pipeline exceeded the bar rating of the pipe where the bursts or cavitation may occur for the simulated scenario, but transient pressures were reduced to a safe limit after providing water hammer protection devices.

scholarly journals Effect of virtual mass force on prediction of pressure changes in condensing tubes

2012 ◽  
Vol 16 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Hamid Saffari ◽  
Nemat Daur
Keyword(s):  
Experimental Data ◽  
Annular Flow ◽  
Fluid Model ◽  
Mass Force ◽  
Virtual Mass ◽  
Vertical Pipe ◽  
Pressure Drops ◽  
Factors Affecting ◽  
Pressure Changes ◽  
Significant Factors

Three-fluid model is used to calculate the pressure drops in a vertical pipe with the annular flow pattern for condensing steam. The three-fluid models are based on the mass, momentum, and energy balance equations for each of the fluid streams in the annular flow. There are discrepancies between predictions of three-fluid model for pressure drops and the experimental data for pressure drops when using the avail?able correlations for steam-film interfacial friction. The correlation by Stevanovic et at provides good match with experimental data, but it does not take into account some important factors affecting the pressure drops in its three-fluid model. One of these significant factors which is considered in the three fluid model used in the present paper is virtual mass (added mass) force term. Inclusion of the virtual mass force improves the pressure drop predictions such that they agree much better with the experiments.

scholarly journals Mining Security Pipe© (TSM)© with Underground GPS Global© (RSPG)© Escape Security Device in Underground Mining

2016 ◽  
Vol 22 (2) ◽  
pp. 101-105
Author(s):  
Rafael Barrionuevo Giménez
Keyword(s):  
Carbon Fibre ◽  
Underground Mining ◽  
Automation System ◽  
Open Hardware ◽  
Work Area ◽  
Pipe Line ◽  
New Material ◽  
Security Device ◽  
Line Network ◽  
Different Levels

Abstract TSM is escape pipe in case of collapse of terrain. The TSM is a passive security tool placed underground to connect the work area with secure area (mining gallery mainly). TSM is light and hand able pipe made with aramid (Kevlar), carbon fibre, or other kind of new material. The TSM will be placed as a pipe line network with many in/out entrances/exits to rich and connect problem work areas with another parts in a safe mode. Different levels of instrumentation could be added inside such as micro-led escape way suggested, temperature, humidity, level of oxygen, etc.). The open hardware and software like Arduino will be the heart of control and automation system.

scholarly journals Achieving Efficiency in Gas Pipeline Connection: Evidence from Ghana

2016 ◽  
Vol 6 (5) ◽  
pp. 28
Author(s):  
Anthony Kudjo Gborgenu ◽  
Frank B. K. Twenefour ◽  
Mathias Gyamfi
Keyword(s):  
Energy Source ◽  
Natural Gas ◽  
Environmental Sustainability ◽  
Environmental Damage ◽  
Long Distance ◽  
Total Distance ◽  
Pipeline Networks ◽  
Pipe Line ◽  
Regional Capital ◽  
Line Network

<p>The demand for the use of natural gas is on the increase as an energy source. Natural gas transportation requires a continuous pipeline network from the source of gas across long distance to the various destinations. The main objective involves extending gas pipelines from Takoradi to all the regional capital towns in Ghana to meet the growing demands of its citizenry in order to provide economy and efficiency with regards to cost and environmental sustainability by developing a straight forward method of locating pipeline facilities and designing pipeline networks. The problem is formulated as a network of distances and the solution is presented based on Prim’s Algorithm for minimum connections. Data on distances are obtained from the Ghana Highways Authority. The total distance covered by the pipe line network if the existing road networks were used from Takoradi to all the regional capitals towns in Ghana is 5,094km. After Prim’s Algorithm was used, the total distance covered decreased to 1,590km which is about 68.8% reduction in the distance covered with regards to cost and the environmental damage caused by construction of pipelines (soil, forest, rivers, wetlands, noise from compressor stations during pipeline discharge and risk of pipeline leakage).</p>

scholarly journals Relationship of orthostatic blood pressure to white matter hyperintensities and subcortical volumes in late-life depression

2011 ◽  
Vol 199 (5) ◽  
pp. 404-410 ◽  
Author(s):  
Sean J. Colloby ◽  
Akshya Vasudev ◽  
John T. O'Brien ◽  
Michael J. Firbank ◽  
Steve W. Parry ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Pressure Drop ◽  
Systolic Blood Pressure ◽  
Grey Matter ◽  
Late Life ◽  
Late Life Depression ◽  
Pressure Drops ◽  
Orthostatic Blood Pressure ◽  
Pressure Changes ◽  
Subcortical Volumes

BackgroundStructural brain abnormalities are associated with late-life major depression, with numerous studies reporting increased white matter hyperintensities (WMH) and reduced cortical/subcortical grey matter volumes. There is strong evidence linking vascular disease to WMH, but limited evidence on its association with subcortical volumes.AimsTo investigate the relationship of orthostatic blood pressure changes to WMH and subcortical grey matter volumes in late-life depression.MethodThirty-eight people with depression and a similarly aged comparison group (n = 30) underwent fluid attenuated inversion recovery (FLAIR) and T1-weighted magnetic resonance imaging as well as systematic orthostatic blood pressure assessments. Volumetric estimates of WMH and subcortical grey matter were obtained for each participant and the relationship to blood pressure drop on active stand was examined.ResultsAn association between orthostatic systolic blood pressure drop and WMH volumes in temporal and parietal regions was found in the depression group (age-corrected partial correlation r’ = 0.31–0.35, P<0.05). Subcortical volumes were not related to blood pressure changes or WMH volumes in either group.ConclusionsWe found evidence for an association between the degree of orthostatic systolic blood pressure drop and WMH volume in the depression group. Since blood pressure drops lead to WMH in animals our findings suggest systolic blood pressure drops may be a factor contributing to these lesions in late-life depression.

ACTIVITY OF TWO SPECIES OF CALLIPHORA (DIPTERA) DURING BAROMETRIC PRESSURE CHANGES OF NATURAL MAGNITUDE

1961 ◽  
Vol 39 (5) ◽  
pp. 623-635 ◽  
Author(s):  
D. K. Edwards
Keyword(s):  
Barometric Pressure ◽  
Flight Activity ◽  
Insect Species ◽  
Calliphora Vicina ◽  
Pressure Drops ◽  
Level Pressure ◽  
Previous Condition ◽  
Per Se ◽  
Pressure Changes ◽  
Experimental Pressure

The amount of flight activity of Calliphora vicina R.D. was monitored during (a) natural, diurnal, barometric pressure changes, and (b) experimental pressure changes of natural amounts and rates. Activity was increased by a change in trend from rising or level to falling pressure, or by two step-like drops of 1 millibar, each lasting 15 minutes, separated by 1 hour of level pressure. The change to falling pressure, not falling pressure per se. stimulated activity in C. vicina. Activity was little, if at all, affected by a change to rising pressure from a previous condition of falling or level pressure. With Calliphora vomitoria (L.) no effects of a changing pressure trend on activity were observed. These findings indicate that natural, and particularly prefrontal, pressure drops under certain conditions can influence the amount of activity of some insect species.

scholarly journals DESIGN AND TEST OF HYDRAULIC DEVICE FOR ELECTRO-HYDRAULIC CONTROLLED HITCH SYSTEM OF A HORTICULTURAL TRACTOR

2020 ◽  
Vol 60 (1) ◽  
pp. 253-260
Author(s):  
Qiang Gao ◽  
Zhixiong Lu ◽  
Jinlin Xue ◽  
Huisong Gao
Keyword(s):  
Structural Design ◽  
Pressure Change ◽  
Hydraulic Actuator ◽  
Pressure Drops ◽  
Lifting Force ◽  
Device Model ◽  
Depth Control ◽  
Tillage Depth ◽  
Performance Results ◽  
Pressure Changes

This paper proposed a structural design scheme of the hydraulic device of the electro-hydraulic controlled hitch system of a YM554A horticultural tractor with hydraulic device model, and the designed hydraulic device was simulated and tested to verify its performance. Results show that the motion of hydraulic actuator is stable with good response for tillage depth control, while the maximum lifting force of 10.62kN and the static settlement value of 13mm all meet the standard requirements. And the oil pressure changes rapidly with a large fluctuation with the plough position changed from transportation state to tillage state, but it quickly stabilizes, and as the tillage depth becomes larger, the oil pressure drops but remains basically stable with the maximum oil pressure change of 0.35MPa.

Water Hammer Analysis for Pipe Line Network Using HAMMER V8i

2021 ◽  
pp. 117-127
Author(s):  
Ajmal Hussain ◽  
Muhammad Mustafa ◽  
S. M. Ahbar Warsi ◽  
Sumit Kumar
Keyword(s):  
Water Hammer ◽  
Pipe Line ◽  
Line Network

scholarly journals Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2313
Author(s):  
Guillermo Romero ◽  
Vicente S. Fuertes-Miquel ◽  
Óscar E. Coronado-Hernández ◽  
Román Ponz-Carcelén ◽  
Francisco Biel-Sanchis
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Large Scale ◽  
Hydraulic Systems ◽  
Transient Phenomena ◽  
Pressure Drops ◽  
Pipeline Route ◽  
Air Pockets ◽  
Pressure Changes ◽  
The Mathematical Model

Air pockets generated during emptying operations in pressurized hydraulic systems cause significant pressure drops inside pipes. To avoid these sudden pressure changes, one of the most widely used methods involves the installation of air valves along the pipeline route. These elements allow air exchange between the exterior and the interior of the pipe, which alleviates the pressure drops produced and thus prevents possible breaks or failures in the structure of the installation. This study uses a mathematical model previously validated by the authors in smaller installations to simulate all hydraulic variables involved in emptying processes over time. The purpose of these simulations is the validation of the mathematical model in real large-scale installations, and to do this, the results obtained with the mathematical model are compared with actual measurements made by the partner company. The hydraulic system selected for the study is a pipeline with a nominal diameter of 400 mm and a total length of 1020 m. The results obtained from the mathematical model show great similarity with the experimental measurements, thus validating the model for emptying large pipes.

scholarly journals Smart Mathematical Model for Chlorine Concentration Decay in Water Pipe Line Network

2020 ◽  
Vol 8 (10S2) ◽  
pp. 1-4
Keyword(s):  
Distribution System ◽  
Point Of View ◽  
Residual Chlorine ◽  
Quality Of Water ◽  
Time Period ◽  
Pipe Line ◽  
Decay Pattern ◽  
Water Conveyance ◽  
Water Chlorination ◽  
Line Network

Water is the critical need of today world. Clean and drinking Water is made drinkable by water chlorination in repositories and water conveyance framework distribution system. To obstruct the bacterial growth a base measure of minimum amount of residual chlorine should remain in the water. It is a serious challenge for the checking point of view about residual chlorine to ensure the quality of water in the distribution system, as there are numerous factors which affect its concentration decay process. At the point when chlorine starts mixing with water it reacts with pipe wall and various other elements present in the water prompting to its concentration decay. This problem makes it necessary to investigate the behavior of chlorine decay pattern. In this paper we investigate that chlorine reducing with increment of the time period and various samples was collected from old age and newly built colony

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