scholarly journals Standoff Distance in Ultrasonic Pulsating Water Jet

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 88
Author(s):  
Madhulika Srivastava ◽  
Akash Nag ◽  
Somnath Chattopadhyaya ◽  
Sergej Hloch
Keyword(s):  
Unit Length ◽  
Traverse Speed ◽  
Water Jet ◽  
Volume Flow ◽  
Standoff Distance ◽  
Water Volume ◽  
True Nature ◽  
Flow Rates ◽  
Erosion Depth ◽  
Pulsating Water Jet

The water hammer effect is the basis of technologies which is artificially responsible for the decay of continuous jets. A recently developed technique enhances the pressure fluctuations using an acoustic chamber, leading to enhanced erosion effects for various water volume flow rates. The optimum standoff distance for an ultrasonic enhanced water jet is not appropriately estimated using an inclined trajectory. The objective of this study is to comprehend the true nature of the interaction of the standoff distance following the stair trajectory and traverse speed of the nozzle on the erosion depth. Additionally, it also critically compares the new method (staircase trajectory) that obeys the variation in frequency of the impingements for defined volume flow rates with the inclined trajectory. In this study, at constant pressure (p = 70 MPa), the role of impingement distribution with the variation of traverse speed (v = 5–35 mm/s) along the centerline of the footprint was investigated. The maximum erosion depth corresponding to each traverse speed is observed at approximately same standoff distance (65 ± 5 mm) and decreases with the increment in traverse speed (h = 1042 and 47 µm at v = 5 and 35 mm/s, respectively). The results are attributed to the variation in the number of impingements per unit length. The surface and morphology analysis of the cross-section using SEM manifested the presence of erosion characteristics (micro-cracks, cavities, voids, and upheaved surface). By varying the water cluster, different impingement densities can be achieved that are suitable for technological operations such as surface peening, material disintegration, or surface roughening.

Effect of pressure of pulsating water jet moving along stair trajectory on erosion depth, surface morphology and microhardness

Wear ◽  
2020 ◽  
Vol 452-453 ◽  
pp. 203278 ◽  
Author(s):  
Sergej Hloch ◽  
Madhulika Srivastava ◽  
Akash Nag ◽  
Miroslav Müller ◽  
Monika Hromasová ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Water Jet ◽  
Erosion Depth ◽  
Effect Of Pressure ◽  
Pulsating Water Jet

scholarly journals A comparison of UK domestic water services sizing methods with each other and with empirical data

2017 ◽  
Vol 38 (6) ◽  
pp. 635-649 ◽  
Author(s):  
Jess Tindall ◽  
Jamie Pendle
Keyword(s):  
Empirical Data ◽  
Cold Water ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Design Flow ◽  
Water Volume ◽  
Practical Application ◽  
Domestic Water ◽  
Flow Rates ◽  
Water Service

Evidence suggests that domestic cold water service sizing methods in many countries around the world tend to overestimate the actual peak water volume flow rate. Oversizing domestic water service systems does waste materials and money, but it also increases the length of time that it takes for water to pass through the system which can increase water temperatures with the associated risks that presents. This paper compares the three commonly used UK domestic cold water service sizing methods and reveals variance in the methods, the design flow rates calculated and the amount of diversity applied by each method. BS EN 806 returns the lowest design flow rates of the three methods and also applies significantly greater diversity. Empirical domestic cold water service volume flow rate data from two case study buildings revealed that all three UK sizing methods significantly overestimated the peak water volume flow rates but that BS EN 806 was the closest. Additional empirical data from seven more buildings have been used to validate the data from this study and add confidence to the findings. This research provides useful evidence to help engineers select the most appropriate UK domestic cold water service sizing method and to anticipate the likely range and fluctuation of domestic cold water service flow rates. Practical application: Engineers tend to be conservative by nature and generally err on the side of caution to ensure that there is never any cause for customer complaint about their designs. This is understandable but there can be negative consequences if the full implications of such decisions are not fully understood. This paper reveals significant oversizing compared to empirical data from each of the three UK domestic water service sizing methods and highlights the reasons for this. The practical application of this paper lies in the presented results data and analysis which will help engineers make this important choice between the available sizing methods.

RENAL RESEARCH INSTITUTE SYMPOSIUM: Effective Diffusion Volume Flow Rates (Qe) for Urea, Creatinine, and Inorganic Phosphorous (Qeu, Qecr, QeiP) During Hemodialysis

2003 ◽  
Vol 16 (6) ◽  
pp. 474-476 ◽  
Author(s):  
Frank A. Gotch ◽  
Froilan Panlilio ◽  
Olga Sergeyeva ◽  
Laura Rosales ◽  
Tom Folden ◽  
...  
Keyword(s):  
Effective Diffusion ◽  
Volume Flow ◽  
Flow Rates ◽  
Inorganic Phosphorous ◽  
Research Institute

Numerical assessment of pulsating water jet in the conical diffusers

2017 ◽  
Author(s):  
Constantin Tanasa ◽  
Tiberiu Ciocan ◽  
Sebastian Muntean
Keyword(s):  
Water Jet ◽  
Numerical Assessment ◽  
Pulsating Water Jet

scholarly journals Ethylene Glycol Regeneration Plan: A Systematic Approach to Troubleshoot the Common Problems

2013 ◽  
Vol 27 ◽  
pp. 21-26 ◽  
Author(s):  
Md Emdadul Haque
Keyword(s):  
Ethylene Glycol ◽  
Gas Flow ◽  
Salt Content ◽  
Dew Point ◽  
Circulation Rate ◽  
Water Volume ◽  
Processing Plant ◽  
Regeneration System ◽  
Column Temperature ◽  
Flow Rates

Mono Ethylene Glycol (MEG) is used primarily at low-temperature processing plant for extracting natural gas liquids. Typically a physical process plant comprises with gas dehydration system which allows for physical separation of water saturated gas by simple dew point depression and water condensation brought about by chilling from cross exchange with propane refrigerant. The resultant wet gas is prevented from freezing by injection of liquid desiccants to inhibit hydrate formation. The resulting dehydrated gas stream will have a dew point preciously equal to the saturated water volume of the gas at its coolest temperature. Mono Ethylene Glycol has been chosen as hydrate inhibitor because of its low volatility, low toxicity, low flammability, good thermodynamic behavior, and simple proven technology requirement and availability. But it has two common characteristic problems in regeneration plant that is fouling of equipment by iron carbonate, Ca+2/Mg+2 salt deposits and cross contamination of MEG and condensate contamination. MEG in condensate causes condensate specification problems, fouling of condensate stabilization equipment and contamination of wastewater streams. Condensate in MEG causes stripping effect due to condensate vaporization, lower operating temperature, higher MEG purities, and contamination of wastewater streams from MEG Regeneration system and burping of column due to condensate buildup. Another common problem is glycol losses due to carryover with dehydrated gas and which finally accumulates in pipelines and causes corrosion. Other reasons of glycol losses are higher column temperature, foaming, leaks at pump or pipe fittings, operated with excessive gas flow rates and rapid changes in gas flow rates. Column Flooding occurred if feed glycol circulation rate exceeded design limit and it does not allow proper separation of glycol and water separator and much glycol losses through vent line. This paper presents an experimental study of glycol losses. Effort has been made to investigate the causes and the study suggests some mitigation plans. Current study suggests the efficiency of the dehydration process depends on a large extent on the cleanliness of the glycol and the regular monitoring of glycol parameters such as glycol concentration, hydrocarbon content, salt content, solids content, pH stabilization, iron content, foaming tendency etc. Losses due to vaporization from reboiler can be minimized by adjusting operating parameters. By developing monitoring procedure and periodic maintenance about 90% operating problems of Glycol Regeneration Plant can be reduced. DOI: http://dx.doi.org/10.3329/jce.v27i1.15853 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 1, June 2012: 21-26

scholarly journals Development of effective methods and means of normalizing the atmosphere of working zones of open-cast mines

2020 ◽  
Vol 34 ◽  
pp. 29-40
Author(s):  
V. Nalyvaiko ◽  
V. Konovaliuk
Keyword(s):  
Experimental Studies ◽  
Negative Temperature ◽  
Water Jet ◽  
Lower Atmosphere ◽  
Water Volume ◽  
Irrigation Systems ◽  
Harmful Substances ◽  
Technical Solutions ◽  
Open Cast ◽  
Air Exchange

The search for technical solutions for effective air exchange in the space of deep open-cast mines. Since intensive air exchange is necessary to remove and disperse harmful impurities from the open-cast mines, improvement can be achieved mainly by intensifying natural air exchange based on phase transformations of liquids in the lower atmosphere of the working zones of the open-cast mines by creating a positive or negative temperature gradient. New technical solutions are considered that provide support for the sanitary-hygienic parameters of the atmosphere of the deep open-cast mines at the normative level. The formation of an ascending gas stream by a cascade explosion of a fuel-air mixture has the greatest efficiency. The proposed method allows for the implementation of a pulsed ventilation mode with a power of the outgoing air flow of more than 1010 W with a blasting fuel mass of 30 tons. It has been established by analytical and experimental studies that it is advisable to use pulsed fine irrigation systems to intensify air exchange in a deep open-cast mines, using the double effect, ventilating gaseous working zones and cleaning them from harmful substances with the help of a fine aerosol freely floating in space. It is also advisable to use such facilities to reduce peak loads on emissions of harmful substances from the open-cast mines into the environment and to normalize the composition of the atmosphere of the deep open-cast mines. Significant peak emissions of harmful impurities in open-cast mines include mass explosions and situations involving the creation of internal inversion zones. In a computational experiment, there are two water guns: big gun (the water jet range is 200 m, water volume per one cycle is 1000 dm3) and small gun(the water jet range is 100 m, water volume per one cycle is 200 dm3). The results of the experiment indicate greater efficiency in the use of a large water gun for airing the lower horizons of the deep open-cast mines. The use of pulsed fine irrigation systems will allow for carrying out internal technological work at a depth of more than 500 meters using a motorized ore delivery system to transfer points of cyclic-flow technology.

Steady inclined flows of granular-fluid mixtures

2009 ◽  
Vol 641 ◽  
pp. 359-387 ◽  
Author(s):  
D. BERZI ◽  
J. T. JENKINS
Keyword(s):  
Volume Flow ◽  
Angle Of Repose ◽  
Recent Theory ◽  
Fluid Mixture ◽  
Flow Rates ◽  
Fluid Mixtures ◽  
Gravity Driven ◽  
Granular Fluid ◽  
Gravity Driven Flow ◽  
Inclined Flow

We extend a recent theory for steady uniform gravity-driven flow of a highly concentrated granular-fluid mixture over an erodible bed between frictional sidewalls. We first include angles of inclination greater than the angle of repose of the particles; then, we introduce a boundary condition for flow over a rigid bumpy bed. We compare the predictions of the resulting theory with the volume flow rates, depths and angles of inclination measured in the experiments on dry and variously saturated flows over rigid and erodible boundaries. Finally, we employ the resulting theory, with the assumption that the flow is shallow, to solve, in an approximate way, for the variation of height and average velocities along a steady non-uniform inclined flow of a granular-fluid mixture that moves over a rigid bumpy bed. The solutions exhibit features of the flow seen in the experiments – for example, a dry bulbous snout in advance of the fluid, whose length increases with increasing number of the particles and that disappears with increasing velocity – for which satisfactory explanations were lacking.

Sign in / Sign up

Export Citation Format

Share Document