scholarly journals Experimental Study on the Adoption of Flushing Technique in Successive Alkalinity-Producing Systems with a Focus on Influence Radius of Orifice

Author(s):  
Dong-Kil Lee ◽  
Young-Wook Cheong

Abstract As a successive alkalinity-producing system pond for purifying mine drainage is operated, sediment accumulates in the limestone layer of the pond, and as the amount of accumulated sediment increases, the water permeability and treatment efficiency of the pond decrease. Hence, a flushing system is required, comprising of a network of perforated pipes installed in the limestone layers, to periodically discharge sediment and mine drainage to the outside. The performance of a flushing system depends on four distinct characteristics of the system: the characteristics of the limestone layer, the sediment, the flow, and the flushing device. However, existing studies have evaluated the performance of the entire system without considering these conditions. In this study, a new experimental method for designing a flushing system is proposed. This method is based on an experiment to evaluate the influence radius of orifice, which is the radius of the spherical volume around an orifice that can suck sludge by flushing. The results showed that the flow rate of water through the orifice in the glass bead layer matched well with the Blake–Kozeny formula, and that the greater the diameter of the orifice, the greater the influence radius of orifice. The influence radius of orifice according to the diameter and spacing of the orifice was evaluated, which provides a key criterion for designing a flushing system.

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2189
Author(s):  
Tingchao Yu ◽  
Xiangqiu Zhang ◽  
Iran E. Lima Neto ◽  
Tuqiao Zhang ◽  
Yu Shao ◽  
...  

The traditional orifice discharge formula used to estimate the flow rate through a leak opening at a pipe wall often produces inaccurate results. This paper reports an original experimental study in which the influence of orifice-to-pipe diameter ratio on leakage flow rate was investigated for several internal/external flow conditions and orifice holes with different shapes. The results revealed that orifice-to-pipe diameter ratio (or pipe wall curvature) indeed influenced the leakage flow, with the discharge coefficient ( C d ) presenting a wide variation (0.60–0.85). As the orifice-to-pipe diameter ratio decreased, the values of C d systematically decreased from about 12% to 3%. Overall, the values of C d also decreased with β (ratio of pressure head differential at the orifice to wall thickness), as observed in previous studies. On the other hand, orifice shape, main pipe flow velocity, and external medium (water or air) all had a secondary effect on C d . The results obtained in the present study not only demonstrated that orifice-to-pipe diameter ratio affects the outflow, but also that real scale pipes may exhibit a relevant deviation of C d from the classical range (0.61–0.67) reported in the literature.


2013 ◽  
Vol 67 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Patrick Atheba ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Didier Robert

The present work evaluates the potential of the photocatalysis (PC) process for the degradation of butylparaben (BPB). Relatively high treatment efficiency was achieved by comparison to photochemical process. Prior to photocatalytic degradation, adsorption (AD) of BPB occurred on the titanium dioxide (TiO2)-supported catalyst. AD was described by Langmuir isotherm (KL = 0.085 L g−1, qm = 4.77 mg g−1). The influence of angle of inclination of the reactor, pH, recirculation flow rate and initial concentration of BPB were investigated. The PC process applied under optimal operating conditions (recirculation flow rate of 0.15 L min−1, angle of inclination of 15°, pH = 7 and 5 mg L−1 of BPB) is able to oxidize 84.9–96.6% of BPB and to ensure around 38.7% of mineralization. The Langmuir–Hinshelwood kinetic model described well the photocatalytic oxidation of BPB (k = 7.02 mg L−1 h−1, K = 0.364 L mg−1).


Author(s):  
Dina Sun ◽  
Shihao Sun ◽  
Genping Meng ◽  
Wenting Guo ◽  
Jun Hai ◽  
...  

The preparation of membranes with improved treatment efficiency and highly enhanced water permeability remains a distant prospect. Herein, a low-cost hybrid membrane composed of silk nanofibers (SNFs) and zeolitic imidazolate...


1987 ◽  
Vol 109 (3) ◽  
pp. 313-318 ◽  
Author(s):  
K. K. Sheth ◽  
G. L. Morrison ◽  
W. W. Peng

Experiments have been carried out in order to determine the effects on slip factor due to the various parameters affecting the performance characteristics of a centrifugal slurry pump. The experiments were conducted with water, sand slurry, and a glass bead slurry at three different pump speeds. Measurements of power, flow rate, head developed by the pump and the density of the slurry were made in order to obtain the characteristic curves of the pump. Using Euler’s equation, equations were derived for calculating the slip and friction factors of the flow. The deduced slip factors for centrifugal slurry pump can be correlated well with suggested non dimensional groups. It shows a consistent trend of decreasing slip factor with increasing slurry mixture density and impeller rotation, or with a decreasing through flow rate. The sizes of the sand and glass bead particles are significantly different (0.71 mm versus 0.09 mm), however, the data correlations do not suggest its effect on the slip factors significantly as the other parameters. The slip factors deduced from head-flow rate curves are more reliable than those deduced from power-flow rate curves, since the shut-off power measurements are likely subjected to errors associated with the particles settling, or the transient effect if the measurements are taken momentarily.


2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 487-494 ◽  
Author(s):  
Aminreza Noghrehabadi ◽  
Ebrahim Hajidavaloo ◽  
Mojtaba Moravej ◽  
Ali Esmailinasab

Solar collectors are the key part of solar water heating systems. The most widely produced solar collectors are flat plate solar collectors. In the present study, two types of flat plate collectors, namely square and rhombic collectors are experi?mentally tested and compared and the thermal performance of both collectors is investigated. The results show both collectors have the same performance around noon (?61%), but the rhombic collector has better performance in the morning and afternoon. The values for rhombic and square collectors are approximately 56.2% and 53.5% in the morning and 56.1% and 54% in the afternoon, respectively. The effect of flow rate is also studied. The thermal efficiency of rhombic and square flat plate collectors increases in proportion to the flow rate. The results indicated the rhombic collector had better performance in comparison with the square collector with respect to the mass-flow rate.


2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Wati Oviana ◽  
Maulidar Maulidar

The research on the use of experimental methods in learning characteristics of material and its usefulness toward students’ achievements and learning responses of Level 4 primary school students of MIN Tungkob Aceh Besar aims to determine students’ learning outcomes and responses toward the use of the method. This study uses experimental research. The data collection techniques were using test and distributing questionnaire to the students. The samples in this experimental study were students of class IV3 totaling 34 people as the experimental class and the class IV4 totaling 31 people as the control class. The data, which is the students’ learning outcomes collected from pretest and posttest, were analyzed using t-test formula. The data from the students’ questionnaire responses were analyzed using percentage formula.The result was that the students’ learning outcomes from the experimental class and the control class showed significant differences. Students’ responses toward the use of experimental methods in learning material characteristics and its usefulness were also very positive, where the students are very excited and interested in learning to use the experimental method in the study of material characteristics and its usefulness.


Author(s):  
Deeksha Vishwakarma ◽  
Jyoti Kale

In this paper, we are studying about solar air heater. The solar air heater are consisting the several component such as flat glass, collector, D.C. fan, photovoltaic cells and electrical storage system. In this study we are achieving the various type of outlet temperature with the help of D.C. fan and various Mass air flow rate using of simple absorber trays forced convection.


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