Perforated Pipe Research Articles

Local site conditions and hydromechanical effects in service life of cantilever retaining walls

The present study has two objectives for the design of cantilever walls based on the local site conditions: i) estimating the minimum foundation width in the seismic loading condition and ii) determining the critical water level, which causes wall failure, for the design of an effective drainage system. Therefore, cantilever retaining walls are designed according to different design considerations such as stem height (H = 2.5, 4, 6 m), local soil class (ZC, ZD, ZE), and seismic characteristics of ground (PGA = 0.095–0.687 and kh = 0.057–0.403). Stability analyses (bearing capacity, allowable eccentricity, sliding, overturn, overall stability, and settlement) were performed using the limit equilibrium method. Static and dynamic earth thrusts were determined using the Coulomb and Mononobe-Okabe methods, respectively. Analysis results show that local soil class is a more effective parameter than PGA in the seismic design of cantilever walls. Regression equations (R2 > 0.97) are proposed to estimate minimum foundation width (B) easily. Moreover, the critical water height decreases to one-fifth of the wall height, especially in regions with low earthquake risk (PGA < 0.2). Regression equations (R2 > 0.98) are proposed to find critical water height. In the design of the drainage system, inclined perforated pipes should be connected to horizontal ones and continued up to the critical water height on the interface layer between the backfill and natural ground.

Investigation of flow regimes, pressure drop, void fraction, film thickness, friction factor and production of two-phase flow in a perforated horizontal wellbore

This study focuses on investigating the impact of flow patterns on production in perforated horizontal wellbores. According to experimental and numerical results, this paper discussion the behaviour of total pressure drop, mixture superficial velocity, void fraction, liquid film thickness, and production that occur with various flow patterns in a perforated horizontal pipe. The flow patterns were predicted experimentally and numerically using a pipe with a length of 3 m and an internal diameter of 0.0381 m, with two perforations of inside diameter 0.004 m with a phasing angle of °180, to simulate the complex flow in horizontal wellbores. Total pressure drop and liquid film thickness were reduced by increasing the radial air flow of the perforations. At the same time, void fraction and mixture superficial velocity were observed to increase. Additionally, the film thickness increased with the holdup fraction but decreased with the void fraction. The local friction factor reflected the behaviour of the mixture's superficial velocity during the region of the perforations. The friction factor with the perforated horizontal pipe was greater than that in the unperforated horizontal pipe. The liquid product increased with an increase in the mixture's superficial velocity, and the percentage amounts of production shown were 10%, 40%, and 75%, depending on the water's superficial velocity. The convergence between experimental and numerical results was good during the flow patterns (slug flow and stratified flow). In contrast, some differences in the static pressure drop behaviour occur during flow patterns (bubble flow, dispersed bubble flow, and stratified wave flow).

Effect of using trailing perforated pipe on irrigation efficiency for maize production

Effect of using trailing perforated pipe on irrigation efficiency for maize production

Case study: Noise attenuating performance of perforated corrugated lined straight-through perforated pipe-resistant muffler

Noise of internal combustion engine is the main source of noise pollution, and mufflers are the main means to reduce exhaust noise of internal combustion engine. In the process of improving the acoustic performance of the exhaust muffler based on the three-dimensional numerical method, the influence of the high speed and high temperature airflow discharged by the engine in the actual working process on the acoustic performance of the exhaust muffler is often ignored, which leads to the obvious deviation between the predicted results and the actual situation. In this paper, based on the structural optimization design of the straight-through perforated pipe resistance muffler, the noise characteristics of the straight-through perforated pipe resistance muffler with perforated corrugated lining was analyzed considering the airflow velocity and temperature inside the muffler. The influence of temperature and velocity fields on the acoustic performance of muffler was studied by using numerical simulation method, which takes the solution results inside muffler as boundary conditions of sound field analysis. The influence of changing the internal structure of muffler on the aerodynamic performance of muffler was discussed, and the pressure loss is analyzed. The research has shown that adding perforated corrugated lining inside muffler could effectively improve the transmission loss of muffler and the noise reduction performance of prototype straight-through perforated pipe-resistant muffler.

A Reduced-Order Fluid Flow Model for Gas Injection into Porous Media: For Application in Carbon Sequestration in Mine Tailings

One method to accelerate carbon sequestration within mine tailings from remote mines involves the injection of diesel generator exhaust into dry stack tailings. The techno-economic feasibility of this approach heavily depends on understanding the flow characteristics inside the perforated injection pipes embedded within the tailings. Two distinctive yet dynamically coupled transport phenomena were identified and evaluated: (i) gas transport inside the pipe and (ii) gas injection into the porous body of the tailings. This paper presents two models to investigate these transport phenomena, a three-dimensional (3D) and a one-plus-one-dimensional (1 + 1)D model. An experimental investigation of the pressure profile through the injection pipe was carried out to validate the models at the experimental scale. To apply the (1 + 1)D model to larger scales, the results were compared with those of the 3D model, as the (1 + 1)D model required significantly less computational resources and time. To include the effect of the perforations in the pipe on the pressure profile of the (1 + 1)D model, an analytical fluid velocity profile was developed in relation to geometric and physical parameters. The performance of the (1 + 1)D model with an impact factor was then evaluated against the 3D model results for the inlet pressure, pressure profile and gas outflow distribution under various conditions than those investigated experimentally. The developed (1 + 1)D model can be used to design an energy-efficient approach for large-scale implementation with a wide range of desired operating parameters.

Large eddy simulation of a row of impinging jets with upstream crossflow using the lattice Boltzmann method

Large eddy simulations of a row of seven jets emerging from a perforated pipe and impinging on a flat heated plate were carried out using a compressible hybrid thermal lattice Boltzmann solver. The average Reynolds number of the emerging jets was 5000, with an exit-to-plate distance of 3 jet diameters. Two levels of upstream crossflow were simulated: one with weak cross flow, with a velocity ratio of ≈9.7, and one with strong cross flow, with a velocity ratio of ≈2. The flow field and heat transfer statistics were validated against experimental PIV and infrared thermography data from a recent study, showing good agreement. The effect of varying the Mach number on the wall heat transfer was subsequently tested. It was found that an increased Mach number lead to an increased value of the Nusselt number near the stagnation points.

High accuracy keyway angle identification using VGG16-based learning method

Aligning perforated pipes in different manufacturing workstations is critical for ensuring the quality of the final product in the oil&gas industry. Keyways inside the pipes are typically used for alignment. In order to automate the alignment process using an industrial robot, the keyway angle must be identified accurately. Because the environmental conditions keep changing in the shop floor, current methods cannot satisfy the accurate alignment requirement. Recently, VGG16 has become one of the most effective ways to deal with vision-based problems with different lighting conditions. Therefore, this paper proposes a method based on the VGG-16 architecture to identify the keyway angle to satisfy the manufacturing requirement (angle accuracy <1o) in different lighting conditions. In order to demonstrate the effectiveness of the proposed method, two traditional methods, a commercial vision method, and a geometrical rule based method, are also investigated. The comparisons of the three methods show that the proposed method performs best, yielding an angle error less than 1° in 98.38% of the testing images. The research results indicate that VGG-16 based method has significant potential to improve manufacturing processes.

State of the art of rational design of efficient mufflers

An efficient exhaust muffler needs to satisfy the rather conflicting requirements of adequate insertion loss (IL) with limited back pressure, weight, size and cost. The unmuffled exhaust noise of an internal combustion engine peaks at the engine firing frequency and the first few harmonics thereof. Designing the muffler (a wide-band low pass acoustical filter) for such low frequencies is quite a challenge. Therefore, design of efficient mufflers has remained an art as well as science. During the last two decades or so, however, (a) multi-hole cross-flow perforates, (b) multiply connected perforated pipes and baffles, and (c) the double-tuned, grazing-flow concentric tube resonators have emerged as promising constituent elements. In this paper, elements (a) and (c) have been combined ingeniously to synthesize efficient muffler configuration for diesel generator (DG) sets as well as automotive engines. Relatively simpler lumped parameter approximation for perforates opening into cavities, electro-acoustic analogies, and the simple expansion chamber equivalence of the double-tuned concentric tube resonator have been used to develop a rational design methodology. A novel feature of this methodology is incorporation of the given back-pressure limit into the acoustic design process. The resulting muffler configurations are robust and can be scaled up (and down) easily for IL as well as back pressure.

Investigating the Relationship between the Manning Coefficients (n) of a Perforated Subsurface Stormwater Drainage Pipe and the Hydraulic Parameters

Subsurface perforated pipes drain infiltrated stormwater runoff while attenuating the peak flow. The Manning roughness coefficient (n) was identified as a fundamental parameter for estimating roughness in various subsurface channels. Hence, in this work, the performance of a six-row non-staggered sand-slot perforated pipe as a sample of the subsurface drainage is investigated experimentally in a laboratory flume at Universiti Sains Malaysia (USM) aimed at determining the Manning roughness coefficients (n) of the pipe and assessing the relationship between the Manning’s n and the hydraulic parameters of the simulated runoff flow under the conditions of the tailgate channel being opened fully (GFO) and partially (GPO), as well as the pipe having longitudinal slopes of 1:750 and 1:1000. Water is pumped into the flume at a maximum discharge rate of 35 L/s, and the velocity and depth of the flow are measured at nine points along the inner parts of the pipe. Based on the calculated Reynolds numbers ranging from 38,252 to 64,801 for both GFO and GPO conditions, it is determined that most of the flow in the perforated pipe is turbulent, and the calculated flow discharges and velocities from the outlets under GFO are higher than the flow and velocity rates under GPO with similar pipe slopes of 1:750 and 1:1000. The Manning coefficients are calculated at nine points along the pipe and range from 0.004 to 0.009. Based on the ranges of the calculated Manning’s n, an inverse linear relationships between the Manning coefficients and the flow velocity under GFO and GPO conditions are observed with the R2 of 0.975 and 0.966, as well as 0.819 and 0.992 resulting from predicting the values of flow velocities with the equations v = ((0.01440 − n)/0.009175), v = ((0.01330 − n)/0.00890), v = ((0.02007 − n)/0.01814), and v = ((0.01702 − n)/0.01456) with pipe slopes of 1:750 and 1:1000, respectively. It is concluded that since the roughness coefficient (Manning’s n) of the pipe increases, it is able to reduce the flow velocity in the pipe, resulting in a lower peak of flow and the ability to control the quantity of storm water in the subsurface urban drainages.

Hydrodynamics of a reactor for thermocatalytic oxidation of sewage sludge

One of the promising methods for the disposal of municipal sewage sludge is its thermocatalytic oxidation in fluidized bed reactors. An important factor determining the stability of the operation of fluidized bed reactors is the uniform introduction of the air flow, which, on the one hand, fluidizes a bed of catalyst solid particles and solid sewage sludge, and, on the other hand, the oxygen of the air flow serves as an oxidizing agent in chemical reactions occurring in the reactor. A pilot plant for thermocatalytic oxidation, created according to the technology of the Boreskov Institute of Catalysis, is operated at JSC Omskvodokanal (Omsk, Russia). The plant's capacity is 50 thousand tons per year of mechanically dehydrated sludge with a water content of 70–80 wt%. The cross-sectional area of the sludge combustion zone is 3.8 m2. The heat flow from the incoming sludge (physical heat and heat of combustion) is 6527000 kcal/h. The air flow was introduced into the fluidized bed reactor with a sparger of 6 perforated pipes arranged horizontally and in parallel. The purpose of this work is to investigate the influence of inlet conditions on fluidized bed hydrodynamics. The results obtained showed that despite the uneven distribution of air flow through the holes of the sparger tubes, each pair of adjacent sparger tubes mutually compensate each other in terms of air flow per unit area of the cross section of the reactor. It is also shown that during the operation of the reactor, air cavities are formed under the sparger pipes, which are practically free of solid particles. The position of such air cavities and their approximate volume are stationary in time for a developed fluidized bed, and the volume of the cavities is approximately proportional to the dimensions of the respective sparger tubes. These air cavities periodically eject bubbles into the overlying portions of the fluidized bed. The dimensions of the bubbles are comparable to the transverse dimensions of the pipes.

Analisis Karakteristik Aliran Irigasi Perforasi Pada Lahan Datar

Perforation irrigation is a unidirectional beam irrigation system that can be used for crop irrigation on dry land, due to the efficient use of water and the ability to wet land with a limited area. Therefore, the perforation irrigation system needs to be studied further in relation to the area of land that can be irrigated and the distribution of discharge to each perforated pipe. By testing several variations of the water level, the perforation irrigation emission capability will be obtained in the form of irrigation distribution, uniformity, emission capability and discharge amount used in irrigation on flat land. This study aims to determine the perforation irrigation capacity on flat land, the distribution of irrigation and the amount of discharge required. The test was carried out on three perforated pipes made of ½” PVC as lateral pipes, three transmission pipe length variations, such as 0.8m, 1m, and 1.2m with a distance between the perforations of 60 cm. The source of irrigation water comes from a 3 m tall tower with a capacity of ± 200 𝑙𝑖𝑡𝑒𝑟. The test uses three variations of head height, namely h1 350 cm, h2 360 cm, h3 370 cm and h4 380 cm. The results showed that the perforation irrigation jet length was around 100cm -120 cm, the uniformity of CU irrigation was above 97% with a total discharge on h1 QT = 0.689 lt/s, h2 QT = 0.690 lt/s , h3 QT = 0.695 lt/s and on h4 QT = 0.701 lt/s. While the range of flow rates for perforation 1 pipe Q1 (0.42 lt/s – 0.429 lt/s), perforation 2, Q2 (0.13 -0.145 lt/s) and perforation 3, Q3 (0.129 - 0.135 lt/s)

Geology‐Climate Interactions are Key Determinants of Climate‐Change Refugia in Japanese Mountain Streams

Photo 1. Example of the confluence of a volcanic and nonvolcanic stream (left panel). The right panel is a thermal photograph of the confluence taken using a TVS-500 camera (Nippon Avionics Co., Ltd.) on September 17, 2019, where blue colors correspond to the cold water from the volcanic stream mixing with the warmer (orange) water from the nonvolcanic stream. Photo credit: Kenta Iwasaki. Photo 2. View of a volcanic stream, Ponnunobe stream, the Sorachi river, Hokkaido, Japan. The stream is located inside the University of Tokyo Hokkaido Forest. Many springs (top panels) occur in around the main channel (bottom panel). In this region, the mean summer water temperature of volcanic streams is 3°C colder than that of nonvolcanic streams on average. Photo credit: Yu Nagasaka. Photo 3. Wrinklehead sculpin (upper panel: Cottus nozawae) and Southern Asian Dolly Varden (lower panel: Salvelinus curilus) two major cold-water species in northern Japan. Their distribution is tightly restricted by summer water temperature. Photo credit: Yu Nagasaka (upper panel) and Chiharu Furusawa (lower panel). Photo 4. View of biotic and abiotic surveys in mountain streams, Japan. Macroinvertebrates (upper left panel) and fish (lower left panel) were collected once in each monitoring stream. Water loggers were installed with short sections of perforated PVC pipes to facilitate water exchange and shield them from sunlight (right panels). Photo credit: Jorge García Molinos. Photo 5. Dynamic changes in riverscapes at a monitoring site due to a large flood associated with Typhoon Hagibis, 2019 (before: upper panel, after: lower panel). Monitoring of water temperature in the Japanese archipelago is very challenging because of the many typhoons hitting the archipelago every summer season. Unfortunately, the temperature data of this site in 2019 was not available due to the loss of the logger. The yellow bridge at the upper-left corner of the picture offers a good visual reference to compare both pictures. Photo credit: Nobuo Ishiyama. These photographs illustrate the article “Underlying geology and climate interactively shape climate change refugia in mountain streams” by Ishiyama, N., Sueyoshi, M., García Molinos, J., Iwasaki, K., Negishi, J. N., Koizumi, I., Nagayama, S., Nagasaka, A., Nagasaka, Y. & Nakamura, F. published in Ecological Monographs. https://doi.org/10.1002/ecm.1566

A Critical Evaluation of Recent Studies on Packed-Bed Bioreactors for Solid-State Fermentation

Packed-bed bioreactors are often used for aerobic solid-state fermentation, since the forced aeration supplies O2 and removes metabolic heat from the bed. Motivated by the potential for applications in biorefineries, we review studies conducted on packed-bed bioreactors over the last decade, evaluating the insights these studies provide into how large-scale packed beds should be designed and operated. Many studies have used low superficial air velocities and suffer from preferential airflow, such that parts of the bed are not properly aerated. Moreover, some studies have proposed ineffective strategies, such as reversing the direction of the airflow or introducing air through perforated pipes within the bed. Additionally, many studies have used narrow water-jacketed packed-bed bioreactors, but these bioreactors do not reflect heat removal in wide large-scale packed beds, in which heat removal through the side walls makes a minor contribution. Finally, we conclude that, although some attention has been given to characterizing the porosities, water sorption isotherms and volumetric heat and mass transfer coefficients of substrate beds, this work needs to be extended to cover a wider range of solid substrates, and work needs to be done to characterize how these bed properties change due to microbial growth.

Low frequency attenuation of acoustic waves in a perforated pipe.

This paper presents new experimental and numerical evidence that perforations in a pipe wall result in a low-frequency bandgap within which sound waves rapidly attenuate. These perforations are modelled as an acoustically soft boundary condition on the pipe wall and show that a low frequency bandgap is created from 0 Hz. The upper bound of this bandgap is determined by the dimensions and separation of the perforations. An analytical model based on the transfer matrix method is proposed. This model is validated against numerical predictions for the pipe with varying perforation geometries. A numerical study is undertaken to model the effect of perforations with ideal acoustically soft boundary conditions and surrounded with an air gap. Close agreement is found between the numerical and analytical models. Experimental evidence shows that the width of the bandgap is accurately predicted with the numerical and analytical models.

Low frequency attenuation of acoustic waves using sound-soft scatterers

The attenuation of acoustic waves by silencers is typically achieved through the employment of rigidly backed cavities, connected to a main waveguide by a perforated panel. This invokes a resonant response at frequencies determined by the dimensions of the perforation and the rigidly backed cavity. A limiting factor in this approach is that to achieve low frequency attenuation, either large cavity depths are required, which is often impractical, or narrow neck regions need to be used, where performance is limited due to the viscothermal losses. Within this paper, a non-rigidly backed perforated pipe is presented where the pressure release condition at each perforation creates an acoustic sound-soft boundary condition. By the introduction of sound-soft boundary conditions, a low frequency band gap is created as the first order mode is shifted to a non-zero value, the frequency of which is determined by the dimensions and separation of the perforations. Experimental results displaying this band gap are presented along with numerical models verifying the phenomenon and an ideal analytical model based upon the transfer matrix method.

Productivity, nutrient uptake and profitability of winter season rice (Oryza sativa) varieties as influenced by alternate wetting-drying irrigation and nitrogen management

A field experiment was conducted on clay loam soil at Agricultural Research Institute, Rajendranagar, Hyderabad, Telangana, during the winter (rabi) season of 2016–17 and 2017–18, to identify optimum scheduling of alternate wetting and drying irrigation (AWD) under different nitrogen levels on rice (Oryza sativa L.) varieties. The treatments consisted of 3 irrigation regimes, i.e. recommended submergence of 2 to 5 cm water level, AWD irrigation when water level falls below 3 cm from soil surface in perforated pipe, AWD irrigation when water level falls below 5 cm from soil surface in perforated pipe, as main plot treatments; 3 nitrogen levels (120, 160 and 200 kg N/ha) as subplot treatments; and 2 rice varieties (‘KNM 118’ and ‘JGL 18047’) as sub-subplot treatments laid out in a split-split plot design with 3 replications. There was no significant difference in terms of growth, yield attributes, yield, nutrient uptake and economics between rice varieties ‘KNM 118’ and ‘JGL 18047’ with continuous submergence, and alternate wetting and drying irrigation under different nitrogen levels during the winter (rabi) season. Irrigation maintained at recommended submergence of 2 to 5 cm water level resulted in higher growth parameters, yield attributes, grain yield (7,123 kg/ha), straw yield (8,045 kg/ha), nutrient uptake and net returns (`57,202/ha), which were comparable with AWD irrigation when water level falls below 3 cm from soil surface in perforated pipe. Application of 200 kg N/ha ensued higher growth parameters, yield attributes, grain yield (7,086 kg/ha), straw yield (7,907 kg/ha and net returns (`57,247/ha), which were at par with 160 kg N/ha.

Environmental aspects of subsurface irrigation and development of a mathematical model of a double-circuit solar heating system

This article discusses the method of subsurface irrigation of agricultural crops. A technological system for subsoil irrigation has been developed using an industrial base for the production of perforated polyethylene pipes of small diameter. In the first moments of water supply for irrigation, when the soil has low initial moisture, the flow through the perforations is maximum. This leads to an intensive increase in the humidification circuit. As the water flow stabilizes, the increase in the size of the circuit in the horizontal and vertical directions practically stops, and further deformation of the humidification circuit occurs mainly due to gravitational forces. When the hydrostatic head at the entrance to the subsurface irrigation system increases above 70 cm, the spread of moisture in the soil in the horizontal and vertical directions increases slightly, but this can lead to the danger of soil destruction and water wedging out on the soil surface. A mathematical model of thermohydraulic processes in a thermosiphon system designed for watering the cultivation layer in solar greenhouses during the cold season according to the subsoil irrigation scheme has been developed. The dynamics equations of all functional blocks were taken into account in accordance with the accepted assumptions.

Methods for increasing the productivity of a water intake well via enlarging the diameter of the filter part

The research data on increasing the flow rate of a water intake well is presented in this paper. The well was drilled in sandy soil. A filter element was used. The source was more than 45 m deep. Two-string wells were chosen as the basis. The wells of this type are drilled onto the rocks of quaternary deposits (sand). A coarse filter, which represents a perforated pipe covered with a filtered mesh, was used in this structure. The objective of the paper was to achieve maximum water yield of the water-bearing stratum from a two-string well via increasing the area of its filtering part to provide water for capital construction projects. The research results showed that an increase in the diameter of the filter part to the maximum (168 mm) increases the flow rate by 82.2% for the rocks of quaternary deposits (sand) with a two-string well system

EFFECTS OF ADDITIVELY MANUFACTURED SURFACE ROUGHNESS ON SMALL DIAMETER PLENUMS WITH MULTIPLE SIDE DISCHARGES FOR HIGH TEMPERATURE GAS TURBINE BLADE COOLING APPLICATIONS

Combined heat and power (CHP) applications have significant environmental and economic benefits that are consistent with the goals of the U.S. Department of Energy (DOE). One area that is currently being studied includes the potential benefits of CHP turbine operation at higher turbine inlet temperatures. Internal cooling concepts enabled by additive manufacturing (AM) are of primary interest. The effectiveness of internal cooling is hindered by many factors such as velocity distribution of the cooling air to the hot surface considering impingement cooling. To simulate cooling air exiting from a series of orifices for internal cooling in an airfoil, a straight smooth wall tubing with multiple side discharging orifices is used and compared to additively manufactured tubing (Ti6Al4V Grade 23) with orifice size and spacing as well as inner and outer diameters identical to the smooth wall tubing. Similar to flow discharging form perforated pipes, the flow discharged from individual orifices along the tubes in this study is found to be nonuniformly distributed, and the horizontal (axial direction) momentum can be observed from the experimental data. Discharge velocities have been measured with two-dimensional (2D) particle imaging velocimetry (PIV) and single element hot wire anemometry. Numerical analysis has also been conducted to predict the velocity distributions along the orifices in the smooth wall and additive manufacturing (AM) tubing, which are inherited with surface roughness. Numerical and measured results in this study are compared, presented, and discussed.

전산유체해석을 활용한 일체형 침전부상조 미세기포수 및 최종처리수 유공관의 설계인자 검증 연구

In this research, the feasibility of the design parameters for microbubble distribution and perforated drainpipes in the integrated sedimentation and dissolved air flotation (SeDAF) process for an advanced wastewater treatment plant was verified using computational fluid dynamics (CFD) analysis. The flow rates for the raw water and the microbubble distribution stage were 100 and 15㎥/d respectively. In the simulation, the raw water was first introduced into the mixing tank and then passed on to the coagulation, sedimentation, and flotation stages in sequence. The flow velocity for each stage increased at the narrowed cross-sectional points. It was observed that some of the coagulated water flowing into the inclined plate module in the sedimentation stage spilled out. As a result of the CFD analysis, the average flow rate for the four perforated distribution pipes was 0.014 kg/s. The standard deviation (SD) for the simulations of original and alternative model was 0.00050 and 0.00062, respectively, which indicated that the simulations were successful and reliable. The SD for the average flow rate for the four perforated pipes was 0.00706, 0.00779, 0.00833, and 0.00938, respectively. The aver age flow rates for each pipe were decreased by 0.0003, 0.0000, 0.0002, and 0.0002 kg/s, respectively compared to the original model. This simulation of characterization of microbubble distribution and perforated drainpipe demonstrated that the design parameters for the distribution pipes were set so that the microbubbles were distributed evenly and that the perforated drainpipes successfully withdrew the treated water within the integrated SeDAF process.