scholarly journals Investigation of the Effect of Pipeline Size on the Cross Flow Injection Process

2016 ◽  
Vol 6 (3) ◽  
pp. 1023-1028 ◽  
Author(s):  
M. Elashmawy ◽  
A. Alghamdi ◽  
I. Badawi
Keyword(s):  
Flow Injection ◽  
Flow Behavior ◽  
Cross Flow ◽  
Industrial Applications ◽  
Injection Process ◽  
Injection Pump ◽  
Flow Mixing ◽  
Injection Dose ◽  
The Cross ◽  
Line Pressure

Injection pumps constitute an essential component for many industrial applications. The main focus of this study is to predict the effect of the size of the pipeline on the cross flow injection process. A test-rig was designed, built and equipped with three different pipelines, 1½", ¾" and ½" diameters. Comparison was made under constant line pressure of 40-bar and line flow rate of 5 liter/min, with a fixed injection pump rotational speed of 100 rpm. The main parameter tested was the injection dose capacity at different pump displacements. Cross flow mixing process is also theoretically studied using 3D-CFD analysis to show the injection cross flow behavior for the same geometry and parameters used for experimental test. Results show that increasing the size of the pipeline increases injection pump doses ability. This effect is insignificant at lower injection pump displacements, while the effect of the size of the pipeline becomes dominant when increasing the displacement. By changing the size of the pipeline from ½" to 1½" diameter injection pump dose capacity increases by 3.24% at 100% pump displacement. Selecting larger pipe sizes for injection ports is recommended whenever possible.

scholarly journals 3D-CFD Simulation of Confined Cross-Flow Injection Process Using Single Piston Pump

2017 ◽  
Vol 7 (6) ◽  
pp. 2308-2312
Author(s):  
M. Elashmawy
Keyword(s):  
Chemical Engineering ◽  
Cross Flow ◽  
Maximum Velocity ◽  
Water Desalination ◽  
Flow Ratio ◽  
Minimum Pressure ◽  
Injection Process ◽  
Injection Flow ◽  
Injection Pump ◽  
Jet Trajectory

Injection process into a confined cross flow is quite important for many applications including chemical engineering and water desalination technology. The aim of this study is to investigate the performance of the injection process into a confined cross-flow of a round pipe using a single piston injection pump. A computational fluid dynamics (CFD) analysis has been carried out to investigate the effect of the locations of the maximum velocity and minimum pressure on the confined cross-flow process. The jet trajectory is analyzed and related to the injection pump shaft angle of rotation during the injection duty cycle by focusing on the maximum instant injection flow of the piston action. Results indicate a low effect of the jet trajectory within the range related to the injection pump operational conditions. Constant cross-flow was used and injection flow is altered to vary the jet to line flow ratio (QR). The maximum jet trajectory exhibits low penetration inside the cross-flow. The results showed three regions of the flow ratio effect zones with different behaviors. Results also showed that getting closer to the injection port causes a significant decrease on the locations of the maximum velocity and minimum pressure.

The Cross Flow Mechanism in the Micro Channel of a Polymer Electrolyte Fuel Cell

2013 ◽  
Author(s):  
K. M. Salahuddin ◽  
Nobuyuki Oshima ◽  
Litan Kumar Saha
Keyword(s):  
Fuel Cell ◽  
Flow Rate ◽  
Oxygen Transport ◽  
Gas Flow ◽  
Flow Behavior ◽  
Cross Flow ◽  
Polymer Electrolyte Fuel Cell ◽  
Micro Channel ◽  
Flow Through ◽  
The Cross

In this article we presented the recent activities in the field of gas flow in the micro channel and porous media of a polymer electrolyte fuel cell (PEFC). The gas flow behavior in the micro-channel, especially in the case of serpentine channel is very complex due to the appearance of cross flow through the gas diffusion layer (GDL). The gas flow behavior in the separator channel and GDL of a PEFC has been studied by using a transient, isothermal and three dimensional numerical models. To predict gas flow phenomena accurately the precise calculation of mass conversation is necessary which is strictly maintained in our present simulation. The effects of physical characteristics and geometrical properties have been investigated to quantify the amount of cross flow and pressure loss. The cross flow has been investigated in terms of volume mass flux through the GDL under the rib. The ratio cross flow rate to the total flow rate increases when gas channel pitch length decreased. Moreover, with increasing of permeability this ratio also increases. The effect of cross flow and bend region characteristics on the pressure loss has been identified. In addition, to isolate the contribution of cross flow on the performance of fuel cell, the simulation was carried out with electrochemical reaction using parallel straight channel. We designed a parallel flow field to induce artificial cross flow through the GDL. The numerical results show that the flow cross-over through the GDL under the rib significantly facilitate the oxygen transport towards the catalyst layer. Therefore, it is possible to overcome the oxygen transport limitation. Consequently, the cross flow can increase the current density by reducing the oxygen transport limitation, although this also increases the non-uniformity in current density.

The Cross-Flow Mixing Analysis of Quasi-Static Pebble Flow in Pebble Bed Reactor

2018 ◽  
Author(s):  
Fang Xiang ◽  
Yang Xingtuan ◽  
Jiang Shengyao
Keyword(s):  
Cross Flow ◽  
Particle Flow ◽  
Research Subjects ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
Slow Particle ◽  
Flow Mixing ◽  
The Cross ◽  
Pebble Flow ◽  
Flow Cross

In the pebble bed reactor, large number of fuel pebbles’ movement law and moving state can affect the reactor’s design, operation and safety directly. Therefore the pebble flow, which is based on the theory of particle streaming, is one of the most important research subjects of the pebble bed reactor engineering. The in-core pebble flow is a very slow particle flow (or called quasi-static particle flow), which is very different from the usual particle motion. How to accurately describe the characteristics of in-core pebble flow is a central issue for this subject. Due to the presence of random flow, the cross-mixing phenomenon will occur inevitably. In the present paper, the mixing phenomenon of pebble flow is generalized on the basis of experiment results. The pebble flow cross-mixing probability serves as the parameter which describes both the regularity and the randomness of pebble flow. The results are provided in the form of diagrammatic presentation.

Effect of operational modes on the removal of a synthetic organic chemical by powdered activated carbon during ultrafiltration

2001 ◽  
Vol 1 (5-6) ◽  
pp. 39-47
Author(s):  
Y. Matsui ◽  
A. Yuasa ◽  
F. Colas
Keyword(s):  
Activated Carbon ◽  
Cross Flow ◽  
Powdered Activated Carbon ◽  
Organic Chemical ◽  
Filtration Cycle ◽  
Dead End ◽  
Synthetic Organic Chemical ◽  
The Cross ◽  
Short Time ◽  
Operational Modes

The effects of operational modes on the removal of a synthetic organic chemical (SOC) in natural water by powdered activated carbon (PAC) during ultrafiltration (UF) were studied, through model simulations and experiments. The removal percentage of the trace SOC was independent of its influent concentration for a given PAC dose. The minimum PAC dosage required to achieve a desired effluent concentration could quickly be optimized from the C/C0 plot as a function of the PAC dosage. The cross-flow operation was not advantageous over the dead-end regarding the SOC removal. Added PAC was re-circulated as a suspension in the UF loop for only a short time even under the cross-flow velocity of gt; 1.0 m/s. The cross-flow condition did not contribute much to the suspending of PAC. The pulse PAC addition at the beginning of a filtration cycle resulted in somewhat better SOC removal than the continuous PAC addition. The increased NOM loading on PAC which was dosed in a pulse and stayed longer in the UF loop could possibly further decrease the adsorption rate.

scholarly journals Numerical Analysis of Air Vortex Interaction with Porous Screen

Fluids ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 70
Author(s):  
Xudong An ◽  
Lin Jiang ◽  
Fatemeh Hassanipour
Keyword(s):  
Physical Properties ◽  
Vortex Ring ◽  
Numerical Study ◽  
Flow Behavior ◽  
Industrial Applications ◽  
Moving Mesh ◽  
Vortex Flows ◽  
Vortex Interaction ◽  
Piston Cylinder ◽  
Porous Screen

In many industrial applications, a permeable mesh (porous screen) is used to control the unsteady (most commonly vortex) flows. Vortex flows are known to display intriguing behavior while propagating through porous screens. This numerical study aims to investigate the effects of physical properties such as porosity, Reynolds number, inlet flow dimension, and distance to the screen on the flow behavior. The simulation model includes a piston-cylinder vortex ring generator and a permeable mesh constructed by evenly arranged rods. Two methods of user-defined function and moving mesh have been applied to model the vortex ring generation. The results show the formation, evolution, and characteristics of the vortical rings under various conditions. The results for vorticity contours and the kinetic energy dissipation indicate that the physical properties alter the flow behavior in various ways while propagating through the porous screens. The numerical model, cross-validated with the experimental results, provides a better understanding of the fluid–solid interactions of vortex flows and porous screens.

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