Predicting pressure drop in pneumatic conveying using the discrete element modelling approach
27 Sep 2010-Progress in Computational Fluid Dynamics (Inderscience Publishers)-Vol. 10, Iss: 5, pp 334-340
TL;DR: In this paper, the authors used the commercial CFD software, STAR-CD, to model pneumatic conveying in a horizontal pipe and obtained reasonable agreement between the predicted pressure drop and the experimental data of Marcus et al. (1990) for spherical particles and Vasquez et al (2008) for non-spherical particles.
Abstract: Pneumatic conveying of solid materials is used in many process industries where solid particles are carried forward in pipes and channels by the fluid. The pressure drop in the system is dependent on a host of parameters such as particle and pipe diameters, particle and fluid properties, pipe roughness and orientation, etc. In this study, the commercial CFD software, STAR-CD is used to model pneumatic conveying in a horizontal pipe. A range of fluid flow rates is studied. Reasonable agreement is obtained between the predicted pressure drop and the experimental data of Marcus et al. (1990) for spherical particles and Vasquez et al. (2008) for non-spherical particles. The sensitivity of the computed results to particle properties and the choice of fluid drag model are also studied.
Citations
More filters
TL;DR: Two fluid or Eulerian modeling incorporating the kinetic theory for granular particles and accounting for four-way coupling was performed to investigate the hydrodynamics and pressure drop characteristics of gas-solid flows in horizontal pipes as mentioned in this paper.
Abstract: Two fluid or Eulerian modeling incorporating the kinetic theory for granular particles and accounting for four-way coupling was performed to investigate the hydrodynamics and pressure drop characteristics of gas-solid flows in horizontal pipes. The model was validated by comparison with the experimental data found in literature and the predictions agreed reasonably well with experimental results. It was found that lift force along with particle-wall collision and specularity coefficient play significant role in the simulation of horizontal gas-solid flows. Granular temperature model by Ding and Gidaspow (1990) predicts the velocity profiles of both phases accurately. The gas-solid two-phase flow in the horizontal pipe generally has an asymmetric structure in the vertical direction, which is due to the effect of gravity. An extensive investigation was also done to study the effect of various flow parameters like particle properties, gas velocity, and solid concentration on pressure drop prediction. Finally...
26 citations
Cites background or methods from "Predicting pressure drop in pneumat..."
...The two fluid model parameters are set comparing the numerical data with the experimental findings of Tsuji and Morikawa (1982). The experiments are carried out in a 30mm diameter pipe at particle diameter of 200 mm and density 1020 kg=m(3)....
[...]
...Singh and Simon (2009) investigated the DEM simulation and suggested that though the total number of collisions increases with increasing particle loading, the increase of number of particle-particle collisions is greater than the increase of wall-particle collisions....
[...]
01 Jun 2020
TL;DR: In this paper, the characteristics of oil-water core-annular flow in a horizontal acrylic pipe were investigated and a pressure loss model was modified by changing the friction coefficient formula with empirical value added.
Abstract: The water-lubricated transportation of heavy oil seems to be an attractive method for crude oil production with significant savings in pumping power. With oil surrounded by water along the pipe, oil–water core–annular flow forms. In this paper, the characteristics of oil–water core–annular flow in a horizontal acrylic pipe were investigated. Plexiglas pipes (internal diameter = 14 mm and length = 7.5 m) and two types of white oil (viscosity = 0.237 and 0.456 Pa·s) were used. Flow patterns were observed with a high-speed camera and rules of flow pattern transition were discussed. A pressure loss model was modified by changing the friction coefficient formula with empirical value added. Totally 224 groups of experimental data were used to evaluate pressure loss theoretical models. It was found the modified model has been improved significantly in terms of precision compared to the original one. With 87.4% of the data fallen within the deviation of ± 15%, the new model performed best among the five models.
17 citations
TL;DR: An overview of pneumatic conveying systems and performance single phase flow in PNEs can be found in this article, where the flow behavior of solids from silos, wear in pNEs, ancilliary equipment control of pNE transport instrumentation system design and worked examples are discussed.
11 citations
01 Jan 2014
TL;DR: In this paper, the effects of particle diameter, particle density, solid volume fraction, and gas phase Reynolds number on the fully developed pressure drop in gas-solid flows in a horizontal pipe of internal diameter 30 mm and length 3000 mm have been studied.
Abstract: Gas-solid flows in pipes are common in industrial applications, such as pneumatic conveying, fluidized beds, pulverized coal combustion, spray drying and cooling, etc. The prediction of the pressure drop is essential in design of the systems, while the addition of granular particles to the gas flow causes an enhancement of heat transfer from the heated wall to the bulk fluid. The fully developed and overall pressure drop and overall heat transfer prediction in gas-solid flows in horizontal pipes have been investigated numerically using the Eulerian-Eulerian (E-E) approach, accounting for four-way coupling. The Gidaspow drag model with the partial differential equation form of granular temperature model has been used for the simulations. For the prediction of fully developed pressure drop, fine particles (fly ash of size 20 to 150 μm) with the solid volume fractions of up to 0.1 have been considered. For the prediction of overall pressure drop and heat transfer, fine particles (flyash of size 30 to 50 μm) have been used in the simulations. A grid independence test has been conducted to get the accurate numerical results. The numerical results are in good agreement with the bench mark experimental data for the pressure drop and heat transfer. The effects of particle diameter, particle density, solid volume fraction, and gas phase Reynolds number on the fully developed pressure drop in gas-solid flows in a horizontal pipe of internal diameter 30 mm and length 3000 mm have been studied. It has been found that the pressure drop increases with an increase in the particle diameter, and reaches a peak value. After reaching the peak value, the pressure drop gradually starts to decrease. The pressure drop increases with increase in the particle density, solid volume fraction, and gas phase Reynolds number. Furthermore, the effects of solid particles on the overall (entrance as well as the fully developed region) pressure drop and heat transfer in gas-solid flows in a horizontal pipe of internal diameter 55 mm and length 5500 mm have been investigated. It has been observed that the pressure drop data are consistent. It increases with the particle size, gas phase Reynolds number, and solid loading ratio (SLR), under the present study operating conditions. The heat transfer data, i.e., the two-phase Nusselt numbers are not consistent with the gas phase Reynolds numbers. The heat transfer increases with respect to the gas phase Reynolds number fora low SLR. However, for the higher SLRs, the heat transfer first increases/decreases and then decreases/increases (after reaching a peak/nadir) with the gas phase Reynolds number. The heat transfer increases with increase in the SLR. Finally, a correlation for the two-phase Nusselt number has been developed using the non-linear regression analysis, which shows an accuracy of ±15%.
5 citations
Cites methods from "Predicting pressure drop in pneumat..."
...Singh and Lo (2009) predicted the pressure drop in a horizontal pipe dilute phase pneumatic conveying using the DEM CFD simulation....
[...]
References
More filters
Journal Article•
TL;DR: The distinct element method as mentioned in this paper is a numerical model capable of describing the mechanical behavior of assemblies of discs and spheres and is based on the use of an explicit numerical scheme in which the interaction of the particles is monitored contact by contact and the motion of the objects modelled particle by particle.
Abstract: The distinct element method is a numerical model capable of describing the mechanical behaviour of assemblies of discs and spheres. The method is based on the use of an explicit numerical scheme in which the interaction of the particles is monitored contact by contact and the motion of the particles modelled particle by particle. The main features of the distinct element method are described. The method is validated by comparing force vector plots obtained from the computer program BALL with the corresponding plots obtained from a photoelastic analysis. The photoelastic analysis used for the comparison is the one applied to an assembly of discs by De Josselin de Jong and Verruijt (1969). The force vector diagrams obtained numerically closely resemble those obtained photoelastically. It is concluded from this comparison that the distinct element method and the program BALL are valid tools for research into the behaviour of granular assemblies. La methode des elements distincts est un modele numerique capab...
12,554 citations
TL;DR: The distinct element method as mentioned in this paper is a numerical model capable of describing the mechanical behavior of assemblies of discs and spheres and is based on the use of an explicit numerical scheme in which the interaction of the particles is monitored contact by contact and the motion of the objects modelled particle by particle.
Abstract: The distinct element method is a numerical model capable of describing the mechanical behaviour of assemblies of discs and spheres. The method is based on the use of an explicit numerical scheme in which the interaction of the particles is monitored contact by contact and the motion of the particles modelled particle by particle. The main features of the distinct element method are described. The method is validated by comparing force vector plots obtained from the computer program BALL with the corresponding plots obtained from a photoelastic analysis. The photoelastic analysis used for the comparison is the one applied to an assembly of discs by De Josselin de Jong and Verruijt (1969). The force vector diagrams obtained numerically closely resemble those obtained photoelastically. It is concluded from this comparison that the distinct element method and the program BALL are valid tools for research into the behaviour of granular assemblies. La methode des elements distincts est un modele numerique capab...
12,472 citations
TL;DR: In this paper, explicit equations for the drag coefficient and for the terminal velocity of falling spherical and nonspherical particles are developed for the CD and ut. The goodness of fit of these equations to the reported experimental data is evaluated and compared with that of other recently proposed equations.
1,632 citations
"Predicting pressure drop in pneumat..." refers methods in this paper
...Probably, the most widely used expression for fluid drag on a non-spherical particle is that proposed by Haider and Levenspiel [Haider and Levenspiel 1989]....
[...]
...…using the expression: ( )ififPfDFluidDrag vvvvACF −−= ρ2 1 [4] where the drag coefficient may be defined using the general expression: ( ) Re 1 Re1 Re 24 D CAC BD + +×+= [5] For a non-spherical particle, coefficients A, B, C and D are a function of particle sphericity [Haider and Levenspiel 1989]....
[...]
TL;DR: In this article, the Stokes' shape factor (K1) and the Newton's shape factor or scruple (K2) were modeled as functions of the geometric shape descriptors' sphericity and the projected area in the direction of motion.
580 citations