Modelling and analysis of flow of powders through long pipelines
TL;DR: In this paper, the authors focus on predicting the pressure drop in fluidized dense phase pneumatic conveying of fine particles through pipelines by modelling the solids friction factor in terms of non-dimensional parameters using experimental data of definite pipeline configuration.
Abstract: The purpose of this paper is to focus on predicting the pressure drop in fluidized dense phase pneumatic conveying of fine particles through pipelines by modelling the solids friction factor in terms of non-dimensional parameters using experimental data of definite pipeline configuration. Finally, the model is to be tested for a different pipeline configuration.,Solids friction factor has been expressed in terms of certain non-dimensional parameters such as density ratio, solids loading ratio and mean particle diameter to pipe diameter ratio, and a certain number of coefficients and exponents. Experimental data of five conveying materials (two types of fly ash, two types of alumina and one type of cement meal) for a pipeline configuration of diameter 53 mm and length 173 m and another conveying material EPS dust for two pipeline configurations (69-mm diameter, 168-m long; 105-mm diameter, 168-m long) have been used to calculate the unknown coefficients or exponents of the mathematical model for solids friction factor.,The developed model gives the best results in predicting the pressure drop for the pipelines that are less than 173-m long, but the model shows a large error for the pipelines more than 173-m long.,Current research will be helpful for the researchers to model the process of pneumatic conveying through long distances.,The method will be helpful in conveying powder materials through long distances in cement or brick industry, alumina industry.,Fly ash piles over at the nearby places of thermal power plants. Pneumatic conveying is the best method for transporting the fly ash from the location of power plants to the nearby brick industries or cement industries.,Solid friction factor has been presented in terms of four non-dimensional parameters and evaluated the accuracy in predicting the pressure drop for two different pipeline configurations.
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TL;DR: In this paper, the Einflus des Luftwiderstandes des Gutes, der Schwerkraft and der Reibungskrafte beim Aufprall der Teilchen auf die Wand wird studiert and allgemein gultige Beziehungen zur Berechnung der Druckverluste werden aufgestellt.
Abstract: Fur Stromungsvorgange von Mehrstoffgemischen werden Ahnlichkeitsbedingungen aufgestellt und auf den pneumatischen Fordervorgang angewendet. Der Einflus des Luftwiderstandes des Gutes, der Schwerkraft und der Reibungskrafte beim Aufprall der Teilchen auf die Wand wird studiert, und allgemein gultige Beziehungen zur Berechnung der Druckverluste werden aufgestellt. Die Aussagen der Theorie werden mit Versuchsergebnissen an senkrechten pneumatischen Forderleitungen verglichen. Bei bekannten Geblaseleistungen kann die Stopfgrenze mit Hilfe der vorgeschlagenen Rechenmethode bestimmt werden.
92 citations
TL;DR: The use of a pneumatic conveying technique for the transportation of drill cuttings within and from offshore drill rigs is a new and challenging research field at present as discussed by the authors.
70 citations
TL;DR: In this paper, a series of calculations were performed on experimental data in order to estimate solids friction factor for four types of material conveyed in the fluidized dense-phase flow regime.
Abstract: There have been numerous correlations proposed for determining a solids friction factor ( u s ) for fully suspended (dilute phase) pneumatic conveying. Currently, there are no equivalent correlations that predict u s in nonsuspension dense-phase flows. In dense-phase conveying there are two basic modes of flow: plug/slug flow, which is predominantly based on granular products, and fluidized dense-phase flow, which is more suited to fine powders exhibiting good air retention capabilities. In plug/slug type flow, the stresses between the moving plug of material and the pipe wall dominate the solid-phase frictional losses. In fluidized dense-phase flow the frictional losses are characterized as a mixture of particle-wall and particle-particle losses but are heavily influenced by the gas-solid interactions. In this paper, a series of calculations were performed on experimental data in order to estimate u s for four types of material conveyed in the fluidized dense-phase flow regime. The solids frictional fact...
63 citations
01 Jan 1986
TL;DR: In this paper, an empirical model to calculate the pipe line pressure loss for a pneumatic conveying system is described, which was originally proposed for lean phase conveying and is modified to use solids friction proposed by Weber (1982).
Abstract: An empirical model to calculate the pipe line pressure loss for a pneumatic conveying system is described. The model was originally proposed for lean phase conveying and is modified to use solids friction proposed by Weber (1982). The calculated pressure loss for a given pipe diameter, pipe length, air mass flow rate and material mass flow rate is compared to recent experimental results of a number of authors. Generally the model predicts the pipe pressure loss to be better than a factor of 2, and this, surprisingly, for a range of product to air mass flow ratios in the range 2 to 530. The model performance was observed to decrease as pipe length increases, for L greater than 500m the model is not applicable. However defining the particle Froude number as Weber (1981) allows successful pressure loss predictions for all pipe lengths considered. The factor of 2 pressure loss estimate will allow a preliminary optimization and economic assessment of possible pneumatic conveying systems. The method may be used to investigate optimal positioning of expansions in pipe diameters, introduced to reduce pressure loss, along a longer pipe line. Conveying tests are necessary to prove the feasibility of economically attractive options and to confirm that products can be conveyed at the selected mass flow ratios and air velocities.
40 citations
TL;DR: Pneumatic conveying is an important operation used in many industries to transport granular materials from one place to another as discussed by the authors, and in recent years, the combined approach of the discrete element metho...
Abstract: Pneumatic conveying is an important operation used in many industries to transport granular materials from one place to another. In recent years, the combined approach of the discrete element metho...
28 citations