The Experts below are selected from a list of 2016 Experts worldwide ranked by ideXlab platform
Akira Rinoshika - One of the best experts on this subject based on the ideXlab platform.
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An Experimental Study on a Horizontal Energy-saving Pneumatic Conveying System☆
Procedia Engineering, 2015Co-Authors: Akira RinoshikaAbstract:Abstract In order to reduce power consumption and Conveying velocity, a new Pneumatic Conveying System where soft fins are horizontally mounted on the center plane of pipe in the front of inlet is proposed in this paper. The experimental study focuses on the effect of the different fin's lengths on the horizontal Pneumatic Conveying System in terms of frequency characteristics of fin's oscillation, pressure drop, Conveying velocity, power consumption and particle flow pattern. Comparing with the conventional Pneumatic Conveying, the pressure drop, minimum and critical velocities and power consumption can be reduced by using soft fins in lower air velocity range. The effective of fin is quite evident with increasing the length of fin. The maximum reduction rates of the minimum velocity and power consumption by using soft fins are about 14.8% and 25.5%, respectively.
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an experimental study on a horizontal energy saving Pneumatic Conveying System with soft fins
Powder Technology, 2012Co-Authors: Akira Rinoshika, Hironobu NonakaAbstract:Abstract In order to reduce power consumption and Conveying velocity, a new Pneumatic Conveying System where soft fins are mounted in a horizontal plane through the pipe axis in the front of inlet is proposed in this paper. The experimental study focuses on the effect of the different fin's lengths on the horizontal Pneumatic Conveying System in terms of frequency characteristics of fin's oscillation, pressure drop, Conveying velocity, particle flow pattern, power consumption and additional pressure drop. The test pipeline consisted of a horizontal smooth acrylic tube with an inside diameter of 80 mm and a length of about 5 m. The polyethylene spherical particles of density 978 kg/m 3 and 952 kg/m 3 with diameters of 2.3 mm and 3.3 mm are used as Conveying materials. The mean air velocity is varied from 10 to 17 m/s, and the solid mass flow rate is from 0.20 to 0.45 kg/s. Comparing with the conventional Pneumatic Conveying, the pressure drop, minimum and critical velocities, power consumption and additional pressure drop can be reduced by using soft fins in lower air velocity range. The efficiency of fin is quite evident with increasing the length of fin. The maximum reduction rates of the minimum velocity and power consumption by using soft fins are about 14.8% and 25.5%, respectively. By analyzing the frequency characteristics of fin's oscillation, Strouhal number of more efficient fins is about S t = 0.65 in the range of low air velocity.
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an experimental study of energy saving Pneumatic Conveying System in a horizontal pipeline with dune model
Powder Technology, 2010Co-Authors: Akira Rinoshika, Masahito SuzukiAbstract:Abstract In order to reduce power consumption and Conveying velocity, a Pneumatic Conveying System where a dune model is mounted in a pipeline is proposed in this paper. The experimental study focuses on the effect of the mounted dune model in the horizontal Pneumatic Conveying System in terms of pressure drop, power consumption and Conveying velocity. The test pipeline consisted of a horizontal smooth acrylic tube with an inside diameter of 80 mm and a length of about 5 m. Polyethylene spherical particles with a density of 952 kg/m3 and diameters of 2.3 and 3.3 mm are used as Conveying materials. The mean air velocity is varied from 9 to 16 m/s, and the solid mass flow rate is from 0.25 to 0.45 kg/s. Firstly, the effect of the dune model location on Pneumatic Conveying is experimentally studied. It is found that in the lower air velocity range, the pressure drop of the Pneumatic Conveying with a mounted dune model is lower than that of a conventional Pneumatic Conveying System. A lower Conveying velocity and energy-saving Conveying can be realized by installing a dune model in the Conveying pipe. Especially the case of fixing the dune model on the bottom of the pipe at the inlet of particle feed is more effective. The particle flow patterns also show that the dune model reduces the deposition of particles. Then, the effect of different surface materials of the dune model is examined. By using a surface material of the dune model with a large coefficient of restitution, the pressure drop of Conveying large particles is the lowest. When Conveying relatively small particles, however, the pressure drop becomes the lowest by a small coefficient of restitution. The maximum reduction rates of the minimum velocity and power consumption by the dune model are about 19% and 34%, respectively.
Haim Kalman - One of the best experts on this subject based on the ideXlab platform.
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Experimental study on the particle velocity development profile and acceleration length in horizontal dilute phase Pneumatic Conveying Systems
Powder Technology, 2018Co-Authors: Nir Santo, Naveen Mani Tripathi, Dmitry Portnikov, Haim KalmanAbstract:Abstract The significance of the acceleration zone is expressed when designing a straight pipeline that follows either the feeding point or a bend in a Pneumatic Conveying System. It is an effective and reliable System that takes into account the acceleration zone in the design process. The current paper presents a thorough experimental investigation of particle velocity profile at the acceleration region obtained from 3-in, 2-in and 1-in horizontal dilute phase Pneumatic Conveying Systems with various operating conditions and conveyed materials. The velocity was obtained by using a high speed camera combined with image processing. Investigation of the statistical velocity distribution resulted in a new correlation for the particle velocity profile throughout the acceleration zone and the acceleration length in the range of the tested operating conditions.
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acceleration pressure drop analysis in horizontal dilute phase Pneumatic Conveying System
Powder Technology, 2018Co-Authors: Naveen Mani Tripathi, A Levy, Haim KalmanAbstract:Abstract In Pneumatic Conveying pipelines, there are specific periods and distances where particles start to accelerate or deaccelerate from specific velocity to steady state. This phenomenon attributes an additional loss of energy also invoke as acceleration pressure drop. The total acceleration pressure drop is defined by measuring the pressure difference between two points at the acceleration zone. The pressure drop of steady state flow for the same length is then reduced from the previous measurement to find acceleration only energy loss. Theoretical equation of momentum change, a material physics, has used to explain the acceleration pressure drop in horizontal pipe. Experimental results have compared with the values of theoretical equation. Results indicated that predicted pressure drop is deviating from the experimental results. Hence, the problem was realized that there was need to precisely predict steady state (collision and friction) pressure drop in this zone, which in classical way of prediction would be used to do just by extrapolation up to the acceleration zone. Hence, a novel factor α has derived by the authors to accurately predict steady state loss in this zone. Experiments have conducted by using different kinds of materials (Bottom ash, Glass beads, Semolina etc.) at different Conveying conditions. To view point of design engineers, contribution of acceleration pressure drop in total pipeline has demonstrated by comparing 10 m and 100 m long horizontal pipe. To a simplest case of Conveying criteria, acceleration loss contribute 25% of total pipeline pressure drop for 10 m pipe and it reduced to 4% for 100 m pipeline. It has concluded that acceleration pressure drop, between any two velocities, would be predicted with momentum change equation and there is need to accurately predict the steady state pressure drop by factor alpha (α) to predict total pressure drop in acceleration zone.
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DEM simulation of particle attrition in dilute-phase Pneumatic Conveying
Granular Matter, 2011Co-Authors: Tamir Brosh, Haim Kalman, Avi LevyAbstract:Three dimensional numerical simulations of particles motion in a given geometry Pneumatic Conveying System are conducted in order to obtain a better understanding of the attrition process. A new and innovative procedure of implementing empirical comminution functions (Kalman et al. in Gran Mat 11:253–266, 2009) into DEM-CFD simulations was used and modified. The comminution functions include: initial strength distribution, selection function, breakage function, equivalence function and fatigue function. The implementation involves converting the probability comminution functions into individual particle properties by a random method and then converting the velocity dependent comminution functions into strength-dependent ones. The predictions of the numerical simulations are used to analyze the flow field characteristics and the size reduction process.
Chi Hwa Wang - One of the best experts on this subject based on the ideXlab platform.
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hazard of electrostatic generation in a Pneumatic Conveying System electrostatic effects on the accuracy of electrical capacitance tomography measurements and generation of spark
Measurement Science and Technology, 2008Co-Authors: Yan Zhang, Yung C Liang, Chi Hwa WangAbstract:The study of the hazard of electrostatic generation in Pneumatic Conveying Systems was attempted by examining the sensitivity of electrical capacitance tomography (ECT) and the phenomena of spark generation due to strong electrostatics. The influence on ECT measurement accuracy of an electrostatic charge was analysed with reference to a switch capacitor configuration model. Consequently, it was found that the electrostatic charge introduced at the bend with sharp angles influenced the ECT results most significantly in Pneumatic Conveying Systems, especially for the cases where a spark was generated. The investigation of spark generation indicated that a strong electrostatic charge can cause major discharges inside or outside the pipeline to damage the experimental instrument in severe cases.
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On the electrostatic equilibrium of granular flow in Pneumatic Conveying Systems
Aiche Journal, 2006Co-Authors: Yan Zhang, Chi Hwa Wang, Yung C LiangAbstract:An analytical methodology involving the concept of “electrostatic equilibrium” is developed for granular flow in Pneumatic Conveying Systems. The methodology can be used for estimation of the electrostatic field distribution at various sections of the System and explanation of the mechanisms involved for various electrostatic phenomena observed. For all cases conducted in the Conveying System, there was a “charging time” required for the System to reach the state of “electrostatic equilibrium.” Experiments conducted at different sections of the System showed that the time required increased in the order: horizontal pipe, vertical pipe, and pipe bend. Through a physical analysis, it is deduced that electrostatic equilibrium is related to the granules' behavior and local flow characteristics. In general, a longer time duration taken to reach equilibrium corresponds to a process with more complicated granular flow patterns. In the electrostatic equilibrium state, the field distribution shows the highest electrostatic field strength near the pipe wall, and this field strength degrades from the pipe wall to the pipe center. At various pipe sections, the highest strength occurs at the bend, in accord with observations that electric sparking first occurs at that location within the entire Pneumatic Conveying System. In the vertical pipe, granular distribution was measured using electrical capacitance tomography (ECT), and granular velocities were cross-referenced with those using particle image velocimetry (PIV). The electrostatic force at low air flow rates is found to be the primary cause for granules sticking to the pipe wall and results in the formation of the half-ring or ring structure. The state of electrostatic equilibrium is physically influenced by several elements in Conveying Systems. In a cyclic Conveying System, a new pipe (or low humidity or no antistatic agent) tends to expedite the process to reach electrostatic equilibrium and attain high magnitude of electrostatic current at the state. In a non-cyclic horizontal Conveying System, a thin film (pipe) is found to prolong the process duration to reach equilibrium, while the case with charged film (pipe) takes shorter duration to do so. © 2006 American Institute of Chemical Engineers AIChE J, 2006
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Granular Attrition due to Rotary Valve in a Pneumatic Conveying System
2005Co-Authors: Chi Hwa WangAbstract:The rotary valve is a widely used mechanical device in many solids-handling industrial processes. However, it may also be responsible for most of the attrition effects occurring in a typical process. In this study, the attrition effects occurring in a rotary valve operating as a stand-alone device and as part of a Pneumatic Conveying System were investigated. In the former case granular attrition was carried out at three different rotary valve speeds and the experimental results obtained were found to be in good agreement with the Gwyn correlation. In the latter case three typical air flow rates were used in the Pneumatic Conveying System. The size distribution of the attrition product obtained at the lowest air flow rate used was not adequately described by the Gwyn correlation. The attrition process and mechanisms involved were analysed and the minimum size of the attrition product obtained from both modes of operations was found
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Electrostatics of the Granular Flow in a Pneumatic Conveying System
Industrial & Engineering Chemistry Research, 2004Co-Authors: J. Yao, Shuji Matsusaka, Chi Hwa Wang, Yan Zhang, Hiroaki MasudaAbstract:The phenomenon of electrostatic charge generation and its effects on granular flow behavior in a Pneumatic Conveying System was studied. The main parameters used for quantitative characterization of the phenomenon were the induced current, particle charge density, and equivalent current of the charged granular flow. These were measured using a digital electrometer, Faraday cage, and modular parametric current transformer, respectively. Three different flow patterns corresponding to different electrostatic effects within the Pneumatic Conveying System were observed, and these were named the disperse flow, half-ring flow, and ring flow patterns. It was found that the induced current, particle charge density, and equivalent current increased with decreasing flow rates. Electrostatic effects generally become stronger with time, and this may lead to clustering behavior occurring even in the disperse flow regime. The effects of several factors such as pipe wall material, particle composition, relative humidity ...
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Electrostatics of the Granular Flow in a Vertical Pneumatic Conveying System
2004Co-Authors: Yan Zhang, Shuji Matsusaka, Chi Hwa Wang, Hiroaki MasudaAbstract:The phenomenon of electrostatic charge generation in a Pneumatic Conveying System was studied. The main parameters used for quantitative characterization of the phenomenon included induced current, particle charge density and equivalent current of the charged granular flow. These were measured using a Digital Electrometer, Faraday Cage and Modular Parametric Current Transformer (MPCT) respectively. Three different flow patterns corresponding to the different electrostatic effects within the Pneumatic Conveying System were observed and these were classified as the disperse flow, half-ring flow and ring flow patterns. It was found that the induced current, particle charge density and equivalent current increased with decreasing flow rates. Electrostatic effects generally become stronger with time and this may lead to clustering behavior occurring even in the disperse flow regime.
David Mills - One of the best experts on this subject based on the ideXlab platform.
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Pipeline Scaling Parameters
Pneumatic Conveying Design Guide, 2016Co-Authors: David MillsAbstract:For the reliable design of a Pneumatic Conveying System, actual Conveying data for the material to be conveyed is required. If this is not available, it would be recommended that the material should be tested in order to obtain the data. A test facility should be used, or possibly data that has been obtained from another installation, but the actual pipeline configuration does not have to be the same or replicated. Scaling parameters are presented in this chapter that will allow such data from one pipeline to be scaled to that of the required facility. Differences in pipeline bore, Conveying distance, number and geometry of bends, and pipeline orientation can all be taken into account. For a given plant pipeline, a number of different combinations of pipeline bore and air supply pressures will generally be capable of meeting the required duty. Such an analysis is included and it is shown how the choice of Conveying parameters can influence both the cost of operating the plant, in terms of power requirements, and the potential capital cost of the plant.
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Chapter 17 – Design Procedures
Pneumatic Conveying Design Guide, 2016Co-Authors: David MillsAbstract:Logic diagrams are presented for the design of Pneumatic Conveying Systems based on the use of both mathematical models and Conveying data. Logic diagrams are also presented for checking the performance of an existing System, or for a potential change of duty, again based on the use of both models and data. There is rarely a single solution to the specification of a Pneumatic Conveying System for a given duty. As a consequence the logic diagrams include numerous checks so that optimum solutions are achieved in terms of either obtaining the minimum power requirement for a given duty, or achieving a maximum material flow rate for the given Conveying parameters. To help in this process several series of design curves are included to illustrate the potential influence of the major System variables such as Conveying distance, pipeline bore, and air supply pressure, as well as the problematical issue of material type.
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First approximation design methods
Pneumatic Conveying Design Guide, 2016Co-Authors: David MillsAbstract:For feasibility studies an approximate solution to a problem will often suffice in the first instance so that a reasonable order of magnitude of the variables involved can be obtained, particularly if a comparison is to be made with alternative mechanical means of Conveying a material. This will give sufficient details of the Pneumatic Conveying System in terms of pipeline bores, air supply pressures, and airflow rates for a given duty, in terms of material flow rate and Conveying distance required, so that capital cost estimates for plant items such as pipelines, compressors, feeding devices, and filtration plant can be made. Operating costs for the plant are also likely to be required and so with data on airflow rate and air supply pressure required, this is a straightforward procedure. As was shown in previous chapters, a given duty can generally be achieved with a range of air supply pressure and pipeline bore combinations, and so this method of analysis will enable the best combination of Conveying parameters to be achieved for the given duty.
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System selection considerations
Pneumatic Conveying Design Guide, 2016Co-Authors: David MillsAbstract:The selection of a Pneumatic Conveying System for a particular application involves the consideration of numerous parameters associated with the conveyed material, the Conveying conditions, and the System itself. The basic specification is usually that a material should be conveyed at a specified flow rate over a given distance. For any given situation, a wide combination of pipeline bores and Conveying line pressure drop values are usually available that adequately meet the requirements. Therefore, there is rarely a problem of not being able to achieve a given duty; however, getting it right the first time is a common problem. Power consumption and hence System-operating costs are an obvious factor in the decision-making process. Furthermore, when selecting a Pneumatic Conveying System for a particular application, it is generally the Conveying potential of the System that is of primary importance. The number of factors that have a potential influence on material flow rate is quite considerable. They can be grouped into three broad categories: those associated with the conveyed material, the Conveying conditions, and the pipeline geometry.
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Chapter 15 – Design procedures
Pneumatic Conveying Design Guide, 2004Co-Authors: David MillsAbstract:Publisher Summary A Pneumatic Conveying System is designed using mathematical models, available test data, or a combination of the two. If mathematical models are to be used, some degree of confidence needs to be established as to their suitability for a particular application, such as Conveying a particular material under closely defined conditions, before they are employed. Test data is used extensively in System design. However, it is essential that the available data relates to the same grade of material for which the new plant design is required. It is also essential that the data is available to slightly higher values of solids loading ratio and to slightly lower values of Conveying line inlet air velocity, than are contemplated for the new design. Further, the chapter discusses a logic diagram for the design of a Pneumatic Conveying System based on the use of mathematical models. The final requirement in the design process is to specify the pipeline bore required and the necessary rating of the air mover.
Hironobu Nonaka - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on a horizontal energy saving Pneumatic Conveying System with soft fins
Powder Technology, 2012Co-Authors: Akira Rinoshika, Hironobu NonakaAbstract:Abstract In order to reduce power consumption and Conveying velocity, a new Pneumatic Conveying System where soft fins are mounted in a horizontal plane through the pipe axis in the front of inlet is proposed in this paper. The experimental study focuses on the effect of the different fin's lengths on the horizontal Pneumatic Conveying System in terms of frequency characteristics of fin's oscillation, pressure drop, Conveying velocity, particle flow pattern, power consumption and additional pressure drop. The test pipeline consisted of a horizontal smooth acrylic tube with an inside diameter of 80 mm and a length of about 5 m. The polyethylene spherical particles of density 978 kg/m 3 and 952 kg/m 3 with diameters of 2.3 mm and 3.3 mm are used as Conveying materials. The mean air velocity is varied from 10 to 17 m/s, and the solid mass flow rate is from 0.20 to 0.45 kg/s. Comparing with the conventional Pneumatic Conveying, the pressure drop, minimum and critical velocities, power consumption and additional pressure drop can be reduced by using soft fins in lower air velocity range. The efficiency of fin is quite evident with increasing the length of fin. The maximum reduction rates of the minimum velocity and power consumption by using soft fins are about 14.8% and 25.5%, respectively. By analyzing the frequency characteristics of fin's oscillation, Strouhal number of more efficient fins is about S t = 0.65 in the range of low air velocity.