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  • Influence of Capillary Die Geometry on Wall Slip of Highly Filled Powder Injection Molding Compounds
    Powder Technol. (IF 2.942) Pub Date : 2017-11-20
    Daniel Sanetrnik, Berenika Hausnerova, Petr Filip, Eva Hnatkova

    Uneven distribution of solid particles contained in the feedstocks used in the process of powder injection molding (PIM) is observed in the close vicinity of the walls. A particle-free thin layer adjacent to the walls is formed by the binder only and is characterized by so-called wall slip. Wall slip is a key to successful modeling of injection molding step of PIM. For its determination we used capillary rheometers equipped with the dies of different entrance angles applied to four PIM feedstocks. The entrance angle has been found to be a crucial parameter to intercept wall slip. Conical dies are more suitable to obtain reliable slip velocity values of highly filled compounds than capillaries having plane entrance, which are used in the majority of studies.

    更新日期:2017-11-20
  • Anomalies in normal and oblique collision properties of spherical particles
    Powder Technol. (IF 2.942) Pub Date : 2017-11-16
    Vikul Tomar, Manaswita Bose

    Collision of particles either between themselves or with the wall, are typically characterized by normal and tangential coefficients of restitution, which depend on material and surface properties of the colliding objects. An accurate estimate of coefficients of restitution is of importance as it is one of input parameters in the discrete element simulations of a large system of particles. Often anomalies in the experimentally obtained values of the coefficients are reported in the literature. In the present work, both normal and tangential coefficients of restitution along with the surface and the local material properties are determined and compared with the predictions of the existing models. In certain cases, the experimentally obtained values agree fairly well with the values determined using the models while in some other cases anomalies in the experimental results are observed.

    更新日期:2017-11-20
  • Development of a preliminary media wear measurement test procedure for cement ball milling applications
    Powder Technol. (IF 2.942) Pub Date : 2017-11-15
    Serdar S. Çolak, Okay Altun, Hakan Benzer, Zeki Gencer, Harun Koçak

    The paper initially focusses on developing a test procedure for measuring the wear of grinding balls and then correlating the results with the wear obtained in industrial scale cement ball milling applications. The cost of grinding media is one of the major items and it needs to be optimized by testing different types of media. Since industrial scale trials are time consuming, there is a need for an easy, accurate and fast media wear testing procedure for cement ball milling applications. Such a procedure enables cement plants to compare wear results of different types of media and choose the optimal one for the economy of the grinding operation. Within the scope of the study, 6 types of 30 mm media having different chemical compositions were subjected to wear measurements at different time intervals by utilizing laboratory scale ball mills. The studies showed that reproducible results can be obtained from the test apparatus hence the methodology is said to be consistent. The wear results concluded that the order of the media wear from the highest to the lowest was the same independent of the mill dimension and whether the material is inside the mill. The results also implied that the chemical composition or the microstructure of the media was an influencing parameter on the wear therefore there is room for improvement with regards to the quality of media. This study proved that the media wear measured at industrial scale cement ball mills was in good agreement with the laboratory scale results.

    更新日期:2017-11-16
  • Experimental characterization of the cohesive behaviour of fine powders by the raining bed test
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    R. Girimonte, B. Formisani

    The paper analyses and discusses the possibility of using the so-called ‘raining bed experiment’ to achieve quantitative characterization of the macroscopic cohesion force that affects fluidization of group A solids. This procedure, originally devised by Buysman and Peersman in 1967 [1], is based on measuring the minimum velocity required to an up-flowing gas stream for an up-flowing gas stream to hold a particulate bed against a porous plate at the top of a column, before bed failure occurs, either as a rain of particles (‘rain-off’) or as a fall of plugs. Rain-off velocities and bed pressure drops relevant to different cuts of glass ballotini, ceramics spheres, alumina, FCC catalyst, Ludox catalyst, silica sand and other powders, with average particle size ranging from 25 to 465 μm, are determined. These data are compared with the corresponding ones obtained by performing fluidization experiments on the same materials. Such a comparison allows a classification of the powders among cohesive and free-flowing solids. Moreover, the raining bed technique is able to provide valuable information about the relationship between macroscopic cohesion and fluidization properties of fine solids. Its development is thus likely to allow evaluating the excess drag force required to overcome interparticle forces in the transition from the fixed to the fluidized state.

    更新日期:2017-11-15
  • Computational fluid dynamics simulations of a binary particle bed in a riser-based carbon stripper for chemical looping combustion
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    Subhodeep Banerjee, Ramesh K. Agarwal

    Chemical-looping combustion (CLC) is a next generation combustion technology that shows great promise as a solution for the need of high-efficiency low-cost carbon capture from fossil fueled power plants. In this paper, numerical simulations are conducted of a binary particle bed associated with a coal-direct CLC system consisting of coal (represented by plastic beads) and oxygen carrier particles and validated against an experimental riser-based carbon stripper. The detailed particle dynamics and solid-gas and solid-solid interactions are investigated using the Lagrangian particle-tracking approach known as the discrete element method coupled with the computational fluid dynamics solution for the flow field. The simulation results of the fluidization behavior and the separation ratio of the particles are in excellent agreement with the experiment. A credible simulation of a binary particle bed is of particular importance for understanding the details of the fluidization behavior; the baseline simulation established in this work can be used as a tool for designing and optimizing the performance of such systems.

    更新日期:2017-11-15
  • Surface modification of Cu-W powder metallurgical alloy induced by high-current pulsed electron beam
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    Conglin Zhang, Qi Gao, Peng Lv, Jie Cai, Ching-Tun Peng, Yunxue Jin, Qingfeng Guan

    This paper is to investigate the microstructure and properties of Cu-W alloys induced by high-current pulsed electron beam (HCPEB) irradiation. The microstructural observation shows that craters were formed after 5 pulses of HCPEB irradiation. With the increasing numbers of pulses, these craters were further fused and eliminated, which results in an excellent surface finishing. In addition, the composition of melted layer was homogenized because of the inter-diffusion between Cu and W atoms. During the process of HCPEB irradiation, several modifications were formed, including Cu (W) solid solution, ultrafine grains, amorphous phase, and long-period superlattice phase, which significantly increased the microhardness of the surface. The results of sliding wear tests indicate that the HCPEB irradiated samples exhibited better properties as compared to that of the initial one, which was attributed to the ultrafine W particles embedded in the Cu matrix.

    更新日期:2017-11-15
  • Flotation intensification of the coal slime using a new compound collector and the interaction mechanism between the reagent and coal surface
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    Jingfeng He, Chengguo Liu, Yake Yao

    Flotation reagents in particular the flotation collector plays a significant role in the cleaning efficiency of coal slimes in the coal preparation and utilization industry. A new collector (NC) was used to achieve the efficient cleaning of coal slimes. Comparing with the conventional flotation collector of diesel oil (DO), the higher yields and lower ash contents of clean coal with the higher combustible material recoveries could be obtained using the NC in flotation. The optimum NC dosage of 500 g/t was acquired through the unit flotation tests. Fourier transform infrared spectroscopy (FTIR) and contact angle measurement were used to study the interaction mechanism between the flotation collector and coal surface. The results indicated that the stronger electron-attracting ability of the ester groups than that of the carbon-carbon double bond resulted in the more stable interaction between the NC and coal surface than that between the DO and coal surface. The contact angle of the coal slime wetting with the NC of 67.1° was larger than that with the DO of 62.6°, suggesting the stronger hydrophobicity of the coal slime with the NC than that with the DO. The chemical composition analysis results suggest that the NC belongs to a compound flotation reagent, which provides an alternative high-efficient collector for coal flotation industry.

    更新日期:2017-11-15
  • A transient model for nozzle clogging – Part II: Validation and verification
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    H. Barati, M. Wu, A. Kharicha, A. Ludwig

    Part I of this two-part work discusses a transient two-way coupling model for clogging of nozzle (fluid passage) due to deposition of suspended particles on the nozzle wall. The purpose of Part II is to validate and verify the model. To this end, the current model simulates a laboratory experiment, designed to study the clogging of a submerged entry nozzle (SEN) during steel continuous casting. It demonstrates that the model can reproduce the experiment satisfactorily: the numerically-calculated clogged section of the nozzle is qualitatively comparable with typically “as-clogged” sections in laboratory experiments; the calculated mass flow rate through the nozzle during clogging process as function of time is also in agreement with the experimentally-monitored result. The simulation-experiment agreement depends on parameters, e.g. mesh size, Lagrangian time scale, correction factor in interpolation of clog permeability, and porosity in the clog materials, which act as inputs for the numerical model. Uncertainties for choosing such parameters, model capabilities/limitations due to model assumptions have been studied and discussed in this paper. In this regard, further model refinements are suggested. The modeling results provide new knowledge about clogging behavior. (1) Clogging is a transient process, and it includes the initial coverage of the nozzle wall with deposited particles, the evolution of a bulged clog front, and then the development of branched structure. This transient growth of clog interacts with the flow. (2) Clogging is a stochastic and self-accelerating process.

    更新日期:2017-11-15
  • Statistical modelling of coating layer thickness distributions: Influence of overspray on coating quality
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    Andreas van Kampen, Reinhard Kohlus

    This paper investigates the layer formation in spray coating processes. Based on a Monte-Carlo simulation, a stochastic model of the coating layer thickness distribution was derived. It couples the stochastic process of droplet deposition on the particle surface with the droplet shape constructed from a spherical cap model and the droplets wetting properties (contact angle). The model was successfully shown to be able to replace the simulation. A parameter study revealed recommendations for designing a coating process, which were in agreement with the works from other authors. The model was then used to investigate the influence of overspray on the coating quality in comparison with experiments. It was found that the presence of overspray not only reduces the process efficiency but also increases the coefficient of variation of the resulting layer thickness distribution. This was caused by an increase in droplet size due to a predominant drying of small drops. It was also found, that a higher solid content of the spray solution increases the coefficient of variation, not only due to a decreased number of droplets, but also due to a greater variability in the layer thickness each droplet introduces.

    更新日期:2017-11-14
  • Efficient preparation of monodisperse CaCO3 nanoparticles as overbased nanodetergents in a high-gravity rotating packed bed reactor
    Powder Technol. (IF 2.942) Pub Date : 2017-11-14
    Fang Kang, Dan Wang, Yuan Pu, Xiao-Fei Zeng, Jie-Xin Wang, Jian-Feng Chen

    The preparation of oil-soluble metal carbonate colloids is of interest in the area of lubricant additives. This study presents a novel mass-transfer intensified approach for efficient preparation of monodisperse CaCO3 nanoparticles as overbased nanodetergents based on W/O microemulsion using a high-gravity rotating packed bed (RPB) reactor. The effects of high gravity level, gas-liquid ratio, gas and liquid flow rates were systematically investigated. The as-prepared products had good transparency, an average particle size of about 6 nm, a high storage stability of over 18 months, a solid content of 38.5 wt% and a highest total base number (TBN) of 417 mgKOH/g. As compared to conventional stirring tank reactor (STR), the product prepared in the RPB reactor had better monodispersity and stability, smaller average particle size, narrower size distribution and higher TBN. Furthermore, the RPB reactor had a greatly shortened carbonation reaction time from 120 min of STR to 53 min, increasing the production efficiency by about 56%.

    更新日期:2017-11-14
  • Preparation of core-shell microspheres of lactose with flower-like morphology and tailored porosity
    Powder Technol. (IF 2.942) Pub Date : 2017-11-13
    Songwen Tan, Amirali Ebrahimi, Timothy Langrish

    Flower-like lactose microparticles with tailored porosity on the core and the shell have been synthesized using sugars, such as sucrose, glucose and fructose as templating agents. The proposed mechanism for tailoring the porosity is based on the difference in the diffusion coefficients of templating sugars compared with that of lactose as the core material, resulting in the migration of template molecules to the core or the shell of spray-dried particles during the spray-drying process. Focused ion beam (FIB) and scanning electron microscopy (SEM) techniques have been used to investigate the internal structure of the porous lactose particles. It has been found that using sucrose, with a lower diffusion coefficient compared with lactose, resulted in a porous shell upon template removal by ethanol washing, since lactose molecules with higher diffusivity tend to migrate to the core. By contrast, glucose and fructose, with higher diffusion coefficients, led to a porous core due to their tendency to accumulate in the core of the spray-dried particles. Nitrogen physisorption tests showed that the flower-like lactose microspheres have a large surface area of 26–31 m2/g and a high pore volume of 0.57–0.78 cm3/g with a pore size distribution predominantly in the micro- and mesoporous range (1.6, 3.8 and 30 nm). The pore size distributions of these flower-like lactose microparticles show that fructose, with the lowest glass-transition temperature (Tg) and consequently the highest crystallization rate during spray drying gave in larger pores, while the sucrose with the highest Tg led to smaller pores.

    更新日期:2017-11-14
  • Effect of spray nozzle attachment geometry on rate of liquid released from agglomerates produced by gas-atomized liquid injection into a fluidized bed
    Powder Technol. (IF 2.942) Pub Date : 2017-11-11
    Nicholas Prociw, Cedric Briens, Franco Berruti, Jennifer McMillan

    Liquid injection into a fluidized bed is employed in several chemical processes in order to maximize contact between liquid reactants and solid particles. For example, in the Fluid Coking™ process, droplets contact the bed particles and form wet agglomerates that impair heat transfer from the hot bed to the reacting liquid, slowing down its endothermic cracking reactions. Agglomerate formation, thus, results in reduced reactor operability and a lower yield of valuable liquid product. The objective of this paper is to test the effect of different nozzle attachments on the rate at which moisture is released from agglomerates in a large scale fluidized bed. The addition of a conical nozzle attachment impacts the performance of the spray inside a fluidized bed. An optimal diverging nozzle tip angle of 20° has been identified. This nozzle tip produces an open air spray angle similar to that produced by a regular nozzle, without an attachment. Increasing the diverging nozzle tip angle beyond 20° reduces the penetration length of the spray, and may induce detrimental instabilities downstream of the spray. Reducing the diverging nozzle tip angle stabilizes the spray, and increases its penetration depth; however, it also significantly reduces the jet-bed interfacial area, thereby reducing the number of solid particles wetted by the spray. As a result, stronger agglomerates are produced, that take longer to release trapped liquid into free moisture. The cloverleaf nozzle attachments improve the performance of the standard spray nozzle by increasing the interfacial area between the jet and the bed.

    更新日期:2017-11-11
  • Experimental study of the mechanical properties of intact and tectonic coal via compression of a single particle
    Powder Technol. (IF 2.942) Pub Date : 2017-11-11
    Jun Dong, Yuanping Cheng, Biao Hu, Congmeng Hao, Qingyi Tu, Zhengdong Liu

    Mechanical properties of coal are key factors that influence coal mining and methane extraction. Considering the difficulties in obtaining the mechanical properties of the tectonic coal and some intact coal, uniaxial compression tests were conducted on both types of coal particles in the size range of 0.2–4.0 mm. The force-displacement curves, effective elastic moduli and tensile strengths of the intact and tectonic coal particles were obtained. The power functions were used to describe the distributions of the effective elastic moduli and tensile strengths with the diameters of both coal particles. Statistical distributions of the effective elastic modulus and tensile strength for each coal sample with different particle size intervals were also plotted using a logistic function. The test results revealed that the intact coal shows obvious brittleness, whereas the tectonic coal has a smaller brittleness. The obtained effective elastic modulus and tensile strength of the intact coal are 2.72–4.57 and 2.86–6.35 times those of the tectonic coal, respectively, with particle diameters of 0.2–4.0 mm. The characteristics of low strength and large deformation of the tectonic coal would result in greater difficulty of methane extraction and increased risk during coal mining. Some considerations on the structural model of the tectonic coal and measures to enhance the methane extraction efficiency and reduce the risk of mining were also analyzed.

    更新日期:2017-11-11
  • Treatment of polymer powders by combining an atmospheric plasma jet and a fluidized bed reactor
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Marius Sachs, Jochen Schmidt, Wolfgang Peukert, Karl-Ernst Wirth

    This contribution addresses possibilities of plasma functionalization of different polymer particles to be used in additive manufacturing processes. The purpose of the surface manipulation is to enhance the wettability of single particles and, thus, the coalescence during melting of the particles in order to achieve an improved mechanical stability of parts built by laser beam melting processes. Surface functionalization is achieved by using an atmospheric pressure plasma jet in combination with a fluidized bed reactor. This allows the functionalization of temperature sensitive polymer particles in a reactor concept which can be scaled up for industrial production. To investigate the behavior of the plasma jet, which can be regarded as a secondary injection into a fluid particle bed, a semi-circle set-up was utilized to estimate treatment times of single particles with reactive plasma species. Hereby, different materials (PA12, PE-HD and PP) have been treated and the formed jet volume inside the reactor was measured. The results obtained by this set-up have then been utilized to improve the actual plasma treatment regarding treatment times. The results show that an optimum of treatment time exists for the wetting behavior of particles with water. In a last step, the influence of different plasma feed gases on the wetting behavior of the treated polymer particles has been examined.

    更新日期:2017-11-11
  • Strategies for evaluating distributive mixing of multimodal Lagrangian particles with novel bimodal bin count variance
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Chanho Park, Hyungtae Cho, Youngjin Kim, Sunghyun Cho, Jiheon Lee, Il Moon

    The variance among bin counts is one of the most effective and convenient indices to quantify the degree of spatial distributive mixing. Although it is suitable for evaluating the spatial distribution of unimodal particles, many practical particle-mixing processes involve bimodal or multimodal particle systems. Herein, the variance among bimodal bin counts is introduced as a new mixing index to quantify the degree of distributive mixing of bimodal or multimodal particles. Four bimodal particle-mixing systems are assumed and analyzed to evaluate index performance: balanced versus imbalanced and fully versus partially distributed particle systems. As a result, we suggest practical usage and the most effective variation of variances among conventional bin counts and bimodal bin counts to quantify the four bimodal particle-mixing systems. Furthermore, variations of the method for evaluating multimodal mixing are proposed.

    更新日期:2017-11-11
  • DEM with attraction forces using reduced particle stiffness
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Kimiaki Washino, Ei L. Chan, Toshitsugu Tanaka

    In Discrete Element Method (DEM), the stiffness of particles is often reduced from the real material property to increase the time step and decrease the calculation cost. Although this approach is widely accepted for dry and relatively coarse particles where only contact force is dominant, it is recently reported that the powder behaviour changes drastically with reducing the particle stiffness when cohesion forces are exerted on the particles  ; . The present study generalises this problem to any type of attraction forces and provides a solution, which is named as the Reduced Particle Stiffness (RPS) scaling. The RPS scaling for both linear and non-linear contact models are developed based on the dimensionless equation of motion where additional attraction forces such as liquid bridge, cohesion and electrostatic forces are exerted on particles. It is proven that, using the RPS scaling, particles with reduced stiffness show similar sticking/rebound behaviour and the bulk velocity as those of the original (stiff) particles.

    更新日期:2017-11-11
  • Comparative analysis of the explosibility of several different hybrid mixtures
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Wentao Ji, Xingqing Yan, Huili Sun, Xiaozhe Yu, Jianliang Yu

    A standard 20 L spherical chamber was used to study the explosibility of hybrid mixtures systematically. Four different hybrid mixtures, which were composed of two different flammable gases (methane and ethylene) and two different flammable organic dusts (lycopodium and polyethylene), were selected. The maximum explosion pressure Pex and the maximum explosion rate of pressure rise (dP/dt)ex of the four different hybrid mixtures were measured under initial high turbulence conditions over a wide range of composition concentrations (volume concentration y for gas and mass concentration c for dust). Explosion behaviours of the four different hybrid mixtures were analysed and compared with each other. Experimental results have shown that adding different flammable gases to the same dust cloud can all increase the explosion severity of the dust. However, the increase is almost equivalent when different flammable gases with the same equivalent ratio at low values are added. Only if the equivalent ratio is sufficiently higher can a higher increase in the explosion severity be induced by the more explosible gas. Adding the same flammable gas to different dust clouds clearly increases the explosion severity of all these dusts, but the increased ratios of Pmax and (dP/dt)max are higher for the less explosible dusts, indicating that the influence of flammable gas on the explosion severity is more pronounced for less explosible dusts.

    更新日期:2017-11-10
  • Numerical analysis of wet plastic particle separation using a coupled DEM-SPH method
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Darius Markauskas, Harald Kruggel-Emden, Viktor Scherer

    The separation of different kind of plastic particles is required in the process of waste recycling. For the separation, drum processes with liquid can be used. The separation is based on the principle that particles either sink or float in a liquid depending on their densities. In this study, this process is numerically analysed for the separation of polyethylene terephthalate (PET) from polypropylene (PP) particles. The discrete element method coupled with the smoothed particle hydrodynamics method (DEM-SPH) is used for modelling purposes. The employment of the SPH for the modelling of the liquid exploits the strong side of this meshless method, namely, the relative ease in modelling large movements of the fluid with free surfaces and moving boundaries. This theoretical model is presented, and verification tests are performed, where a dam-break problem is considered as an example. Simulations of the plastic particle separation in the rotating drum are performed thereafter. The influences of the different operational and design parameters, such as the rotational velocity, feed rate, number of lifters, etc., on the resultant purity of the plastic are estimated. It is expected that, in the future, the performed analysis will allow the numerical optimisation of drum separation processes.

    更新日期:2017-11-10
  • Investigation of the discharge law for drill cuttings used for coal outburst prediction based on different borehole diameters under various side stresses
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Cheng Zhai, Jizhao Xu, Shimin Liu, Lei Qin

    Prediction is the first step to prevent and control coal outburst geological disasters. Generally, both limits and disadvantages are generated for the traditional prediction methods of drill cuttings from a Φ42 mm borehole with increased mining depths. To investigate the discharge law of drill cuttings and improve the prediction index, briquettes were drilled with different borehole diameters under various side stresses. All the briquettes were loaded by a tri-axial experimental system to simulate the side stress of coal rock, and acoustic emission (AE) was used to monitor the AE events and record their characteristics during the separate drilling processes. The results showed that a larger borehole diameter and higher surrounding rock stress caused an increase in the quantity of drill cuttings (S). A power function relationship between S and the borehole diameter was found under the same side stress, and S was positively correlated to the side stress of a certain borehole diameter. Incremental drill cutting quantity (ΔS) was proposed to be the prediction index and the relationship between ΔS and the borehole diameter was fitted as a power function with a fitting coefficient of more than 0.99. The coupled values of ΔS and AE energies measured from a Φ85 mm borehole were more sensitive than those of a Φ35 mm borehole. In addition, the peak stress area using the larger drill bit was delayed by approximately 40 mm compared to that of the Φ35 mm drill bit. Larger diameter boreholes are preferable for larger regions of stress-relief and outburst removal; as a result, the use of larger diameter boreholes provides technological support to improve mine safety and increase production efficiency.

    更新日期:2017-11-10
  • Effect of turbulence on explosion of aluminum dust at various concentrations in air
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Qi Zhang, Lijuan Liu, Shilei Shen

    Energy released in explosion of aluminum dust at a given concentration in air depends on pre-ignition turbulence. The combined effects of turbulence and concentration on aluminum dust/air explosion in a 20 L spherical vessel were examined by numerical calculation in this study. It is found that role of pre-ignition turbulence in the aluminum dust/air explosion is related to the nominal concentrations. At lower nominal concentrations, the turbulence is a dominant factor affecting an aluminum dust/air explosion over uniformity of aluminum dust suspended in air. However, at higher nominal concentrations, the uniformity of aluminum dust suspended in air is a dominant factor affecting an aluminum dust/air explosion over turbulence.

    更新日期:2017-11-10
  • CoCrWCu alloy with antibacterial activity fabricated by selective laser melting: Densification, mechanical properties and microstructural analysis
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Yanjin Lu, Ling Ren, Songquan Wu, Chunguang Yang, Wenlie Lin, Suli Xiao, Yang Yang, Ke Yang, Jinxin Lin

    In the study, self-developed CoCrWCu gas-atomized powders with antibacterial activity were fabricated and used in selective laser melting (SLM). To determine whether a reliability of the SLMed CoCrWCu alloy for dental application could be obtained by using those powders, processing optimization was conducted to maximize density. Surface analysis and tensile tests were performed to verify an optimal processing parameter for fabrication of nearly full density alloy with few pores. Based on tailored parameter variation studies, a highly dense CoCrWCu alloy with 99.74% relative density could be fabricated at the energy input of 53.14 J/mm3. The outcome from tensile test suggested that the SLMed CoCrWCu alloy met the standard of ISO 22764 for dental restorations. SEM observation showed that an extremely fine microstructure with cellular and columnar structures was obtained in the SLMed CoCrWCu alloys. As such, a large density of bar-like precipitates was found to exist, which were confirmed to be sigma phase from the indexation of fast fourier transform pattern. The preliminary antibacterial test indicated that the SLMed CoCrWCu alloy has an excellent antibacterial performance against E.coli. It was considered that the energy input of 53.14 J/mm3 was promising candidate for fabricating the dense CoCrWCu alloy with acceptable properties and part reliability. Also, this study can thus aid in a further improvement of CoCrWCu powders.

    更新日期:2017-11-10
  • Fractal dimensions of low rank coal subjected to liquid nitrogen freeze-thaw based on nuclear magnetic resonance applied for coalbed methane recovery
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Lei Qin, Cheng Zhai, Shimin Liu, Jizhao Xu, Shangjian Wu, Ruowei Dong

    The aims of this research are to quantitatively evaluate the complexity of the pore structure in coal frozen with liquid nitrogen (LN2) and then study the influence of the modified pore system on coalbed methane (CBM) extraction. To do this, nuclear magnetic resonance (NMR) and fractal dimension theory were used to determine the properties of the coal's pore system after samples of low rank coal had been frozen and then thawed. The fractal dimensions of pores in frozen-thawed coal samples were divided into five types according to pore size and the state of the fluid in the coal pores. The results showed that the fractal dimension DA of adsorption pores was less than two, indicating that these pores did not exhibit fractal characteristics. The fractal dimensions Dir and DT representing closed pores and total pores presented low fitting precision, so the closed pores showed insignificant fractal characteristics. However, the fractal dimensions DF and DS representing open pores and seepage pores had high fitting precision, suggesting that open and gas seepage pores exhibited a favorable fractal characteristic. Correlation analysis revealed that DF and Ds were negatively correlated with LN2 freezing time and the number of freeze-thaw cycles. After being frozen and thawed, coal porosity and permeability showed a strong negative correlation with fractal dimension and this relationship allowed predictive models for permeability and fractal dimensions (DF and DS) to be constructed. The models showed that the smaller the fractal dimension, the more uniformly the pores were distributed and the higher their degree of connection. These properties favor the production of CBM. This study also showed that compared with single LN2 freezing events, repeated cyclic freezing with LN2 followed by thawing is more favorable for CBM production.

    更新日期:2017-11-10
  • Analysis of interparticle forces and particle-wall interactions by powder bed pressure drops at incipient fluidization
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Wan-Yi Hsu, An-Ni Huang, Hsiu-Po Kuo

    A novel method is proposed to evaluate the interparticle forces and particle-wall interactions based on the pressure drop measurements at incipient fluidization. In the first experiment, we used the liquid bridge force as the model interparticle force of the glass ballotini (53 μm–105 μm). The theoretical relationship between the model liquid bridge force and the liquid addition volume was successfully presented. In the second part of experiment, the interparticle forces and the particle-wall interaction of cornstarch powders in a Perspex cylinder are determined. While the particle-wall interaction shows a linear relationship with the apparent bed-wall contact area, the interparticle force follows a logarithm relation with the bed mass for the Warren-Spring-type cornstarch powders. The results were also compared to the cohesion values obtained by a conventional shear tester. The results conclude that our method serves as an economically and accurate alternative to conventional shear testers.

    更新日期:2017-11-10
  • Mathematical modeling of the capillary rise of liquids in partially soluble particle beds
    Powder Technol. (IF 2.942) Pub Date : 2017-11-10
    Martim Victor Hammes, Eduardo Schirmer Heberle, Patricia Rodrigues da Silva, Caciano Pelayo Zapata Noreña, Alexandre Hahn Englert, Nilo Sérgio Medeiros Cardozo

    One of the most widely used techniques for evaluating the wettability of powdered foods is the capillary rise method, in which the contact angle is usually estimated using the classical Washburn model. However, this model does not take into account the effect of the dissolution of the particle bed in the rising process, which is an important limitation for its application to many powdered foods. This work presents a new mathematical model for the analysis of capillary rise data considering the partial dissolution of the particle bed. As in the case of the classical Washburn model, the proposed model, designated Dissolution-Modified Washburn Model (DM-Washburn), was obtained by the integration of the Navier-Stokes equation, but introducing a dependency of the capillary diameter as a function of meniscus position and time as a strategy to quantify the dissolution effects. The comparison between the DM-Washburn and the classical Washburn models in terms of quality of fit was performed using experimental data of capillary rise in d-(+)-glucose and lactose using as wetting liquids pure water and aqueous solutions of these two materials with concentrations up to saturation. The DM-Washburn model provided better fit to the height versus time data, with mean relative deviation (MRD) values lower than 5% for all tested conditions. Further, the estimates of contact angle obtained with the DM-Washburn model showed to be independent of the carbohydrate concentration in the wetting liquid, differently from what was observed using the classical Washburn model. Additionally, tests with microcrystalline cellulose (MCC), a water insoluble material, showed the consistency of the DM-Washburn model in conventional capillary experiments, i.e., without significant dissolution of the particle bed. The obtained results indicate that the model has great potential for evaluating the wettability of soluble materials.

    更新日期:2017-11-10
  • Effect of confinement on heat transfer in aqueous nanofluids from a heated sphere
    Powder Technol. (IF 2.942) Pub Date : 2017-11-09
    Anoop K. Gupta, Garima Mishra, N. Nirmalkar, R.P. Chhabra

    A systematic numerical investigation on heat transfer from a heated sphere settling in aqueous nanofluids has been carried out to elucidate the effect of confinement and the other pertinent dimensionless numbers on heat transfer. In this work, four types of nanoparticles (NPs) have been considered, namely, Al2O3, CuO, SiO2 and ZnO, each of two different diameters of dnp = 20 nm and 80 nm. In order to account for the variation of properties with temperature, the temperature-dependent equations for the viscosity and thermal conductivity of nanofluids are employed here. Extensive results on streamline and isotherm contours, wake characteristics (length), drag coefficient and local and average Nusselt Number have been obtained and discussed to elucidate the effect of Peclet number (Pe), nanoparticle volume fraction (ϕ) and blockage ratio (λ) over the following ranges of conditions: 5 ≤ Pe ≤ 600, 0 ≤ ϕ ≤ 0.05 and 0.1 ≤ λ ≤ 0.9 where λ is the sphere-to-tube diameter ratio. Overall, the recirculation length shows a positive dependence on both Peclet number (Pe) and particle size (dnp) while it exhibits inverse trends with respect to ϕ and λ. A significant enhancement (20–30%) in the rate of heat transfer over the conventional Newtonian fluids is observed and it is seen to increase with the increasing values of the Peclet number. Finally, a simple predictive correlation for the average Nusselt number is developed which includes the conduction limit and, it enables the estimation of the Nusselt number for the intermediate values of the parameters reported in a new application.

    更新日期:2017-11-10
  • Effect of fractal gas distributor on the radial distribution of particles in circulating turbulent fluidized bed
    Powder Technol. (IF 2.942) Pub Date : 2017-11-09
    Ci Peng, Min Lv, Shengnan Wang, Xianliang Sun, Hongjiang Liu, Zhiyong Tang, Yuhan Sun

    A novel gas distributor fabricated with 3D printing was used in the present work to improve the radial distribution of particles in a circulating turbulent fluidized bed (CTFB). The effect of fractal distributor on a CTFB was studied using cold model tests and numerical simulations. At constant bed height and with other operating conditions, a higher particle concentration was obtained from the two-layer gas distributor, while the one-layer gas distributor produced a more even radial distribution. Additionally, based on the Eulerian/Eulerian method, a computational fluid dynamics (CFD) model incorporating a modified gas-solid drag model has been used to simulate the fluidized bed. Compared with a traditional drag force model, the modified model produced more accurate predictions (from a comparison of simulated and measured values) for the distribution of the gas and solid phases.

    更新日期:2017-11-10
  • A study of the effect of liquid viscosity on density-driven wet granular segregation in a rotating drum
    Powder Technol. (IF 2.942) Pub Date : 2017-11-08
    Chun-Chung Liao

    Experiments were conducted for this study to investigate the effects of liquid viscosity on density-induced granular segregation in a thin rotating drum. The goal of this study is to ultimately quantify the effect of the liquid bridge force on density-induced granular segregation. The movements of the granular materials were recorded by high-resolution and high-speed cameras. Image processing technology and particle tracking methods were applied to measure the segregation index, velocities, the fluctuation velocity and granular temperatures of heavy particles. The results of the experiment indicate that by adding small amounts of liquid with varying viscosities the segregation behavior and dynamic properties of wet granular materials are significantly influenced due to the formation and rupturing of liquid bridges. The segregation behavior is mitigated with the viscosity of the liquid due to the energy dissipation caused by the formation and rupturing of the liquid bridges that increase as liquid viscosity increases. The correlation between the intensity of the segregation and the angle of repose is also discussed in this study.

    更新日期:2017-11-10
  • Multi-objective optimization of a gas cyclone separator using genetic algorithm and computational fluid dynamics
    Powder Technol. (IF 2.942) Pub Date : 2017-11-08
    Xun Sun, Joon Yong Yoon

    In the present study, multi-objective optimization of a gas cyclone is performed using a genetic algorithm (GA) and computational fluid dynamics (CFD) techniques to minimize pressure drop and maximize its collection efficiency. The reference model is a well-optimized cyclone from a previous study. First, a screening experiment for seven factors is performed to determine the statistically significant factors. Then, to define the fitness function used in the GA, four of the factors are studied using the central composite design in the response surface methodology. The second-generation non-dominated sorting genetic algorithm is utilized to optimize the four significant factors of the cyclone according to the well-defined fitness functions, and 53 non-dominated optimum cyclone design points are suggested. The reasonable accuracy of the results from the GA is confirmed via CFD validation of five representative optimum points. The obtained Pareto front comprises important design information for the new cyclones. Finally, the performance and flow field of a representative optimal design are compared with those of the classical Stairmand model and the reference model. The optimal design reduces the pressure drop and cut-off size by 7.38% and 9.04%, respectively, compared to the reference model. In addition, compared to the Stairmand model, decreases of 19.23% and 42.09% are achieved for the pressure drop and cut-off size, respectively.

    更新日期:2017-11-10
  • A dynamic cluster structure-dependent drag coefficient model applied to gas-solid risers
    Powder Technol. (IF 2.942) Pub Date : 2017-11-07
    Dan Li, Shuyan Wang, Guodong Liu, Huilin Lu, Xiaoxue Jiang, Ming Tao, Zhenjie Li

    A dynamic cluster structure-dependent (CSD) drag coefficient model is proposed to be consistent with the temporal-spatial characteristics of dynamic clusters through the convective accelerations and temporal accelerations of the dense phase and the dilute phase. The CSD drag coefficient is determined by a nonlinear micro-meso-grid scales equation set which consists of three momentum conservation equations, two mass balance equations, one equation for volume fraction balance, and an extreme value of a function in combination with the bivariate extreme value (BEV) theory. Flow behavior of gas and particles is predicted by means of gas-solid two-fluid model coupled with CSD drag model and kinetic theory of granular flow. The distributions of independent variables of dense phase and dilute phase are predicted in the riser. Numerical analysis suggests that the inertial difference between the dense phase and the dilute phase affects flow behavior of dynamically temporal-spatial clusters in risers. The simulated solids volume fraction, cluster existence time fraction and frequency of cluster occurrence are compared to experimental measurements in the literature.

    更新日期:2017-11-10
  • Mixing performance of ribbon mixers: Effects of operational parameters
    Powder Technol. (IF 2.942) Pub Date : 2017-11-07
    M. Halidan, G.R. Chandratilleke, K.J. Dong, A.B. Yu

    Ribbon mixers are widely used in practice because they are capable of providing high speed convective mixing. Here, the discrete element method (DEM) is used to investigate the effects of impeller speed and fill level on the mixing behaviours of mixtures of particles with different cohesion in two-bladed and four-bladed ribbon mixers, each having a horizontal cylindrical vessel. The mixing behaviours are characterized by a particle-scale mixing index. Simulations show that the mixing rate increases with the impeller speed for both the cohesive and non-cohesive particle mixtures up to a certain speed, beyond which it shows a reduction. The mixing rate becomes poorer at higher impeller speeds for mixing of cohesive particles in the 2-bladed mixer. Inspection of velocity fields shows that many localized recirculation flows exist when the mixing non-cohesive particles, preventing the overall mixing. By contrast, when mixing cohesive particles, there exist circumferential flow about the shaft axis and convective flow in the horizontal axial direction, improving the particle mixing. The mixing rate deteriorated with an increase of the fill level in both the two-bladed and four-bladed mixers. The mixing rate of the particles is higher in the four-bladed mixer compared to the two-bladed mixer. With the increase of fill level, the particle flow changes successively from the sliding type of flow to recirculation flow and then to cascading flow for non-cohesive particles. The four-bladed mixer performs better for mixing at high fill levels and stronger cohesion, consolidating its advantage for mixing cohesive particles.

    更新日期:2017-11-10
  • Mechanical strength of microspheres produced by drying of acoustically levitated suspension droplets
    Powder Technol. (IF 2.942) Pub Date : 2017-11-06
    M. Kreimer, I. Aigner, S. Sacher, M. Krumme, T. Mannschott, P. van der Wel, A. Kaptein, H. Schroettner, G. Brenn, J.G. Khinast

    Spray drying is widely used in pharmaceutical manufacturing to produce microspheres from solutions or suspensions. The mechanical properties of the microspheres are reflected by the morphology formed in the drying process. In suspension drying, solids dissolved in the carrier liquid may form bridges between the suspended primary particles, producing a microsphere structure which is resistant against mechanical loads. Experiments with individual, acoustically levitated droplets were performed to simulate the drying of suspension droplets in a spray drying process. The suspensions studied consisted of a binary liquid mixture as the carrier liquid, and primary particles of suspended lactose material which is partially soluble in the liquid. The solubility of lactose was varied by the composition of the liquid mixture. The experiments revealed longer first and second drying stages for higher lactose solubility. Electron micrographs revealed the morphology of individual microspheres produced by drying in the levitator. Microspheres with only primary particles and no visible crust were obtained for low lactose solubility, whereas higher contents of dissolved lactose resulted in a more densely packed microsphere with crust formation. To quantify the hardness of individual microspheres, the maximum breaking force upon mechanical loading was measured for a range of varying suspension compositions. These measurements confirmed that densely packed structures with a thick crust reveal high mechanical strength. It was shown that, for primary lactose particles to be conserved in spray drying, the dissolved lactose mass loading Xd must be below 5.2%.

    更新日期:2017-11-10
  • Permeability evolution and mesoscopic cracking behaviors of liquid nitrogen cryogenic freeze fracturing in low permeable and heterogeneous coal
    Powder Technol. (IF 2.942) Pub Date : 2017-11-06
    Guangzhi Yin, Delei Shang, Minghui Li, Jie Huang, Tiancheng Gong, Zhenlong Song, Bozhi Deng, Chao Liu, Zhicheng Xie

    Fracking to approach permeability enhancement is indispensable to enhance coalbed methane recovery, which can significantly reduce greenhouse gas emissions and produce substantial clean energy. To access efficient fracking, samples of Permian low permeable coal reservoir were cracked into different sizes or scales of blocks and particles with liquid nitrogen cryogenic freeze fracturing (FF) by maximizing the underlying heterogeneity of coal. To investigate the crack efficacy, this study systematically examined the permeability evolution and mesoscopic cracking behaviors of coal with different water contents and cleat–fracture systems in the context of cryogenic FF. Results showed that the permeability enhancement and microcracking tended to occur with increasing water content of coal sample; and the efficacy of cryogenic FF on the tighter coal sample was more remarkable. However, the permeability does not strictly increase with the cycles of cryogenic FF and has a close relationship with water content, structural plane direction, efficacy of cryogenic FF, and porosity compaction. The mesoscopic cracking behaviors indicate that numerous smaller pores are iteratively, not strictly sequentially, cracked and become connective in this process. The permeability evolution of coal sample is identified as significantly associated with the mesoscopic cracking behaviors. Notably, the first cycle of cryogenic FF acted on the detected several scales of pores and micro fissures, and partially caused these structures to be opened and interconnected to be permeable. Two main changes were observed in the microcracking of the coal samples in this study: 1) nonuniform shrinkage deformation and micro fissure expansion; and 2) pores opening mostly in the macropore and mesopore scale. It is reasoned that thermal cracking and intermittent opening of seepage pores due to the phase transition of free water in pores or micro fissures ultimately contribute to the permeability enhancement in low permeable and heterogeneous coal.

    更新日期:2017-11-10
  • The electrical resistivity and relative permittivity of binary powder mixtures
    Powder Technol. (IF 2.942) Pub Date : 2017-11-06
    Janne Peltonen, Matti Murtomaa, Kelly Robinson, Jarno Salonen

    Effective electrical resistivities and static relative permittivities of binary powder mixtures were measured and compared to theoretical equations given by Generalized Mixture Rule (GMR). The measured values for mixtures were influenced by the resistivity and permittivity of the pure component materials, the particle sizes and by the sticking between the different particles. According to the Random Model (RM), the effective resistivity and relative permittivity of any randomly packed mixture material can be calculated from the component resistivities and relative permittivities, respectively, and their concentrations. It was shown that RM gave good predictions for both quantities for powders if the particle sizes of the component materials were almost the same. However, this was not the case when large NaCl particles were mixed with fine sugar particles. When these mixtures were prepared, finer, more numerous sugar particles coated the larger NaCl particles, and the mixtures were not random but closer to the series configuration. Effect of particle size was studied briefly by mixing very fine NaCl particles with sugar of similar size. With these mixtures, results predicted by RM were obtained.

    更新日期:2017-11-10
  • Investigation of the vibration sorting of non-spherical particles based on DEM simulation
    Powder Technol. (IF 2.942) Pub Date : 2017-11-06
    Ying You, Malin Liu, Huaqing Ma, Lei Xu, Bing Liu, Youlin Shao, Yaping Tang, Yongzhi Zhao

    Vibration sorting is a common means in separating non-spherical particles from spherical particles. In this paper, the discrete element method (DEM) is applied to simulate the behavior of spherical particles and non-spherical particles motion on an inclined vibrating plate (IVP), and the influence of different operating parameters on the separation performance of the mixed particles is investigated. In the DEM simulations, both the spherical and non-spherical particles are modeled by super-ellipsoids. The simulation results show that the optimal vibration amplitude and frequency exist for the high separation efficiency of the mixed particles. The separation efficiency can also be enhanced by properly increasing the friction coefficient or decreasing the restitution coefficient between particles and plate. It is easier to separate the non-spherical particles from the spherical particles by diminishing the sphericity of particles. Besides, as long as the inclination angle of the plate is set at appropriate range and the feed rate of the mixed particles is moderate, the non-spherical particles can be separated effectively from the spherical particles. This research could be helpful for the understanding and optimal design of vibration sorting device.

    更新日期:2017-11-10
  • Simulation of deformation and fragmentation of a falling drop under electric field
    Powder Technol. (IF 2.942) Pub Date : 2017-11-06
    E. Ghasemi, H. Bararnia, Soheil Soleimani, C.X. Lin

    Physical properties and especially the size of drops are important parameters in many industrial and medical applications. High voltage electric field is one of the effective means to control the final size of drops during the fabrication process which could greatly influence the final size of the product. Therefore a detailed study of electric field effect on a liquid drop is very important. In this work deformation and fragmentation of a falling droplet under gravity and electric force have been studied numerically. Electric force is used as an effective external controlling mechanism to influence the deformation of a drop. The three-dimensional deformation of a falling droplet is studied numerically using the open-source volume-of-fluid solver, Gerris. The numerical results are compared with previous analytical, experimental and numerical data and great agreements between the results are obtained. The results are presented for broad range of Bond numbers (Bo) from low Bond number (drop with small deformation) to large Bond number (drop breakup and fragmentation). The results revealed that the electric field can be used as a powerful controlling tool in delaying and expediting the falling drop breakup process. The results also showed that falling drop deforms severely by increasing Bo number which leads to the breakup and fragmentation compared to the cases of low Bo number in which the drop deforms mildly without breakup.

    更新日期:2017-11-10
  • Measurement of moisture content in a fluidized bed dryer using an electrostatic sensor array
    Powder Technol. (IF 2.942) Pub Date : 2017-11-05
    Wenbiao Zhang, Xufeng Cheng, Yonghui Hu, Yong Yan

    Fluidized bed dryers have been widely applied to dry raw materials or final products due to the advantages of good mixing efficiency and high heat and mass transfer rate. In order to control and optimize the drying process of fluidized bed dryers, it is necessary to develop reliable methods to measure the moisture content of solid particles in the bed. Because of the advantages of non-intrusiveness, simple structure and high sensitivity, an electrostatic sensor array has been developed to monitor the drying process. Experimental investigations were conducted on a lab-scale fluidized bed dryer. The moisture content during the drying process was measured using the sampled particles as reference. It is found that the fluctuation of the electrostatic signals can reflect the change in moisture content. However, the relationship between the fluctuation of the electrostatic signal and the moisture content depends on the air velocity in the dryer. To eliminate the velocity effect on moisture content measurement, a model between the moisture content and the root-mean-square magnitude of the electrostatic signal is established. The effectiveness of the model is validated using experimental results under a range of conditions. The findings indicate that the electrostatic sensor array can measure the moisture content in the bed with a maximum error of ± 15%.

    更新日期:2017-11-10
  • Modeling and stability study of the anthocyanin-rich maoberry fruit extract in the fast-dissolving spray-dried microparticles
    Powder Technol. (IF 2.942) Pub Date : 2017-11-05
    Bancha Yingngam, Karnnuttha Tantiraksaroj, Thitima Taweetao, Wandee Rungseevijitprapa, Nuttapun Supaka, Adelheid H. Brantner
    更新日期:2017-11-05
  • A study on the carbonization and alloying process of MnO2 by methane-hydrogen gas mixture in the presence of Fe2O3
    Powder Technol. (IF 2.942) Pub Date : 2017-11-05
    Bingbing Liu, Yuanbo Zhang, Zijian Su, Manman Lu, Guanghui Li, Tao Jiang
    更新日期:2017-11-05
  • Agglomerate behavior in a recirculating fluidized bed with sheds: Effect of bed properties
    Powder Technol. (IF 2.942) Pub Date : 2017-11-05
    Francisco J. Sanchez Careaga, Cedric Briens, Franco Berruti, Jennifer McMillan, Murray Gray
    更新日期:2017-11-05
  • Enhancement of louver dust collector efficiency using modified dust container
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Jung-Bo Sim, Un-Hak Yeo, Gwang-Hun Jung, Su-Beom Park, Gwi-Nam Bae, Se-Jin Yook
    更新日期:2017-11-05
  • The effect of changes in pH on the depression of talc by chitosan and the associated mechanisms
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Bo Feng, Jinxiu Peng, Wei Guo, Wenpu Zhang, Guanghua Ai, Huihui Wang
    更新日期:2017-11-05
  • DEM simulation on the vibrated packing densification of mono-sized equilateral cylindrical particles
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Quan Qian, Lin Wang, Xizhong An, Yongli Wu, Ju Wang, Haiyang Zhao, Xiaohong Yang
    更新日期:2017-11-05
  • Physicochemical and antioxidant properties of hard white winter wheat (Triticum aestivm L.) bran superfine powder produced by eccentric vibratory milling
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Shudong He, Jing Li, Qian He, Huifang Jian, Yi Zhang, Jialiang Wang, Hanju Sun
    更新日期:2017-11-05
  • Preparation of CNT/Cu nano composite powder with uniform dispersion and strong interface bonding by SP method
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Lanbo Li, Rui Bao, Jianhong Yi, Liang Liu, Shuai Mao
    更新日期:2017-11-05
  • 更新日期:2017-11-05
  • The effect of electrostatics on single bubble in fluidized bed and its mechanism analysis
    Powder Technol. (IF 2.942) Pub Date : 2017-11-03
    Zhen Tan
    更新日期:2017-11-05
  • Grains3D, a flexible DEM approach for particles of arbitrary convex shape - Part II: parallel implementation and scalable performance
    Powder Technol. (IF 2.942) Pub Date : 2017-10-24
    Andriarimina Daniel Rakotonirina, Anthony Wachs
    更新日期:2017-10-25
  • Comments on “A novel magnetic chitosan/clinoptilolite/magnetite nanocomposite for highly efficient removal of Pb(II) ions from aqueous solution”
    Powder Technol. (IF 2.942) Pub Date : 2017-10-24
    Yuan-dong Huang

    A mistake of applying pseudo-first order kinetic model for determining kinetic parameters of adsorption has been pointed out. Also, this discussion gives a corrected pseudo-first order kinetic equation.

    更新日期:2017-10-24
  • Effect of Y2O3 doping on FCC to HCP phase transformation in cobalt produced by ball milling and spark plasma sintering
    Powder Technol. (IF 2.942) Pub Date : 2017-10-24
    Zongyu Xie, Song Ni, Min Song
    更新日期:2017-10-24
  • 更新日期:2017-10-24
  • A new multiple-time-step three-dimensional discrete element modeling of aerosol acoustic agglomeration
    Powder Technol. (IF 2.942) Pub Date : 2017-10-23
    Guangxue Zhang, Lili Zhang, Jinqing Wang, Zuohe Chi, Eric Hu
    更新日期:2017-10-23
  • Microencapsulation of vanilla (Vanilla planifolia Andrews) and powder characterization
    Powder Technol. (IF 2.942) Pub Date : 2017-10-23
    S.J. Calva-Estrada, M.R. Mendoza, O. García, V.M. Jiménez-Fernández, M. Jiménez
    更新日期:2017-10-23
  • Spatial filtering velocimetry for surface velocity measurement of granular flow
    Powder Technol. (IF 2.942) Pub Date : 2017-10-22
    J.M. Gong, H. Yang, S.H. Lin, R. Li, V. Zivkovic
    更新日期:2017-10-23
  • Dry beneficiation of fine coal using planar air jets
    Powder Technol. (IF 2.942) Pub Date : 2017-10-22
    Xuliang Yang, Yadong Zhang, Song Wang, Yuemin Zhao, Zhenfu Luo
    更新日期:2017-10-23
  • Effect of vertical length on asymmetric flow and inclusion transport in vertical-bending continuous caster
    Powder Technol. (IF 2.942) Pub Date : 2017-10-21
    Zhongqiu Liu, Baokuan Li
    更新日期:2017-10-23
  • Development of a novel bentonite–acrylamide superabsorbent hydrogel for extinguishing gangue fire hazard
    Powder Technol. (IF 2.942) Pub Date : 2017-10-20
    Yibo Tang, Huae Wang
    更新日期:2017-10-20
  • Oxidation of gaseous formaldehyde with ozone over MnOx/TiO2 catalysts at room temperature (25 °C)
    Powder Technol. (IF 2.942) Pub Date : 2017-10-19
    Minsu Kim, Eunseuk Park, Jongsoo Jurng
    更新日期:2017-10-20
  • Measurement of solid mass flow rate by a non-intrusive microwave method
    Powder Technol. (IF 2.942) Pub Date : 2017-10-19
    Lei Pang, Yingjuan Shao, Chamin Geng, Wenqi Zhong, Guoyao Liu, Longhai Liu, Wanjun Tian
    更新日期:2017-10-19
  • Evaluation of the mechanical properties of compacted paraffin powders. Effect of formulation
    Powder Technol. (IF 2.942) Pub Date : 2017-10-18
    K. Dunchych, C. Loisel, A. Arhaliass, O. Goncalves, J. Legrand, M. Pouliquen, S. Saint-Jalmes
    更新日期:2017-10-18
  • A new correlation for predicting the thermal conductivity of ZnO–Ag (50%–50%)/water hybrid nanofluid: An experimental study
    Powder Technol. (IF 2.942) Pub Date : 2017-10-18
    Navid Nasajpour Esfahani, Davood Toghraie, Masood Afran
    更新日期:2017-10-18
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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