Numerical Simulation of Conveying Fine Powders in a Screw Conveyor Using the Discrete Element Method

Due to their high efficiency and spatial utilization, screw conveyors are widely used in pharmacy, agriculture, and industry. Recently, this has made it a popular research subject in the numerical modelling of the transport of bulk solids. Modelling of granular systems at the level of individual particles is mainly possible due to the use of discrete numerical methods. The most common is the use of the Discrete Element Method (DEM), which is still limited from the point of view of simulations on an industrial scale, as increasing the size of the system also increases the cost of simulation. Certain powders with low density, large angles of repose, poor fluidity, and bad flowability can accumulate during transportation, causing inaccurate and non-uniform movement. Additionally, the friction and impact between the particles can cause wear. To address these issues, the present study utilizes the discrete element method to simulate and analyse powder transportation in an inclined screw conveyor using the commercial software ANSYS-ROCKY. Numerous phenomena that arise while transporting and feeding small-sized or irregularly shaped particles, often present in industrial processes, remain insufficiently investigated. This paper aims to analyse the transportation process of adhesive powders in a screw conveyor, with a focus on evaluating the impact of different screw blade speeds on transport. Multiple simulations were conducted, along with the implementation of an additional wear model, to better understand the transport phenomena and wear. An example was used to demonstrate the impact of screw speed on the wear of the transporter due to the interaction between the material and the structure of the conveyor, power consumption, and performance

Bisociative knowledge discovery for microarray data analysis

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SegMine workflows for semantic microarray data analysis in Orange4WS

Peer reviewe

Innovative approaches to wear reduction in horizontal powder screw conveyors: A design of experiments-guided numerical study

Numerical simulations play a vital role in the modern engineering industry, especially when faced with interconnected challenges such as particle interactions and the structural integrity of conveyor systems. This article focuses on the handling of materials and emphasizes the importance of using parametric numerical analysis to improve efficiency, reduce wear, and enhance the structural integrity of horizontal screw conveyors. Through the utilization of the Design of Experiments, we systematically investigated critical parameters such as screw pitch, clearance, wear, rotational velocity, and additional structural factors. This examination was carried out within a well-defined parametric framework, utilizing a combination of software tools provided by the Ansys suite and Minitab. The findings demonstrate the effectiveness of the Design of Experiments analysis in achieving improved performance and provide valuable insights for engineers and researchers involved in the design of conveyor systems. Furthermore, this comprehensive approach clarifies how conveyor systems respond to changes in parameters and highlights the complex interaction between transported particles and the conveyor system. We present a detailed analysis that clarifies the complex relationships and dependencies among different parameters, providing engineers and researchers with valuable insights. By understanding the interactions of these factors, the methodology provides not only results but also a strategic framework for advancing conveyor system design and engineering practices

Designing the main hatch lever on a small hydroelectric plant

Diplomsko delo prikazuje postopek iskanja optimalnega dizajna ročice, ki je nameščena na glavni loputi male hidroelektrarne. Dizajn nove ročice se išče na osnovi obstoječega mehanizma, ki trenutno služi odpiranju in zapiranju glavne lopute. Skozi nalogo se srečamo z raznimi metodami, kot sta metoda končnih elementov ter optimizacija topologije, s katerimi si pomagamo pri iskanju optimalne konstrukcijske rešitve. Metode so najprej predstavljene teoretično in kasneje aplicirane na konkretnem primeru.The thesis presents the process of searching for the optimal design of a lever, positioned on the main hatch of a small hydroelectric plant. The design of the new lever is being searched on the ground of the existing mechanism, which currently serves for opening and closing of the main hatch. Through the thesis, we are getting to know different methods, like the finite element method and topology optimization, which aid us in the search for an optimal construction solution. The methods are first presented theoretically and later applied to a specific case

Modelling and code development for static response analysis of geometrically nonlinear planar structures

V zaključnem delu obravnavamo statični odziv ravninskih konstrukcij s pomočjo metode končnih elementov. Za ravninsko napetostno stanje je izpeljan štirivozliščni izoparametrični končni element, ki ga uporabimo za razvoj lastne programske kode, s pomočjo katere lahko analiziramo linearne in nelinearne odzive konstrukcij. Najprej so teoretično predstavljene vse metode in količine, ki jih kasneje uporabimo pri razvoju algoritmov. Prav tako je predstavljeno teoretično ozadje nastanka nelinearnosti v numeričnih simulacijah. Osnovo za razvoj kode predstavlja formulacija linearnega odziva, ki je osnova za opis iteracijskih in inkrementalnih formulacij, s katerimi lahko opišemo različne nelinearnosti. Naloga torej predstavi celoten razvoj programa za analizo po metodi končnih elementov, s katerim je moč izvesti procesiranje in poprocesiranje linearnih in nelinearnih ravninskih analiz.In the final thesis, we discuss the static response of planar structures with the help of the final element method. A four-node isoparametric finite element is derived for the plane stress state, which we use to develop our own software code, with the help of which we can analyse linear and nonlinear construction responses. First, we theoretically present all methods and quantities, which we use later in the development of algorithms. We also present the theoretical backgrounds of the emerge of nonlinearity in numeric simulations. The basis for the development of the code is the formulation of linear response, which is the basis for the description of iterative and incremental formulations, with which we can describe different nonlinearities. The thesis thus presents the entire development of the software for the analysis according to the final element method, with which we can perform processing and post-processing of linear and nonlinear planar analyses

Numerical Simulation of Conveying Fine Powders in a Screw Conveyor Using the Discrete Element Method

Due to their high efficiency and spatial utilization, screw conveyors are widely used in pharmacy, agriculture, and industry. Recently, this has made it a popular research subject in the numerical modelling of the transport of bulk solids. Modelling of granular systems at the level of individual particles is mainly possible due to the use of discrete numerical methods. The most common is the use of the Discrete Element Method (DEM), which is still limited from the point of view of simulations on an industrial scale, as increasing the size of the system also increases the cost of simulation. Certain powders with low density, large angles of repose, poor fluidity, and bad flowability can accumulate during transportation, causing inaccurate and non-uniform movement. Additionally, the friction and impact between the particles can cause wear. To address these issues, the present study utilizes the discrete element method to simulate and analyse powder transportation in an inclined screw conveyor using the commercial software ANSYS-ROCKY. Numerous phenomena that arise while transporting and feeding small-sized or irregularly shaped particles, often present in industrial processes, remain insufficiently investigated. This paper aims to analyse the transportation process of adhesive powders in a screw conveyor, with a focus on evaluating the impact of different screw blade speeds on transport. Multiple simulations were conducted, along with the implementation of an additional wear model, to better understand the transport phenomena and wear. An example was used to demonstrate the impact of screw speed on the wear of the transporter due to the interaction between the material and the structure of the conveyor, power consumption, and performance

Planning and construction of the lifting and towing device of the autonomous mobile robot MiR 100 for the delivery of transport trolleys in intralogistics

Intralogistics is a very important area in warehousing and production for managing the flow of materials and informational flow. In recent years, automation and especially robotisation have had a major impact on throughput performance in intralogistics. Especially important is the transport of materials and products based on automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) with different top modules, such as the lifting and towing device. In this paper, planning and construction of the lifting and towing device of the autonomous mobile robot MiR 100 for the delivery of transport trolleys in intralogistics is presented. Using the engineering design methods, a new design of the lifting and towing device has been proposed and evaluated

Energetska učinkovitost avtomatiziranih regalnih skladiščnih sistemov pri uporabi tehnologije regeneracije energije: primer avtomatskega skladiščenja v jeklarski industriji

Z namenom doseganja visoke zalogovne velikosti in zahtevane pretočne zmogljivosti se tudi v jeklarski industriji vse pogosteje uporabljajo avtomatizirani regalni skladiščni sistemi za uskladiščenje težkih polizdelkov oz. jeklenih palic in profilov, nameščenih v namenskih kasetah. Izrazito visoka teža jeklenih palic in profilov ter zahtevane pretočne zmogljivosti z dodatnimi zahtevami tehnično robustnega in visoko učinkovitega skladišča, prinaša s sabo tudi visoko potrošnjo električne energije za delovanja skladišča. V članku je na primeru avtomatiziranega regalnega skladišča za jeklene palice in profile predstavljena možnost zmanjšanja porabe električne energije z uporabo koncepta regeneracije pri zaviranju regalnega dvigala in spuščanju dvižne mize regalnega dvigala

Postmortem chondrocyte viability in porcine articular cartilage

The aim of the present study was to investigate the effects of time, temperature, and burial in a natural environment on the viability of chondrocytes in porcine femoral condyles using confocal laser scanning microscopy. Hind trotters from 10 pigs were buried or left unburied. Samples were collected daily and stained with a combination of vital dyes (calcein-AM and ethidium homodimer-1). The chondrocytes showed an intense staining corresponding to their vitality. In the first 3 days, viability decreased slowly and showed no statistical difference between buried and unburied samples. After the first 3 days, it decreased rapidly, with the viability of the buried samples being 66% on day 4, decreasing to 25% on day 8 and to 16% on day 10, while in the unburied samples it decreased to 43% on day 4, 13% on day 8 and 5% on day 10. Our results indicate a time, temperature, and burial dependent decrease in chondrocyte viability and suggest the use of chondrocyte viability as a marker for estimating PMI in both the natural environment and in animals, as well as its potential use in humans