Journal articles: 'Cross-flow fluidized bed'

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Jading, Abadi, Eduard Tethool, Paulus Payung, and Sarman Gultom. "KARAKTERISTIK FISIKOKIMIA PATI SAGU HASIL PENGERINGAN SECARA FLUIDISASI MENGGUNAKAN ALAT PENGERING CROSS FLOW FLUIDIZED BED BERTENAGA SURYA DAN BIOMASSA." Reaktor 13, no. 3 (2011): 155. http://dx.doi.org/10.14710/reaktor.13.3.155-164.

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PHYSICOCHEMICAL CHARACTERISTICS OF SAGO STARCH OBTAINED FROM FLUIDIZED BED DRYING USING SOLAR AND BIOMASS POWERED CROSS FLOW FLUIDIZED BED DRYER. The research aim is to study the comparative quality of sago starch drying results using cross flow fluidized bed dryer powered by solar and biomass in conventional drying, particularly the chemical composition and physicochemical characteristics. This research was conducted through a drying phase of wet sago starch using a cross flow fluidized bed dryer, and drying in conventional as well as dried sago starch quality testing results are drying. The results of this study indicate that dry sago starch which has been drained by means of cross flow fluidized bed dryer has a chemical composition that does not vary much with starch which is dried by conventional drying, so that the dried sago starch produced by the dryer is very good. On the other hand the use of dryers is the more correct because the physicochemical properties of sago starch using a low drying temperature and drying time is short. Tujuan penelitian ini adalah mempelajari perbandingan kualitas pati sagu hasil pengeringan menggunakan alat pengering cross flow fluidized bed bertenaga surya dan biomassa dengan pengeringan secara konvensional, khususnya komposisi kimia dan karakteristik fisikokimia. Penelitian ini dilakukan melalui beberapa tahapan yaitu pengeringan pati sagu basah menggunakan alat pengering cross flow fluidized bed, pengeringan secara konvensional serta pengujian kualitas pati sagu kering hasil pengeringan. Hasil dari penelitian ini menunjukkan bahwa pati sagu kering yang telah dikeringkan dengan alat pengering cross flow fluidized bed memiliki komposisi kimia yang tidak berbeda jauh dengan pati yang dikeringkan dengan cara pengeringan secara konvensional, sehingga pati sagu kering yang dihasilkan oleh alat pengering tersebut sangat baik. Di sisi lain penggunaan alat pengering ini semakin memperbaiki sifat fisikokimia pati sagu sebab menggunakan suhu pengeringan yang rendah dan waktu pengeringan yang singkat. Kata Kunci: pengering unggun terfluidakan; fisikokimia; pati sagu

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Jayarathna, Chameera K., Michael Balfe, Britt M. E. Moldestad, and Lars-Andre Tokheim. "Improved multi-stage cross-flow fluidized bed classifier." Powder Technology 342 (January 2019): 621–29. http://dx.doi.org/10.1016/j.powtec.2018.10.026.

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Sopornonnarit, Somchart, Somkiat prachayawarakorn, and Ornanong Sripawaatakul. "Development of Cross-Flow Fluidized Bed Paddy Dryer." Drying Technology 14, no. 10 (1996): 2397–410. http://dx.doi.org/10.1080/07373939608917212.

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Ramli, Wan, and Wan Daud. "A Cross-Flow Model for Continuous Plug Flow Fluidized-Bed Cross-Flow Dryers." Drying Technology 25, no. 7-8 (2007): 1229–35. http://dx.doi.org/10.1080/07373930701438618.

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Jading, Abadi, Paulus Payung, and Reniana Reniana. "KAJIAN TEKNIS-EKONOMIS ALAT PENGERING PATI SAGU MODEL CROSS FLOW VIBRO FLUIDIZED BED (Study on Technical-Economic of Sago Starch Dryer Model of Cross Flow Vibro Fluidized Bed)." Jurnal Agritech 34, no. 04 (2015): 448. http://dx.doi.org/10.22146/agritech.9440.

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The purpose of this research was to evaluate performance of vibro cross flow fluidized bed dryer using biomass fuel for drying sago starch. The phase of research were evaluation of dryer heated by a biomass stove using coconut shell as a fuel and observation of the drying temperature, moisture content, drying time, energy analysis, and drying effiviency, as well as calculation of its economic analysis. The dryer has dimension of 200x50x1500 cm for length, width, hight, respectively, and working capacity of 35kg/process. The results showed that biomass fuel consumption for drying sago starch for 7 hours was 12740,00 MJ (70 kg/process) and electricity consumption for blower and vibrator was 37,80 MJ. Furthermore, the dryer reduced moisture content of sago starch from 42% (wb) to 12% (wb) with temperature in the vibrator chamber of 40-60 oC and relative humidity of 50%, as well as ambient temperature of 30 3C and drying efficiency of 46,02%. Economic analysis showed that the dryer had NPV of Rp. 16.002.858, BCR of 1,53, IRR of 35%, and PBP of 3,51 years.Keywords: Cross flow, vibro fluidized bed dryer, biomass stoves, sago starch, financial analysis ABSTRAKTujuan penelitian ini adalah melakukan pengujian terhadap alat pengering pati berbasis sagu model cross flow vibrofluidized bed bertenaga biomassa. Tahapan penelitian meliputi pengujian alat pengering menggunakan tungku biomassa berbahan bakar tempurung kelapa dengan melakukan pengamatan suhu selama pengeringan, penurunan kadar air, waktu pengeringan, kebutuhan energi, efisiensi pengering, dan analisis finansial. Konstruksi alat pengering pati sagu model vibro fluidized bed bertenaga biomassa berukuran panjang, lebar dan tinggi masing-masing (200x50x1500) cm, serta memiliki daya tampung atau kapasitas maksimum pati sagu basah 35 kg/proses. Hasil pengujian menunjukkan bahwa alat pengering ini mampu mengeringkan pati sagu selama 7 jam, dengan konsumsi bahan bakar tempurung kelapa sebanyak 70 kg/proses (1274MJ), kebutuhan daya listrik untuk tenaga blower dan vibrator(37,80 MJ), serta mampu menurunkan kadar air pati sagu dari 42%bb menjadi 12%bb dengan suhu dalam ruang vibrator adalah 40-60 oC, RH 50%, suhu lingkungan 30C dan efisiensi pemanasan (pengeringan) 46,02%.Hasil analisis finansial menunjukan bahwa investasi alat pengering vibro fluidized bedsangat layak dilaksanakan berdasarkan kriteria NPV = Rp. 16.002.858, BCR= 1,53, IRR= 35%, dan PBP tertutupi setelah 3,51 tahun. Kata kunci: Aliran silang, vibro fluidized bed dryer, tungku biomassa, pati sagu, analisis finansial

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Mikulášek, Petr. "Effect of Fluidized Bed on Permeate Flux in Ceramic Membrane Cross-Flow Microfiltration." Collection of Czechoslovak Chemical Communications 60, no. 12 (1995): 2074–84. http://dx.doi.org/10.1135/cccc19952074.

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The microfiltration of a model fluid on an α-alumina microfiltration tubular membrane in the presence of a fluidized bed has been examined. Following the description of the basic characteristic of alumina tubular membranes, model dispersion and spherical particles used, some comments on the experimental system and experimental results for different microfiltration systems are presented. From the analysis of experimental results it may be concluded that the use of turbulence-promoting agents resulted in a significant increase of permeate flux through the membrane. It was found out that the optimum porosity of fluidized bed for which the maximum values of permeate flux were reached is approximately 0.8.

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Soponronnarit, Somchart, Mustafa Yapha, and Somkiat Pracbayawarakorn. "Cross-Flow Fluidized Bed Paddy Dryer: Prototype and Commercialization." Drying Technology 13, no. 8-9 (1995): 2207–16. http://dx.doi.org/10.1080/07373939508917075.

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Wang, Sheng Dian, Xue Yao Wang, Xiang Xu, and Yun Han Xiao. "Flow Phenomena in the Riser of a Circulating Fluidized Bed." Advanced Materials Research 516-517 (May 2012): 906–9. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.906.

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Numerical simulation of gas-solid two-phase flows in circulating fluidized bed is proved to be a low-cost and high-efficient method to research the instability essence of flow character. In this work, numerical simulation based on the discrete element (DEM) method is applied to analyze behaviors in a rectangular cross-section fluidized bed. The models of physical and mathematical models are introduced in detail, and the schematic of DEM method also described clearly. It indicates that the DEM method may be used as a powerful tool for the simulation of the gas-solid flow.

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Vogtenhuber, Hannes, Dominik Pernsteiner, and René Hofmann. "Experimental and Numerical Investigations on Heat Transfer of Bare Tubes in a Bubbling Fluidized Bed with Respect to Better Heat Integration in Temperature Swing Adsorption Systems." Energies 12, no. 14 (2019): 2646. http://dx.doi.org/10.3390/en12142646.

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In this paper experimental and numerical investigations on heat transfer within a bubbling fluidized bed will be presented with respect to better heat integration in continuous temperature swing adsorption (TSA) processes for biogas upgrading. In the literature, mainly heat transfer measurements with glass or sand particles are carried out, thus special reference measurements with adsorbent material in a fluidized bed are missing. Therefore firstly, a series of experiments were carried out in the fluidized bed test facility to obtain heat transfer coefficients between tube surface and bed which were then compared to calculated heat transfer coefficients to determine whether suitable models were available. Horizontal bare tubes with different arrangements (i.e., single tubes and especially tube bundles) are immersed in fluidized amine layered particles with a mean diameter of 650 μ m which are used in the adsorption industry as adsorbent. The test facility enables a cross-current flow of the solids and gas phase as it prevails in a multi-stage fluidized bed reactor for TSA-applications. The heat transfer measurements with different arrangements and adsorbent material show very similar values in the range of 200 W/m 2 K. The mathematical model for single tubes multiplied by a tube diameter factor shows approximate agreement with the experimental results. However, the mathematical models for tube bundles were not able to predict the measured heat transfer coefficients with the required accuracy. Secondly, a computer fluid dynamics (CFD) program was used to perform a numerical investigation of the test facility using the Euler–Euler method in order to describe the required two-phase characteristic of a fluidized bed. The results of the numerical simulation were compared and validated with the experimental results. Bubbling fluidized bed flow regimes could be reproduced well but the heat transfer coefficients between tube and bed were clearly underestimated. However, a numerical study for a bubbling fluidized bed with external circulation, as used in novel continuous TSA systems, could be carried out and thus a tool for better heat integration measures was developed.

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Wu, Zhen-Qun, Hui Jin, Yi-Fei Ren, and Lie-Jin Guo. "Investigation on drag coefficient of supercirtical water cross-flow past cylinder biomass particel at low Reynolds numbers." Thermal Science 22, Suppl. 2 (2018): 383–89. http://dx.doi.org/10.2298/tsci170804250w.

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The supercritical water gasification of biomass technology is a promising approach for the efficient and clean conversion of wet-biomass to hydrogen-rich gas production. Many of the biomass materials are of rodlike shape and gasified in supercritical water fluidized bed. So the particle-fluid two-phase flow behaviors insider supercritical water fluidized bed are of great importance. Constrained by the extreme operating condition, numerical methods, such as the Euler-Euler method and Euler-Lagrange method, are used to study the flow behaviors inside the supercritical water fluidized bed. As the accuracy of these methods are depended on the drag force model and there is little investigation on that at supercritical condition, this work is focused on the drag coefficient of cylinder biomass particle with different ratio of length to diameter. The simulated results show that there is no differ- ence for the drag coefficient of a certain particle at different condition when the Reynolds number is same. The variation tendency of the pressure and viscous drag coefficient with Reynolds number and the ratio of length to diameter is also given in this paper.

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Kong, Weibin, Bin Wang, Jan Baeyens, et al. "Solids mixing in a shallow cross-flow bubbling fluidized bed." Chemical Engineering Science 187 (September 2018): 213–22. http://dx.doi.org/10.1016/j.ces.2018.04.073.

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Murray, D. B., P. O'Connor, and P. Gilroy. "Cross-Flow Heat Transfer in The Freeboard Region of a Fluidized Bed." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 210, no. 3 (1996): 245–53. http://dx.doi.org/10.1243/pime_proc_1996_210_194_02.

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This paper describes an experimental investigation of heat transfer in two tube banks, one in-line and one staggered, located in the freeboard region of a gas fluidized bed. The objectives of this study are twofold. Firstly, examination of the local heat transfer results is used to identify the dominant heat transfer mechanisms. Secondly, the overall heat transfer performance of the two tube configurations is of relevance for the design, selection and siting of heat exchangers for fluidized bed combustors. The experimental results show that the dominant influence on heat transfer is the local concentration of particles, with the impact over the rear of tubes by particles disengaging from the flow having a significant effect on wake heat transfer. The latter mechanism is less important for tubes in the first and second rows of the in-line array, due to the shielding effect of the surrounding tubes. This difference in wake heat transfer contributes to higher mean Nusselt numbers, on average, for the tubes located in the staggered array.

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Yang, Chen, Haochuang Wu, Kangjie Deng, Hangxing He, and Li Sun. "Study on Powder Coke Combustion and Pollution Emission Characteristics of Fluidized Bed Boilers." Energies 12, no. 8 (2019): 1424. http://dx.doi.org/10.3390/en12081424.

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The fluidized reactor is widely used in a number of chemical processes due to its high gas-particle contacting efficiency and excellent performance on solid mixing. An improved numerical framework based on the multiphase particle-in-cell (MP-PIC) method has been developed to simulate the processes of gas–solid flow and chemical reactions in a fluidized bed. Experiments have been carried out with a 3-MW circulating fluidized bed with a height of 24.5 m and a cross section of 1 m2. In order to obtain the relationship between pollutant discharge and operating conditions and to better guide the operation of the power plant, a series of tests and simulations were carried out. The distributions of temperature and gas concentration along the furnace from simulations achieved good accuracy compared with experimental data, indicating that this numerical framework is suitable for solving complex gas–solid flow and reactions in fluidized bed reactors. Through a series of experiments, the factors affecting the concentration of NOx and SOx emissions during the steady-state combustion of the normal temperature of powder coke were obtained, which provided some future guidance for the operation of a power plant burning the same kind of fuel.

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Venkiteswaran, Vinod Kumar, Syaida Hazira Ramli, and Vijay R. Raghavan. "CFD Simulation of Air Flow through the Annular Distributor of a Swirling Fluidized Bed." Applied Mechanics and Materials 700 (December 2014): 619–25. http://dx.doi.org/10.4028/www.scientific.net/amm.700.619.

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Fluidized beds are widely used in a variety of industrial processes. The air distributor being an integral part of the fluidized bed, the air flow characteristic through it is of great importance as far as the design and working of it is concerned. Inappropriate design will lead to an incomplete fluidization and improper mixing of the air and bed particles. The current study was carried out to investigate the flow characteristics and predict non-uniformity in flow through the annular distributor of a Swirling Fluidized Bed and its variation with various aspects of the distributor like blade overlap angle and blade inclination. In this study, the commercial CFD package FLUENT 6.3 was used for analysis. The velocity and pressure profiles for various blade designs were investigated at the distributor outlet based on several operating variables including air inlet velocities, blade overlap angles (9o, 12o, 15o, and 18o), blade inclinations (10oand 15o), along with variations in the opening between the distributor blades. The most significant finding of this work is that the fluid tends to flow through a path with least resistance. The flow path with the largest cross section area and shortest path length has been identified and explains the velocity profile at blade exit.

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Pang, Jianming, Yaoxin Song, Shiwen Li, Chongfeng Yue, Zhimin Zhao, and Lingen Luo. "Fluidization characteristics of iron ore powder in fluidized bed." Journal of Physics: Conference Series 2720, no. 1 (2024): 012012. http://dx.doi.org/10.1088/1742-6596/2720/1/012012.

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Abstract The fluidization characteristics of iron powder were studied on a self-made cold fluidized bed in the laboratory. The pressure distributed in the axial inside the lifting pipe of a fluidized bed gradually decreases to a constant value from underbody to roof. As the gas flow rate in the fluidized bed increases, the pressure on each axial section first increases and then decreases. When the inflation numbers are fixed, as the operating gas speed increases, the pressure on the same height segment decreases. When the operating gas speed of a fluidized bed is constant, the pressure increases with the increase of inflation numbers. The pressure at different bed heights is affected differently by the operating air speed: at the underbody of the bed, the pressure rapidly decreases with increasing operating airspeed. As the cross-sectional height increases, the influence of operating gas speed on pressure gradually decreases. As the charge increases, the pressure at the underbody of the fluidized bed rises rapidly, while the pressure at the roof changes gently. When iron ore fine powder is fluidized, distribution in axes of particle concentration shows an uneven distribution of upper dilute and lower dense. Under a certain loading number, increasing the operating airspeed will reduce the average concentration of granules in each axial section of the entire bed, and the particle concentration distribution in that section will become uniform. As the number of charges increases, the average concentration of granules in the riser increases, and the difference in particle concentration between the underbody and roof parts of the riser decreases.

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Li, Hai Guang, Zeng Wu Zhao, Ke Li, Yong Chuan Wang, and Wen Fei Wu. "Studying the Bubble Characteristics of Gas – Particle Flow in a CFB through Image Analysis." Advanced Materials Research 341-342 (September 2011): 328–32. http://dx.doi.org/10.4028/www.scientific.net/amr.341-342.328.

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This study is based on the image processing system by the authors, and performs microscope observations of the bubbles flow in dense-phase transport region of circulating fluidized beds. The research has tested and experimented on a cold scale-model circulating fluidized bed with a riser that has a 0.30mm × 0. 28mm cross-section and is 2.90 m tall with a video camera utilized to visualize the bubble structure through a transparent Plexiglas wall. The experiment was carried out at different particle sizes, different bed materials ,different heights and different height regions .The result analyzes the impact factor of the bubble size, shape and so on in the wall.

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Verma, Rupesh, Gaurav Srivastava, and Nishith Verma. "Novel multi-staged radially cross-flow fluidized bed ion-exchange column." Chemical Engineering and Processing: Process Intensification 48, no. 1 (2009): 396–407. http://dx.doi.org/10.1016/j.cep.2008.05.005.

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Shishatskii, Y. I., S. A. Tolstov, A. A. Derkanosova, and A. A. Ryndin. "On the equilibrium and stability of a fluidized bed as a thermodynamic system." Proceedings of the Voronezh State University of Engineering Technologies 83, no. 2 (2021): 56–60. http://dx.doi.org/10.20914/2310-1202-2021-2-56-60.

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The transfer of the dispersed layer into a fluidized state makes it possible to intensify the drying process. The small size of the particles leads to an increase in the surface of their contact with the coolant at a relatively low hydrodynamic resistance. Other positive qualities of fluidization are listed, which is very important when carrying out exothermic processes. We studied the behavior of the fluidized bed during the drying process. The curve of fluidization of beet chips is shown. The suspended state of the material began when the forces of the hydrodynamic layer were equal to the weight of all its particles per unit area of the cross-section of the working chamber. The region of existence of the fluidized bed is marked. In this area, the flow was relatively equilibrium (fluidized). On the surface of the layer, small waves were observed with different frequencies and amplitudes of oscillations, as well as with spontaneous fluctuations. This mode of operation was achieved as a result of the study of the structures of the support - gas distribution grid and the drying chamber. The flow velocity profile in the working chamber is investigated. An efficient equalization of velocities with the help of flat stamped grids has been established. The results were confirmed by the spectra of the flow in the drying chamber. Oscillations on the free surface of a fluidized bed are considered. The Euler equation was written, which made it possible, as a result of various transformations, to obtain a formula for calculating the oscillation frequency of the fluidized bed. The studies carried out made it possible to establish the regimes of pseudo-fluidization, to a certain extent minimizing the heterogeneity of the layer, which is of significant practical importance. However, the operating parameters need to be adjusted depending on the type of material to be dried and other indicators. The research results do not obscure the general provisions of nonequilibrium thermodynamics. The fluidized bed cannot be in an equilibrium state, since the transfer of substances is obvious: energy, mass and momentum. It is correct to regard the fluidized bed as unstable. Small and spontaneous fluctuations always exist in the layer. The absence of conditions for their decay becomes a condition for the instability of the process.

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Zeng, Tao, Shao Bei Liu, and Hai Bo Lin. "Global Flow Structure in a Square Gas-Solid Fluidized Bed." Advanced Materials Research 791-793 (September 2013): 540–44. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.540.

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Turbulent fluidization is a flow regime between bubbling fluidization and fast fluidization. The influence of static bed heights and axial locations on transition velocity was studied from bubbling fluidization to turbulent fluidization in a 368 mm×368 mm square fluidized bed, based on the pressure gradient fluctuation by measurement differential pressures transducer of FCC. Experiment results show that the transition velocities increase with decreasing location of observation or increasing static bed heights. And the transition of regime from bubbling fluidization to turbulent fluidization is a process gradually happened from the upper to the lower bed section and is not instantaneous behavior in the whole bed. Based on those, the prediction model is built that the average solids concentrations of bed cross-section are used to reflect the variation of gas-solid interaction along the bed height. The new prediction correlation by fitting parameters of experimental data is in well agreement with experiment results

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Esence, Thibaut, Hadrien Benoit, Damien Poncin, Michael Tessonneaud, and Gilles Flamant. "A shallow cross-flow fluidized-bed solar reactor for continuous calcination processes." Solar Energy 196 (January 2020): 389–98. http://dx.doi.org/10.1016/j.solener.2019.12.029.

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Geng, Shujun, Yanan Qian, Jinhui Zhan, Hongling Zhang, Guangwen Xu, and Xiaoxing Liu. "Prediction of solids residence time distribution in cross-flow bubbling fluidized bed." Powder Technology 320 (October 2017): 555–64. http://dx.doi.org/10.1016/j.powtec.2017.07.085.

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Izadifar, M., and D. Mowla. "Simulation of a cross-flow continuous fluidized bed dryer for paddy rice." Journal of Food Engineering 58, no. 4 (2003): 325–29. http://dx.doi.org/10.1016/s0260-8774(02)00395-3.

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ESPIN, M. J., J. M. VALVERDE, M. A. S. QUINTANILLA, and A. CASTELLANOS. "Stabilization of gas-fluidized beds of magnetic powders by a cross-flow magnetic field." Journal of Fluid Mechanics 680 (May 19, 2011): 80–113. http://dx.doi.org/10.1017/jfm.2011.151.

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In this paper we present an experimental study of the stabilization of gas-fluidized beds of magnetic powders by application of a cross-flow magnetic field. The powders tested consist of magnetite and steel powders in a range of particle size dp between 35 and 110 μm, allowing us to investigate the effect of particle size and material properties on magnetic stabilization. In the operation mode employed by us the magnetic field is applied to the unstable bubbling bed and the gas velocity is slowly decreased. According to our observations, the bed is stabilized at a critical gas velocity by the jamming of particle chains formed during bubbling because of the attractive forces induced between the magnetized particles, which are thus responsible for stabilization. Although the magnetic field is applied in the horizontal direction, these chains are mechanically stable at orientations close to the gas flow direction, in agreement with the prediction of an unconfined chain model based on the balance between gas flow shear and interparticle magnetic force fm. Since fm is increased as dp is increased, the critical gas velocity at marginal stability vc for a fixed field strength B is seen to increase with dp. As the gas velocity v0 is decreased below vc, there is a rearrangement of the structure depending on particle size. Restructuring of the bed depends on particle size as derived from measurements of its permeability to the gas flow, which causes the yield stress to be a function of particle size. It is also inferred from our results that natural agglomeration of fine particles (in the absence of a magnetic field) due to van der Waals forces enhances the yield stress of the magnetically stabilized bed. From our experimental results it is concluded that structural effects, as affected by operating conditions and material properties, play a main role in the rheology of the stabilized magnetofluidized bed (MFB).

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Verma, Rupesh, Ravi Kumar, Devesh M. Pandey, and Nishith Verma. "Hydrodynamic study on radially cross-flow fluidized bed multi-staged ion-exchange column." Chemical Engineering and Processing: Process Intensification 49, no. 11 (2010): 1199–204. http://dx.doi.org/10.1016/j.cep.2010.09.001.

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Hua, Leina, Hu Zhao, Jun Li, Qingshan Zhu, and Junwu Wang. "Solid residence time distribution in a cross-flow dense fluidized bed with baffles." Chemical Engineering Science 200 (June 2019): 320–35. http://dx.doi.org/10.1016/j.ces.2019.01.054.

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Song, Jing Hui, Tao Wang, Jing Gao, Xian Bin Xiao, Chang Qing Dong, and Xiao Ying Hu. "Erosion in the Rectangular Biomass Circulating Fluidized Bed." Advanced Materials Research 608-609 (December 2012): 214–19. http://dx.doi.org/10.4028/www.scientific.net/amr.608-609.214.

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Through MFIX software, a three-dimensional numerical gas-solid flow models without chemical reactions is developed to the distributions of solids phase volume fraction and velocities in a 220t/h rectangular cross-section biomass CFB with a height of 3m. The maximum of erosion occurs at the near-wall side at y=0.95m on the front-wall and back-wall. In transition region(0.8-1.4m) of the left-wall and right-wall, typical core-annular regime can be observed, particle in the core region have the tendency to move to the corner. The maximum of erosion occurs at the corner formed between the walls in the role of downward movement of particle. And the lateral movement of particles are obvious enhanced between the core region and back-wall in the role of exit effect, which lead a certain degree of lateral erosion between the core region and back-wall at the left-wall and right-wall.

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Aronsson, Jesper, David Pallarès, Magnus Rydén, and Anders Lyngfelt. "Increasing Gas–Solids Mass Transfer in Fluidized Beds by Application of Confined Fluidization—A Feasibility Study." Applied Sciences 9, no. 4 (2019): 634. http://dx.doi.org/10.3390/app9040634.

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Fluidized bed applications where the bed material plays an active role in chemical reactions, e.g. chemical looping combustion, have seen an increase in interest over the past decade. When these processes are to be scaled up to industrial or utility scale mass transfer between the gas and solids phases can become a limitation for conversion. Confined fluidized beds were conceptualized for other purposes in the 1960’s but are yet to be applied to these recent technologies. Here it is investigated if they can prove useful to increase mass transfer but also if they are feasible from other perspectives such as pressure drop increase and solids throughflow. Four spherical packing solids, 6.35–25.4 mm in diameter at two different densities, were tested. For mass transfer experiments the fluidizing air was humidified and the water adsorption rate onto silica gel particles acting as fluidizing solids was measured. Olivine sand was used in further experiments measuring segregation of solids and packing, and maximum vertical crossflow of solids. It was found that mass transfer increased by a factor of 1.9–3.8 with packing solids as compared to a non-packed reference. With high-density packing, fluidizing solids voidage inside the packing was found to be up to 58% higher than in a conventional fluidized bed. Low density packing material favoured its flotsam segregation and with it higher fluidization velocities yield better mixing between packing and fluidizing solids. Maximum vertical cross-flow was found to be significantly higher with low density packing that fluidized, than with stationary high-density packing. Conclusively, the prospect of using confined fluidized beds for improving mass transfer looks promising from both performance and practical standpoints.

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Zhang, Yi, Kheng-Lim Goh, Yuen-Ling Ng, Yvonne Chow, and Vladimir Zivkovic. "Design and Investigation of a 3D-Printed Micro-Fluidized Bed." ChemEngineering 5, no. 3 (2021): 62. http://dx.doi.org/10.3390/chemengineering5030062.

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Micro-fluidized bed has aroused much attention due to its low-cost, intensified-process and fast-screening properties. In this paper, a micro-fluidized bed (15 × 15 mm in cross-section) was designed and fabricated with the use of the stereolithography printing technique, for the investigation of bubbles’ hydrodynamics and comparison of the solids (3D-printed particles VS fungal pellets) fluidization characteristics. In a liquid–gas system, bubble flow regime started from mono-dispersed homogeneous regime, followed by poly-dispersed homogeneous regime, transition bubble regime and heterogeneous bubble regime with increasing gas flowrates from 3.7 mL/min to 32.7 mL/min. The impacts from operating parameters such as gas flowrate, superficial liquid velocity and gas sparger size on bubble size, velocity and volume fraction have been summarized. In liquid–solid fluidization, different solid fluidization regimes for both particles bed and pellets bed were identified. From the bed expansion results, much higher Umf of 7.8 mm/s from pellets fluidization was observed compared that of 2.3 mm/s in particles fluidization, because the hyphal structures of fungal pellets increased surface friction but also tended to agglomerate. The similar R–Z exponent n (5.7 and 5.5 for pellets and particles, respectively) between pellets and particles was explained by the same solid diameter, but much higher Ut of 436 µm/s in particles bed than that of 196 µm/s in pellets bed is a consequence of the higher density of solid particles. This paper gives insights on the development of MFB and its potential in solid processing.

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Zhou, J., J. R. Grace, C. J. Lim, C. M. H. Brereton, S. Qin, and K. S. Lim. "Particle cross-flow, lateral momentum flux and lateral velocity in a circulating fluidized bed." Canadian Journal of Chemical Engineering 73, no. 5 (1995): 612–19. http://dx.doi.org/10.1002/cjce.5450730504.

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Gueguen, Ronny, Guillaume Sahuquet, Samuel Mer, Adrien Toutant, Françoise Bataille, and Gilles Flamant. "Gas-Solid Flow in a Fluidized-Particle Tubular Solar Receiver: Off-Sun Experimental Flow Regimes Characterization." Energies 14, no. 21 (2021): 7392. http://dx.doi.org/10.3390/en14217392.

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The fluidized particle-in-tube solar receiver concept is promoted as an attractive solution for heating particles at high temperature in the context of the next generation of solar power tower. Similar to most existing central solar receivers, the irradiated part of the system, the absorber, is composed of tubes in which circulate the fluidized particles. In this concept, the bottom tip of the tubes is immersed in a fluidized bed generated in a vessel named the dispenser. A secondary air injection, called aeration, is added at the bottom of the tube to stabilize the flow. Contrary to risers, the particle mass flow rate is controlled by a combination of the overpressure in the dispenser and the aeration air velocity in the tube. This is an originality of the system that justifies a specific study of the fluidization regimes in a wide range of operating parameters. Moreover, due to the high value of the aspect ratio, the particle flow structure varies along the tube. Experiments were conducted with Geldart Group A particles at ambient temperature with a 0.045 m internal diameter and 3 m long tube. Various temporal pressure signal processing methods, applied in the case of classical risers, are applied. Over a short acquisition time, a cross-reference of the results is necessary to identify and characterize the fluidization regimes. Bubbling, slugging, turbulent and fast fluidization regimes are encountered and the two operation modes, without and with particle circulation, are compared.

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Hao, Xiao Wen, Chun Yuan Ma, and Qiang Zhao. "Study on Swirl Composite Fluidization Mode with Circulating Fluidized Beds for Flue Gas Desulfurization." Advanced Materials Research 233-235 (May 2011): 915–19. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.915.

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Circulating Fluidization Bed (CFB) for Flue Gas Desulfurization (FGD) is widely used. But its desulfurization efficiency is lower than Wet FGD. Its investment is not much lower than Wet FGD. Flow field of CFB for FGD is hard to be uniform. Swirl Composite Fluidization Mode (SCFM) was brought forward compared to Venturi Fluidization Mode (VFM). Experiment and simulation under cold condition was proceeded. From the test, flow field along axis and in cross-sections for SCFM are uniform. Turbulent velocity fluctuation is violent. And particles concentration is high. SCFM has better flow effect than VFM. Uniformity increases with higher superficial velocity and more tangential swirl devices. Recommended tangential swirl devices number is between 3-6. SCFM technology has good foreground.

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Gao, Peng Fei, Bin Yang, Ming Gong, and Xiao Xun Ma. "PIV Measurement of the Fluidized Particles’ Velocity Field in a Cylindrical Spouted Bed." Advanced Materials Research 560-561 (August 2012): 632–36. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.632.

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In this paper, the instantaneous velocity fields of the particles in the spouted bed were measured by the particle image velocimetry (PIV). In the experiment, the spouted particles achieved the visible accumulation effect when the fountain height was 0.85 times of the packed bed height h. Since the particles are dispersed with each other, the PIV recordings were evaluated by the multiple-pass recursive method based on the FFT cross-correlation algorithm. The time-averaged velocity field of the particles obtained from the PIV experiment had similar distribution with the velocity field calculated by the numerical simulation. In the averaged particle velocity field, there was a continuous region which divided the whole flow field into two parts. The particle velocities in the region approximated to zero especially in vertical direction, which means the particles with upwards motion were basically equated to those with downwards motion in the region. Therefore the effects of particles’ face-to-face friction and even abrasion were much stronger in the region. Further, the experimental results also show that the area of the region could be about 11.19% of the whole flow field.

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Tu, Qiuya Y., and Haigang G. Wang. "Investigation of the riser cross-sectional aspect ratio effect on the flow dynamics in circulating fluidized beds by electrical capacitance tomography." Transactions of the Institute of Measurement and Control 42, no. 4 (2019): 655–65. http://dx.doi.org/10.1177/0142331219851913.

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With the increase of capacity, most of the circulating fluidized beds (CFB) risers are constricted to have rectangular cross section. Therefore, it is important to find out the cross-sectional aspect ratio effect on the gas-solids flow characteristics. In this study, a lab-scale CFB with two rectangular risers, which have the aspect ratio of 1:1 and 3:1, respectively, were studied by the electrical capacitance tomography (ECT), with the aided of pressure measurements and computational particle fluid dynamics (CPFD) simulation. Key issues related with ECT sensor design and image reconstruction, such as sensitivity map and excitation frequency, are also discussed. The results show that ECT image quality is affected by the sensitivity map and excitation frequency, and high excitation frequency and voltage are not equivalent of high image quality. In the riser bottom region, cross-sectional aspect ratio has big effect on ECT measured particle distribution and pressure drop, fewer particles are brought away from the bottom when the aspect ratio is larger. Multiple bubbles exist in the bottom region at Ve= 2.7 m/s, and bubble size decreases in the rectangular riser with larger cross-sectional aspect ratio. Static bed height influences the bubble behaviour that bubbles with smaller size scattered around and behave collapse or coalescence in the moving process when the static bed height is high.

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Al-Hajeri, M. H., A. Aroussl, K. Simmons, and S. J. Pickering. "A parametric study of filtration through a ceramic candle filter." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 219, no. 1 (2005): 77–90. http://dx.doi.org/10.1243/095765005x6908.

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Ceramic candle filters have been developed for cleaning high-temperature high-pressure (HTHP) gas streams. They meet environmental and economical considerations in combined cycle power plant, where gas turbine blades can be protected from the erosion resulting from the use of HTHP exhaust from the fluidized bed. Ceramic candle filters are the most promising hot gas filtration technology and have demonstrated high collection efficiencies at high-temperature high-pressure conditions. This paper reports a computational fluid dynamics (CFD) investigation of a candle filter in cross-flow arrangement. The aim is to increase understanding of the deposition process and the factors that affect the build-up of the filter cake. A parametric investigation is undertaken, with particular emphasis on the effects of the ratio of the approach cross-flow velocity to filter face velocity on the deposition pattern as a function of the particle size (1–300 μm). Velocity fields and particle tracks are presented, in addition to the radius of convergence which is a parameter that characterizes the deposition process for each flow regime. Furthermore, a method has been developed for predicting filter cake growth using CFD and particle deposits distributed around the filter element surface uniformly for particle sizes below 50 μm. The paper contains a potential flow solution for the flow around a single porous filter element in cross-flow.

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Razzak, Shaikh A. "Study of Phase Distribution of a Liquid-Solid Circulating Fluidized Bed Reactor Using Abductive Network Modeling Approach." Chemical Product and Process Modeling 8, no. 2 (2013): 77–91. http://dx.doi.org/10.1515/cppm-2013-0008.

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Abstract This communication deals with the Abductive Network modeling approach to investigate the phase holdup distributions of a liquid–solid circulating fluidized bed (LSCFB) system. The Abductive Network model is developed/trained using experimental data collected from a pilot scale LSCFB reactor involving 500-μm size glass beads and water as solid and liquid phases, respectively. The trained Abductive Network model successfully predicted experimental phase holdups of the LSCFB riser under different operating parameters. It is observed that the model predicted cross-sectional average of solids holdups in the axial directions and radial flow structure are well agreement with the experimental values. The statistical performance indicators including the mean absolute error (~4.67%) and the correlation coefficient (0.992) also show favorable indications of the suitability of Abductive Network modeling approach in predicting the solids holdup of the LSCFB system.

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Razzak, Shaikh A., Muhammad I. Hossain, Syed M. Rahman, and Mohammad M. Hossain. "Application of Support Vector Machine Modeling on Phase Distribution in the Riser of an LSCFB Reactor." International Journal of Chemical Reactor Engineering 12, no. 1 (2014): 123–34. http://dx.doi.org/10.1515/ijcre-2013-0122.

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Abstract Support vector machine (SVM) modeling approach is applied to predict the solids holdups distribution of a liquid–solid circulating fluidized bed (LSCFB) riser. The SVM model is developed/trained using experimental data collected from a pilot-scale LSCFB reactor. Two different size glass bead particles (500 μm (GB-500) and 1,290 μm (GB-1290)) are used as solid phase, and water is used as liquid phase. The trained model successfully predicted the experimental solids holdups of the LSCFB riser under different operating parameters. It is observed that the model predicted cross-sectional average of solids holdups in the axial directions and radial flow structure are well agreement with the experimental values. The goodness of the model prediction is verified by using different statistical performance indicators. For the both sizes of particles, the mean absolute error is found to be less than 5%. The correlation coefficients (0.998 for GB-500 and 0.994 for GB-1290) also show favorable indications of the suitability of SVM approach in predicting the solids holdup of the LSCFB system.

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37

Jayarathna, Chameera K., Jana Chladek, Michael Balfe, Britt M. E. Moldestad, and Lars-Andre Tokheim. "Impact of solids loading and mixture composition on the classification efficiency of a novel cross-flow fluidized bed classifier." Powder Technology 336 (August 2018): 30–44. http://dx.doi.org/10.1016/j.powtec.2018.05.026.

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Vasanova, L. K., V. V. Korotke, A. V. Sokolov, G. P. Yasnikov, and V. S. Belousov. "Characteristic Features of Heat Transfer of Tube Bundles in a Cross Water–Air Flow and a Three-Phase Fluidized Bed." Heat Transfer Research 34, no. 5-6 (2003): 7. http://dx.doi.org/10.1615/heattransres.v34.i5-6.140.

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39

Corella, Jose, Rafael Bilbao, Antonio Monzon, Javier Lezaun, and Fernando Fernandez. "Flow model for the solid in a continuous fluidized bed with increase of the cross section in its upper zone." Industrial & Engineering Chemistry Process Design and Development 25, no. 1 (1986): 188–97. http://dx.doi.org/10.1021/i200032a030.

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40

Alforov, Serhii. "INVESTIGATION OF THE FUEL-AIR FLOW INSIDE A VORTEX FURNACE WITH A FLUIDIZED BED USING A SPECIAL AIR-DISTRIBUTING NOZZLE." Collection of Scientific Works of the Ukrainian State University of Railway Transport, no. 202 (December 22, 2022): 15–21. http://dx.doi.org/10.18664/1994-7852.202.2022.273568.

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The article presents the results of an experimental study of the fuel-air flow inside a vortex furnace with a fluidized bed using a special air distribution nozzle. Nowadays, the issue of dependence on fossil energy resources is the most important problem for the countries of Europe. One of the promising solutions to this problem is the use of vortex solid fuel furnaces for burning low-calorie types of fuel, such as waste from the woodworking and agricultural industries. Our country has developed agricultural and woodworking sectors of the economy, so the amount of waste from these industries is significant, which allows them to be used to cover the energy needs of the state. At the same time, there is a significant number of solid fuel boilers on the territory of Ukraine that can be used for this task. The main difficulties in burning low-grade fuels in solid-fuel boilers are the low level of efficiency of these vortex furnaces and insufficient theoretical information about this. To conduct the experiment, a special installation in the form of a cylinder with a nozzle inside is used. The nozzle has a plate inclination of 15 °, which does not exceed 10% of the total live cross-sectional area of the chamber of the experimental setup. In the course of the experiment, the boundary conditions for the formation of a vortex flow at different amounts of fuel and different air flows were determined, and the values of pressure loss and flow velocity were shown. The results are presented in graphical and tabular form. For example, for 2.9 kg of sawdust, the maximum speed of vortex flow formation is 0.72 m/s, for 5.8 kg this value is 0.57 m/s. The obtained results make it possible to formulate recommendations for the improvement of existing solid fuel furnaces due to the use of special nozzles for the intensification of combustion processes. This creates prospects for the development of the country's energy sector. Keywords: fuel combustion, vortex furnaces, furnace aerodynamics, special nozzle.

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Jayarathna, Chameera K., Michael Balfe, Britt E. Moldestad, and Lars-Andre Tokheim. "Comparison of Experimental Results from Operating a Novel Fluidized Bed Classifier with CFD Simulations Applying Different Drag Models and Model Validation." Processes 10, no. 9 (2022): 1855. http://dx.doi.org/10.3390/pr10091855.

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A cold-flow lab-scale cross-flow fluidized bed classifier was simulated using the CFD software Barracuda VR®. The purpose of the study was to identify the most suitable drag model and make the model adjustments that provide the best representation of the flow situation in the classifier when comparing the results with the experimental data. Two particle types were used in the simulations and in the experiments: zirconia (median diameter 69 µm, skeletal density 3830 kg/m3) and steel (290 µm, 7790 kg/m3). Ten different cases, with different solids loading values, were investigated: three with pure zirconia particles, three with pure steel particles, and four with a mixture of zirconia (28%) and steel (72%). Several different drag models were tried out in the simulations. However, none of the available models were able to predict the classification efficiency observed in experiments with their default settings. Although most of the drag models correctly predicted the inversely proportional behavior of the classification efficiency vs. solids loading, the classification efficiency was overpredicted. It was observed that a combined WenYu/Ergun drag model gave a wide range of accuracy, by being able to capture the behavior of both dense and dilute particle systems. Even though the predictions of the classification efficiency for steel particles were acceptable, a larger deviation was observed with Geldart A zirconia particles. CFD simulations with the WenYu and Ergun combined drag model were used for further validation against the experimental observations. In this case, previously published experimental data for fluidization of pure Zirconia particles were used. The fluidization of zirconia was modelled in Barracuda VR® with adjustment of the combined WenYu/Ergun drag model parameter (k1), to obtain a suitable validation. Furthermore, the effect of adding the blended acceleration model (BAM) for the fluidization simulations is discussed. It was observed that the fixed bed pressure drop was very accurate compared to the experimental observation, but the pressure drop after the fluidization was slightly overpredicted.

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42

Wang, Zhilong, Tong Zhao, Xiayi Liu, et al. "Clarification of the influences of superficial velocity U_g and particle diameter d_p on the gas–solid flow characterizations in a rolling circulating fluidized bed (RCFB) by electrical capacitance tomography (ECT) method." AIP Advances 12, no. 10 (2022): 105202. http://dx.doi.org/10.1063/5.0098154.

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The influences of the superficial velocity and particle diameter on gas–solid flow characterizations in a rolling circulation fluidized bed (RCFB) are clarified by using the electrical capacitance tomography method. Gas–solid flow characterizations include the time-space averaged particle volume fraction [Formula: see text], the time transition of the cross-sectional average particle volume fraction 〈 α〉t, and the radial profile of the particle volume fraction 〈 α〉r/R. Two kinds of particles are selected in the case that the particle diameter is 0.22 mm and the superficial velocity is set to 2.0, 3.0, and 4.0 m/s and in the case that the particle diameter is 0.45 mm and the superficial velocity is set to 3.0, 4.0, and 5.0 m/s. After analyzing the results, the main conclusions are able to be summarized as follows: First, when compared with the superficial velocity, [Formula: see text] visualized from particle distribution images is much more influenced by the particle diameter. Second, the fluctuations of 〈 α〉t and 〈 α〉r/R tend to be more serious under the conditions of larger particle and lower riser’s height, which are able to be quantitatively explained by the fast Fourier transform of 〈 α〉t and the spatial standard deviation 〈σs〉 of 〈 α〉r/R. Consequently, a strategy to guarantee both particle distribution stability and particle distribution uniformity within the RCFB is proposed.

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43

Yukhymenko, Mykola, Ruslan Ostroha, and Jozef Bocko. "Design of a shelf pneumatic classifier for separating a polydisperse mixture of granulated superphosphate." Eastern-European Journal of Enterprise Technologies 6, no. 1 (120) (2022): 33–42. http://dx.doi.org/10.15587/1729-4061.2022.267037.

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The object of this study is a polydisperse mixture of granular superphosphate. It is emphasized that existing technologies of granulation and processing of granules lead to the formation of dusty fractions of small particles. The content of small fractions in the finished product should be minimal and, in connection with this problem, the task is to remove small particles from the mixture. The purpose of the current experimental study is to classify a polydisperse mixture of granular superphosphate in a pneumatic classifier. The device includes an inclined perforated shelf with an unloading space between its end and the wall of the apparatus. It has been experimentally revealed that the maximum efficiency of extraction into the entrainment of small particles is achieved with a width of the discharge space equal to 0.5 of the length of the cross-sectional side of the apparatus; the degree of perforation of the shelf is 5 %; the angle of inclination of the shelf is 25–30°; the speed of the gas flow in the free section of the apparatus is 3.7 m/s. It is shown that the degree of extraction into the entrainment of a small fraction less than 1 mm in size reaches 70–75 %, the content of the small fraction in the carry-over is 96–98 %, and the large fraction is less than 5 %. By processing experimental data, an empirical equation was built that makes it possible to determine the concentration of particles in the gas stream for individual fractions of the material. It is shown that due to the implementation of an active aerodynamic weighing mode, the shelf pneumatic classifier works at specific loads for air flow rate less than the typical designs of fluidized bed separators. It is noted that the effective operation of the shelf pneumatic classifier in the production of granular mineral fertilizers is ensured at a productivity of no more than 10–12 t/h. With greater productivity, there is a need to install several devices in the technological line

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Mykola, Yukhymenko, Ostroha Ruslan, and Bocko Jozef. "Design of a shelf pneumatic classifier for separating a polydisperse mixture of granulated superphosphate." Eastern-European Journal of Enterprise Technologies 6, no. 1 (120) (2022): 33–42. https://doi.org/10.15587/1729-4061.2022.267037.

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The object of this study is a polydisperse mixture of granular superphosphate. It is emphasized that existing technologies of granulation and processing of granules lead to the formation of dusty fractions of small particles. The content of small fractions in the finished product should be minimal and, in connection with this problem, the task is to remove small particles from the mixture. The purpose of the current experimental study is to classify a polydisperse mixture of granular superphosphate in a pneumatic classifier. The device includes an inclined perforated shelf with an unloading space between its end and the wall of the apparatus. It has been experimentally revealed that the maximum efficiency of extraction into the entrainment of small particles is achieved with a width of the discharge space equal to 0.5 of the length of the cross-sectional side of the apparatus; the degree of perforation of the shelf is 5 %; the angle of inclination of the shelf is 25–30°; the speed of the gas flow in the free section of the apparatus is 3.7 m/s. It is shown that the degree of extraction into the entrainment of a small fraction less than 1 mm in size reaches 70–75 %, the content of the small fraction in the carry-over is 96–98 %, and the large fraction is less than 5 %. By processing experimental data, an empirical equation was built that makes it possible to determine the concentration of particles in the gas stream for individual fractions of the material. It is shown that due to the implementation of an active aerodynamic weighing mode, the shelf pneumatic classifier works at specific loads for air flow rate less than the typical designs of fluidized bed separators. It is noted that the effective operation of the shelf pneumatic classifier in the production of granular mineral fertilizers is ensured at a productivity of no more than 10–12 t/h. With greater productivity, there is a need to install several devices in the technological line

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Stepanenko, Sergey, Boris Kotov, Sergiy Hrushetskiy, and Anatolii Rud. "MATHEMATICAL SIMULATION OF THE MOVEMENT OF GRAIN MATERIAL ON THE SURFACE OF THE SPREADER UNDER ITS INTRODUCTION INTO THE ASPIRATION CHANNEL OF THE SEPARATOR." Vibrations in engineering and technology, no. 2(101) (June 29, 2021): 46–55. http://dx.doi.org/10.37128/2306-8744-2021-2-5.

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Develop a mathematical model and calculated analytical dependences to determine the trajectories and parameters of grain movement on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator. They are based on the methods of mathematical modeling and theoretical mechanics with the application of the equations of motion of a material point under the variable action of vibrations. Theoretical research was conducted using mathematical analysis and modeling theory. The research results are processed using elements of probability theory and mathematical statistics using application packages. A mathematical description of the movement of grains of grain material components (GMC) on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator under the conditions of vibration on the GMC. The trajectories of grains on the surface of the vibrating feeder with different size are obtained. The obtained equation of motion of the particle under the action of vibrations allows to determine the dependence of the velocity of the material in the vibrated fluidized bed on a number of factors: geometrical parameters of the vibrating feeder, feed angle, initial kinematic mode of grain material, kinematic mode of the vibrating feeder and friction coefficient. The process of grain material movement on the flat surface of the vibrating feeder is described, which allows to determine the rational parameters of material introduction into the aspiration channel of the separator for its further fractionation. The dependence for the function of the grain flow rate on the flat surface of the vibrating feeder is obtained, which allows to determine the parameters of the grain material distribution by the cross-sectional area of the aspiration channel of the separator. The velocity of grain material on the flat surface of the vibrating feeder is estimated on the basis of a mathematical model constructed by hydrodynamic analogy, which in turn determines the analysis of grain recombination by the thickness of the vibrated liquid layer of grain material.

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Che, Hanqiao, Haigang Wang, Jiamin Ye, and Wuqiang Yang. "Control of pellets coating in a Wurster fluidised bed by means of electrical capacitance tomography." Transactions of the Institute of Measurement and Control 42, no. 4 (2019): 729–42. http://dx.doi.org/10.1177/0142331219875349.

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Wurster fluidised bed is commonly used for coating pellets in the pharmaceutical industry. Normally, the control in a Wurster fluidised bed for coating is based on point-based measurement, that is, pressure and optical probes. However, the point-based measurement methods only provide local flow information and cannot reveal the cross-sectional flow dynamics characteristics and it is difficult to control the whole process with limited data. In this paper, electrical capacitance tomography (ECT) is applied to reconstruct the solids distribution in a lab-scale Wurster fluidised bed for coating pellets and the measurements are used in a control loop of the process. The flow regime is identified from the ECT images using a simple but efficient approach. The objective of control is to keep stable minimum fluidisation and avoid undesired flow regime in the region between the outside wall and the Wurster tube, such as intermittent, plug and defluidisation. To achieve this target, a PID controller is applied to keep a low volume fraction in the annular region by adjusting the fluidisation air rate, and bang-bang control is applied to a peristaltic pump used for spraying coating solutions based on the detected flow regime. It has been found that the proposed control scheme based on the ECT measurement is effective for keeping a stable flow regime, reducing the degree of pellets agglomeration and avoiding defluidisation.

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Zozulyak, Igor. "SIMULATION OF THE PROCESS OF VIBRATING SUNFLOWER DRYING." ENGINEERING, ENERGY, TRANSPORT AIC, no. 3(122) (December 2, 2023): 14–21. http://dx.doi.org/10.37128/2520-6168-2023-3-2.

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This work is devoted to the research and substantiation of the technology of drying sunflower seeds and the development of technological and technical proposals for the creation of drying equipment that would ensure work on this crop, both in seed and food modes. The technological value of sunflower seeds is determined by their oil content. Therefore, it is important to preserve the quantity and quality of oil. Under optimal drying conditions, the oil content in sunflower seeds increases. Therefore, the question of selecting technological equipment for the drying process arises. Analysis of the mechanical and technological parameters of series-produced dryers showed that these machines are mainly intended for the processing of grain crops. The disadvantages of well-known mine grain dryers are low moisture removal during one pass of the material through the dryer, overheating of the seed and a decrease in its quality in the area of contact with the surface of the intake boxes, increased fire hazard. Drum grain dryers when drying sunflower seeds are very fire-hazardous and do not allow obtaining seeds with uniform moisture content, and the use of high-temperature modes leads to a decrease in the sowing qualities of seeds due to overheating. When drying sunflower seeds in recirculation type dryers, it is very important to evenly distribute the seeds over the entire cross-section of the chamber, as well as to prevent the accumulation of oil dust in the heating chamber and to eliminate the ingress of sparks from the furnace into the heating chamber. One of the promising methods of drying bulk materials is the method of drying in a vibrating fluidized bed, which can be achieved on vibrating dryers of various types. A number of experiments were conducted to substantiate the technological and technical proposals for the process of drying sunflower seeds and to determine the operating parameters of the dryer. Based on the results, graphs were constructed. The results of the research proved the expediency and necessity of using vibrating dryers during drying of sunflower seeds. The best parameters of the infrared radiation drying process with a selected wavelength of 1,5-3,0 μm , a sunflower seed layer height of 15 mm, and a heat flow density of IR radiation were found. 5 kW/m 2 , the height of the placement of the IR generator blocks relative to the layer of the irradiated product is 25 mm, while the drying time will be 11 minutes.

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Kaneesamkandi, Zakariya, Ateekh Ur Rehman, Yusuf Siraj Usmani, Abdul Sayeed, and Hammed Sodiq Alabi. "Methodology for Selecting an Ideal Thermal Gasification Technique for Municipal Solid Waste Using Multi-Criteria Decision Analysis." Applied Sciences 13, no. 23 (2023): 12675. http://dx.doi.org/10.3390/app132312675.

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Awareness of the consequences of waste mismanagement has resulted in urban planners looking for effective disposal techniques with the added benefit of energy generation. The decision regarding an energy conversion technique to adopt on a community level is based on different technology assessment factors with maximum weightage on environmental effects. Gasification techniques in general and thermal gasification strategies in particular are appropriate methods when environmental impacts are to be minimized. Thermal gasification techniques have evolved with different configurations, syngas generation rates, and other advantages and disadvantages; hence, the selection of the right technique is essential, and establishing guidelines for decision-makers is necessary. The six different gasifiers considered in the present study were updraft gasifiers, downdraft gasifiers, cross-draft gasifiers, bubbling fluidized bed gasifiers, circulating fluidized bed gasifiers, and dual-bed fluidized bed gasifiers. The assessments performed in the present study are based on the attributes of the different techniques using the multi-criteria decision method. Multi-criteria decision analysis is an appropriate method proven to be an ideal procedure in these situations. Attribute values for gasifier performance, environmental effects, economic performance indices, and fuel requirements were determined from collected waste assessment data and published information. Analysis was performed for both recycling and non-recycling scenarios of waste utilization by applying different weight scenarios for the attributes. Results of the study indicate that downdraft gasifiers showed the best performance in terms of environmental effects under the recycling scenario, with 0.1% and 0.0125% by volume of carbon dioxide and methane emissions, and under the non-recycling scenario, with 0.125% and 0.02% by volume of carbon dioxide and methane emissions. Downdraft gasifiers had high overall rankings in performance when evaluated against different entropy weights for both scenarios. The results of the study can be applied to urban communities in different climatic regions as well as for different scales of operation.

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van der Meer, E. H., R. B. Thorpe, and J. F. Davidson. "Flow patterns in the square cross-section riser of a circulating fluidised bed and the effect of riser exit design." Chemical Engineering Science 55, no. 19 (2000): 4079–99. http://dx.doi.org/10.1016/s0009-2509(00)00081-6.

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50

Lee, Jinyi, Eunho Choe, Cong-Thuong Pham, and Minhhuy Le. "Measurement of Thinned Water-Cooled Wall in a Circulating Fluidized Bed Boiler Using Ultrasonic and Magnetic Methods." Applied Sciences 11, no. 6 (2021): 2498. http://dx.doi.org/10.3390/app11062498.

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Abstract:

In this paper, a nondestructive inspection system is proposed to detect and quantitatively evaluate the size of the near- and far-side damages on the tube, membrane, and weld of the water-cooled wall in the fluidized bed boiler. The shape and size of the surface damages can be evaluated from the magnetic flux density distribution measured by the magnetic sensor array on one side from the center of the magnetizer. The magnetic sensors were arrayed on a curved shape probe according to the tube’s cross-sectional shape, membrane, and weld. On the other hand, the couplant was doped to the water-cooled wall, and a thin film was formed thereon by polyethylene terephthalate. Then, the measured signal of the flexible ultrasonic probe was used to detect and evaluate the depth of the damages. The combination of the magnetic and ultrasonic methods helps to detect and evaluate both near and far-side damages. Near-side damages with a minimum depth of 0.3 mm were detected, and the depth from the surface of the far-side damage was evaluated with a standard deviation of 0.089 mm.

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Journal articles on the topic 'Cross-flow fluidized bed'

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