Bed Stability Research Articles

Case Study of Transient Dynamics in a Bypass Reach

The operating conditions of Nordic hydropower plants are expected to change in the coming years to work more in conjunction with intermittent power production, causing more frequent hydropeaking events. Hydropeaking has been shown to be detrimental to wildlife in the river reaches downstream of hydropower plants. In this work, we investigate how different possible future hydropeaking scenarios affect the water surface elevation dynamics in a bypass reach in the Ume River in northern Sweden. The river dynamics has been modeled using the open-source solver Delft3D. The numerical model was validated and calibrated with water-surface-elevation measurements. A hysteresis effect on the water surface elevation, varying with the downstream distance from the spillways, was seen in both the simulated and the measured data. Increasing the hydropeaking rate is shown to dampen the variation in water surface elevation and wetted area in the most downstream parts of the reach, which could have positive effects on habitat and bed stability compared to slower rates in that region.

Particle segregation in spouted bed pyrolysis reactor: Sand-coconut shell and sand-cocoa shell mixtures

The singularity of air-particle flow characteristics and segregation phenomenon are still the main obstacles for application of conical spouted bed (CSB) for fast pyrolysis. This paper aims to investigate statistically the operating parameters (minimum spouting velocity and bed pressure drop) and biomass segregation (biomass mixing index) in a CSB composed of biomass (coconut and cocoa shells) and sand mixtures. Models for the pressure drop and inlet air velocity at the minimum spouting condition and for the axial mixing index were obtained. The bed voidage does not change significantly with the increase of biomass mass fraction (coconut and cocoa shells), therefore, larger amounts of biomass can be used without greatly increasing or decreasing the inlet air velocity to stabilize the spouted regime. From the analysis of bed stability and particle segregation, significant insights were obtained for future application of the CSB for the pyrolysis of biomasses. It is recommended the use of mixtures with 40 wt% of coconut shells and 75 wt% of cocoa shells in initial pyrolysis tests in CSB reactor. The cocoa shells particles are more suitable to pyrolysis because of their higher flowability.

Hot Air-Assisted Radio Frequency Stabilizing Treatment Effects on Physicochemical Properties, Enzyme Activities and Nutritional Quality of Wheat Germ

Wheat germ (WG) is a nutritional milling byproduct of wheat with short shelf-life. This study investigated hot air-assisted radio frequency (HA-RF) stabilizing treatment of WG. Physicochemical properties, enzyme activities and nutritional quality of HA-RF stabilized WG were evaluated and compared with WG stabilized by fluidized bed heating. Results indicated HA-RF heating to 100 °C with 15-min holding at 100–105 °C or heating to 110 °C with 6-min holding at 110–115 °C reduced lipase activity to about 10%. HA-RF inactivation of lipase, peroxidase, polyphenol oxidase and lipoxygenase was more effective in WG with initial moisture content of 14.5% or 20.0%, but less effective in WG with moisture content of 10.0%. For oils extracted from HA-RF stabilized WG with moisture content of 14.5%, peroxide and acid values were stable after storing at 25 °C for 3 days. After both HA-RF and fluidized bed stabilizations, color of WG and WG oils became darker, lipid content increased and reducing sugar content decreased, while extraction oil yield and protein content had no significant change (p > 0.05). HA-RF heating had no influence on α-tocopherol content, but fluidized bed stabilization decreased it from 299.42 mg/kg to 236.73 mg/kg. HA-RF heating had no distinct effects on amino acid and fatty acid composition. This study indicated that HA-RF heating had great potential in WG stabilization.

Numerical Studies on Teeter Bed Separator for Particle Separation

Teeter Bed Separators (TBS) are liquid–solid fluidized beds that are widely used in separation of coarse particles in coal mining industry. The coal particles settle in the self-generating medium bed resulting in separation according to density. Due to the existence of self-generating medium beds, it is difficult to study the sedimentation of particles in TBS through experiments and detection methods. In the present research, a model was built to investigate the bed expansion characteristics with water velocity based on the Euler–Euler approach, and to investigate the settling of foreign particles through bed based on the Euler–Lagrange approach in TBS. Results show that the separation of in TBS should be carried out at low water velocity under the condition of stable fluidized bed. Large particles have a high slip velocity, and they are easily flowing through the bed into the light product leading to a mismatch. The importance of self-generating bed on separation of particle with narrow size ranges are clarified. The model provides a way for investigating the separation of particles in a liquid–solid fluidized bed and provides suggestions for the selection of operation conditions in TBS application.

Dimensionless morphological ratios versus stream power variations at bankfull stage in an ephemeral channel

Dimensionless morphological ratios (DMR) generally are used in systemic proposals for stream classification and river restoration projects. Often, such morphometric parameters, including field data from channel cross sections, develop into a template for a given geomorphic reference site. In this study, high-resolution Digital Terrain Models (HRDTMs), combined with orthophotographs from 2018 and ground-based surveys, were used to analyze the spatial variability of DMR in a semi-arid ephemeral stream subject to changes in stream power under bankfull conditions. In particular, a channel reach of 2.7 km in length along the Upper Mula stream in southeastern Spain was chosen to test the relationships between the two types of variables. Rosgen's DMR (width to depth ratio, entrenchment ratio, bank height ratio) and hydraulic data at bankfull stage (flow velocity, Froude number, shear stress, mean stream power and energy gradient, among others) were calculated by 1D hydrodynamic modeling and HRDTMs prior entry of field information. The resulting maps allowed comparison of stream power with DMR in relation to the channel stretch class and bed stability. The results showed similar spatial patterns for the width to depth ratio and the bank height ratio. The average values estimated in bend stretches were lower than along straight and slightly sinuous stretches and very similar to those of sub-reaches from the inflection point to the meander bend apex. However, the entrenchment ratio followed a different pattern, according to which the straight and slightly sinuous stretches were the most entrenched and the bend stretches presented a more moderate average entrenchment ratio. In addition, the energy balance and power gradient also experienced spatial variations in relation to the bed stability and DMR. Only in highly incised sub-reaches were such relationships not significant. The lack of a significant correlation between excess energy and bank height ratio or width to depth ratio over short lag distances was also verified, regardless of the affected bedforms. An ANOVA showed important differences between the straight and slightly sinuous stretches and bend stretches, which were strongly influenced by the incision and entrenchment ratios and the maximum bankfull depth.

Biodiesel synthesis using a novel monolithic catalyst with magnetic properties (K2CO3/γ-Al2O3/Sepiolite/γ-Fe2O3) by ethanolic route

A novel magnetic monolithic catalyst based on K2CO3/γ-Al2O3/Sepiolite/γ-Fe2O3 was developed seeking to convert efficiently soybean oil and bioethanol to ethanolic biodiesel and glycerol. The magnetic monolithic was attained by extrusion method and characterized by EPR, VSM, SEM, Dynamometry, XRD, BET, and CO2-TPD, showing satisfactory magnetic, morphological, mechanical, structural and textural properties. The catalytic performance of this monolithic catalyst was also evaluated in a reactor assisted by magnetic field. The reactor was operated in a closed loop, recycling the reaction mixture. High oil conversion to biodiesel was obtained using 5 wt% of catalyst with 1:12 oil/ethanol molar ratio at 70 °C after 1.5 h. The magnetic properties of this monolithic catalyst allowed the bed stabilization under magnetic field and the catalysts separation, enabling its reuse by four reaction cycles.

How does the bed surface impact low‐magnitude bedload transport rates over gravel‐bed rivers?

AbstractBedload transport is a complex phenomenon that is not well understood, especially for poorly sorted sediment and low transport rates, which is what is typically found in alpine gravel‐bed rivers. In this paper, the interaction between bedload rate, bed stability and flow is investigated using flume experiments. Significant differences in bedload rates were observed for experiments conducted on beds formed with the same gravel material but presenting diverse arrangements and bedforms. Tests were performed under regimes of low transport rate, which are mainly controlled by gravel‐bed roughness. Different scales of roughness were identified using the statistical characteristics of detailed bed elevation measurements: grain, structure and large bedform scales. The role played by these different roughness scales in bedload dynamics was examined. For quasi‐flat beds, bed stability was quantified using a combination of bed surface criteria describing grain and structure scales. It was found that bed stability affects the bedload rate directly and not only through its influence on the flow or on the incipient motion. For beds with large bedforms, the analysis of bedload dynamics also showed the importance of accounting for effective bed shear stress distributions. An empirical bedload model for low transport regimes was suggested. Compared with previous formulae developed for alpine rivers, this model accounts for bed stability and distribution of effective bed shear stress. It significantly improves the understanding of gravel dynamics over complex beds such as arranged beds or those with large bedforms. However, further tests are needed to use the model outside the range of conditions of this study. © 2019 John Wiley & Sons, Ltd.

Hydrodynamics and subsequent separation of gas-solid separation fluidized bed with secondary air injection

Dry coal separation is mainly restricted by the spatial instability in the fluidized bed. Secondary air injection provides a new way to improve the bed stability. In this study, the hydrodynamics and separation operations of the fluidized bed under secondary air injection were investigated using a numerical simulation and experiment. The results show that secondary air injection changed the internal particle circulation mode: the particle flow-field appeared in the middle of the rising stream on both sidewalls, and the sidewall effect was eliminated, thus improving the fluidization quality of the bed. At the appropriate jet velocity (uj = 2.4 m/s), the minimum variance of bed density fluctuation was less than 0.127 g/cm3, further enhancing the bed stability. In addition, 6–50 mm coal was separated in the fluidized bed under secondary air injection. The lowest probable deviation E value was 0.06 g/cm3, which indicates a good separation performance.

Truly continuous low pH viral inactivation for biopharmaceutical process integration.

Continuous virus inactivation (VI) has received little attention in the efforts to realize fully continuous biomanufacturing in the future. Implementation of continuous VI must assure a specific minimum incubation time, typically 60 min. To guarantee the minimum incubation time, we implemented a packed bed continuous viral inactivation reactor (CVIR) with narrow residence time distribution (RTD) for low pH incubation. We show that the RTD does not broaden significantly over a wide range of linear flow velocities—which highlights the flexibility and robustness of the design. Prolonged exposure to acidic pH has no impact on bed stability, assuring constant RTD throughout long term operation. The suitability of the packed bed CVIR for low pH inactivation is shown with two industry‐standard model viruses, that is xenotropic murine leukemia virus and pseudorabies virus. Controls at neutral pH showed no system‐induced VI. At low pH, significant VI is observed, even after only 15 min. Based on the low pH inactivation kinetics, the continuous process is equivalent to traditional batch operation. This study establishes a concept for continuous low pH inactivation and, together with previous reports, highlights the versatility of the packed bed reactor for continuous VI, regardless of the inactivation method.

SewerSedFoam: A Model for Free Surface Flow, Sediment Transport, and Deposited Bed Morphology in Sewers

This paper aims to bridge the gap in the detailed modelling of flow and sediment process interactions in sewers through the development of a computational fluid dynamics (CFD) model. It draws on previous models developed for surface water sediment transport in the OpenFOAM CFD framework and builds on them to improve their suitability for sewer sediment processes. Three distinct sediment processes, suspended sediment transport, bedload transport, and deposited bed morphology, are incorporated into a free surface flow solver, interFoam. This sewer sediment model, called SewerSedFoam, models the impacts of sediment deposition and erosion on flow velocity by using dynamic mesh deformation to capture the movement of the deposited bed and its morphology. Further, three sediment classes, two suspended and one bedload sediment, can be modelled along with some bed stabilization and consolidation effects during deposition and erosion, respectively. The functionality of the overall model in modelling sewer sediment deposition and erosion is promising, although the validation of a large magnitude sediment erosion event has been limited by the availability of granular data in existing case studies.

Co‐evolution of coarse grain structuring and bed roughness in response to episodic sediment supply in an experimental aggrading channel

ABSTRACTWe use flume experiments to better understand how gravel‐bed channels maintain bed surface stability in response to pulses of sediment supply. Bed elevations and surface imagery at high spatial resolutions were used to quantify the co‐evolution of surface grain‐size distribution (GSD), bed roughness statistics, and bed surface structures (clusters, cells and transverse features). Using a new semi‐automated method, we identified individual stone structures over a 2 m × 1 m area throughout the experiments. After an initial coarsening, surface GSD and armouring ratio remained nearly stable as sediment pulses caused net bed aggradation. In contrast, individual grain structures continued to form, increase or decrease in size, and disappear throughout the experiments. The response of the bed to sediment pulses depended on the history of surface roughness evolution and bed surface structure development, as these factors changed much more in response to supply perturbations earlier in the experiments compared to later, even as the bed continued to aggrade. We interpret that the dynamic production and destruction of bed surface structures can act as a ‘buffer’ to sediment supply pulses, maintaining a stable bed surface during aggradation with minimal change in grain size or armouring. © 2019 John Wiley & Sons, Ltd.

CFD investigations of scour beneath a submarine pipeline with the effect of upward seepage

A numerical model of scour beneath subsea structures considering the effect of upward seepage in the seabed is proposed. A small seepage can cause significant changes to the hydrodynamic force on the bed surface and stability of bed particles, which can further affect the sediment transport processes and scour patterns around subsea structures. The present model is developed based on a fully-coupled hydrodynamic and morphologic sediment transport model. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations are solved together with the k−ω turbulence closure. In the presence of seepage, the bed friction velocity, the bed shear stress, and the bed load transport rate will be changed as compared to conditions without seepage. The sediment particle stability is also affected and the critical Shields parameter is changed. In the presence of upward seepage forces, the repose angle of the sediment is also reduced. The present model is validated against existing experiments in terms of streamwise flow velocity distribution subjected to upward seepage. The fully-coupled hydrodynamic and morphologic model is validated against existing experiments of scour beneath a pipeline in the live-bed regime and clear-water regime, respectively. The validated model is then applied to investigate the scour development beneath a submarine pipeline subjected to different upward hydraulic gradients. It is found that the equilibrium scour width is increased with a large upward hydraulic gradient. The equilibrium scour depth stays in the range of 0.6–0.8 of the pipeline diameter for the live-bed cases. For the clear-water case, with a large upward hydraulic gradient, the equilibrium scour depth slightly decreases.

Recent Patents on Radiotherapy Bed

Background: In order to increase the accuracy of radiotherapy and to improve the patient's comfort, diverse structures of radiotherapy bed have been designed and improved constantly. Objective: To provide an overview of recent patents about radiotherapy bed and to introduce their characteristics and development. Methods: In this study, various representative patents related to the radiotherapy bed were reviewed. Additionally, the structural characteristics and applications of the typical radiotherapy bed were introduced. Results: The characteristics of different radiotherapy beds were analyzed and concluded. Moreover, the main problems concerning their development were analyzed, and the current and future developments of patents on radiotherapy bed were also discussed. Conclusion: Radiotherapy bed is an important part of radiotherapy system, which also determines the therapeutic outcomes of radiotherapy. Further improvements are required in the aspects of accuracy, comfort, flexibility and result stability of the radiotherapy bed. More invention should be laid on more patents on radiotherapy beds.

Influence of a tamping operation on the vibrational characteristics and resistance-evolution law of a ballast bed

A ballast bed provides a stable foundation and a sufficient vibration-damping performance for a railway line due to its loose and porous structure. Tamping operations change the compactness of ballast stacks and improve and maintain the state of ballast beds, which also affect the vibration-transfer characteristics and resistance performance of ballast beds. In the present study, impact excitation technology was used to test and analyze the influence of the number of tamping operations performed by a tamping car on the damping and stiffness of a ballast bed. Additionally, the influence of different tamping operations on the longitudinal vibration-transmission characteristics of the ballast bed was obtained by the methods of “single-point excitation and multi-point pick-up”. The mode of analysis of the railway structure was carried out by numerical simulation, and the resistance test on site was used to study the evolution law of the longitudinal and lateral resistance of the ballast bed during three tamping operations. The results showed that a large machine tamping operation changed the values of the two dominant resonances (140.75 Hz to 202.35 Hz and 381.25 Hz to 418.75 Hz) of track structure in the range of 0–600 Hz. The tamping operation also affected the resistance, damping, and stiffness of the ballast bed (the longitudinal and lateral resistances decreased by 17.39% and 20.34%, respectively, and the damping and stiffness increased by 204.07% and 148.80%, respectively), which suggests that the longitudinal/lateral resistances, damping, and stiffness of the ballast bed were strongly negatively correlated with one another. The modal shapes of the track structure caused by the first tamping and the second tamping were obviously different, and the positions and values of the maximum displacement changed (1.92 mm to 1.71 mm). The tamping also affected the longitudinal vibration transmission between the sleepers, and the maximum attenuation rate between adjacent sleepers was 81.25%. The change of the resistance work of the ballast bed with the displacement was more significant than the change of the resistance of the ballast bed with the displacement (when the ballast bed resistance decrement rates were 4.34%, 16.19%, and 20.34%, the track bed resistance work decrement rates were 13.14%, 28.15%, and 39.35%, respectively). Thus, the resistance work was more applicable when describing the variational degree of the stability of the ballast bed.

Tidal amplification and salt intrusion in the Mekong Delta driven by anthropogenic sediment starvation

Natural resources of the Mekong River are essential to livelihood of tens of millions of people. Previous studies highlighted that upstream hydro-infrastructure developments impact flow regime, sediment and nutrient transport, bed and bank stability, fish productivity, biodiversity and biology of the basin. Here, we show that tidal amplification and saline water intrusion in the Mekong Delta develop with alarming paces. While offshore M2 tidal amplitude increases by 1.2–2 mm yr−1 due to sea level rise, tidal amplitude within the delta is increasing by 2 cm yr−1 and salinity in the channels is increasing by 0.2–0.5 PSU yr−1. We relate these changes to 2–3 m bed level incisions in response to sediment starvation, caused by reduced upstream sediment supply and downstream sand mining, which seems to be four times more than previous estimates. The observed trends cannot be explained by deeper channels due to relative sea level rise; while climate change poses grave natural hazards in the coming decades, anthropogenic forces drive short-term trends that already outstrip climate change effects. Considering the detrimental trends identified, it is imperative that the Mekong basin governments converge to effective transboundary management of the natural resources, before irreversible damage is made to the Mekong and its population.

Hydraulic requirements of freshwater mussels (Unionidae) and a conceptual framework for how they respond to high flows

AbstractSpatiotemporal variability in flow determines the physical structures of habitat. During low flows, aquatic organisms can be exposed to reduced dissolved oxygen concentrations, increased water temperature, and desiccation, whereas at high flows, increased velocity and hydraulic forces on the streambed can be equally detrimental. These constraints create a mosaic of habitat that influences the distribution and abundance of aquatic biota. This mosaic can change due to stochastic events or those mediated by humans. Understanding how low and high flow conditions affect aquatic organisms is critical not only for advancing ecological knowledge but also for protecting imperiled aquatic species such as unionid mussels. The overall goal of this project was to examine how substrate and hydrologic conditions affect mussel habitat and to then use the resulting information combined with life‐history traits and shell morphology (i.e., sculpturing) to better understand how flow shapes mussel assemblage structure. Using quantile regression, we found that low values of relative shear stress (RSS), a measure of substrate stability, were associated with high mussel species richness and density. Change point analysis using threshold indicator taxa analysis (TITAN) indicated species‐specific preferences for varying levels of bed stability. These preferences were best explained by life‐history strategy and shell morphology based on the results of a principal component analysis. Using these results, we then present a conceptual model from which to derive expectations concerning taxonomic composition, life‐history strategy, and shell sculpture type based on the degree of substrate mobility using RSS and variability in RSS.

Design and Development of a Delta 3D Printer Using Salvaged E-Waste Materials

The next phase of industrialization in the world is the use of 3D printing technology. Various 3D printing technologies are employed all over the world and for different purposes, from 3D printed houses to 3D printed food nutrients. Printer movement is achieved by carriages moving in a clearly defined X, Y, and Z orientation. The 3D printer has a lower work rate; subsequently, many printouts consume a lot of time due to their complexity. This paper elaborates on the design and development of a faster and fixed build platform 3D printer (Delta 3D printer) using locally available materials and e-waste. The Delta 3D printer movement is faster with a stable bed. Printer movement is achieved using three vertical axes placed 120° apart. Accuracy and speed are achieved with the use of NEMA 17 stepper motors to drive the various carriages on the vertical axes. Design calculations show that the least force delivered by the stepper motor is 1.73 N which exceeds 0.8334 N, the weight of the load to be carried. Furthermore, a stepper motor must turn 80 steps (rotational motion) in order to achieve 1 mm advance (linear motion). This ensures a higher printout resolution. In place of traditional linear rails, locally sourced square pipes were adopted coupled with bearings and a 3D printed carriage support, and a relatively cheaper but stable linear rail was developed. The goal of this research was to develop an alternative easy-to-build Delta 3D printer using locally sourced materials. This goal of this research was achieved, and the developed prototype was test-run under load conditions. It is recommended that salvaged e-waste should be properly managed for easy acquisition.

Eliminating the effect of hot spots on underground power cables using cool pavements

It is well known that hot spots limit the ampacities of underground power cables. There are many commonly applied methods to control the thermal environment in hot spots of underground power cables. However, applications of cool pavements for this specific purpose would be a novelty in the field of power cable engineering. This paper considers the use of different cool pavements in combination with thermally stable bedding and/or pure quartz sand for mitigating or eliminating the thermal effect of an actual hot spot on the ampacities of a 110 kV cable line and a group of four 35 kV three-core cables installed in Belgrade, the Republic of Serbia. In the hot spot, the 110 kV cable line is installed in parallel with the group of 35 kV cables and crosses a district heating pipeline. All distances between these underground installations are lower than the recommended ones, and the 110 kV and 35 kV cables are laid at depths greater than required. The mutual thermal effects between the underground installations in the hot spot are simulated using FEM-based models for different environmental conditions. An experimental background is also provided. In comparison with the corresponding base cases, it has been found that the ampacities of the 110 kV cable line and group of 35 kV cables can be increased up to 25.1% and 60.9% in summer, and up to 62.8% and 170% in winter, respectively.

Kelp-bed dynamics across scales: Enhancing mapping capability with remote sensing and GIS

Kelp are important drivers of productivity and biodiversity patterns in cold-water and nutrient-rich rocky reefs. Scuba- and boat-based methods are routinely used to study submerged kelp beds. However, these time-consuming and labor-intensive methods enable monitoring of beds or the factors and processes that control their distribution over only small spatial (few 100s of m2) and temporal (<5 years) scales. Remote sensing and geographic information system (GIS) technologies are increasingly used to compare marine species distribution over multiple spatiotemporal scales. However, there is currently no clear framework and limited demonstration of their potential for studies of broad-scale changes in completely submerged kelp beds. The present study aims to establish the foundation of a simple, accessible, and robust set of remote sensing and GIS-based methods to address key questions about the stability of subtidal kelp beds across multiple spatial and temporal scales. It tests the suitability of conventional image classification methods for mapping kelp from digital aerial (acquired on board a helicopter) and satellite (SPOT 7) imagery of ~250 ha of seabed around four islands in the Mingan Archipelago (northern Gulf of St. Lawrence, Canada). Three classification methods are compared: 1) a software-led unsupervised classification in which pixels are grouped into clusters based on similarity in spectral signature among pixels; 2) a software-led supervised classification in which pixels are assigned to categories based on similarity in the spectral signature of pixels and that of reference data from each category; and 3) a visual classification carried out by a trained observer. Supervised classification of satellite imagery and visual classification of aerial imagery were the top methods to map kelp, with overall accuracies of 89% and 90%, respectively. Unsupervised classification of both types of imagery showed poor discrimination between kelp and non-kelp benthic classes. Kelp bed edges were more difficult to identify on satellite than aerial imagery because the former presented poorer contrasts and a lower spatial resolution. Kelp bed edges identified with visual classification appeared artificially jagged for both types of imagery, mainly because of the coarse (225-m2) spatial units used for this classification. Kelp bed edges were smoother on maps created with the unsupervised and supervised classifications, which used 1-m-pixel images. The present study demonstrates that conventional remote sensing and GIS methods can accurately map submerged kelp beds over large spatial domains in the Mingan Archipelago or in other benthic systems with similar oceanic conditions and a largely dichotomous (kelp-barrens) biological makeup.

Oil shale upgrading by gas-solid high density separation fluidized bed under secondary accumulation distribution

In the separation of oil shale using gas–solid separation fluidized beds, the waste rocks fall on the distribution plate after separation and the scraper fails to discharge them in time, causing the airflow entering the bed to be redistributed. Due to its unique secondary layout effect on airflow, the existence of stacking beds is an important factor affecting the stability of the fluidized bed, and indirectly affects the separation performance of gas–solid fluidized beds. Therefore, it is necessary to carry out further research on the stacking bed to provide a strong basis for optimizing the practical operation and sorting performance of the gas–solid fluidized bed. Here, the effects of stacked beds on energy consumption, density uniformity, and bed stability were systematically analyzed experimentally. The results showed that the secondary accumulation bed has a synergistic effect on the fluidization stability of the bed and can improve the fluidization quality of the ordinary bed. Oil shale was sorted under optimized test operating conditions (accumulation height HS = 35 mm, accumulation particle diameter D = 6 mm, fluidization number N = 1.3), and the refined mineral yield was 29.85%, oil yield was 9.42%, tail mineral yield was 70.15%, and oil yield was 1.54%. The possible deviation, E, was 0.085.