A modular and automated cleaning device for floating solid waste was developed to tackle the problems of low collection efficiency, high energy consumption, and frequent clogging in rural ditches and ponds. According to field monitoring data, the inlet velocity and filter mesh size were determined. The device comprises a cleaning module, a collection module, and a bottom filter connected in series, which is driven mainly by gravity with low-power electric control as assistance. CFD and FEA were employed to simulate the flow field around the cleaning roller, the stress of the retention plate, and the head loss of the bottom filter. The results demonstrate that the flow field on the cleaning roller is stable, and the maximum velocity exhibits a linear relationship with the inlet velocity. The maximum equivalent stress of the retention plate is 38.6 MPa, and the rubber head can absorb more than 80% of the impact energy. With a 3 mm aperture for the bottom filter, the head loss is about 26 mm at the designed flow rate, achieving a good balance between interception efficiency and low flow resistance. The device can effectively intercept floating waste such as plastics and straws, making it suitable for routine cleaning of small rural water bodies.
The growing demand for decentralised, sustainable power in Nigeria, combined with the poor management of organic waste in rural and peri-urban areas, motivates the development of small-scale, waste-to-energy technologies. This paper reports the design, fabrication and performance evaluation of a mini-biogas plant that converts cow dung and kitchen waste into electricity through anaerobic digestion, gas conditioning and a modified petrol generator, while a fully passive, electronics-free automatic pressure relief system based on an adjustable water seal protects the digester from over-pressurisation. The 1000 L high-density polyethylene (HDPE) digester was filled with 70% cow dung and 30% kitchen waste in the ratio of 1:1 of dung to water and kept under observation for 5 weeks of retention time.The pH of digester was maintained in the desired range of 6.8 to 7.5 from Week 2 onwards whereas the average digestion temperature ranged from 28.1 °C to 30.8 °C. Average biogas production was 0.92 m³/day (design target 0.5-1.5 m³/day), with a peak of 1.18 m³/day. Gas conditioning raised methane content from 58.4% in the raw biogas to 67.2% after CO₂ scrubbing, within the 60-70% target band. The water-seal pressure relief system activated within 3-4% of its calculated set point at all three tested submerged depths (8, 10 and 12 cm) and re-sealed within 4-6 seconds, confirming that safe, automatic pressure regulation can be achieved without sensors, controllers or external power. These results demonstrate that a low-cost, locally fabricated mini-biogas system with a passive safety mechanism is a technically viable route to decentralised electricity generation and organic-waste management in resource-limited settings.
Alase David Ayomide, Prof. Aborisade David O· Global Journal of Engineerin...· 0 citations
To achieve rapid and uniform mixing requirements for fluid agitation tanks in industrial processes, this study takes a fluid agitation tank used in wastewater treatment as the research object and conducts numerical simulation research on its internal flow field using the flow field analysis software Fluent. A three-dimensional geometric model of the agitation tank is established using SOLIDWORKS software. Meshing is performed in Fluent with local refinement applied to the blade region, and simulation analysis is carried out using Fluent software. The research results indicate that the density distribution of the mixture within the agitation tank gradually becomes uniform over time, reaching a dynamic equilibrium. The Fluent simulation method effectively overcomes the shortcomings of traditional theoretical calculations and physical experiments, offering advantages such as shorter cycles, lower costs, and higher safety, thus providing a reliable technical basis for the structural design and process optimization of agitation tanks.
Zhen Wei, Ning Liu, Peng Du et al.· Journal of Physics, Conferen...· 0 citations
Spent water-based drilling fluids generated during the construction of technological wells impose substantial environmental, water-management, transportation, and energy burdens. Conventional practices, including storage in temporary pits, prolonged settling, and off-site disposal, do not enable process-water recovery and require repeated handling of suspensions with a high solids content. This study evaluates a pressure-driven cylindrical hydrodynamic disperser as the central component of a compact on-site treatment system. Unlike conventional mechanical mixers, the disperser contains no driven shaft within the active chamber. Particle–reagent contact is intensified through controlled jet shear, vortex-induced redistribution, and the motion of freely moving steel balls. Field-derived drilling fluids containing 30–40 wt.% solids, with densities of 1.12–1.17 g/cm3, pH values of 7.4–8.2, and median particle sizes of 15–50 μm, were treated at velocity gradients of 500–1500 s−1 for 60–180 s using Superfloc N-300 dosages of 0–100 g/t. The optimal operating conditions were G = 1300 s−1, τ = 150 s, and D = 50 g/t. Under these conditions, the separation efficiency reached 91–93%, the residual suspended-solids concentration decreased to 120–130 mg/L, process-water recovery reached 80%, sludge volume decreased by 40–60%, and specific energy consumption was approximately 0.30 kWh/m3. More intensive treatment increased the separation efficiency to 94–95% but resulted in a less favorable balance among energy consumption, reagent dosage, and resource recovery. Compared with mechanical mixing, the selected treatment system reduced flocculant consumption by 37.5%, treatment time by more than threefold, and specific energy consumption by 40%. These results support the use of modular on-site systems for process-water recirculation and reduced sludge-transport requirements at remote drilling sites.
B. Mauletbekova, B. Kaliyev, Beibit Myrzakhmetov et al.· Applied Sciences· 0 citations
The present work develops the design and analysis of a swirl chamber for vacuum drying, oriented to the post-harvest treatment of agro-industrial products, through Computational Fluid Dynamics (CFD) simulations. In various agricultural regions, adverse climatic conditions, such as heavy rainfall, hinder traditional drying methods, negatively affecting the final quality of products. Faced with this problem, a technological alternative based on a vacuum chamber with dry air injection in induced rotational flow is proposed, which allows greater control of the drying process, especially benefiting small and medium-sized agro-industrial producers. The study focuses on the analysis of the aerodynamic behavior of the cyclonic type of air flow and its interaction with the particles inside the drying chamber, evaluating parameters such as pressure distribution, temperature and speed for the preservation of properties in food. The results obtained allow us to understand the performance of the system and propose design recommendations aimed at its application in the agro-industrial sector in general.
W. García, K. Gonzalez, J. Becerra et al.· Journal of Physics, Conferen...· 0 citations
With the advancement of industrial IoT and artificial intelligence technologies, bearing maintenance is gradually evolving toward predictive maintenance. For large bearings, the internal grease must be replaced promptly once it has deteriorated. As the core lubrication component of such bearings, the suction and discharge device directly determines the efficiency of grease discharge and the operational stability of the bearing. To address the issue of insufficient intake capacity in existing units, this study employs the Herschel–Bulkley non-Newtonian fluid model to analyze intake characteristics and conduct multi-parameter co-optimization, revealing the underlying mechanisms by which vacuum level, grease temperature, and the chamfer structure of the grease inlet pipe influence suction performance. Based on the yield stress and shear thinning characteristics of the grease, the flow equation for the inlet section was derived, and the analytical and CFD results showed consistent trends. With the volumetric flow rate in the inlet section as the optimization objective, a multi-parameter co-optimization of the vacuum level, temperature, and chamfer radius was conducted through orthogonal experiments. The results show that under the optimal parameter combination, the inlet volumetric flow rate was significantly increased, and grease supply stability was markedly improved. The research findings provide a theoretical basis and engineering reference for the design optimization of the suction and discharge device for wind turbine bearings.
Han Peng, Budi Peng, Linjian Shangguan et al.· Machines· 0 citations
Flywheel energy storage systems impose high demands on the mechanical properties and structural integrity of rotors, particularly in high-speed applications. This study focuses on the numerical analysis of gravity casting of a steel rotor manufactured from low alloy 34CrMo4 steel, with the aim of identifying critical regions related to molten metal flow, solidification behaviour and shrinkage defect formation. Numerical simulations were calculated using a MAGMASOFT® 5.5 software environment based on the finite volume method and included both mold filling and subsequent solidification and cooling stages. Flow stability, temperature field distribution and solidification characteristics were researched thoroughly. The results showed that optimization of the gating and feeding system lowered porosity under 2% within the casting and relocated shrinkage defects to the risers. At the same time, solidification directionality was improved and the Hot Spot value was reduced. From the perspective of casting quality, the proposed design represents the most suitable solution, despite a lower metal utilization rate. The analysed casting forms the structural body of a hybrid flywheel rotor intended for the subsequent integration of high-density tungsten segments.
Jan Růžička, Adéla Macháčková, F. Radkovský et al.· Applied Sciences· 0 citations