Modelling of baffles in electostatic precipitator (ESP0 to achieve optimum flow distribution

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.Electrostatic Precipitators (ESP) are the most reliable emission control devices that are used in coal fired power plants to capture fine particles for reducing exhaust emission. Its efficiency is more than 99% or more. However, capturing submicron particles are still a problem due to complex flow distributions and design limitations of ESP. In this study, two different shapes of baffles inside the ESP have been considered to assess their influence on the flow pattern using computational fluid dynamics (CFD) code ‘ANSYS FLUENT’.. Due to different shapes, the flow distribution will be changed inside the ESP which is expected to affect and increase the residence time of flue gas. The results of this paper indicate that the proposed shapes can influence in collecting more fine particles.am201

Forced convection heat transfer performance of porous twisted tape insert

Heat transfer performance of porous twisted tape insert in a circular tube was experimentally investigated. Tube wall temperatures and pressure drops along the axial distance of the test section at steady state condition were measured for different flows having Reynolds number ranging from 1.4 x 104 to 5.2 x 104 for both the plain and the tube with porous twisted tape insert. Heat transfer coefficient, friction factor, and pumping power were calculated from the measured data. Heat transfer and fluid flow characteristics of the porous twisted tape inserted tube were explained from the measured and calculated values. Performance of the porous twisted tape inserted tube was also evaluated. The results showed for porous twisted tape inserted tube, the average heat transfer coefficient was 2.60 times higher, the heat flux was 1.55 times higher, the friction factor was 2.25 times higher and the pumping power was 2.0 times higher than those of plain tube values for similar flow conditions

Re-engineer apparel manufacturing processes with 3D weaving technology for efficient single-step garment production

Traditional apparel assembly technology - cut and sewn process - requires labour-intensive pre- and post-production. While conventional weaving technology has made efforts to streamline the garment-making process, additional assembly processes are still required - sewing or joining after removing the woven samples from the loom. This challenge in the garment-making process discloses the need for a novel type of advanced textile technology and manufacturing techniques incorporating shaping and assembly capabilities. Exploiting 3D-to-2D-to-3D methodology integrated 3D weaving technology, the 3D woven bra prototype is practically demonstrated in a significant effective manufacturing process, shaped in one weaving cycle without additional assembly needs. The bra manufacturing process is also assessed by traditional industry loom, and the same efficient manufacturing process is also achieved. This indicates that 3D weaving technology contributes as an innovative manufacturing technology in the apparel industry to facilitate the manufacturing process significantly and eliminates further joining and sewing processes

Maximizing energy density of lithium-ion batteries for electric vehicles: A critical review

Currently, lithium-ion batteries (LIBs) have emerged as exceptional rechargeable energy storage solutions that are witnessing a swift increase in their range of uses because of characteristics such as remarkable energy density, significant power density, extended lifespan, and the absence of memory effects. Keeping with the pace of rapid development, specific purpose-oriented features of LIBs are being searched for to satisfy certain requirements. In the case of Electric Vehicles (EVs), the expected growth of LIB use is hindered because of the present level of driving range and battery pack size. However, both issues can be improved with elevated energy density at the cell level. Because high energy density will not only increase the driving range but also reduce the number of cells that will be required to deliver the same amount of power, thereby reducing the battery pack size. Higher energy density is achievable by designing LIB cells through materials-oriented design as well as cell parameter-focused design. Herein, a brief critical overview of LIB cell configuration for maximizing energy density of LIBs for EVs is presented considering viewpoints related to both material-oriented and cell parameter-focused optimization approaches

Washing Durability of PDMS-Conductive Fabric Composite Realizing Washable UHF RFID Tags

International audienceIn this letter, we present experimental investigations on washing durability of a polydimethylsiloxane (PDMS)-conductive fabric composite to validate its applicability for the realization of flexible wearable antennas that can withstand multiple washing cycles. For this purpose, we designed an ultrahigh-frequency (UHF) radio frequency identification (RFID) passive tag antenna and fabricated several prototypes using such materials combination. Understanding the challenge of having a robust integration of a lumped electronic component (e.g., RFID IC) on a flexible antenna, a new way to improve the interconnection has also been investigated. The tag prototypes were subjected to recurrent machine-washing tests, and after each washing cycle, their performance was analyzed mainly in terms of the read range. The results reveal that, with a proper treatment on the antenna-IC fixture interconnection, the tag antennas developed with the PDMS-conductive fabric composite can maintain their performance very well, showing a minimum degradation in the read range after 15 cycles of washing. © 2002-2011 IEEE

Performance assessment in a heat exchanger tube fitted with double counter twisted tape inserts

The present study explored the effects of the double counter twisted tapes on heat transfer and fluid friction characteristics in a heat exchanger tube. The double counter twisted tapes were used as counter-swirl flow generators in the test section. The experiments were performed with double counter twisted tapes of four different twist ratios (y = 1.95, 3.85, 5.92 and 7.75) using air as the testing fluid in a circular tube turbulent flow regime where the Reynolds number was varied from 6950 to 50,050. The experimental results demonstrated that the Nusselt number, friction factor and thermal enhancement efficiency were increased with decreasing twist ratio. The results also revealed that the heat transfer rate in the tube fitted with double counter twisted tape was significantly increased with corresponding increase in pressure drop. In the range of the present work, heat transfer rate and friction factor were obtained to be around 60 to 240% and 91 to 286% higher than those of the plain tube values, respectively. The maximum thermal enhancement efficiency of 1.34 was achieved by the use of double counter twisted tapes at constant blower power. In addition, the empirical correlations for the Nusselt number, friction factor and thermal enhancement efficiency were also developed, based on the experimental data

Utilization of fruits and vegetables wastes for the dietary fiber enrichment of biscuits and its quality attributes

This study explores the use of dietary fiber-rich waste products as alternatives to traditional wheat flour in biscuit production, with the aim of improving nutritional profiles and valorizing byproducts. Due to their innate health benefits, banana peel powder, broccoli stem powder, and cauliflower stem powder were selected as viable sources of dietary fiber (DF). The intention was to enhance biscuits’ properties by substituting different percentages (5%, 10%, and 15%) of these fiber sources for wheat flour. The moisture, ash, protein, fat, and carbohydrate content of the DF powders varied according to the proximate analysis, showing the possible influence of these constituents on the final product composition. Additionally, the hydration properties of the DF powders were assessed to shed light on their water absorption behavior, swelling capacity, solubility, and hydration kinetics. Broccoli stem fiber powder (BSP) demonstrated the highest water-holding capacity of 11.43% and oil-holding capacity of 6.36%. Biscuits formulated with 15% substitution of BSP may be preferred for an optimally soft texture with increased elasticity. The addition of DF powders also changed the amount of calories present, perhaps altering the energy density. While color, texture, taste, and flavor qualities varied somewhat, according to sensory assessments, the biscuits' overall acceptance remained high. Biscuits formulated with BSP at 5% and 15% substitution levels, as well as those incorporating cauliflower stem fiber (CSPB) at 10%, obtained higher ratings for overall acceptability. This investigation contributes to ongoing efforts to identify substitute components that support the development of healthier and more nutritionally diverse food items. The results pave the way for further research into the production of fiber-enriched baked goods with enhanced nutritional profiles, meeting consumer preferences for healthy and well-balanced dietary options