Simulation and experimental study of the sensor emitting frequency for ultrasonic tomography system in conducting pipe

Ultrasonic tomography techniques provide flow visualization capability, non-invasively and non-intrusively, to enhance the understanding of complex flow processes. There is limited ultrasonic research in tomography imaging systems in the tomogram analysis of fluid flow in a conducting pipe because of a high acoustic impedance mismatch, which means that very little ultrasonic energy can be transmitted through the interface. The majority of industrial pipelines are constructed from metallic composites. Therefore, the development and improvement of ultrasonic measurement methods to accommodate a stainless steel pipe are proposed in this paper. Experimental and simulation distribution studies of the ultrasonic emitting frequency in acrylic versus stainless steel pipes were studied, measured and analyzed. During the simulation, ultrasonic transducers were placed on the surface of the investigated pipe to inspect the ultrasonic sensing field. The distribution of the sound wave acoustic pressure was simulated based on the physical dimensions and parameters of the actual experimental hardware set-up. We developed ultrasonic acoustic models using the finite element method with COMSOL software, and experiments were carried out to validate the simulation results. Finally, by performing the static phantoms tests, a feasibility study of ultrasonic tomography system was presented to investigate the void fraction of liquid column inside a stainless steel pipe

Ball milled bauxite residue as a reinforcing filler in phosphate-based intumescent system

Bauxite residue (BR) is an alumina refinery waste with a global disposal problem. Of the 120 MT generated annually, only 3 MT is disposed via utilization. One of the significant challenges to sustainable utilization has been found to be the cost of processing. In this work, using ball milling, we achieved material modification of bauxite residue. Spectrometric imaging with FESEM showed the transformation from an aggregate structure to nano, platy particulates, leading to particle size homogeneity. BET analysis showed surface area was increased by 23%, while pH was reduced from 10.8 to 9.1 due to collapsing of the hydroxyl surface by the fracturing action of the ball mill. Incorporation of this into a phosphate-based fire retardant, intumescent formulation led to improved material dispersion and the formation of reinforcing heat shielding char nodules. XRD revealed the formation of ceramic metal phosphates which acted as an additional heat sink to the intumescent system, thereby reducing char oxidation and heat transfer to the substrate. Steel substrate temperature from a Bunsen burner test reduced by 33%. Therefore, ball milling can serve as a simple, low-cost processing route for the reuse of bauxite residue in intumescent composites

Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage

Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorber and TES cavity for the DSSS-TES attained are 65.2 ◦C, 77.5 ◦C, 82.4 ◦C, 79.5 ◦C and 68.4 ◦C, respectively. DSSSTES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards