Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Comparative Study of two Stator Designs for the International Electrotechnical Commission 100 Motor Frame for 2.2kw Squirrel Cage Induction Motor
Get PDFThe International Electrotechnical Commission totally enclosed, fan cooled 100 Motor frame for 2.2 kilowatts squirrel cage induction motor have been manufactured with both 24-slot stator and 36-slot stator. This study compared the two solutions along the lines of rated performance, material consumption, and robustness of design. Since the difference between the two motors is basically the number of slots in the stator, similar machine data were adopted for them. The unknown data were calculated from standard machine equations carefully suited for the motors. The data so obtained were used as input to the RMxprt model where the motors were simulated. The results show marginal difference in all the parameters considered such as efficiency (0.09% in favour of the 36-slot Stator), power factor (0.0014 in favour of the 24-slot Stator), annual cost of operation (N687.88 saved by the36-slot stator), and overload capacity. The inference of this study is that the two stator designs are adequate solutions for the 3hp motor having International Electrotechnical Commission totally enclosed, fan cooled 100 Motor frame, and that while the 24-slot stator design would be easier and cheaper to manufacture, the 36-slot stator design is however more robust and cheaper to operate.
 
Development and Performance Evaluation of a Motorized Tigernut Oil Extraction Machine
Get PDFTiger nut is a common nut in Africa which contains 24.5% oil. The extraction of this oil has been a major challenge to developing countries as most oil is locally extracted because of high cost of importation of oil expellers. A motorized tiger nut oil extracting machine was designed and fabricated consisting of four sections namely feeding, extraction, heating and power sections using available local materials, and was evaluated and optimized. The oil yield (OY), operational rate (OR), extraction efficiency (EE), throughput capacity (TC) and extraction loss (EL) of the machine were determined as affected by barrel temperatures (BT) of 30°C, 45°C, 60°C range, screw speeds (SS) of 60 rpm, 75 rpm, 90 rpm range., 0.5 mm, 1 mm, 1.5 mm range of choke clearance (CC) of the machine and yellow/brown varieties of tiger nut. The optimum ER, EE, OY, EL and TC values of 9.93 kg/hr., 89.02%, 23.78%, 1 kg/hr. and 50.06 kg/hr. were achieved at 60°C barrel temperature, 60 rpm and 0.5 mm choke clearance while the lowest values gotten at 30°C barrel temperature, 90 rpm and 1.5 mm choke clearance were 6.33 kg/hr., 52.40%, 13.90%, 0.33 kg/hr. and 33.96 kg/hr. respectively. Analysis of variance revealed that barrel temperature, screw speed, choke clearance and variety have significant effects on all the machine parameters evaluated at p<0.05 except for the EL. The evaluation results revealed that the brown tiger nut has more oil than the yellow tiger nut and that the developed machine is deemed efficient for small scale tiger nut oil production.
 
Impact of Acid Leaching on Upgrading Indigenous Low-grade Chromite ore for Iron and Steel Plant Development
No full textLow-grade chromite concentrate from the Tunga Kaduka Benue trough region of north-eastern Nigeria is contaminated with iron and aluminium impurities. To transform it into useful material, such impuririties must be removed for it to be useful for the production of special steel and ferrochrome alloys. Consequently, in this study, a Nigerian chromite was treated by hydrochloric acid (HCl) solution. The influence of leaching duration, acid concentration, reaction temperature, and particle size on the extent of impurities dissolution was determined. From the results obtained, the dissolution of iron and aluminium increases with increasing leaching time, HCl concentration, reaction temperature, and decreasing particle size. Under these conditions, the highest recovery of iron and aluminium was obtained to be 95.54 and 82.51%, respectively. The dissolution kinetics of iron and aluminium was evaluated by shrinking core models. The finding reveals that diffusion through the fluid was the leaching kinetics rate-controlling step of iron and aluminium. The activation energy was found to be 25.33 kJ/mol for iron and 18.42 kJ/mol for aluminium. The residual samples at optimal conditions as analyzed by X-ray powder diffraction and scanning electron microscopy were found t
Design, Construction and Testing of a Weighing Equipment for Powdered Food Products
Get PDFIn local markets in third world countries, no standards are followed in terms of selling and buying powdered food products. This leads to variation in the amount of products sold or received by retailers or customers respectively. Ensuring a standard for such products are vital in maximizing profit for business owners and optimizing quantity of products received by customers. To solve this problem, a weighing equipment was designed, constructed, and tested. All materials used in the construction were locally sourced and assembled. After completion of the weighing equipment, it was tested with a powder product for about 300 s (at 60 s interval) and the corresponding mass (kg) was compared to a readily available digital scale. The results from the analysis showed that the developed weighing equipment have an approximate accuracy of about 95%. This meant that the average mass (kg) difference from the analysis was 5.06%. In addition, there was an average savings of about 0.150 kg of the powder product. Therefore, the developed weighing equipment will be vital to small scale businesses in third world countries.
 
Delignification Trends in Pretreatment of Musa Paradisiaca Pseudo-Stem and the Production of Bioethanol
Get PDFThis study was conducted to assess the potential of pre-treated Musa paradisiaca pseudo-stem as an alternative source of raw material for ethanol production. The pseudo-stem was pre-treated with NaOH and NaOH-AQ at varying time and liquor concentrations using a digester. Cellulose yield (CY) was determined gravimetrically, Residual Klason Lignin (RKL) was evaluated in accordance with TAPPI T236 standards and the effect of the pre-treatment variables were examined. Acid hydrolysis using dilute solutions of HCL and H2SO4 followed pre-treatment, while fermentation was achieved by the addition of an active yeast strain (Saccharomyces cerevisae). The ethanol produced was distilled, qualitative analysis was conducted using the Fourier Transform Infrared Spectroscopy (FTIR) and other standard methods. There was a general decrease in CY and RKL with increasing pulping time and alkali charge, using both NaOH and NaOH-AQ. CY ranged from 2.4 – 4.2g and 3.2 - 5.0g while RKL ranged from 2.46%-3.9% and 1.94-3.00% for both NaOH and NaOH-AQ pre-treatments respectively. However, there was significant difference between the effects of liquor concentration and time on CY at p=0.05. The addition of 0.1% anthraquinone to soda pulping liquor significantly increased CY and decreased RKL. The difference in glucose yields between the two dilute acid hydrolyses was not significant. Various qualitative tests on bio-ethanol showed traits very similar to the laboratory grade ethanol while FTIR confirmed the presence of ethanol. It is therefore proven that NaOH and NaOH-AQ are suitable pretreatment methods in the production of bioethanol from Musa paradisiaca.
 
Modular Cryogenic Energy Storage System: Simulation and Techno-Economic Analysis.
Get PDFSustaining economic growth while reducing reliance on fossil fuels for environmental protection is a global challenge. Efforts are made to decrease energy utilization by enhancing energy efficiency and discovering clean renewable energy sources. Cryogenic energy storage (CES) is a grid-scale energy system where electricity is stored in the form of liquefied gas. It is regarded as a solution because it allows for increased electricity generation while also providing economic benefits by avoiding costly operational consequences. The CES was modeled and simulated in Aspen HYSY V8.8 using three system confirmations: standalone adiabatic, waste heat integration, and combustion integration. Unlike in the conventional CES, Dowtherm-Q was used as the thermal fluid due to its thermal stability, non-corrosiveness, and high temperature resistance. The results indicated that the higher the adiabatic efficiency of the turbine, the greater the power generated; also, increasing the turbine inlet temperature enhanced the performance of the system configuration by lowering the pressure and increasing the power of the turbine. The economic analysis revealed that the waste heat-based system has both the lowest operating cost, capital cost, utility cost, and higher energy savings. Waste heat integration produces the most power (653.70 kW) and saves the most energy (69.58%), with lower capital costs, operating costs, and utility costs due to the increased adiabatic efficiency of the turbine. It implies that CES with waste heat integration is economically more promising compared to adiabatic standalone and the integration of combustion.
 
Production and Evaluation of the Physiochemical and Sensory Property of Biscuits From Wheat-Maize-Cashewnut Flour Blends
Get PDFThis study aimed to prepare and evaluate the quality characteristics of biscuits produced from wheat, maize and cashew nut flour blends. The flours were processed and blended using different proportions of eight (8) formulations with whole wheat flour as a control. The proximate composition of the flour blends, physical properties and sensory evaluation of the biscuits produced were determined using the standard analytical techniques. The data obtained were statistically analyzed using Analysis of Variance (ANOVA). The results show that moisture, ash, fat, protein and carbohydrate of the flours used for the blends ranged from 5.43-10.12 %, 1.74- 29.51, 9.34-26.56 and 34.48-77.25% respectively. Also, the moisture, ash, protein, fat, fibre carbohydrate and energy values of the biscuit ranged from 2.90 -3.92%, 0.99 - 1.57%, 11.19 - 14.59%, 16.24 - 20.30%, 0.97 - 4.85%, 56.04 - 66.96% and 457.68 - 470.80 Kcal/100g respectively. However, with an increase in maize flour (Mf), a significant increase in fibre contents was observed while moisture content decreased drastically. Additionally, the protein, fat and energy contents of supplemented samples were found to be higher than the control but decreased with an increase in maize flour levels. The weight, length, width, thickness and spread ratio of the biscuit samples differed significantly (p<0.05) ranging from 15.25 - 17.36g, 51.70 - 53.03mm, 50.54 - 52.36mm, 9.57 - 11.27mm and 4.48 - 5.47mm respectively. The spread ratio and overall acceptability of biscuit samples decreased with the increased level of maize flour although the sensory evaluation showed that most values obtained are closer to the control. This shows that the acceptance level of the biscuits samples was higher except for sample Wmc 8 ( sample produced from wheat, maize and cashew nut flour at the ratio of 20:70:10). In conclusion, the production of biscuits supplemented with cashew nuts and maize flour increased protein, energy contents and taste, which could be used to address protein-energy malnutrition prevalence.
 
Maximum Power Point Tracking in Partial Shaded Photovoltaic System using Smell Agent Optimization Algorithm
Get PDFWith partial shading conditions, it is essential to acquire Maximum Power Point at which the Photovoltaic systems (PV) operate effectively despite the variation in the cell temperature and incident angle of sunlight rays on the panels. This study explores the use of a Smell Agent Optimization (SAO) algorithm for Maximum Power Point Tracking (MPPT) in partial shaded PV systems. The proposed MPPT system is composed of a PV model, a DC-DC converter model and a control part. The Smell Agent Algorithm (SAA) was adopted in the control part of the MPPT system to implement the optimization algorithm using four different shading patterns (SPs) and to calculate the optimal switching duty cycle of the DC-DC converter. The effectiveness of the proposed system was verified using simulations in the MATLAB/Simulink environment. The SAO respectively track maximum values for Power, Voltage and Current as 845.8476 W, 211.7308 V, 3.99492 A while the maximum values for Power, Voltage and Current for Perturb and Observe (P and O) are 845.0465 W, 211.6305 V, 3.993028 A respectively during SP1. The results showed that the SAO algorithm has excellent tracking results in terms of convergence speed, accuracy, power extracted stability, and dynamic response in reaching the optimum point
Evaluating the Performance Properties of Asphalt Produced from Bitumen Modified with Thermoplastic Polymer
Get PDFFlexible pavements, particularly in urban areas, deteriorate rapidly after construction due to poor workmanship and inadequate drainage facilities. The demand for roads continues to increase. Engineers of the highway system are concentrating on alternative solutions to meet this expanding challenge. Highway system engineers are currently focused on developing alternative solutions in order to address this growing challenge. To prevent the premature deterioration of the road system, the performance of flexible pavements must be enhanced. The addition of waste polymers to asphalt mixtures is one method that can significantly enhance the quality of the pavements. This study examined the mechanical properties of asphalt produced from waste plastic polymer-modified bitumen. The addition of thermoplastic polymer (0 to 12%) increased the softening point, viscosity, flash and fire points of bitumen, but decreased its penetration and ductility for the production of hot mix asphalt. The Marshall stability and flow of all asphalt concrete formulations were greater than 9 kN and within 2 - 6 mm of the General Specifications of Nigerian for Road and Bridges, Federal Ministry of Works and Housing, 2016 and the Asphalt Institute, 1991. Modification of asphalt with thermoplastic polymer is suitable for enhancing the performance properties of the asphalt. Additional research is required for the development of recyclable additives that do not significantly increase the final cost of bitume
Multi-Response Optimization of Planting Process of a Seed Ridge Planter using Response Surface Methodology (RSM)
Get PDFThe performance of a two- row self-propelled seed planter, Institute for Agricultural Research (IAR) single row animal drawn planter and the manual method of planting were investigated under laboratory and field conditions to optimise the planting process using Response Surface Methodology (RSM). Parameters optimisation of seed planting process becomes imperative in order to find parameter values that match predictions with reality and choose the right set of parameters that improve the performance of planter. Experiments conducted in this study were based on Central Composite Design (CCD), one of the designs in RSM Experimental treatments were three planting methods, three soil moisture levels, and three planting depths randomly assigned in a 3x3 factorial experiment arranged in a Randomized Complete Block Design (RCBD) in three replications. The results show increased plant population with increasing planting speed and moisture content values. Also, increased seedling emergence was observed with increasing moisture content and decreasing planting speed values. However, further increase in seed planting moisture content beyond the optimum point caused a decrease in the seedling emergence. Similarly, there was increased depth of planting with increasing seed planting speed and moisture content values. Further increase in soil moisture content beyond the optimum point caused a decrease in the depth of planting. Conclusively, soil moisture availability is an important factor affecting the depth of seed planting in the study area