Browsing by Author "A.T. Abdulrahim"

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    DEVELOPMENT AND PERFORMANCE EVALUATION OF A SPINDLE PRESS FOR OIL EXTRACTION
    (2007-10) Oluwole, F.A; A.T. Abdulrahim; N.A. Aviara
    A manually operated spindle oil press adaptable to rural areas was designed, constructed using locally available materials and tested to evaluate its performance. The spindle press, which consists of tool frame, power transmission unit made of a spindle and its lever arm, and oil expression unit comprising of the upper and lower press plates and the perforated cage, operates on the principle of power screw to express oil from milled oil seeds. Each of these components was analyzed and the results obtained were used as parameter for sizing and fabrication of the components. The raw material used for testing the developed spindle press was groundnut paste and a nylon clothing material was used as filter. Results of the performance tests carried out on the machine using groundnut paste showed a maximum oil recovery of 78.1% and the cake produced is of the same quality when compared with those produced with the traditional method. Also the oil extraction time is reduced by about 50%
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    Development and performance evaluation of impact bambara groundnut sheller
    (Institute of Agrophysics, Polish Academy of Sciences, 2007-09-01) F.A. Oluwole; A.T. Abdulrahim; M.B. Oumarou
    A centrifugal bambara groundnut sheller was designed, constructed and evaluated. The sheller consists of a feed hopper with a flow rate control device, shelling unit, separating unit and power system. Nine different impellers were used for the investigation at three different pod moisture contents. Results of the performance tests were examined using a 3x3x3 factorial design with moisture content, impeller slot angulations and number of impeller slots as variables. Results showed that moisture content, impeller slot angulations, number of impeller slots and interaction between these variables statistically affected the per formance indicators (shelling efficiency, percentage of breakage, percentage of partially shelled pods, percentage of unshelled pods and winnowing efficiency) at the significance level of 5%. The forward facing impeller with eight slots gave the best performance of 96% shelling efficiency, 3.4% breakage, 0.6% partially shelled pods. No unshelled pods were recorded, and winnowing efficiency of 97.3% was recorded at an average feed rate of 215.8 kg h-1
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    Effect of moisture content on crackability of bambara groundnut using a centrifugal cracker
    (Institute of Agrophysics, Polish Academy of Sciences, 2007-04-17) F.A. Oluwole; A.T. Abdulrahim; R.K. Olalere
    One of the most tedious operations in processing bambara groundnut is the shelling operation. However, moisture content normally affects the handling and processing of agro materials, such as nut shelling/cracking. This study was conducted to determine the effect of moisture content on shelling efficiency of bambara groundnut using a centrifugal cracker. A 50 kg bag of bambara groundnut obtained from Damboa Local Government Area of Borno State, Nigeria, was divided into three groups. These groups were prepared for tests by soaking them in ordinary water at room temperature for different periods of 0, 60 and 90 min to obtain different levels of moisture content. Moisture content of each sample was determined by oven drying at 130°C for 6 h. The moisture content levels were found to be 5.3, 9.6, and 12.2% (d.b.) for samples A, B and C, respectively. The samples were subjected to impact energy through a centrifugal impaction device operating at an angular velocity of 1920 r.p.m., using three different types of impellers. Data obtained on the percentage of fully shelled pods and unbroken seeds, fully shelled pods with broken seeds, partially shelled pods and unshelled pods were statistically analysed. Results showed that both moisture content and impeller angula tions have a significant effect on these performance indices. The most effective performance was obtained at moisture content of 5.3% (d.b.), at which the shelling efficiency, percentage of dama ged seeds, percentage of partially shelled pods and percentage of unshelled pods were 96, 3.4, 0.6 and 0, 86.6, 3.6, 5.6 and 4.2, 85, 2.4, 5.4, and 7.2% for the forward facing impeller, radially posi tioned impeller and the backward facing impeller, respectively. The study further showed that development of a centrifugal impact bambara groundnut sheller with winnower would eliminate the tediousness of the present manual pod cracking methods.
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    Performance Testing Of a Truncated Pyramid Solar Thermal Cooker
    (2013) I.L. Mohammed; U. J. Rumah; A.T. Abdulrahim
    This paper presents the results of performance testing of a truncated pyramid solar thermal cooker developed in the Department of Mechanical Engineering, Kaduna Polytechnic, Kaduna, Nigeria. The truncated pyramidal geometry concentrates the incident solar energy radiations towards the absorber placed at the bottom, and the glass glazing material at the top facilitates the trapping of energy inside the cooker. During testing, the highest plate stagnation temperature achieved, under no-load condition and reflector covered with black cloth, was 145 oC. In full-load condition the temperature of 5.2 kg of water inside the cooker rose from 60 oC to 90 oC in 72 minutes. The First Figure of Merit, F1, was calculated to be 0.120 and the Second Figure of Merit, F2, was found to be 0.410, thus meeting the standard prescribed by the Bureau of Indian Standards for box-type solar cookers. The relatively high absorber plate temperature developed during testing demonstrates that the cooker can be used for all the four major methods of cooking, viz: boiling/ steaming, baking, roasting/grilling, and frying (of eggs).
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    VIABILITY OF SOLAR PHOTOVOLTAIC SYSTEM FOR RURAL ELECTRIFICATION IN NIGERIA
    (2004-10) Alkali, A.B; A.T. Abdulrahim; B.M. Mustapha
    Electricity availability in rural areas is identified as one of the social amenities that drastically reduce poverty problem by bridging the gap between the rural area and the urban centres. A suitable, cheap and reliable source of power, which could be minimally maintained and manipulated, is necessary to transform the life of an average rural family. This paper focuses on the solar system as a possible alternative to meet the above need. The paper presents a solar photovoltaic (PV) design and cost analysis for a typical single bedroom apartment. It also recommends integration of renewable energy into national strategies to cope with the economic and technical uncertainties that may constrain the supply of conventional energy.