Technical appraisal of some maize shellers in Oyo and Kwara States of Nigeria

This study assessed the performance of some maize shellers in use in grain markets in Oyo and Kwara States, Nigeria. A preliminary survey conducted identified shellers in use as basic maize sheller (BMS) without blower, maize sheller with blower attachment (MSB) and the multi-purpose sheller (MPS). The shelling/cleaning performance of the shellers were assessed using yellow maize (SWAN 1 variety) and some key equipment parameters, which impact performance were measured. The air velocity for MSB and MPS ranged between 0.4 and 2.4 m/s which was not sufficient for efficient cleaning of chaff from shelled grains. Shaft speed for BMS, MSB and MPS were 845, 920 and 820 rpm, respectively. Average throughput for BMS, MSB and MPS was 1,714, 600 and 840 kg/hr, respectively with mean shelling efficiencies of 92.9, 82.7 and 97.9%, respectively. Mean cleaning efficiencies were 54.0 and 57.7% for MSB and MPS, respectively. The percentage grain loss for BMS, MSB and MPS were 17, 7.1 and 1.9%, respectively. It was observed that many fabricators do not consult agricultural engineers when producing machines, relying more on previous experience. Additionally, there was a lack of consideration for operator safety with the exposure of moving parts of the equipment in all the designs evaluated. A key recommendation from this study is that sheller designs should be standardized to ensure the provision of quality and highly efficient machinery for processors

The effect of moisture content on the grinding performance of corn and corncobs by hammermilling

The grinding behavior of corn and corncobs was investigated at moisture content levels of 10.39%, 16.02%, and 19.64% (wet basis) for shelled corn and 10.04%, 14.65%, and 20.13% (wet basis) for corncobs. Grinding performance was assessed by determining the throughput, specific rate of breakage, particle size distribution, power consumption, and energy required for grinding using a hammermill. The physical and flow properties investigated were loose and tapped bulk density, compressibility index, Hausner ratio, particle density, and static angle of repose. The throughput and specific rate of breakage of corncobs were very low compared to corn and decreased with increasing moisture content. The energy required for grinding corncobs was higher than that for corn. The particle size of ground corn was smaller than that of ground cobs; however, there were no significant differences across moisture levels. The particle size distribution of ground corn was narrower than that of ground cobs. Physical and flow properties were not significantly different across moisture levels for both ground corn and cobs. The smaller size of the corn particles explains why the bulk density, compressibility index, Hausner ratio, and angle of repose were higher for ground corn than for ground cobs

Technical Appraisal of some Maize Shellers in Oyo and Kwara States of Nigeria

This study assessed the performance of some maize shellers in use in grain markets in Oyo and Kwara States, Nigeria. A preliminary survey conducted identified shellers in use as basic maize sheller (BMS) without blower, maize sheller with blower attachment (MSB) and the multi-purpose sheller (MPS). The shelling/cleaning performance of the shellers were assessed using yellow maize (SWAN 1 variety) and some key equipment parameters, which impact performance were measured. The air velocity for MSB and MPS ranged between 0.4 and 2.4 m/s which was not sufficient for efficient cleaning of chaff from shelled grains. Shaft speed for BMS, MSB and MPS were 845, 920 and 820 rpm, respectively. Average throughput for BMS, MSB and MPS was 1,714, 600 and 840 kg/hr, respectively with mean shelling efficiencies of 92.9, 82.7 and 97.9%, respectively. Mean cleaning efficiencies were 54.0 and 57.7% for MSB and MPS, respectively. The percentage grain loss for BMS, MSB and MPS were 17, 7.1 and 1.9%, respectively. It was observed that many fabricators do not consult agricultural engineers when producing machines, relying more on previous experience. Additionally, there was a lack of consideration for operator safety with the exposure of moving parts of the equipment in all the designs evaluated.  A key recommendation from this study is that sheller designs should be standardized to ensure the provision of quality and highly efficient machinery for processors

Bioenergy production from diluted poultry manure and microbial consortium inside Anaerobic Sludge Bed Reactor at sub-mesophilic conditions

In this study, anaerobic treatability of diluted chicken manure (with an influent feed ratio of 1 kg of fresh chicken manure to 6 L of tap water) was investigated in a lab-scale anaerobic sludge bed (ASB) reactor inoculated with granular seed sludge. The ASB reactor was operated at ambient temperature (17-25 degrees C) in order to avoid the need of external heating up to higher operating temperatures (e. g., up to 35 degrees C for mesophilic digestion). Since heat requirement for raising the temperature of incoming feed for digestion is eliminated, energy recovery from anaerobic treatment of chicken manure could be realized with less operating costs. Average biogas production rates were calculated ca. 210 and 242 L per kg of organic matter removed from the ASB reactor at average hydraulic retention times (HRTs) of 13 and 8.6 days, respectively. Moreover, average chemical oxygen demand (COD) removal of ca. 89% was observed with suspended solids removal more than 97% from the effluent of the ASB reactor. Influent ammonia, on the other hand, did not indicate any free ammonia inhibition due to dilution of the raw manure while pH and alkalinity results showed stability during the study. Microbial quantification results indicated that as the number of bacterial community decreased, the amount of Archaea increased through the effective digestion volume of the ASB reactor. Moreover, the number of methanogens displayed an uptrend like archaeal community and a strong correlation (-0.645) was found between methanogenic community and volatile fatty acid (VFA) concentration especially acetate