Effect of Expression Conditions on the Yield of Dika Nut (Irvingia Gabonesis) Oil under Uniaxial Compression

Efficient expression of Dika nut oil from the kernel is required for its subsequent use in producing comparatively cheap lubricant. Various factors responsible for proper oil expression include particle size, moisture content, heating temperature, heating time, pressing pressure and pressing time. Sundried Dika kernel ground to two particle sizes (fine: ≤ 1.4 mm and coarse: between 1.4 and 2.8 mm) were conditioned to moisture content of 3, 6 and 9 wt%. Considered in the study, are heating temperature ranging from 50 to 150oC in steps of 25 degrees Celsius and heating time of 5 to 25 minutes in steps of 5 minutes. Pressing pressure of 5 to 25 MPa in steps of 5 MPa and pressing time of 2 minutes interval were also considered. The maximum oil yield was then correlated with the processing conditions. Test results showed that coarse particle gave higher oil yield. Maximum oil yield of 72.2% of the available oil was obtained at 6% moisture content, heating temperature of 100oC and heating time of 10 minutes. Regression analyses of the oil yield with heating temperature, heating time, and pressing gave r2 values of 0.9678, 0.999 and 0.9128. The processing conditions therefore has significantly influence the quantity of oil obtained from Dika kerne

Experimental Verification of a New Technique for the Dry Separation of Palm Kernel and Shell Mixture

Effective separation of the cracked palm nut mixture is an important process in the downstream utilisation of the constituent palm kernel and shell in some existing and emerging agro-economy. Whilst, the conventional wet separators are sophisticated and energy inefficient, the dry systems are at experimental stages and are inadequate for separating kernel and shell of comparable sizes. However, the difference in the path variables of particles of same size, but different shapes, in circular motion, suggests the possibility of separating the dry mixture in a rotating trammel with a co-axial spout. Based on the theory, the study investigated the dispatch angles for palm kernel and shell from a friction lining on the inner curved surface of drums of different diameters and rotating speeds. A built experimental facility allowed estimation of the dispatch angle for particles placed on the lining. The results show that palm kernels oscillate and move axially with the dispatch angle increasing with the drum diameter, but consistently less than 90o for the different diameters and speeds of the drum. The shells are dislodged at higher dispatch angles and in curvilinear trajectories away from the drum surface, causing a separation of the mixture. It is concluded that the experimental data are in good agreement with the theory and that the theory is sufficiently adequate for the determination of the design parameters of a proprietary separator

Dika nut oil as base oil for lubricants—effect of processing conditions on physicochemical properties

The paper presents a report on the effect of processing conditions of Dika nut oil on its physicochemical properties and also on the assessment of the oil for use as biodegradable lubricant. The oil was expressed mechanically from coarsely ground kernel meals at 3 and 9 wt.% moisture content (wet basis), preheated at 75, 100 and 150 °C for 10, 20 and 30 min. The plots showed that the chemical properties of the oil had quadratic and linear relationships with the heating temperature and heating time, respectively. At 95% confidence level, the free fatty acid content, the saponification, the iodine and the acid values of the oil were significantly affected by various processing conditions. The processing conditions therefore showed significant influence on the physicochemical properties of the oil and consequently on its suitability for use as lubricant. Copyright © 2012 John Wiley & Sons, Ltd

Computer Aided Plumbing Design

This study has been used to eliminate the rigorous activities and time consuming mathematical analysis involved in Plumbing design. The various mathematical steps employed in the design of plumbing systems has been converted into easily interpreted hand user computer program that can be used to generate automatically all the various parameters needed for full design work, when the input data such as head available, various number of fittings, actual length of pipe run and assumed pipe diameter are provided. This has been used to provide a pathway to easy plumbing desig

Hydro power potentials of water distribution networks in public universities: A case study

Public Universities in Southwestern Nigeria are densely populated student-resident campuses, so that provision of regular potable water and electricity are important, but power supply is not optimally available for all the necessary activities. This study assesses the hydropower potential of the water distribution networks in the Universities, with the view to augmenting the inadequate power supplies. The institutions with water distribution configuration capable of accommodating in-pipe turbine are identified; the hydropower parameters, such as the flow characteristics and the pipe geometry are determined to estimate the water power. Global positioning device is used in estimating the elevations of the distribution reservoirs and the nodal points. The hydropower potential of each location is computed incorporating Lucid® Lift-based spherical turbine in the pipeline. From the analysis, the lean and the peak water power are between 1.92–3.30 kW and 3.95–7.24 kW, respectively, for reservoir-fed distribution networks; while, a minimum of 0.72 kW is got for pipelines associated with borehole-fed overhead tanks. Possible applications of electricity generation from the water distribution networks of the public universities are recommended

Mathematical modelling of palm nut cracking based on Hertz's theory

A mathematical model based on Hertz's theory of contact stress was developed for the prediction of force required to break the palm nut. Using nuts subjected to a uniaxial compression stress, in their lateral axis between rigid parallel plates, and those propelled to impinge a rigid cylindrical seat along its lateral axis, experimental verification of the model was conducted comparing the theoretical predictions with estimates from the representations of conventional methods employed in nut cracking. Properties including size, shape and mass, required in the derived model were determined for two varieties of the palm nut. Material stiffness was obtained from the force–deformation curve. Regression analysis showed an exponential variation of the cracking force with nut deformation. Material stiffness obtained was 654 N/mm and 303 N/mm for the ‘Dura’ and ‘Tenera’ nuts, respectively. The respective ranges of geometric mean diameters were 17·07–27·68 mm and 22·32–26.51 mm. There was no significant variation of nut sphericity with size or variety. Force prediction from the Hertzian model proposed gave good prediction of cracking force that was not significantly different from that obtained from a centrifugal nutcracker driven at 1500 min−1, with a 40 cm diameter cracking chambe

Separation theory for palm kernel and shell mixture on a spinning disc

The separation of palm kernel from the shell is an important process in the recovery of the kernel for use in vegetable oil production. The inherent shortcoming of the fertiliser spinner spreader, resulting in non-uniform distribution, has led to investigations into the possibility of its use in the separation of palm kernel from shell. The differences in the physical properties of the kernel and shell provided the basis for separation. Models describing the motion of the kernel and the shell on a spinning disc with vanes, feeding a segment at a time, were developed, and comparisons between the predictions and experimental results were made. Discharge angles obtained from the predictive models and from the experiment were in close agreement. The experiment, however, indicated a mid-span, between the discharge angles for kernels and shells, containing the mixture. The models reasonably predict approximate ranges of discharge angles for palm kernels and shells on a spinning disc with specified diameter, friction coefficient and rotational speed

Development of a Machine for Expressing Vernonia amygdalina Leaf Juice

Vernonia amygdalina leaf juice is known for its nutritive value and as food supplement. There is therefore, a need for a simple processing device for the leaf juice expression. This study developed a machine for producing contamination-free V. amygdalina leaf juice. The design of the machine was based on the principle of a pressure deferential applied to the incoming leaf mash compared with that applied to the discharged material. Macerated leaves were compressed through a tapered screw conveyor; whose shaft terminates as a rising but short conical kink. The maximum juice yield of 41.39% was expressed from the leaf mash at pressing pressure and residence time of 6.09 MPa and 11 min, respectively. The throughput of the machine was 9.60 kg/h and the juice extraction rate was 1.86/h at leaf to water ratio of 1: 0.8. The maximum juice expression efficiency was 15.54% at 1: 1.2 leaf to water ratio, 60 rpm constant rotational motor speed and 11.99 kg/h feeding rate. Approximately 26.38% of the inherent moisture content of the leaf was expressed by the machine. It is expected that the machine may be used to express juice from other plant leaves having comparative physical properties. The machine therefore provides a viable technique for mechanical expression of good quality V. amygdalina leaf juice.

Removal of metals from flat lubricating oils using a fabricated packed-bed reactor

Packed bed reactor (PBR) was fabricated and its performance in removing metals from used (flat) lubricating oils was evaluated. A blend of locally produced diatomaceous materials was employed as sorbent. Flat lubricating oils from two brands (Mobil Super SAE-20W-50 and Total Quartz 5000 SAE-20W-50) were run through the PBR. Concentrations of the analysed metals in the used and treated oils were measured using Atomic Absorption Spectrophotometer and the results compared with those of unused (virgin) oils. Zinc, Mg, Ca, Na and K were detected in virgin oils; while all the analysed metals were detected in the treated and used oils but are of higher concentrations in the used oils. Cross plots have R2 values > 0.96, indicating high linear relationships of the impact of the treatment on the used oils. T-test results indicated that most of the metals showed significant differences between the mean values of the treated and used oils, indicating good treatment effects; while most of them indicated no significant differences between the mean values of the brands of oils used, indicating similar treatment effects on the two brands of oils. These results confirmed the high efficacy of the fabricated PBR for the purpose of recycling used oils

Anthropometric characteristics of roadside auto-mechanics: a case study

The study evaluated the relevant/corresponding anthropometric characteristics of the people involved in engine-repair activities. The study was carried out on the selected roadside auto-engine repairers along Lagos-Ibadan express way, in Nigeria. This was with a view to providing ergonomic design data for optimal working condition among this set of workforce and redesigning the mechanics inspection-pit. Material and methods: The static and the functional anthropometric characteristics of the mechanics were measured. The data obtained from 110 auto-mechanics, randomly selected, were employed to evaluate efficient design parameter for roadside workstations. Results: The results indicated that inspection-pit is about 1626 mm deep; seat height ranges between 375 mm and 405 mm; optimal work posture sitting is between 483 mm and 622 mm. Conclusions: Adopting the data presented in this paper in optimizing the auto-mechanics working conditions for effective workplace comfort and productivity among the roadside auto-mechanics in Nigeria will be of immense advantage