Optimal Scheduling of Petroleum Products Distribution in Nigeria

One major problem in Nigeria is the persistent scarcity and inequitable distribution of petroleum products even with the establishment of three refineries, many storage depots and pipelines interconnecting them. This paper is applied to the situation in the downstream petroleum sector in order to determine an efficient and equitable distribution of three blends of petroleum products, namely; Premium motor spirit (PMS) Dual purpose kerosene (DPK) and Automotive Gasoline (AGO). For effective distribution, three refineries and seventeen storage depots were considered because of their interconnections with pipelines.  The model was formulated as a linear programming problem with 20 constraints and 51 variables and was solved using LINDO Optimization software which uses simplex approach. Post-optimality analysis was performed investigating the effect of varying supply from refineries and demand at storage depots.  The optimal solution was obtained for each of the product in the target year “2010” and the result was compared with the result of optimal solution obtained during uncertainty period say “2015”.  The study reveals that any variation in supply, demand and transportation cost changes the optimal solution

Kinematics and Dynamic Evaluation of the Screw Conveyor of a Cassava Centrifuge Dewatering Machine

This paper presents the volumetric performance of a horizontal enclosed screw conveyor with reference to the influence of vortex motion. Vortex motion is as a result of internal friction, friction between the granular material and surface of the helical blade, and the variable helix angle of the helical flight from the outer periphery of the blade to the shaft. The vortex motion and the degree of fill, govern the volumetric efficiency and the volumetric throughput. An analysis of the vortex motion in a horizontal screw conveyor of a Cassava Centrifuge Dewatering Machine is presented. It is shown that the vortex motion is characterised by the tangential component of the absolute grain velocity being constant with the radial position of a point on the blade. On this basis, an expression for the volumetric efficiency is derived. The volumetric throughput can then be predicted. The study also showed the results of an experimental screw conveyor where the analytical predictions correlate closely to the measured results

Continuous-Flow Depulping Machine for Treculia Africana

A continuous flow machine for the depulping of partially fermented fruit of Treculia Africana is presented. The machine is designed to improve upon an existing batch depulper, and consists of four main units, namely the hopper/depulping chamber, the connector-pipe, the separation chamber and power system. The machine operation involves the introduction of fermented breadfruit into the hopper from where it falls under gravity into the de-pulping chamber for further processing. The combination of crank and separation chamber is idealized as a six-member crank-rocker mechanism. Detailed kinematic and dynamic analysis of the idealized system is undertaken using an existing computer programme, SIXBAR. In this way, appropriate dimensions of each element are determined. A laboratory scale model of the machine is constructed and tested. Preliminary results indicate that 69–93% of the seeds could be effectively depulped. Further work is continuing to improve on the system performance and its acceptability by the stakeholders

Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer

Performance simulation of a natural circulation solar air heater with phase change material energy storage

The one-dimensional radial heat conduction in a phase change material (PCM) heat storage system that is encapsulated in cylindrical pipes in a single glazed flat plate natural circulation solar air heater is presented. The PCM is prepared in modules, with the modules equispaced across the absorber plate. Enthalpy method is applied to convert the relevant energy balance equations into dimensionless forms for easy tracking of the moving phase boundaries. Crank-Nicolson implicit finite difference scheme which has the features of being stable, accurate and fast in its solution is used in the solution of the governing equations subject to suitable initial and boundary conditions. The scheme is applied at each node and the resulting simultaneous equations are solved using the Gauss-Seidel iterative method. An existing computer programme in BASIC known as the EGGINC which was developed for the rectangular channel containing the PCM is modified to cylindrical coordinate for the pipes containing the PCM to predict the temperature distributions in the solar air heater. The predicted temperatures of the system are compared with the experimental data under daytime no-load condition over the ambient temperature range of 18.5-36.0OC and daily global irradiation of 4.9-20.1MJ/m2-day. The predicted temperatures were found to agree closely with experimental data.Keywords: Phase change material, Natural circulation; Solar air heater; implicit finite difference, Predicted temperature

Continuous-flow depulping machine for Treculia Africana

continuous flow machine for the depulping of partially fermented fruit of Treculia Africana is presented. The machine is designed to improve upon an existing batch depulper, and consists of four main units, namely the hopper/depulping chamber, the connector-pipe, the separation chamber and power system. The machine operation involves the introduction of fermented breadfruit into the hopper from where it falls under gravity into the de-pulping chamber for further processing. The combination of crank and separation chamber is idealized as a six-member crank-rocker mechanism. Detailed kinematic and dynamic analysis of the idealized system is undertaken using an existing computer programme, SIXBAR. In this way, appropriate dimensions of each element are determined. A laboratory scale model of the machine is constructed and tested. Preliminary results indicate that 69– 93% of the seeds could be effectively depulped. Further work is continuing to improve on the system performance and its acceptability by the stakeholders