Influence of temperature difference (water-cover surface) on the performance of a compact hemispherical solar still

The study investigated the influence of temperature difference (ΔT) between evaporative and condensing surface temperature on water productivity of hemispherical solar still. The still was developed, tested and evaluated under the climatic conditions of Ile-Ife, Nigeria, to obtain an average distillate yield per hour per day for different combination of basin temperature, water temperature, transparent cover temperature, ambient temperature and solar intensity. Results indicated a decrease in the hourly water yield as (ΔT) increases. Regression analysis revealed that ΔT has no significant influence on the hourly water yield (P > 0.05). Maximum water productivity was obtained for a low condensing surface temperature and a high evaporative surface temperature. The study concluded that the improvement on water productivity of solar still can be achieved by enhancing the evaporative and condensing surface temperature. Methods for obtaining higher evaporating temperature should be sought in order to boost water productivity of solar stills. Keywords: Temperature difference, Evaporative surface, Condensing surface, Hourly water yield, Heat losses

Effects of Soybean Methyl Ester on the Performance Characteristics of Compression Ignition Engine

Depletion and hazardous gas emissions associated with fossil fuels have caused scientists and global attention to focus on the use of "alternative, eco-friendly substitutes for use in Compression IgnitionEngines. In this work, biodiesel was produced by trans-esterification of soybean obtained from a Nigerian market using Sodium Hydroxide (NaOH) as a catalyst." After the production, the physical properties (specific gravity to kinematic viscosity and net calorific value) of the Soybean-biodiesel produced and petrol diesel obtained from a filling station in Nigeria were determined, and these properties conform to conventional standards (ASTM). A cummins-6V-92TA DDEC diesel (Compression ignition, CI) engine was run on various biodiesel-petrol diesel blends (0/100, 10/90, 20/80, 30/70 and 40/60), the B20 (blend 20/80) was found to be the most satisfactory

Energy output assessment of Lafia-Obi coal in a fluidized bed combustor

This work investigated the energy output from the fluidized bed combustion of Lafia-Obi coal using five range of fuel equivalent diameters (FED) of 125 μm, 250 μm, 355 μm, 2.5 mm and 5.0 mm. Energy output in response to variation in bed temperature, FED, bed pressure, and fluidizing velocity was examined in the fluidized bed heat exchanger. Results indicated an increase in heat transfer rate by 80, 11 and 25% when 5 mm coal was reduced to 355, 250 and 150 μm respectively. Bed temperature increased by 8% for 355 μm and decreased by 6% when 5.0 mm coal was fired. Higher bed pressure was observed when larger particle sizes (5.0 and 2.5 mm) were fired. This resulted in poor bed temperature and increasing fluidization velocity and thus, reduced steam discharge temperature at the heat exchanger outlet.Keywords: Lafia-Obi coal, energy output, fluidized bed, particle size, bed temperature, combustion efficienc

DETERMINATION OF HEAT TRANSFER PROPERTIES OF VARIOUS PVC AND NON-PVC CEILING MATERIALS AVAILABLE IN NIGERIAN MARKETS

In this study, heat transfer properties of 10 polyvinyl chloride (PVC) ceiling composites and 4 other non-PVC ceiling materials, such as particle board, cardboard, plywood and asbestos were determined using an automated Lee’s disc apparatus and XRY-1C bomb calorimeter. Results obtained indicated that asbestos were consistent in being inert to ignition in addition to having the lowest specific heat capacity (SHC). Polyvinyl chloride ceiling composites had advantageous thermal conductivities in comparison to the non-PVC ceiling materials. The SHCs and thermal characteristics of ceiling materials for building constructions and other applications should be appraised by manufacturers where combustion requirements are of utmost consideration

Comparison of the Elemental Structure and Emission Characteristics of Selected PVC and Non PVC Ceiling Materials Available in Nigerian Markets

The recurring fire outbreak in buildings in Nigeria is quite alarming, just as the shift to the use of PVC as a choice for ceiling material due to its aesthetic appearance is on the increase. Hence this study determined the emission characteristics PVC and non-PVC samples. This was done with a view to establishing their suitability as ceiling materials in building designs for tropical countries and providing thermal and combustion data for building stakeholders that could help to checkmate man made fire disasters. This experiment involves the burning of a consistent mass, 50g of 6 samples of 3 PVC and 3 non-PVC in an open furnace where the combustion is carefully controlled. It investigates the flue gasses concentration emitted in the cause of fire outbreak and its effect on occupants. It responds to the question in mind that not only visible flame kills but also toxicity from flue gas can be detrimental to health of victims. The results showed that PVC samples are unwelcome in terms of their emission characteristics which were due to their elemental makeup of their composites such as PVC recorded highest Carbon composition of 77.9% and lowest oxygen composition of 18.0 %. VOCs are cancerous, cause dizziness, rapid heartbeat, vomiting and eventual death. Benzene, a known VOC, is used in making PVC which is a human carcinogen compound. Ceiling materials that will achieve low noxious emission and as well fire retardant should be investigated and employed for use. These materials can be improved upon to achieve environmental friendly building materials

Effects of Emission Characteristics on Elemental Composition of Selected PVC Ceiling Materials

This research work determined the emission characteristics and elemental composition of selected PVC ceiling materials common in Nigerian markets especially during service. This research work determined the emission characteristics and elemental composition of selected PVC ceiling materials common in Nigerian markets. The emission data and elemental structure gave insight to appraise their suitability as ceiling materials. Three PVC ceiling materials were used for this analysis: Nigerian made PVC, layered Composite PVC and white PVC. Rutherford Backscattering Spectrometry (RBS) was performed to obtain the elemental structure of the ceiling materials using Ion Beam Analysis facility. 0.05 kg of the samples were combusted in a controlled fire chamber and the gasses emitted; CO, SO2, NO, and volatile organic compounds (VOC) were identified using four gas analyzers. Elements were detected in total and data collected from the experiment were analyzed. Results showed that Nigerian made PVC has the highest total noxious gas among the three samples with value of 3732.5 ppm while layered composite PVC has the lowest among the PVCs with the value of 1477.5 ppm. The elemental make-ups of the samples influence their emission characteristics. The study established that PVC samples were noxious in terms of their emission characteristics due to the effects of their elemental basis

Flame Behaviour Comparison of Building Ceiling Composite using Combustion Calorimeter

This study determined the heat of combustion characteristics of selected building ceilings materials. The study was intending to appraise the flame affinity or retardance of building ceiling materials during combustion. Careful selection of ceiling composite was carried out in areas like Osun state, Ogun state, Lagos state, and Kaduna State. The heat of combustion was determined, having identified the heating value from the XRY-1C Oxygen Bomb Calorimeter. The heat flux and heat release rates were determined from the results of the combustion experiment. Based on the data obtained from the discrete experiments, the combustion integrity of the samples was appraised. Particleboard has the highest heat of combustion of 45.666J/kg, while asbestos failed to ignite. Other Polyvinyl chlorides (PVC) left ≤ 0.0007kg of char after combustion and became deliquescent after long minutes of exposure to air. The heat release rate is highest with particleboard, 118.9219 J/s, and lowest with sample 7, 2.230 J/s. The study thus establishes that PVC is safer in terms of combustion properties compared to plant-based building ceilings. Asbestos has the overall most reliable properties, but for asbestosis, its use isn't safe for use. It is necessary to develop building ceilings with flame retardant characteristics of asbestos as an alternative to it

Surface Chemistry Studies of Emission and Thermal Behaviour of Developed Composites for Building Ceiling Materials

The emission of harmful elements from burning building ceiling materials and their attendant health effects on inhabitants within the vicinity of the emitted harmful elements is increasingly becoming a source of concern globally. Hence, the need to develop eco‐friendly flame‐retardant composite materials suitable for house ceiling purposes to forestall unwanted toxic emissions. This work identified the chemical structure of developed composite products and their emission performance during combustion. X‐ray Diffraction (XRD) analysis was used for phase quantification and E550 combustion gas analyzer for emission characterization of the developed composites. Thermolyne 950 °C oven was employed for the combustion analysis of the prepared composite at 500 °C. Quasi negligible SO2 and CO2 levels existed, while A4, 0.3Aldr0.23Cmt0.3Si0.05G0.12CS recorded maximum CO level, indicating toxic affluence. The low mass losses of all composite materials, especially for A2, 0.6Aldr0.34Cmt0.05G0.01OBSretard significantly due to its activities by the retardant constituent. The flame retardant nature of all produced composites was evidenced in their elemental composition. There was an absence of a flammable element and stable insulating compounds providing retardance to flame occurrences. These suppressions in flame inclination of the reinforced materials were noticed within the boundaries of the ceiling crystals from the structural examination. The intermetallic phase from the diffraction intensities showed the presence of a significant second bond interstitial solid‐phase across the matrix, especially for 0.6Aldr0.34Cmt0.05G0.01OBS ceiling material. This study has established the eco‐friendliness of developed building ceiling composite and the potential to reduce the importation of building ceilings. The developed ceiling composite evidently demonstrated high potential to compete favourably with imported ceiling materials in terms of fire resistance performance, low cost of production, and abundant availability of raw materials in the environment. Oil beanstalk is a novel material introduced as a reinforcement to developed building ceiling composite. This research provides a blueprint for manufacturers, construction and allied industry, and stakeholders in developing ecofriendly flame retardant composite ceilings whose materials can be readily sourced locally available in the environment

Comparison of the Elemental Structure and Emission Characteristics of Selected PVC and Non PVC Ceiling Materials Available in Nigerian Markets

The recurring fire outbreak in buildings in Nigeria is quite alarming, just as the shift to the use of PVC as a choice for ceiling material due to its aesthetic appearance is on the increase. Hence this study determined the emission characteristics PVC and non-PVC samples. This was done with a view to establishing their suitability as ceiling materials in building designs for tropical countries and providing thermal and combustion data for building stakeholders that could help to checkmate man made fire disasters. This experiment involves the burning of a consistent mass, 50g of 6 samples of 3 PVC and 3 non-PVC in an open furnace where the combustion is carefully controlled. It investigates the flue gasses concentration emitted in the cause of fire outbreak and its effect on occupants. It responds to the question in mind that not only visible flame kills but also toxicity from flue gas can be detrimental to health of victims. The results showed that PVC samples are unwelcome in terms of their emission characteristics which were due to their elemental makeup of their composites such as PVC recorded highest Carbon composition of 77.9% and lowest oxygen composition of 18.0 %. VOCs are cancerous, cause dizziness, rapid heartbeat, vomiting and eventual death. Benzene, a known VOC, is used in making PVC which is a human carcinogen compound. Ceiling materials that will achieve low noxious emission and as well fire retardant should be investigated and employed for use. These materials can be improved upon to achieve environmental friendly building materials

Effects of Emission Characteristics on Elemental Composition of Selected PVC Ceiling Materials

This research work determined the emission characteristics and elemental composition of selected PVC ceiling materials common in Nigerian markets especially during service. This research work determined the emission characteristics and elemental composition of selected PVC ceiling materials common in Nigerian markets. The emission data and elemental structure gave insight to appraise their suitability as ceiling materials. Three PVC ceiling materials were used for this analysis: Nigerian made PVC, layered Composite PVC and white PVC. Rutherford Backscattering Spectrometry (RBS) was performed to obtain the elemental structure of the ceiling materials using Ion Beam Analysis facility. 0.05 kg of the samples were combusted in a controlled fire chamber and the gasses emitted; CO, SO2, NO, and volatile organic compounds (VOC) were identified using four gas analyzers. Elements were detected in total and data collected from the experiment were analyzed. Results showed that Nigerian made PVC has the highest total noxious gas among the three samples with value of 3732.5 ppm while layered composite PVC has the lowest among the PVCs with the value of 1477.5 ppm. The elemental make-ups of the samples influence their emission characteristics. The study established that PVC samples were noxious in terms of their emission characteristics due to the effects of their elemental basis