Browsing by Author "Lucas, E. B."

Now showing 1 - 4 of 4

Comparative studies of temperature fluctuations within wooden and steel silos in Ibadan
(The Nigerian Society of Engineers, 1997-12) Lucas, E. B.; Mijinyawa, Y.
Temperature fluctuations and moisture condensation within the interiors of a steel and wooden silos were determined experimentally. The steel silo is of 1mm thickness while the wooden silo is a two-layered wall panel of 12mm and 6mm thick plywood separated by 50mm air-gap. Measurements taken during the hotter months of March and April in Ibadan showed that temperature fluctuations in the steel and wooden silos were 9°C and 7°C respectively. Corresponding maximum temperature in the silos were 38.5°C and 37.2°C. While the interior of the wooden silo remained dry, the steel silo had condensed moisture droplets lining its inner walls. Since moisture condensation in a silo contributes to grain spoilage by biological agents, wooden silos are rated superior in respect of reducing this adverse feature.
The design, construction and testing of a wooden silo for grain storage
(The Nigerian Society of Engineers, 1996-03) Lucas, E. B.; Mijinyawa, Y.
A hexagonal, double-walled, wooden silo of sides 1.2m, height 1.8m and of 7m3 capacity was designed. The walls and floor were taken as stressed skin panels. These were fabricated using Mansonia altissima for the ribs, while exterior grade structural plywood was used as sheathing. The silo was subjected to nondestructive testing in accordance with the British Standard Code of Practice CP: 112 and joints separation, consolidation movement of the foundation and floor deflection were periodically measured over a period of two weeks during which the structure was under load. At the end of the test period there was no measurable consolidation movement and the joints remained intact while the floor deflection was within permissible limit of ∆ ≤ L/180. Further testing and evaluation including subjecting the silo to loading for longer duration and taking measurements of stresses induced on the silo components are to be undertaken.
Temperature fluctuations within and outside a silo with treated termite mound clay as construction material
(Research Communications, 2007) Mijinyawa, Y.; Lucas, E. B.; Adegunloye, F. O.
Elevated temperatures and excessive fluctuations -within a grain silo result in condensation of moisture on the inner wall surfaces and its migration within the grain bulk, leading to moulding and caking. There is the need to identify appropriate materials for silo construction that will minimize temperature fluctuations and reduce grain spoilage on storage. A 5.6m3 grain silo construction from 15mm-thick treated termite mould clay bricks tested for temperature fluctuations. Morning, afternoon and evening temperatures, and the maximum and minimum temperatures recorded over a 24hr period within and outside the silo were monitored for 60 days. The walls were physically examined for possible moisture condensation. The maximum and minimum temperatures recorded within the silo were 20°C and 30°C, respectively as against 21°C and 36°C for the ambient. The average temperature fluctuation within the silo was 9.5°C as against 10.3°C for the ambient. The temperature within and outside the silo were quite distinct without any overlap. There was no sign of moisture condensation on the wall surfaces. Grain silo constructed from termite mound clay have the potential to reduce the temperature fluctuations within the silo, eliminate moisture condensation and reduce grain spoilage.
Termite mound clay as material for grain silo construction
(CIRG, 2007-07) Mijinyawa, Y.; Lucas, E. B.; Adegunloye, F. O.
Silos are the most appropriate structures for the bulk storage of grains. Their performances are greatly influenced by the materials of construction and the climatic environment where they are used. Under the warm and humid climate prevalent in Nigeria, metal silos which are the predominant structures used for grain storage experience moisture condensation, resulting in grain deterioration. There is therefore the need to source for construction materials that will eliminate moisture condensation, durable, easy to construct, cheap and readily available to farmers. Termite mound clay was identified as a potential material. A 5.6m3 silo was designed and the prototype constructed with treated termite mound clay bricks. Temperatures were measured inside and outside the silo and the quality of grain stored in the silo was monitored over a period of two months. Viability tests of stored grain were also undertaken. Minimum and maximum temperatures outside the silo were 21°C and 36°C as against 20°C and 30°C inside the silo. Temperature fluctuation within the silo was 9.5 °C compared with 10.3 °C outside. Grain quality was maintained during the storage period, the viability before and after storage were 88% and 84% respectively. The treated termite mound clay silo demonstrated great potential for reducing temperature fluctuations and maintaining grain quality in storage. It is recommended that the simulation of moisture content, relative humidity and temperature profiles under full load should be undertaken. A comparative evaluation of the silo performance with those of other materials of silos construction should also be undertaken.