Experimental Evaluation of Drying Characteristics of Animal’s Hide and Skin with Different Drying Media
Joseph Amechi Ujam
Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria
Johnpaul Nkemjika Onovoh
Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria
Christian Emeka Okafor *
Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria
*Author to whom correspondence should be addressed.
Abstract
Experimental Evaluation of Drying Characteristics of Animal’s Hide and Skin with Different Drying Media
Aims: The design and development of low-cost drying technologies suitable for animal hides and skins in rural areas require a clear knowledge of its characteristics. Therefore, the aim of this study is to carry out the experimental evaluation of drying characteristics of animal’s hide and skin with different drying media.
Study Design: Experimental Study Design was used in the study.
Place and Duration of Study: The study was conducted in the Faculty of Engineering workshop, Nnamdi Azikiwe University, Awka, Nigeria from June 2016 and July 2017.
Methodology: Samples of cattle hides, donkey hides and sheepskins were used. The hides and skins were thoroughly washed to ward off blood and dirt. Different drying techniques employed include solar drying, oven drying, open sun drying and hot air conventional drying. The effect of drying air speed and temperature on the drying of cattle hides, sheepskin and donkey hide was also investigated under varying conditions. Classical equations were utilized in calculating Water Activity, Mold-Freed Shelf Life (MFSL), Effective Moisture Diffusivity Deff, Shrinkage Ratio (SR) and Moisture Ratio (MR).
Results: Computation of mold-free shelf life (MFSL) showed 1790 days for the dried products. The result revealed that the effective moisture diffusivity of Donkey hide is generally greater than that of Sheepskin and Cattle hide. The moisture diffusion constant ranged from 1.1213 x 10-8 m2/s to 2.2797 x 10-8 m2/s, 1.0128 x 10-8 m2/s to 1.5046 x 10-8 m2/s and 1.34815 x 10-8 m2/s to 1.7326 x 10-8 m2/s for Solar Dried Donkey Hide (SDDH), Solar Dried Sheep Skin (SDSS) and Solar Dried Cattle Hide (SDCH) respectively as the air speed increased from 2.0 to 4.0 m2/s.
Conclusion: The drying of Cattle hide, Sheepskin and Donkey hide occur mainly in the falling rate period. The drying time decreased with air-speed and temperature. The water activity-dependent of the moisture content and its value affects the estimated mold-free shelf life. The effective moisture diffusivity increased with the air speed and temperature.
Keywords: Solar drying, oven drying, open sun drying, hot air conventional drying, water activity, Mold Free Shelf Life and shrinkage ratio