Investigating The Performance Improvement Of An Electric Injera Baking Mitad Using Copper Powder As Additive Material

Abstract

In this research work, the improvement of an electric Injera baking Mitad using copper powder as additive material was experimentally studied. The improvement required due to the inaccuracies in the manufacturing of the conventional electric Injera baking Mitad. These inaccuracies leads for requirement range of 1.23−1.41 kWh energy for initial heating with uneven temperature distribution on the baking surface. The objective of the study was reducing the time required for initial heating, maintaining uniform temperature distribution on the baking surface and enhancing the thermal efficiency. Using standard sampling and guidelines four different samples with different ratios of the clay soil and copper powder the composite material was developed, and experimentally studied. The experimental result shows that the composite material property is improved due to the additive material and it fulfills the objective with the composition of 20% copper powder and 80% clay soil. Using similar composition ratio with the selected sample, the electric Injera baking Mitad is constructed and experimentally studied for initial heating time, uniform heat distribution and energy consumption. Initial heating time and baking surface temperature profile of the baking Mitad are studied and the time it takes to reach the baking temperature is 11 minutes with 200 ℃ baking surface temperature at heating rate of 15.6 ℃/min. The experimental results of an improved baking Mitad is compared with that of conventional baking Mitad available in the market. The comparison shows it reduces the initial heating time for more than 10 minutes. Then, the uniformity of the baking surface temperature is studied after recording the temperature at the center, 13 cm and 26 cm away from the center of baking surface. The result shows the variation of temperature for improved electric Injera baking machine on the baking surface during the baking process is uniformly distributed. Finally, the energy consumption analyses is performed for both improved and conventional baking Mitads for 13 Injera baking per cycle. The gross energy consumed is 2.13 and 3.54 kWh respectively for improved and conventional baking Mitads with maximum losses through bottom surface. The average thermal efficiencies of improved and conventional electric baking Mitad are 87.51% and 52.91%, respectively.