Evaluation and Verification of Small-scale Portable Biomass Bread Baking Oven

Bread baking was the most energy-intensive activity in Ethiopia and preparation of bread was rather a long process relative to other Ethiopian food. This study presented the evaluation and verification of small-scale portable biomass bread bread-baking oven parameters of an indigenous wood-fired bread-baking oven for small-scale farmers, householders, and small-scale entrepreneurs, pre-urban and urban populations with an electrification shortage. It was an insulated rectangular box-like chamber made of mild and stainless steel sheet metal with a total dimension of 1350mm*1030mm*845mm. The oven characteristics were evaluated in terms of the baking capacity, baking efficiency, and weight loss of the baked bread. This oven comprises two baking compartments within one chamber and two combustion chambers. Each compartment bread carrying capacity for small, medium, and large bread trays with bread dough weights of 100 g, 500 g, and 2000 g of bread was 80, 16, and 4 pieces of bread. When fully loaded it has the carrying capacity of 160 pieces of loaf bread per batch of operation at two compartments baking capacity and efficiency of 96.6% and 86.9%, respectively, and a weight loss of 12.6% on average. The machine's baking time was observed at 100 g, lying between 10-15 minutes, and with a single biomass fuel feed of 5kg by 5kg for each fire chamber, the machine's performance was very effective.