Abstract
Garlic (Allium Sativum L.) is a valuable root crop that can be utilized to season foods and is widely utilized in Ethiopia to treat many different kinds of diseases. The cloves are separated by hand for plantation and processing functions. This technique can be very exhausting and take a lot of time. To fill this gap, a garlic bulb-breaking machine was fabricated and tested with the clove variety grown in Holeta, Ethiopia. The major component of the machine is two rollers that revolve in opposing directions, and shearing the bulbs to separate the cloves. The performance test experiments were carried out in a full factorial design with feed rate as the first factor having three levels (3.7, 4.2, and 5.2 kg/min) and roller speed as a second factor with also three levels (276, 326, and 376 rpm). All tests were done at 66 % moisture content of garlic and 19 mm clearance between the breaking rollers. The interaction effect of the two factors shows an important difference (p < 0.05) in machine performance. The maximum breaking efficiency of (87.05 %) occurred at a feed rate (4.2 kg/min) and roller speed (326 rpm). Likewise, the maximum breaking capacity (306.98 kg/h) was recorded for the highest (5.2 kg/min) feed rate regardless of the 276 rpm roller speed. The minimum clumps of cloves (10.27 %) were obtained at combinations of 4.2 kg/min and 326 rpm. The lowest values of damaged cloves (1.79 %) and fuel consumption (5.61 ml/kg) were observed for the combination of the 3.7 kg/min with the 276.85 rpm whereas the maximum clove damage (2.29 %) was at the 5.2 kg/min feed rate combined with the maximum roller speeds (376 rpm). Therefore, the machine could be operated at the combination of 4.2 kg/min and 326 rpm for best performance in the majority of the parameters.