Development and Performance Evaluation of a Dough Mixing Machine

Abstract

In view of the numerous problems encountered with the manual method of mixing, an electric motor gear driven dough mixing machine was designed and fabricated from available local materials using standard engineering principles.
A step turned shaft of diameters 16 mm and 32.5 mm was attached to a speed reducer gearbox which engaged a 1hp, single-phase electric motor to transmit torque required to effectively turn and mix the dough in the bowl.The performance evaluation was carried out, the average mixing time for dough of 3.964 kg was 7.67 minutes and the average mixing efficiency was 94.6% with a mixing capacity of 31 kg/hour operating at 280 rpm of the agitator shaft blade/arm.
The dough produced using the mixing machine was baked into bread and sensory evaluation was conducted and compared favourably with bread baked through hand mixing of dough at 0.05 level of significance.The results further showed that sample B was most accepted followed by sample A (control). Sample C received the least mean score. However, no significant mean difference among the bread attributes at the 0.05 level except for bread texture where samples A and D differ significantly.The cost of fabrication was ₦67,550.00 (147 dollars) and result of operating cost analysis on a per day basis indicated that the owner of the machine can pay back the capital investment in a period of 359 days (1 year) of continuous production.