Development and performance evaluation of a motorized tumble barrel feed/food mixer

Abstract

A tumble barrel food /feed mixer was designed and fabricated. It has a volumetric capacity of 0.33 m3 . The tumble barrel mixer consists of a hopper, a stainless steel barrel with baffles. It is mounted on a steel framework and driven by a shaft connected to stirrers inside the baffles. The baffles are alternatively placed in the barrel in such a way that they do not touch the stirrers during operation. The shaft is driven by a 3HP (2,25 kW) variable speed electric motor. Performance tests were conducted on the machine after fabrication using the ASAE (R2006) test standards, and also Completely Randomized Design (CRD). Three speeds of the mixer, 100,150 and 200 rpm (min-1 ) ( and four mixing times of 5,10,15 and 20 minutes were studied as they affected the Degree of Mixing (DM) of ground and shelled corn samples in the mixer. Results obtained showed, there was an increase in the degree of mixing as the speed of the machine increased from 100 to 200 rpm (min-1 ). Also the degree of mixing increased as the time of mixing increased from 5mins to 20 minutes for the three speeds studied. From the Analysis of variance tables, the calculated F-values were very much higher than the tabulated values at 5% probability. These indicate a high significance of the effect of speeds of mixing on the degree of mixing of the tumble barrel mixer. The speed of 150 rpm (min-1 ) gave the highest effect in the tumble mixer. From the difference of means tables, there were significant differences in the degree of mixing for 100 and 150 rpm (min-1 ) speeds for all the different time of mixing durations. However, in the 200 rpm (min-1 ) speed, there was no significant difference in the DM between the 15 to 20 minutes mixing time duration.