DEVELOPMENT AND MANUFACTURE OF LOCAL PADDLE MIXER FOR RABBITS FORAGE PREPARATION

A paddle mixer was designed. fabricated and tested to improve the mixing homogeneity In premix feed processing. it operates at low speed and has large impellers. which sweep the whole vessel to mix high viscosity material in laminar flow. The fabricated mixer was evaluated and tested among the studying effects of some engineering and operating parameters on the mixing homogeneity and energy requirement. These parameters include the batch volume ratio (0.5. 0.75 and 1.0). mixing time (5. 10. 15. and 20 min.), impeller peripheral speed (0.36, 1.73, 2.6. and 3.47 m/s), blade setting angle (15, 30 and 45 degree) and batch moisture content (16.06 %, 20.12 %. and 24.03 ‘36). The results indicated that increasing the time 15 min more had a negative effect on the process. causing component segregation. And an increase in energy requirement. Peripheral speed of the mixer should be 0.86-1.73 W3. To prepare the best mixture conditions, it is recommended to keep the blade resting angle on mixing shaft in the range from 15' to 309. To achieve an adequate mixing homogeneity, vessel mixer must have a batch volume ratio (Vb/V...) as close to 0.75 as possible. A moisture content of 16.06 % gave the best mixing homogeneity. The mixing time has not to exceed 15 minutes. blade setting angle in the range from 15ii to 309 and mixing speed should be equal 1.73 mfs, to avoid extra cost in energy consumption. The developed model that can be used for predicting mixing homogeneity is expressed as follows: cv = 45.08 imam)“ (vb/v.17“2 (Bill-““3 (millet-“5 Based on the experimental results. the best mixing homogeneity (CV: 1.2 %) with the lowest energy requirement (2.11 ktton) could be obtained with impeller speed of 1.73 mfsec, mixing time 15 min., blade setting angle 30 degree. Batch volume ratio 0.75 and batch moisture content of 16.06%.