Performance of the machine was carried out using paddy rice; it was tested as a pre-cleaner for its ability to separate whole paddy, small grains, glumes, chaff, stalks and tiny stones from grain impurity mixture fed into the machine. Mixtures of known weights of paddy rice (whole grains) and undesirable materials like glumes and straws / stalks were fed into the machine. All the machine parameters such as fan speed, sieves, and sieve slope, eccentricity and tilt angle were set at the appropriate position prior to running the cereal cleaner. The machine was operated until the whole admixture was separated. Four collection points were used namely:
(i) Air passage away from the machine for light chaff, glumes and stalks
(ii) Sieve end near to the fan, for heavy materials (over tailings)
(iii) Receptacle for undersized and broken grains
(iv) Receptacle for whole clean grains
All the materials collected from the collection points except for the whole paddy receptacle are regarded as reject while that of whole paddy is considered as the product.
I. Test results
For purposes of this test the following terms and nomenclature were adopted for the separation efficiency using reference [6] method for separation processes as shown in Figure 2.