be seen, consistent DPI values are obtained for different food products (potato, banana and wheat) irrespective of dryer design tested, indicating more or less independent nature on food product characteristics. However, for same food product, the mixed mode dryer exhibits higher DPI values as compared to that of cabinet dryer. The reason for such trend may be attributed to better effectiveness of mixed-mode dryer because of its improved design charac- teristics. It can be noticed from Tables 2 and 3 that DPI for outdoor test condition is found to be marginally higher to the extent of 1.8% than that of indoor tests. Thus, the close consistency in DPI results for different operating con- ditions and food product characteristics implies that the proposed parameter can be used as the performance index for evaluation of dryer system on equitable basis.
5.3. Assessment of prediction capability of proposed correlation for DPI
Prediction capability of the proposed correlation repre- sented by Eq. (4) is tested to check its accuracy on the basis
XN XN!XN!
Table 3
Comparison of DPI values of different dryer designs for variety of food products in real climatic conditions.
r1⁄4
i1⁄41
ð/exp;i