Drying of Matricaria recutita Flowers in Vibrofluidized Bed Dryer: Optimization of Drying Conditions Using Response Surface Methodology

Drying of Matricaria recutita flower was investigated experimentally in a VibroFluidized Bed Dryer (VFBD). The aim of the present work was to optimize the best operating conditions for the drying of Matricaria recutita flower in the VFBD based on experimental design techniques. Response Surface Methodology (RSM) and Central Composite Design (CCD) based on 4-variable with 5-level have been employed to achieve the desirable possible combinations of frequency of vibration (7-15 Hz), inlet air temperature (36-68 °C), air flow rate (16-24 m3/h), and drying time (30-70 min) for the highest responses in terms of moisture removal (MR) and thermal efficiency (). A full quadratic model was used to describe the effects of individual and interactive parameters on the responses. The analysis of the obtained results showed that the inlet air temperature has the largest effect on responses. The optimal process parameters were as follows: frequency of vibration of 10.88 Hz, inlet air temperature of 64.08 °C, air flow rate of 20.63 m3/h and drying time of 69.11 min in which the predicted value for the MR (%) and  (%) was 86.76 and 53.05, respectively. The proposed optimal conditions were examined in the laboratory and MR (%) and  (%) achieved as 87.12±0.25% and 52.78±0.34%, respectively. The experimental values agreed with those predicted by RSM models, thus indicating the suitability of the model employed and the success of RSM in optimizing the drying conditions.