Abstract
In the drying of food is essential to know the time required to achieve the dry bulb temperature, with the goal of reducing energy consumption without affecting product quality. Appropriate estimate is required to determine in advance the heat transfer coefficient by forced convection between air and product. In this paper we developed a procedure for a drying system in the form of Gooseberry hemispherical and four helmets in a pilot dehydrator trays. The heating time was determined by measuring the moisture loss vs. drying time. Based on statistics reported by the company which conducted the research, significant variables were selected as follows: temperature 58 ° C, inlet velocity 3.55 m / s, presentation of two helmets and a temperature of 62 ° C , velocity of 5.85 m / s presentation at four feet, respectively. These values provided the combinations of different variables and it was concluded by a 23 factorial design as favorable conditions, the presentation in four hooves, a dry bulb temperature of 62°C and inlet velocity of 3.55 m / s.
With these results, the drying conditions scaled by a dimensionless analysis on industrial equipment, maintaining the temperature of 62 ° C and the presentation of four feet, giving a result for the air inlet velocity of 8m / s. The above conditions allow to reduce the drying process in 4 hours, with a final moisture content of 13.8% without significantly affecting the quality of the product.