STUDY OF THE MICROWAVE VACUUM DRYING PROCESS FOR A GRANULATED PRODUCT

The objectives of this work were to study and evaluate the process of drying a pharmaceutical granule from 21% to 3% (d.b.) moisture, also determining the power absorbed by the product, using a microwave assisted vacuum dryer with two absolute pressures: 50 and 75 mbar. A specific objective was to compare the drying kinetics of the microwave assisted vacuum process (MAVP) with two other drying processes, one using hot air convection and the other combining microwaves with hot air convection. The results of such a study showed that the drying kinetics were not affected by the vacuum levels, whereas the absorbed microwave power was higher for smaller vacuum levels. It was also observed that the samples obtained by the microwave assisted vacuum process, when submitted to compression, complied with the required specifications. The drying kinetics of the MAVP showed the shortest drying times when compared to the other drying processes.26231732

Evaluation of short cut pasta air dehydration assisted by microwaves as compared to the conventional drying process

Drying is one of the most important unit operations of the industrial production of pasta, both from the viewpoint of the final product quality and from the economical aspects of its manufacture. This work was aimed at evaluating the efficiency of air drying the type Penne short cut pasta with the assistance of microwave energy, from 23% to 12% (w.b.) product moisture, by using at first an adapted domestic microwave oven and later transferring the bench scale experimental parameters to test a continuous pilot scale microwave assisted hot air rotary dryer. The observed average drying time was reduced by more than ten times when compared to the air conventional drying, without being harmful to the appearance of the final product. An estimate of the economy of using a continuous hot air rotary dryer assisted by microwaves in industrial scale showed that this new option could be potentially competitive with the traditional short cut pasta drying process. (C) 2004 Elsevier Ltd. All rights reserved.68217518

The analysis of an alternative approach to the venting process in retorts operating under steam pressure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The operation named venting is a step in the sterilization process in retorts using steam pressure. It is intended to remove all air from the inside of the equipment by injecting steam. Although only for a short period of time, great quantities of steam are used, making venting an expensive operation. This study aimed to evaluate an alternative to the venting process with a reduction in steam energy expenditure. A system was adapted and instrumented, which allowed for the study of the phenomenon of venting using water for the air displacement. The alternative methodology proposed was shown to be promising and efficient for an empty retort with no load. The efficiency at this stage of the study was based on evaluating the differences in the temperature readings using a glass mercury thermometer and the temperatures recorded by thermocouples distributed within the retort. (C) 2011 Elsevier Ltd. All rights reserved.1093388398Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP