Estudo do desempenho de secadoras mecanicos e barcacas ventiladas, na secagem do café
In order to study quantitative as well as qualitative performance characteristics of different kinds of coffee drying equipment (two) sucessive trials were carried out. Installed volume capacity as well as fuel and power requerid to drive off one metric ton of water per hour were determined for several types of mechanical dryer and for forced draft stationary beds. The effect of different initial moisture levels on evaporation rates was studied, as was the effect of different stages of cherry maturity on the consumption of drying resources, and the effect of the rate of drying on final product quality. Work with stationary bed was limited to the third trial. A comparison between the mentioned effects as observed in mechanical dryers as observed in stationary beds, thus, was possible in the third trial only. The results obtained permit the following conclusions: 1) in mechanical dryers a uniformly dried product is difficult to obtain if the batches contain a wide spread of cherry maturity stages; 2) a higher final product quality is associated with slow drying processes than with fast ones; 3) a higher evaporation rate and a lower resource use per unit of water driven off are associated with higher initial moisture levels, in mechanical dryers as well as in stationary beds; 4) it is more expensive to dry green cherries than to dry ripe cherries of the same initial moisture level; 5) as the moisture level of the batch decreases the evaporation rate also decreases; 6) the furnaces described were more effective than the solar heaters described when used for air heating in conjunction with the draft stationary beds; 7) for reducing moisture between 55 percent and 30 percent forced draft stationary beds were found to be more efficient then mechanical dryers
| Main Authors: | , , , |
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| Format: | biblioteca |
| Published: |
Oct
|
| Subjects: | CAFE, SECADORAS, SECADO POR VENTILACION, |
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