The Food Drying Equipment and Methods
Friday, June 4th, 2010
The Food Drying Equipment and Methods
A rotary food drying equipment is used in the preferred embodiment of this drying equipment for drying the food granules. In some cases, for certain types of food granules, a vacuum freeze dryer may also be used. In the drying of rice, for example, a rotary dryer and a bed dryer typically are used. Further, in making a highly dehydrated rice such as a quick rehydrating variety of rice, a vertical dryer also is used to reduce the moisture content of the rice to a low level.
Of course there are numerous methods of transporting the food granules from the steam cooker to the rotary drying apparatus, and transport by using a water slurry is only one method. For example, a dry transport method could use a combination of rice/air transport by blowing the rice through a conduit, or rice could be transferred on a conveyor belt, if sufficient apparatus (such a breakers) are employed to prevent lumping of the food granules.
The food granules are provided to the body of the grain dryer where they are dried as they proceed into the various heat zones of the dryer. The heat zones that may be seen in FIG. 14 are the first heat zone 268, the second heat zone 270, the third heat zone 272, and the fourth heat zone 274. The heat zones may be regulated to various temperatures for various types of drying, depending upon the food particle to be dried and the temperature of each zone may be regulated to achieve the maximum drying effect for the minimum amount of energy consumption of the spray dryer.
Four separate burners 222 are provided, one to each heat zone, and blower fans 56 recirculate heated air from the main drying chamber through the baffle plate 234 into the rotating barrel, and then into the recirculation duct 232 and then eventually back into the food drying equipment. As cooked food granules 238 proceed through the body of the dryer, their moisture content is reduced. Exhaust fan 216 is provided at the upper end of the rotary dryer to provide a positive air current flow along the path of the food particles being dried. Dried food granules 218 emerge from the distal end of the rotary dryer.
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