A sieve on which food is spread hung above the stove is a simple drying device and one of the most practical for home use. The heat currents rising from the stove pass thru this and dry the food.
Many dryers are constructed on this same principle, having a heating unit below and trays of food above. These trays have to be shifted from time to time, as the moisture from the lower ones rises with the heat to the upper trays, thus retarding their drying. The top trays, if too numerous, are useless on this account. Two or three seem to be all that can be used with advantage at one time in home dryers, the some machines are made with many more.
Another type of dryer has a fan device in it which forces the air thru at a faster rate than would be accomplished by heat alone. Such air should pass thru a strainer. Ordinary air, even when drawn from a clean room, carries much dust with it, and if the dust is not strained out previously, it is strained out by the food. This injures the quality of the product. Large commercial dryers provide such a strainer.
221. Care of Dryers. Dryers should be kept clean. They should not be heated enough to cook the food. Set them in a dry, airy place.
CHAPTER XXXI
Separators and Emulsifiers
222. Cream Separators. A cream separator is a device for separating cream from milk. Separation can be done best while the milk is still warm (Fig. 124).