There are various dryers on the market. The most common dryers are central dryers, compressed air dryers and honeycumb dryers. Central dryers are dryers where a drying unit is connected to one or more hoppers. The drying unit has two drying towers with drying material. The dryer starts with drying at a set dew point value, often a lot lower than -20°C, and then slowly rises to a set dew point often higher than -20°C. Because of this the dewpoint is not constant.
The honeycumb dryers work with a rotating disc that simultaneously regenerates, cools and absorbs moisture.
Because these processes occur simultaneously, a very constant dew point is created and regeneration can take place at a much lower temperature. The dryers therefore use much less energy. This type of dryer also has a drying unit per hopper so that contamination no longer occurs. These dryers are also easier to move because they only need electricity.
Besides the dryers with drying towers there are also compressed air dryers. These dryers have a very constant dew point and especially for small drying quantities these dryers are very suitable. The disadvantage of compressed air dryers however is that they need compressed air. When compressed air is not available, it costs a lot of energy and therefore money to create compressed air.