It is recommended to change between two tanks ever 4 hours of operation of feed tanks. Due to high temperatures of 45-50ºC, there is a risk of bateria growth in the feed tanks. While one of the feed tanks is in operation, the other is being washed. The size of each tank should correspond to 15-30 min. of the capacity of the dryer. The feed tanks are equipped with level indicators and spray nozzles for automatic Cleaning In Place. Sometimes, the feed tanks are replaced by vacuum tanks as an integrated part of the last calandria of the evaporator.