In the work, the specified features of the temperature regime in the drying chamber showed that when the coolant moves in the chamber, both the temperature and humidity regime of the air and the temperature and drying rate of the product change, and the drying rate is almost proportional to the increase in air humidity. Based on the studies carried out, simplifications were obtained in describing the drying process, which makes it possible to more reasonably carry out engineering calculations in the design of the dryer, in particular, to set the input and output air humidity, to determine the length (or height) of the drying chamber.