CALCULATION OF A LOW-TEMPERATURE SPRAY DRYER FOR APPLE MARKS WITH A HEAT PUMP
The results of heat engineering calculations of an air low-temperature spray dryer for Apple pomace with a heat pump (HP) are presented. Comparative calculations of three schemes of operation of heat pump units (HPU) were performed. To assess the energy efficiency of the TN application in the dryer, a complete factor experiment of type 2<sup>2 </sup>was conducted and the dependence of the heat conversion coefficient (K) of the selected TN scheme on the boiling point ( t<sub>k</sub><sub>и</sub><sub>n</sub> ) and condensation ( t<sub>kon</sub> ) of the refrigerant was determined. A regression equation is obtained and the response surface K = K (t<sub>k</sub><sub>и</sub><sub>n</sub>; t<sub>kon</sub>) is constructed. The simplex method with a sufficient degree of accuracy justified the optimal thermal parameters of the refrigerant at K→max for HPU equipped with an intermediate heat exchanger and a supercooler. The conducted research will allow for the selected type of freon to assign the optimal thermal mode of joint operation of the specified dryer with the HPU and ensure the lowest heat costs for the operation of the considered dryer.