Search

Results:

Vol. 28 (2025 year), No. 2, DOI: 10.21443/1560-9278-2025-28-2

Kharkov V. V., Lavrova K. Z.
Численное исследование процесса распылительной сушки молока

Spray drying is one of the most common and energy-consuming technological operations used to obtain dry products. Dry skim milk is used in the production of baby and dietary food, in the confectionery industry, etc. The short residence time of droplets in the spray dryer and the drying mechanism allow the use of high-temperature heating gas without negative consequences for the quality of dry milk. Based on the consideration of existing models for predicting the kinetics of drying droplets in a sprayed state for thermal dehydration of skim milk, a mechanistic model has been adopted that includes the following successive stages: heating, quasi-equilibrium evaporation, formation of a dry crust, drying of a porous particle. Numerical modeling is an effective tool for modernization and design of spray drying units, as it reduces the need for expensive and complex measurements of the parameters of the continuous and dispersed phases during the drying process. The aim of the work is a numerical study of the process of spray drying of skim milk droplets according to the proposed drying model, taking into account the retreat of the evaporation front formed between the wet core and the crust of the dried particle. Based on the numerical calculation, time dependences for the change in the mass and temperature of the droplet at different temperatures of the heating gas have been constructed. Comparison of the results of the numerical calculation of the drying of the droplets with the available experimental data has shown their satisfactory agreement: the relative error of the droplet mass values at heating gas temperatures of 323 and 363 K during the drying process has averaged 10.7 %, and the absolute error of the averaged droplet temperature values is no more than 5 K. The results of modeling for the distribution of temperature and moisture content inside a single drop of skim milk during the period of decreasing drying rate have been presented.

(in Russian, стр.10, fig. 5, tables. 1, ref 25, AdobePDF, AdobePDF 0 Kb)