drying

Among the large number of modern environmental problems in Ukraine, waste of wastewater treatment stations occupies a special place. During biological water treatment, the separated sludge deposits are sent to the silt fields, which are the biggest problem. Today, these fields reached their capacity three times over and pose a danger, the consequences of which go far beyond environmental problems and have grown into a chain of socio-economic, technical, medical-biological and moral-ethical problems.

The kinetics of the process of drying hot (80°C) and cold (20°C) candied pears were studied. The drying coefficient is found and an analytical dependence is derived for the drying time calculation. Experimental data of the change in the temperature of the thermal agent along with the height of the candied fruit layer was obtained.

Equilibrium moisture of combined vegetable powders obtained from vegetable raw materials is one of the main technological properties and it is important. Because the final moisture content and energy costs for the dehydration process depend on this indicator. To determine the equilibrium humidity of the samples of combined powders, depending on the relative humidity, the tensometric (static) method of Van Bamelen was used. As a result of researches, kinetic curves of adsorption of water vapor of mono- and combined vegetable powders, which were compared among themselves, were received.

An energy-saving scheme for the production of candied carrots has been developed. The developed scheme includes: washing of raw materials with 1% NaHCO3 solution, reduction of water consumption for blanching, reduction of syrup consumption for saturation of raw materials with sugar. A new drying technology is introduced: candied fruits are dried in a variable temperature mode, namely: in the initial stages with a heat agent at a temperature of 70 0C, at the final stage - with a heat agent at a temperature of 20 0C.

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process.

Heat-mass exchange processes during regenerated activated carbon drying was studied to determine the minimum height of heat-mass exchange zone and termination time of hot heating agent supply based on criterion equations and heat balance calculations. The heating agent temperature changes with time and the adsorbent bed height, as well as the time of moisture content change and drying rate were studied experimentally. Minimum height of a wet material layer ensuring rational use of the heating agent was determined.

The article develops a mathematical model of non-isothermal moisture transfer and viscoelastic deformation of wood during drying, which takes into account the anisotropy and variability of heat-mechanic characteristics. By finite element method was formulated by the implementation of mathematical models for viscoelasticity with regard to the accumulation of irreversible deformation. By object-oriented analysis is designed and implemented software implementation model in the form of documented classes.

In this paper there are considered the basic methods of mathematical modeling that are used to describe the processes of convective, convective-thermal and active hydrodynamic drying of dispersed materials, taking into account the structure of individual object of drying.  They are described from perspective of continuum mechanics, the theory of mixtures, statistical approaches, which allows taking into account the volume fraction of each phase, the layering of the structure of the object and their changes in the process of phase transitions and chemical transformations.

This  article  is  devoted  to  solving  problems  of  disposal  and  use  of phosphogypsum.  Chosen  as  the  most  optimal  and  economically  feasible  method  of drying  phosphogypsum,  namely  filtration  drying  method.  Experimental  study  on drying kinetics of phosphogypsum.  
Вирішенно  проблеми  утилізації  та  використання  фосфогіпсу.  Обрано найоптимальніший  та  економічно  обґрунтований метод  сушіння фосфогіпсу,  а сааме: фільтраційний метод сушіння. Проведені експериментальні дослідження з кінетики сушіння фосфогіпсу. 

Досліджено зміни температурних режимів процесу сушіння у виробництві цукатів
з груш. Проведені експериментальні дослідження з теплообміну та кінетики сушіння
цукатів з груш за різної температури. Експериментально підтверджено доцільність
проведення процесу сушіння за температур цукатів, що дорівнюють температурі
гарячого теплового агенту. Згідно з тепловим балансом розраховано кількість енергії,
накопиченої шаром груші, та необхідної енергії для випарювання вологи. Встановлено,