drying

A technological production line for candied lemon slices was developed to maximize the preservation of vitamin C. A new drying method was introduced: the thermal agent is filtered through a wet layer of lemon slices at a temperature of 70°C. After a certain period, when the upper layers have reached their final moisture content, a thermal agent at a temperature of 18°C is supplied. The lower layers of the material are dried using the energy accumulated by the upper layers. This process reduces energy consumption by 4659 kJ/kg of moisture.

The main indicators of the filtration drying process of barley brewer’s spent grains for industrial drying, as well as the parameters of the necessary drying equipment, were calculated. To compare the effectiveness of the filtration method of drying barley brewer’s spent grain, the drying was calculated for a similar technical task in a rotary dryer. It was found that filtration drying can reduce the required drying time by more than 10 times while increasing the specific energy consumption for removing 1 kg of moisture by 16.8% compared to drying in the rotary dryer.

Static and dynamic characteristics of the drying process as an object of automation are experimentally determined in the work. It was established that the drying object can be represented as two linked "air" – "drying object" and has interconnected input and output parameters. A mathematical description of the static and dynamic characteristics of the drying process as an object of automatic regulation has been researched and carried out.

In this work, the calculation of specific energy consumption for the process of the barley brewer’s spent grain filtration drying was investigated.

The paper describes the study of the kinetics of filtration drying of barley brewer’s spent grain. The dependencies of the process at different parameters of the stationary layer and the heating agent are presented: different heights of the wet material H (40 mm, 80 mm, 120 mm, and 160 mm), different temperatures of the heating agent T (50 °C, 70 °C, 80 °C, and 90 °C), and the velocities of the heating agent through the stationary layer of material v0 (1.26 m/s, 1.55 m/s, 1.81 m/s, 2.31 m/s, and 2.82 m/s).

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.