Разработка и исследование технологии получения порошков сельхозпродуктов с помощью солнечной энергии

Анотація

UDC  662.997.534

DEVELOPMENT AND RESEARCH TECNOLOGY FOR POWDERING AGRYCULTURAL PRODUCTS BY SOLAR ENERGY

A. Ismanzhanov,

Kyrgyz-UzbekUniversity

N. Tashiev

Osh Technological University, Osh, Kyrgyzstan

In this article were given the results of research on technology development and installations for receiving agricultural powders with the help of solar energy.

According to developed technology, at first products are cleaning, big (water melon, melon, pumpkin and others) cutting into small pieces, washing, then chopping by mechanical crushing machine till past like condition, lays on trays with thickness 6-8 mm. Trays put into drying chamber of solar drying installation radiation-convection type and dries till low (5-8%) remaining humidity. At the last stage dried product hopped till powder condition in mechanic crushing machine.

How experiments show, product drying in past like condition happens more quickly, then whole or divided into big pieces products. This explains that’s hort length broken capillaries and coming out the water from them and situation it between small particles of past like product. Practically, moisture evaporation from such product till the end of the drying process going on from free surface of the water. 

Products, containing much sugar (apricot, cherry, melon and others) even loose a great amount of moisture, as yet leaves soft: they keep 12-15 % moisture, which is not allowed to chop them into powder. Even in further drying such products in ССУ remaining moisture substantially is not reducing. In this case for their drying is additionally necessary, for example, drying by vacuum-sublimation method.

How our experiments showed, thickness of product about 6-8 mmis optimal from the point of view of moisture evaporation with such mass of products during one day light hours in solar radiation density, observing in the summer period in conditions of the Central Asia. As the whole duration of products’ drying put together 5-7 hours.

In big thicknesses of products, they cannot dry enough till minimum low remaining humidity and stay soft, which does not let to change them into a powder.

In more low density meanings of solar radiation one must reduce the thickness of drying product.

It should be noted that in past like products’ drying consist of one stage and is not observed existing place in drying usual agricultural products in two stage drying process.

Experiments, conducted with 16 kinds of fruit and melon products: cherry, apricot (two sorts), peach, plum, apple, pear, quince, strawberry, raspberry, water melon, melon, pumpkin, tomatoes, carrot and others showed that:

- developed technology and solar drying installation let to receive agricultural products’ powders with the help of solar energy.

         - in the high density of solar radiation (700 W/m² and more) agricultural products recommended to dry by radiation–converting method. Preferable contact-convective drying method in low density of solar radiation.

- technological scheme of agricultural products’ drying depends from sugar content in them: for sugary products need additional final drying of products vacuum- evaporation method.

- skinny products (grape, plum, cherry and others) drying slowly, that brings the moisture evaporation difficulty from skinny layers.

- less sugary and fibrous products: quince, pear, carrot and others have quick high speed of drying, then usual chopped products. In their chopping and putting on trays between fibers remain spaces that lead to more intensive evaporation of moisture.

         Solar energy usage for drying and receiving agricultural products’ powders let not only to reduce the usage scales of organic fuel and let substantially reduce the emission of СО₂ into atmosphere.