Tag Archives: drying coefficient

5-13 A. Aboltins and J. Palabinskis
Fruit Drying Process Investigation in Infrared Film Dryer
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Fruit Drying Process Investigation in Infrared Film Dryer

A. Aboltins* and J. Palabinskis

Latvia University of Agriculture, Institute of Agricultural Machinery, Cakstes blvd. 5, Jelgava, LV – 3001, Latvia:
*Correspondence: aivars.aboltins@inbox.lv

Abstract:

The work analyzes three different product (apple slices, banana slices and grape halves) drying process in the infrared film dryer. Such drying takes place at low temperatures (to 40 °C), allowing to keep the maximum value of fresh products. The drying process is analyzed in detail in the first 8 hours. The quantity of water runoff, drying product temperature changes and flowing air humidity changes during drying were analyzed. It demonstrates the impact of the product placement on the drying progress. Using the experimental data, average diffusion coefficients are obtained for each product group. The results showed that diffusion coefficients were changing during the drying process. Using mathematical modelling and experimental data, the concentration-dependent diffusion coefficient for apple slices was obtained. The study finds that apple and banana drying using the infrared film is comparatively successful, but the drying process of the half of grape berry is slower. This can be explained by the impact of grape peel on the water diffusion.

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215-222 A. Aboltins, and P. Kic
Forced convection in drying of poultry manure
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Forced convection in drying of poultry manure

A. Aboltins¹,* and P. Kic²

¹Latvia University of Agriculture, Institute of Agricultural Machinery, Cakstes blvd. 5, Jelgava, LV–3001, Latvia; *Correspondence: aivars.aboltins@inbox.lv
²Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 165 21, Prague 6, Czech Republic

Abstract:

Pollution of environment by animal waste can be problem of intensive animal production in many countries with high density of animal farms. The aim of this paper is to inform about the experimental and theoretical investigations of moisture content reduction from poultry manure by forced convection. The experimental data created the background for calculation and modelling, which resulted in definition of the theoretical drying coefficient, useful for description and modelling of the drying process. The theoretical model has been verified and compared with experimental results obtained from the measurement. The laboratory equipment was used for test the forced convective drying of poultry manure due to vertical air streams going from bottom through supporting trays with holes and therefore through the manure up. Changed opened area of trays with different density has been used for definition of main parameters, which can serve especially in designing and construction of the new equipment for housing of poultry or improvement of the use of drying tunnel or in similar applications. The experimental data show that the air flow significantly increase the amount of moisture carried away from the material. Holes´ size does not significantly affect water runoff by convection without additional air flow.

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