Preliminary Researches on Some Technical-Functional Parameters of an Experimental Model of Convective Dryer With Total Energy Independence

Abstract

In order to be consumed whole year at a nutritional value close to the freshly picked product, seasonal vegetal products (vegetables, fruits, aromatic and medicinal plants, seeds, berries, mushrooms etc.) are preserved by artificial dehydration. Unlike other preservation methods and techniques, dehydration leads to obtaining products with a weight 8-10 times reduced and a volume 3-4 times smaller, a fact that contributes to the reduction of the spaces required for storage and the substantial reduction of handling and transport costs, compared to those for fresh vegetal products. Taking into account the general context related to global warming, as well as the need to reduce energy consumption from fossil fuels, the paper approaches the preliminary experimental research of a small capacity convective dryer, with total energy independence from the electricity network, intended for small agricultural producers from isolated hill and mountain areas. The technical equipment consists of a thermal generator operating on TLUD principle, which utilizes existing biomass at the local level, a high-efficiency air-air heat exchanger and a drying room with trays. The aim was to determine some important technical-functional parameters in the working process of the equipment, such as: the temperature of the burnt gases, the biomass loading capacity of the gasification reactor, the capacity to regulate the air flow required for the thermo-chemical processes, the temperature at various keypoints inside equipment etc. Following the analysis of the experimental data, there were highlighted quantitative values useful for estimating the inputs required for a normal operation of the equipment.