Підвищення ефективності сушіння детриту з використанням енергії сонця

Abstract

In Ukraine, there is a problem of sewage sludge disposal. The volume of sediment is growing every year, and the existing silt sites of water supply systems are not able to accept their entire volume. At the same time, experts say that sludge in sewage treatment plants is not a problem, but an asset that can help farmers grow environmentally friendly products, because these fertilizers will have a number of advantages over chemicals: they can be cheaper, more useful and more efficient. At the same time, the processing of the so-called detritus (wet mixture of mineral and partially decomposed biological components) is complicated by the high initial humidity of the product. And according to the results of previous studies, if the humidity of the raw material is in the range of 45… 80 %, processing technologies can become economically feasible only if the intensification of its drying processes - as the most energy-intensive of technological processes. The aim of the work is to study the possibility of using renewable energy sources, in particular solar energy, to reduce energy consumption during pre-drying of wet material - one of the most important processes in the manufacture of granular fertilizers from waste treatment plants. A polycarbonate-coated greenhouse was used for sludge drying. The elongated side of the greenhouse is located in the east-west direction and has an angle of inclination to the horizon of 30°. The northern side of the roof covering is opaque and insulated. On the inside, it has a light-reflecting coating that directs rays at the material. The experiments were carried out in summer without additional heat, except for the heat of the sun. The experiments changed: weather conditions, the thickness of the material layer, the amount of mixing, the initial humidity of the material. Main results: Identified factors: - which lead to the most noticeable changes in the specific productivity of the laboratory dryer: ambient temperature, clarity-cloudiness; relative humidity in the environment, the amount of stirring, floor heating; - which do not lead to a significant impact: the thickness of the material layer, the initial humidity of the material. Key words: biomineral fertilizers, detritus, solar dryer