Justification of the effective distribution of energy emitted by a film electric heater on stacked lumber

Abstract

The research was carried out at the expense of the grant of the Russian Science Foundation No. 23-76-01090, https://rscf.ru/project/23-76-01090/. The article considers the issue of placing boards in a drying plant using infrared film electric heaters. Two options for placing one cubic meter of boards with a thickness of 25 mm and 50 mm are proposed for consideration. The boards are placed between shields with film electric heaters and are separated from each other by transverse gaskets, it is obvious that more gaskets are needed to accommodate boards with a thickness of 25, which means that the distance between the boards will be greater. Hence the hypothesis: an increase in the distance between the shields will lead to an increase in drying time and electrical energy costs. For a theoretical solution, the following is proposed – to present the piled stack in the form of a prism and, considering the known dimensional parameters of the skipped shield, according to a well-known formula, it is possible to obtain a dependence describing changes in the irradiation coefficient on the distance in the radiator-receiver system. The considered irradiance coefficient shows how much of the total radiation from the area of the “receiver” falls on the surface of the “receiver”. As a result, an exponential dependence is obtained, according to which it can be determined that the irradiation coefficient for the placement of boards with a thickness of 25 mm is 8% less than for boards with a thickness of 50 mm, which ultimately will affect the duration of the drying process and the cost of electrical energy. Options are proposed to increase the drying efficiency by increasing the irradiation coefficient by reducing the distance between the panels with film electric heaters. In conclusion, in view of the result described in this article, the main directions for further research on improving the “radiator-receiver” system in relation to drying plants based on film electric heaters are given.