Микроволновый метод отверждения труб из полимерных композиционных материалов
The results of microwave influence aimed at the temperature rise in local area in multilayered biological tissues are given. the experimental results of temperature distribution in multilayered biological tissue are presented at the electromagnetic field frequency of 2450MHz. The model and analytic calculations for the temperature distribution inside the biological tissue are presented. The calculation results for the temperature distribution in multilayered biological tissues are given.
Methods for decreasing spurious radiation for microwave devices intended for thermal treatment of sheet materials are considered. Microwave installation is created on the basis of sections slow –wave structure with variable parameter. To reduce spurious emissions to slow the system of microwave devices were placed in special screen mesh. It is shown that spurious radiation from microwave device is less than maximum permissible limit.
Theoretical and experimental results of heat curing of concrete using ultra-high frequency electromagnetic energy as a source of heat are presented. The advantages of microwave method of heat curing of concrete are compared with traditional methods. The results of studies on the accelerated curing of concrete slabs in a beam-type microwave setup are presented.
A beam-type microwave setupwas developed to accelerate the curing the concrete slab, with the size of 200 mm x 2000 mm x 3000 mm, weight 2760 kg at the temperature of +70°C and the electromagnetic field frequency oscillations of 2450 MHz, and power output of 38.4 kW. A setup allows to reduce the energy consumption for the technological process of the heat treatment of concrete products, increase productivity and improve working conditions for the staff. Basic expressions for the temperature distribution calculation along the thickness and the surface ofconcrete slabs are presented. The time of heating a slabto the temperature of +70°C, 2760 kg of weight, was 50 minutes. The deviation from the nominal value of the temperature of the concrete slab across the area doesn't exceed 2°C, and across the thickness of the plate does not exceed 5°C. As a result, the research shows the prospects of using microwave radiation for the production processes associated with accelerated hardening of the concrete. Currently work is underway to improve the strength characteristics of concrete due to uniform heating of the concrete, which contributes to the absence of internal stresses and other defects in the structure. The results of accelerating curing of the concrete slabs with the use of microwave radiation as a source of heat were obtained, that allows to refuse the use of expensive foreign additives for accelerated hardening of concrete, which lead to degradation of strength characteristics due to the increase of acidity.