Improvement of IR emitter to create non-reflector dryer for plant raw materials

Abstract

The object of research is an improved flexible film resistive electric heater of emitting type (FFREHET) for creating a non-reflector IR dryer and vegetable raw material on the example of Antonovka apples. It is proposed to improve the FFREHET by spraying a resistive element based on current-conducting nichrome paste on a flexible electrical insulating film with additional coating on top and bottom by layers of a flexible electrical insulating film. Also, FFREHET is provided with drainages for connection to the power grid. The spectral-optical properties of the Antonovka apple are determined, namely the acceptable IR regions of its absorbing capacity (2.5...3, 6, 9 and 12...15 μm). This confirms the effectiveness of using FFREHET during the drying of plant raw materials. It is confirmed the low inertia of the FFREHET at a temperature of 60 ºC with the heating duration τ^/ = 87 s, which simultaneously corresponds to the constant uniform temperature of the working surface and is characterized by a clear dynamics of operation. Non-reflector VC IR dryer with a vibrating mechanism and a heat exchanger is developed. Improved FFREHET follows the geometric shape of the working chamber of the device, ensuring a reduction in the geometric dimensions and simplicity of device design. According to experimentally obtained kinetics of moisture content for Antonovka apples, the shortest duration of heat treatment is 160 s^-1 with conservation of BAS and natural color.