Microwave power drying

P., 2007. Microwave convective drying of plant foods at constant and variable microwave power. Drying Technol. 25 1149-1153. 

Venkatachalapathy, K. and Raghavan, G.S.V. 1998. Microwave drying of osmotically dehydrated blueberries. J. Microwave Power Electromagn. Energy 33, 95-102. 

Figure 1 shows that there is an increase in drying rate because of the microwave power density. 

The silicon carbide-based ceramic layer is obtained by CVD activated by a microwave plasma (2.45 GHz) on the tantalum previously cleaned by an argon plasma (56 min, 133 Pa, 250 W) at a temperature identical to the deposition temperature (T = 570°C), lower than the substrate annealing temperature. After readjustment of the total pressure and microwave power by introduction of a precursor (TMS) in the argon flow, the SiC coating is produced under selected conditions (66 Pa, TMS/Ar = 0.2/5.5 l.h-, T = 570°C, 350 W) derived from a previous parametric study. Coatings obtained then presented low dry friction coefficients. The mechanical properties, which are essential in order to be able to appreciate the mechanical stability, were acquired by several methods ... 

The influence of microwave power input and inlet temperature on microwave fluid-bed drying. (From... 

The limitations on heat transfer rates in conventionally conducted freeze drying operations have led early to the attempt to provide internal heat generation with the use of microwave power [21,22]. Theoretically, the use of microwaves should result in a very accelerated rate of drying because the heat transfer does not require internal temperature gradients and the temperature of ice could be maintained close to the maximum permissible temperature for the frozen layer without the need for excessive surface temperatures. 

As seen in Figure 62.7, increase of microwave power significantly reduces the drying time and thus also the energy consumption. The main barrier in limiting the application of microwave drying is the capacity limitation and the high cost of the equipment. 

FIGURE 62.7 Drying curves by convective drying of kaolin clay samples enhanced with different microwave powers. 

Figure 7 Relationship between microwave forward power, microwave reflected power, and product temperature during microwave vacuum drying.

A microwave-assisted drying system is generally composed of a magnetron as microwave power source, a waveguide, a drying chamber, a material plate, a... 

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