mango slice industrial microwave dryer&sterilization machine

Specifications

mango slice industrial microwave dryer&sterilization machine

1 the principle
Microwave is at 300 MHZ ~ 300 GHZ frequency (wavelength LMM ~ 1 m) between the electromagnetic wave. On the industrial heating allows the use of two frequency: 915 MHZ and 915 MHZ. Microwave drying is the use of polarization effect happens at the molecular and atomic level. In under the action of alternating electromagnetic field, the polarity of molecules in a material from the original random distribution state, turned to aligned according to the polarity of the electric field orientation, due to the friction between the molecules in the extrusion effect, make the material quickly fever [". When exposed to the alternating magnetic field, the material can absorb microwave: type in the factory, the frequency of the electromagnetic field, E, a voltage d__ the distance between electrodes, 8 - material dielectric constant, tg 6 a loss tangent, P per unit volume of a material to absorb microwave power of Iu. 915 MHZ and 2450 MHZ electromagnetic waves can be water material or other loss "to" some material such as carbon and organic matter absorbed, converted to heat. Because microwave can penetrate into the material directly, is heated volume () from inside to outside, can make the products be rapid heating heating up. Water molecules can quickly absorb energy cause rapid moisture evaporation, water vapor quickly escape from inside to outside. In addition to improve the drying rate, the water to drain out of the can also help to prevent most of the organizational structure of the conventional air heating technology occur contraction phenomenon. So the product has better compound water characteristics of microwave drying

The characteristics of the microwave drying
Using the general advantages of microwave drying fruits and vegetables

(1) is more effective in the falling rate drying stages drying,

(2) energy spread rapidly in the material,

(3) easy to used in combination with other drying technology,

(4) according to the appropriate product features concentrated local heating,

(5) avoid overheating to prevent the surface temperature is too high,

(6.) Can make the bulk material, all landowners can reduce product temperature, combined with vacuum

processing was reduced water-soluble component shift, pet-name ruby to save energy use of the disadvantages of microwave drying fruits and vegetables is

(1) uneven heating problem. Product edge and corner temperature could lead to irreversible overheating. Consumers will feel the low product quality.

(2) the need to control the energy input to control the mass transfer, mass transfer too fast may cause food organization" fluffy ".

(3) initial investment is too large, affect the microwave can expand the application of research.

(4) operating big expensive magnetron need frequent replacement.

3 microwave drying fruits and vegetables is reviewed
Because the water has fast absorption dielectric properties of microwave energy, microwave drying is more suitable for drying high moisture content of products, such as carrots, mushrooms, cabbage. At present, has reported the application of microwave drying of fruit and vegetable varieties mainly include: apple, strawberry, soybeans, mushrooms, carrot, green vegetables, etc. Research focuses on microwave drying method and the influencing factors of microwave drying, microwave drying on the quality of the fruit and vegetable and the characteristics of microwave drying, etc. In order to shorten the drying time, improve the quality of end products, lower costs, microwave drying often with other drying methods (such as vacuum drying, hot air drying, freeze drying and penetration drying, etc.) used in combination.