Because conventional heating requires heating the heat transfer medium and the environment, and then entering the food, it takes a long time to reach the required heating temperature. Microwave heating is the heating object directly absorb microwave energy, heating speed is much higher than the conventional heating method, at this time only one tenth to one percent of the time to complete the whole heating and drying process.
Due to the short heating time and the non-thermal effect, the color, aroma and flavor of the processing raw materials can be preserved. And the vitamins are less damaged.
Conventional heating is the surface of food first heat, and then heat through the heat conduction, and microwave heating is to make the food surface and the internal heat at the same time so heating evenly, can avoid the general heating and drying process easy to cause the inside and outer coke and uneven phenomenon, improve the quality of the product.
When the frequency and electric field strength are certain, the material absorbs the microwave power during drying. Mainly depends on the value of the dielectric loss factors. The dielectric loss factors of different dry substances are different, such as water than industrial substances. Therefore, the absorption of more energy, water evaporation is fast. Therfore, microwave will not concentrate in the dry material part, avoid the overheating of the substance, has automatic balance performance, so as to ensure the original characteristics of the material.
With conventional heating method whether electric steam, hot air, etc., to reach a certain temperature needs to preheating for a period of time, when the failure or stop heating, the temperature drop needs a long time, and the use of microwave heating, boot a few minutes can be normal transport
Line. Adjust the microwave output power, the material heating situation immediately without inert change, so it is easy to automatic control.economize on manpower.
Because microwave heating and drying is the internal heating method, so the heating equipment itself can be said to do not radiate heat, so the heat loss is small, the thermal efficiency is higher, can reach about 80%, compared with the conventional method, can save 30%~50% electricity. At the same time, the volume of microwave heating equipment is also relatively small, compared with the ordinary heating and drying method, the required plant area is small.
Microwave equipment has no waste heat, no pollution, no radiation heat, so greatly improved the working conditions.