Discussion on the Application of Microwave Drying Technology in Ceramic Technology

The microwave drying equipment irradiates the green body with microwaves. The direction and size of the electromagnetic field are periodically changed with time so that the polar water molecules in the body change with the alternating high-frequency electric field, causing the molecules to make violent rotation, and the friction is converted into heat energy. , To achieve the overall uniform temperature rise to achieve the purpose of drying. Microwave penetration is much greater than far infrared, and the smaller the frequency, the greater the half-power depth of the microwave.

Microwave drying technology is needed in some special industries. First of all, we analyze the principle of microwave generation and the characteristics of using microwave drying technology.

What is a microwave?
Microwave refers to the electromagnetic wave between the high frequency and the far infrared, the wavelength is O.001-1m, and the frequency is 300-300000MHz.

Microwave drying features:
a. With the microwave heating chamber itself does not absorb heat, does not absorb microwaves, all the emission acting on the blank, thermal efficiency.
Microwave heating equipment is mainly composed of several parts such as DC power supply, microwave tube, connecting waveguide, heater and cooling system. Microwave heater can be divided into standing wave field resonant heater and traveling wave field waveguide in the form of heating object and microwave field. Heaters, radiant heaters, slow wave heaters and other major categories. With high thermal efficiency and responsiveness, the heat directly comes from the inside of the dry material, and the heat loss in the surrounding medium is minimal.
b. At the same time as the microwave heating is carried out at the same time, the internal moisture can be quickly heated and evaporated directly, so that the ceramic body can be heated and demoulded in a short time. With selectivity, microwave heating is related to the nature of the substance. In a microwave field with a certain frequency, water has a larger dielectric loss than other materials. Therefore, moisture absorbs much more heat than other dry materials.
c. Regardless of how complex the shape of the body, the heating is even and rapid, which makes the body dehydrated quickly, stripping uniformity, deformation is small, easy to produce cracks. Evenly and quickly, this is the main characteristic of microwave drying. Since the microwave has a large penetrating power, it can directly generate heat inside the medium when heated.

The drying of ceramics is one of the very important processes in the production process of ceramics, and a large part of the quality defects of ceramic products are caused by improper drying. The drying of the ceramic industry has experienced natural drying, room drying, and now a variety of heat source continuous dryers, far-infrared dryers, solar dryers and microwave drying technology. Although drying is a relatively simple technology and widely used industrial process, it not only affects the quality and yield of ceramic products, but also affects the overall energy consumption of ceramic companies. According to statistics, the energy consumption during the drying process accounts for 15% of the total industrial fuel consumption. In the ceramic industry, the energy consumption for drying accounts for far more than the total fuel consumption. Therefore, the energy saving of the drying process is related to the enterprise. Energy-saving events. The rapid drying, energy saving, high quality, and pollution-free ceramics are the basic requirements for drying technology in the new century.

Because of the use of microwave drying can improve the quality of ceramic drying, and energy saving, high quality, no pollution.