First, the drying process of handicrafts

The drying technology of ceramic crafts generally uses hot air drying technology, and the energy source is natural gas combustion, coal combustion and electric furnace, but the drying cycle is long and the capital turnover is slow, the uniformity is slightly poor, and the ceramic drying kiln occupies a large area and the energy consumption is large. The hot air rapid drying is that the drying atmosphere varies according to the different body and the drying degree of the body, and the best drying atmosphere is maintained at all times to improve the drying speed. Automatic temperature and humidity regulation rapid drying room has the following characteristics:

① Small space, fast response when parameter adjustment, high accuracy;

② Different drying curves can be set according to the condition of the billet;

③ Industrial computer control, high degree of automation, reduce the factors of human error, high qualification rate of body drying. The system is composed of six parts, such as house structure, hot blast stove, air distribution system, stirring system, control system and humidity system.

Ceramic body moisture content is generally between 5%-25%, body moisture is balanced water and free water composition, in a certain state of air, the drying limit is to make the body balance water. The equilibrium water is a part of the bound water, and its amount depends on the temperature and relative humidity of the drying medium. When the bound water is discharged, the volume of the billet does not shrink and is relatively safe.

In the case of stable drying conditions, the body surface temperature, moisture content, drying rate and time have a certain relationship, according to the change characteristics of the relationship between them, the drying process can be divided into: heating stage, equal speed drying stage, slow drying stage three processes:

1. Heating stage

Since the heat transmitted by the drying medium to the surface of the body per unit time is greater than the heat consumed by the evaporation of surface water, the temperature of the heated surface gradually increases until it is equal to the wet bulb temperature of the drying medium, at which time the heat obtained by the surface and the heat consumed by evaporation reach a dynamic balance, and the temperature remains unchanged. At this stage, the water content of the billet decreases and the drying rate increases.

2. Constant speed drying stage

Unbound water discharge continues at this stage. Due to the high water content of the body, the amount of water evaporated on the surface, the amount of water can be added inside, that is, the internal water movement speed (internal diffusion speed) of the body is equal to the evaporation speed of the surface water, which is also equal to the external diffusion speed, so the surface maintains a wet state. At the end of the constant drying stage, the moisture of the material is reduced to the critical value. At this time, although the inside of the material is still unbound water, bound water begins to appear in the surface layer.

3. Slow down the drying stage

In this stage, the water content of the billet decreases, the internal diffusion rate cannot catch up with the surface water evaporation rate and the external diffusion rate, the surface no longer maintains moisture, and the drying rate gradually decreases. As the heat required for evaporation of surface water decreases, the temperature of the material begins to rise gradually. The partial pressure of water vapor on the surface of the material is less than the partial pressure of saturated water vapor at the surface temperature. This stage is to discharge the bound water, the body does not produce volume shrinkage, will not produce dry waste. When the water discharged by the material drops equal to the equilibrium water, the drying rate becomes zero and the drying process terminates.

Second, the advantages of Nysta drying dehumidifier drying solution

(1) Automatic control system, according to the process requirements of different products, choose the best drying temperature and humidity, completely solve the other drying methods of long drying time, high temperature, large energy consumption and many other problems, with unparalleled desk characteristics.

(2) The use of high efficiency centrifugal fan, with strong wind, uniform air supply, low noise characteristics, material drying uniform and fast.

(3) During the drying process, the material is not deformed, no cracking, no discoloration, no deterioration, no oxidation, dry thoroughly, good rehydration after drying, less loss of nutrients, long storage period, and more effectively protect the color, aroma, taste, type and effective composition of the dry material.

(4) The unit is integrated design, and the pipeline and power supply can be used on site; Easy to operate, after setting the parameters, you can achieve automatic control, high reliability.

(5) Less investment, quick effect, can be used to transform old kilns, garages, etc., and can be migrated, save land area, etc., simple and convenient.