Characteristics of firebrick and drying process of firebrick

Time：2020-04-02 14:55 Browse：

Characteristics of light firebrick:

1. Economy: it can reduce the cost of the foundation, reduce the section of the frame, and save the reinforced concrete, which can significantly save the comprehensive cost of the building. Compared with solid clay brick, light brick can reduce the cost by more than 5%.

2. Practicability: the use area can be increased by using light bricks. At the same time, due to the heat insulation of aerated concrete, the heat preservation effect is good. In the hot summer, the indoor temperature is 2-3 ° C lower than that of solid clay bricks. Air conditioning is used to reduce the power consumption.

3. Constructability: light brick has good machinability and is easy to construct. Because of its large size and light weight, it can reduce labor intensity, improve construction efficiency and shorten construction period.

The drying process of firebrick can be divided into three stages

The first stage:

In the isokinetic drying stage, a large amount of water is discharged in this stage. When the temperature and humidity of the surrounding environment are constant, the water discharge rate is approximately constant, so it is called the isokinetic drying stage. In addition, the evaporation of water only occurs on the surface of the green body, and the drying speed is equal to the evaporation speed of water, so any speed that affects the evaporation of the surface can affect the drying speed. Therefore, in the constant speed drying stage, the drying speed has nothing to do with the thickness and initial moisture content of the green body, but with the temperature, humidity and moving speed of the drying medium.

The second stage:

In the accelerated drying stage, with the increase of drying time, the moisture in the green body decreases, the effective evaporation area in the green body decreases, and the drying speed decreases gradually.

In addition, the evaporation rate of water from the surface is faster than that from the body to the surface, so the drying speed is less affected by the temperature, humidity and moving speed of air. The speed of water diffusion to the surface depends on the water content, the internal structure of the green body, the viscosity of water and the properties of materials. Generally, the internal diffusion of water in non-plastic and weak plastic materials is stronger, the coarse particles are stronger than the fine particles, and the higher the drying temperature is, the easier the diffusion is.

The third stage:

In the equilibrium drying stage, the drying speed gradually approaches to zero, and the water content in the green body is no longer reduced. The water content in the green body is equal to the equilibrium water adsorbed by the solid particles. The content of the equilibrium water depends on the nature of the material, the particle size and the temperature and humidity of the drying medium. According to the requirements of process conditions, the final moisture content is determined. If the moisture content is too high, the brick strength and furnace efficiency will be reduced; if the moisture content is too low, the drying energy will be wasted.