Function and structure of small furnace of sodium silicate melting furnace

Small furnace of melting furnace has different types according to the different fuels used.

When the fuel is gas from the generator, its combustion equipment is called small furnace, and the small furnace mouth is called flame nozzle.

When the fuel is heavy oil or other liquid fuel, a nozzle (i.e. burner) is used, so there is no small furnace mouth, only a jet mouth.

What is the main function of the small furnace?

The small furnace is the connecting part between the heat storage chamber and the melting furnace. It is a device for preheating, mixing and organizing combustion of fuel and air, and provides a channel for secondary air in the sodium silicate pool kiln. Its structure should keep the flame of a certain length and have a large enough coverage area, so that the flame is close to the surface of the sodium silicate liquid, without floating or stratification, and also meet the temperature and atmosphere requirements required in the kiln.

After being preheated by the regenerator, the coal gas and air enter the pre-combustion chamber through the vertical channel (ascending channel) and the horizontal channel, where they are mixed and partially burned, and then sprayed into the kiln in a certain direction and speed to continue burning. At this time, the smoke enters the small furnace opposite. Therefore, the small furnace plays the role of an air channel and a smoke exhaust channel. However, the structure of the small furnace plays an important role in the heat transfer in the kiln and the melting process of sodium silicate.

What is the structure of the small furnace?

The small furnace consists of a top arch, side walls and a bottom bed. The arch connecting the small furnace to the melting furnace is called a small furnace flat arch, the arch connected to the regenerator is called a rear flat arch, and the arch in the middle is an inclined arch. Figure 1 shows the structure of a small furnace burning oil (natural gas). The arch, side walls and bottom bed form the space of the small furnace. The flat arch of the melting furnace adopts an inserted structure, which is flat on the top and curved on the bottom, and matches the breast wall of the melting furnace. The above-mentioned measure to prevent the breast wall from tilting inward is to design the breast wall to be tilted inward, and the arch bricks of the large arch are directly pressed on the breast wall. Therefore, the flat arch of the small furnace should also be designed into a structure as shown in Figure 1(b), which is also commonly used at present.

The downward inclination angle of the small furnace is generally selected in the range of 18°~35°, and the oil-fired small furnace is generally selected in the range of 22°~25°. The downward inclination angle of the small furnace burning natural gas can be larger. In actual production, the oil gun has an upward inclination angle of about 5°, and the elevation angle when using natural gas is even larger. The purpose is to make the flame parallel to the sodium silicate liquid surface.