There are four main combustion modes of fuel in the furnace, namely stratified combustion, suspended combustion, cyclone combustion and fluidized combustion.

First, stratified combustion

This combustion method is suitable for all kinds of solid fuels. Its characteristic is that the whole combustion process of fuel is mainly carried out on the grate.

Layered combustion boiler is called chain boiler in industry.

Taking chain furnace as an example, the working principle and characteristics of its combustion process are introduced.

Solid fuel falls from the coal hopper to the grate and then moves back and forth with the grate. Air passes from bottom to top.

Through the coal seam.

The ignition heat source of fuel comes from the hot flue gas in the furnace and the thermal radiation of the furnace wall. The fuel surface is first heated and burned.

After that, the heat is transferred downwards until all the coal on the grate is burned. The smoke of combustion products moves upward. The fuel is in the fireplace.

The middle and rear parts burn out and turn into ash, which falls into the cold ash hopper and is discharged.

The advantage of this combustion method is that the fuel layer can keep a considerable amount of heat, and the combustion is relatively stable and it is not easy to extinguish the fire. the same

At this time, the newly entered fuel can fully contact with the ignited fuel and be baked, and the ignition conditions are good.

The disadvantage of this combustion method is that it can only burn solid block fuel, and air passes through the gaps between coal blocks from bottom to top.

However, the mixing conditions are poor. Therefore, it is suitable for small-capacity boilers.