1. The structure and working principle of the forced air diffusion burner. In the forced air burner, all the air required for gas combustion is supplied by the blower at one time. However, the gas and air are not premixed before combustion, so the combustion process is not It belongs to premixed combustion, but it is diffusion combustion.
The combustion intensity and flame length of a forced draft burner are determined by the mixing intensity of gas and air. In order to strengthen the combustion process and shorten the flame length, various measures are often used to accelerate the mixing of gas and air. For example, the gas is divided into many small jets and injected into the air flow or air swirl is used. According to the measures taken to enhance the mixing process and the flame requirements of the process, the blast burner can be made into various styles such as sleeve type, swirl type, advection type, etc.
2. Characteristics and application scope of blast diffusion burner
Compared with natural induced draft diffusion burners, forced draft burners have greater combustion heat intensity and adjustable flame length. Compared with the jet burner with the same heat load, it has a compact structure, light body and small footprint. Especially when the thermal load is large, this advantage is more prominent. In addition, the blast burner requires low gas pressure and a large heat load adjustment range, can adapt to the positive pressure furnace, and can easily realize pulverized coal-gas or oil-gas combined combustion. Preheated air or gas can also be used. The preheating temperature can even be close to the gas ignition temperature, so the combustion temperature can be greatly increased, which is necessary for high-temperature industrial furnaces.
The blast burner requires blast and consumes electricity. The combustion chamber volume thermal intensity is usually smaller than that of a fully premixed burner, and the flame is longer, so a larger combustion chamber volume is required. In addition, the blast burner itself does not have the automatic adjustment feature of proportional change of gas and air. It needs to be equipped with an automatic proportional adjustment device and is mainly used in various industrial furnaces and boilers.