1. Great moisture in fuel
The moisture content of biomass fuel is generally 40%-50%. This kind of fuel enters the furnace, releases a large amount of water vapor in the process of preheating and gasification, and reduces the furnace temperature.
2. Great ash content
The ash content of the fuel in the furnace is more than 40%. High concentration of ash prevents the combustion of combustibles. When biomass boilers are burning, the amount of air mixed into them needs to penetrate the ash layer in order to mix with combustion. A large amount of air used for combustion is consumed in the disturbance of material layer and ash layer.
3. Low calorific value of fuel
The calorific value of man-made furnace fuel is 5600 kJ/kg. The characteristics of low calorific value combustion are short flame length, flame rigidity is weak and the flame ignitability is poor.
4. Oxygen insufficiency in combustion
In order to overcome the combustion and smoke products and meet the needs of the seeding air, the hydraulic coupler of the feed and induced draft fan has reached the maximum opening. Increasing secondary air means reducing primary air, making primary air unable to penetrate the burning material, and secondary air unable to suppress and stir the flame.
ZBG takes a variety of ways to avoid or overcome these disadvantages for the combustion characteristics of biomass fuels and to improve boiler performence.
1. The vibration interval of grate is 300s, the vibration time is 11s and the vibration frequency is 90%. The vibration interval can be changed according to the combustion conditions of biomass boilers and the thickness of grate bed.
2. Adjusting the speed of the reclaimer and the plug board of the batching machine to keep the fuel uniformity of the grate and prevent blockage and material breakage.
3. Maintaining the water level and high power operation of dredger can't make dredger bring no ash.