Causes of coking in biomass boilers12/31/2021
1. Biomass boiler air distribution ratio: Under the condition of certain biomass pellet fuel, the uneven distribution of blast in the incinerator hearth constitutes part of the high temperature which is also the cause of coking in the incinerator hearth. Lower the blast air pressure and install or Enhancing boiler exhaust will also reduce the degree of coking, so it is very important to select an appropriate air distribution ratio. Excluding the reasons of biomass fuel itself and the air distribution ratio of biomass boilers, biomass boiler furnace planning, feeding speed, etc. will also cause coking. Therefore, if you encounter coking problems, you need to investigate them step by step. Don't blindly think that it is the cause of the particulate material or the problem of the biomass boiler. Improper operation will also be an important element of coking.
Second, the coking formed by the ash content of the biomass fuel itself and the doped substances.
1. Biomass boiler coking mainly refers to the ash that occurs after fuel incineration. Most of the ash melts into liquid or softened state at high temperature. It is assumed that the ash still persists in softened state when it meets the heated surface, and it is bonded due to cooling. On the heated surface, coking is formed.
2. The temperature level of the heating surface in the furnace. When the ash melting point is certain, the temperature level in the furnace and its distribution become an important factor in whether coking occurs. Experience has shown that the coking of fuel furnaces is mostly on the surface of flue and superheater. During the process of moving liquid or soft ash particles to the heating surface due to the effect of inertia, due to the fast movement of the ash particles, the cooling effect is poor, and the molten ash particles Very simple adhesion, so that the slag layer quickly accumulates and grows. Temperature has a very important effect on coking in the furnace. Research has shown that the higher the temperature, the degree of coking will increase according to the exponential rule.