Agglomeration problem mainly occurs on the fireside in the fluidized bed boilers. Agglomeration is basically the ash-related problem of biomass-fired boilers. Ashes which are formed from high-sulfur and low-ash fuel agglomerate if they are prone to sulfating condition for long time.
The slugging for the circulating fluidized bed boiler means that the bubbles in the feed layer converge and grow. When the diameter of the bubbles grows close to the cross section of the bed, the feed layer is divided into several sections to be particle layers with intervals of bubble sections. The particle layers are pushed by bubbles to move upwards to a certain height and then they burst into a large number of small particles that are thrown out of the bed and carried away by bubbles, while the large particles fall down like rain.
The characteristics of dust collector of coal-fired boiler:
1) Separating the particulate matters. The dust collector of coal-fired boiler can effectively separate the big particulate matters with ignition conditions, so as to reduce the obstruction of dust removal system and improve efficiency.
2) Reducing dust. The dust collector of coal-fired boiler can prevent the dust-contained gas from washing the bag to lower the dust concentration of dust-contained gas and extend the service life of filtering bag and pulse magnetic valve.
3) Adopting materials with high quality. The dust collector of coal-fired boiler adopts high-temperature resistant materials that can extend the service life of dust collector.
4) Adopting elastic piston ring. The mouth of filtering bag adopts elastic piston ring to ensure the leakproofness, which is firm and reliable.
Circulating fluidized bed boiler is a specific type of boilers, and compared with the other boilers, it has certain advantages, which are: it has great improvement in combustion technology, which can improve the boiler combustion quality and combustion effect, and in turn, to improve the boiler effect. This is achieved because two return feeders are used in this type of boiler to allow the fuel to form a circulation loop between the furnace and the return feeder.
The bed temperature rises sharply.
Oxygen levels go down and sometimes drop to zero.
The electric current of primary air fan is less and wind pressure of air compartment is higher.
Negative pressure of furnace is increased while the electric current of induced draft fan is reduced.
The slag discharge is difficult or unsuccessful.
When appearing bed clinkering, the bed temperature and bed pressure will be uneven distributed and not at normal condition; the measuring point of part bed tempe...
(Question Details) Specific Performance:The pipe of superheater bursts in circulating fluidized bed boiler operation.The bed pressure indicator fluctuates little. Answer: causes of failure:(1) Design Factors.(2) Manufacturing process, installation and maintenance quality.(3) The temperature control device is unreasonable or does not work properly.(4) Effect of operating conditions on overheating and explosion of superheater. Troubleshooting:(1) Report the fact to operator on duty and require operating the boiler in low load.(2) When the overheat damage is serious,please report it to operator on duty and require stoping the boiler immediately to prevent blowout of the near pipes.(3) Adjust the steam temperature as much as possible within the normal range.(4) If the superheater tube is not damaged badly, it has little effect on the temperature level of the steam, and it can be allowed to run in a low load range for a short period of time.
(Question Details) Specific Performance:(1) There are blasting sounds in the furnace, and the furnace chamber is under positive pressure. There is smoke emitted from the combustion chamber in a leakage. In severe cases, the explosion-proof door of the boiler body opens.(2) Drum water level drops rapidly and the feedwater flow rate is not abnormally larger than steam flow. MFT acts when the water level is below -280mm.(3) Drum pressure, steam flow rate, exhaust temperature decrease, smoke temperature difference increases on both sides.(4) The negative pressure at the inlet of the flue and suction fan becomes smaller and the temperature difference between the two sides increased. (5) Smoke temperature decreases at the inlet and outlet of the cyclone separator, and the temperature of the material returned is low.(6) Bed pressure increases, bed materials clean, fluidization poof, bed temperature distributes unevenly and bottom slag discharge difficultly. Answer：cause of failure:(1) Fly ash
