文章來源： 作者：羅茨機電 發布時間：2021-08-19 瀏覽次數：1692
(1) After the conveying pressure of the conveying main pipe drops to 0.03mpa, the three conveying air valves are closed successively, and the conveying cycle is ended. This lower limit is set too high, resulting in residual ash deposition in the ash conveying pipe after each conveying, which will affect the next ash conveying. It can be seen that the setting of the lower limit value of the bin pump pressure is more important, which is generally set to 0.01Mpa. If the lower limit value is set higher, the purging time must be extended to supplement, so as to avoid the impact of residual ash deposition in the pipeline on the next ash transportation.
(2) Low gas source pressure and insufficient gas volume increase the ash gas ratio and the transmission concentration is too large, resulting in increased pipeline resistance and easy pipe blockage.
(3) Pipe blockage caused by oil and water in the air source: the main reason for oil in the air source is the leakage or blockage of the filter screen of the oil-gas separator of the air compressor, resulting in a large amount of oil in the air source. The air source carries water, the desiccant A / b tower is not switched, and the desiccant is not replaced on schedule, which will increase the water content in the air, resulting in oil and water in the air source and blocking the ash caking.
(4) Settled ash: settled ash refers to the ash that falls on the ash hopper when the flue gas passes through the electrostatic precipitator that is not put into operation, and part of the gravity is greater than the buoyancy of the flue gas. Ash settled by kerosene mixed combustion in boiler ignition stage and ash settled after electrostatic precipitator fault shutdown. Generally, the settled ash particles are coarse and the surface is rough, resulting in a high probability of transportation accidents. During the transportation process, the ash particles gradually settle and are prone to pipe blockage. At this time, try to reduce the ash gas ratio. Therefore, during boiler ignition, pay attention to observe the transportation of ash removal equipment and make appropriate adjustment.
Adjustment method: ① it is appropriate to change the feeding time and control the amount of ash entering the bin pump, which is about 1 / 3 of the volume of the bin pump. ② Adjust the size of the flow orifice of the blowing aid valve to reduce the ash concentration (ensure that the air make-up check valve is in good condition without blockage and leakage).
(5) Influence of ash source: ① plasma ignition is adopted for boiler ignition, the fuel burnout is poor, and the carbon content in fly ash combustibles is as high as 30%. A large amount of unburned pulverized coal enters the electrostatic precipitator and falls into the ash hopper. When the boiler was shut down, the pneumatic conveying was stopped before the ash in the ash hopper was emptied, and part of the ash remained in the ash hopper, coupled with the entry of wet and cold air, resulting in ash hardening. At the initial stage of operation, the start and stop times are frequent, and a large amount of unburned fly ash is accumulated in the ash hopper. Oxidation reaction occurs slowly, and ignition occurs when the accumulated heat reaches a certain degree. As the coke block generated by combustion blocks the lower ash channel, the higher the ash level is.