The blockage of the pneumatic conveying pipeline often occurs in the initial section 150m below the outlet of the transmitter, such as the silo pump. This is because the flow rate is low and the concentration is high in the initial stage, and the flow pattern is the most unstable. As the compressed air friction resistance consumes the compressed air energy during the conveying process, the pressure in the pneumatic conveying pipeline gradually decreases, the specific volume increases, the compressed air volume expands, the flow rate increases, and it is not easy to be blocked. The later part of the pneumatic conveying pipeline will be automatically dredged even if it is blocked, because the latter section of the pneumatic conveying pipeline usually adopts an enlarged design. Due to the high flow control, it prevents the increase of the diameter of the passing pipe and the decrease of the concentration, and the initial velocity is also higher than that of the front part. is designed so that large particles tend to deposit at the bottom of the pneumatic conveying pipe.

When the flow rate is within a certain range, the flow at the bottom of the pneumatic conveying pipeline can continue to convey; the embolism, due to the large gap and large particles, can flow through the middle of the air, and at the same time, the pressure will rise to increase the static state of the push material after the embolism at the front of the blockage Press the plug so that the material bolts collapse and unclog so that the conveying continues. Of course, when material bolts break, pressure fluctuations, vibrations and noise are caused. The jargon is "shoot the gun". Therefore, on the one hand, it is necessary to reasonably control the design of the conveying speed, and on the other hand, it also needs to pay attention to the strength of the rear pipe support and control the gap of the sliding support, so as to avoid the damage to the pneumatic conveying pipeline and structure caused by the blasting.

There are many reasons for blocking the pipe, such as the turning radius of the elbow is too small or does not meet the specification requirements when changing the pipe diameter. The key problem is the speed control

Blockages in pneumatic conveying lines can be caused by one or more of the following reasons.

1. Misoperation. During the conveying process, the compressed air is closed by mistake, causing the material in the pneumatic conveying pipeline to settle, and the pneumatic conveying pipeline is easily blocked when re-inflated.

2. When the air compressor fails, the pressure and flow of the conveyed air will be reduced, or when the centralized air compressor station is used for air supply, a large amount of gas will be suddenly used in other places, resulting in the reduction of the conveyed air volume and the reduction of materials caused by Resolve the pressure, and the pneumatic delivery line will be blocked.

3. There is leakage in the air pipe between the air compressor and the silo pump or delivery pipe.

4. When designing the system, the pressure or flow of the compressed air is too small, or the pipeline is not matched, so that the initial flow cannot fully suspend the material. In this case, blockage of the pneumatic conveying line often occurs.

5. The inlet valve or exhaust valve of the silo pump leaks under the conveying conditions. In the case of dual-silo operation, this leakage not only prolongs the delivery time of the leaking silo pump, but also causes blockage of the pneumatic conveying pipeline when the other silo pump is conveyed.

6. The gap between the silo pump horseshoe tube is adjusted too large, resulting in too high conveying concentration and blockage of the pipeline.

7. The primary and secondary air of the silo pump are improperly adjusted, resulting in excessive concentration and blockage.

8. The silo pump is overcharged, the material gasification is poor, and the material fluidity becomes poor, which affects the transportation.

9. The bag filter on the ash silo at the end of the conveying pneumatic conveying pipeline is not running well, and the excess ash on the filter bag cannot be dropped, resulting in excessively high conveying back pressure, resulting in blockage of the pneumatic conveying pipeline.

10. Due to the change of materials, the decrease of material temperature, the increase of particle size, the failure of electrostatic precipitator caused by the change of moisture and ash content or chemical composition, the system cannot adapt to the changed conditions.

11. Due to the intrusion of rainwater or water spray, the material is damp, adhered, and the particles increase, and the frictional resistance increases during the conveying process, resulting in blockage of the pneumatic conveying pipeline.

12. The valve of the pneumatic conveying pipeline or the air main pipe is not fully opened, resulting in large local resistance or insufficient air supply.

13. Poor gasification of the ash hopper leads to poor material fluidity.

14. There are foreign objects or blockages in the cleaning pneumatic conveying pipeline.

15. When the air compressor is in the unloaded state, start the pump to convey, and the air compressor needs a certain time to reload, resulting in insufficient air supply system. During this time, the material flow of the conveying pipe will drop, resulting in deposition and blockage.