In the pneumatic conveying system, due to the different wind speeds of different pipe sections, the flow state of the material will change significantly. There are six different flow states for horizontal conveying pipes. Pneumatic conveying expert Corey will introduce you to six different material flow states in a pneumatic conveying system.

The first is uniform flow. When the air velocity in the pneumatic conveying system is large, the particles are almost evenly distributed, and the material is conveyed in a suspended state.

The second is the tube underflow. When the airflow speed of the pneumatic conveying system begins to decrease, the material begins to approach the bottom of the pipeline, and the closer it is to the bottom of the pipeline, the denser the distribution. However, the material conveying process did not stop. Its state is irregular rolling on one side, collision, and conveying on one side.

The third is density flow. When the airflow speed is less than a certain value, the material begins to flow in an uneven state in the horizontal pipe, and some particles slip during the management, but the material conveying has not stopped.

The fourth is stagnant flow. As the air flow rate is further reduced, most of the particles begin to lose their suspending ability and stagnate at the bottom of the tube. At this time, the inner section of the local pipe becomes smaller due to the accumulation of materials, resulting in an increase in the air velocity in this area, and the retained material is blown away. Material transport is in the cycle of stagnation, accumulation and sublation, forming an unstable transport state.

The fifth is partial flow. In the pneumatic conveying system, the airflow speed is too small, the material particles accumulate at the bottom of the pipeline, and the airflow flows above the accumulated materials. Under the blowing of the airflow, the particles above the materials move irregularly. Over time, the layers of accumulation flowed forward like sand dunes.

The sixth is embolic flow. If the material accumulation layer in the pneumatic conveying system begins to fill the pipeline, due to the existence of compressed air, a pressure difference will be formed before and after the material column, and the material will be pushed and conveyed by the pressure difference.

In general, in a horizontal conveying pipeline, the higher the wind speed, the closer the conveyed material is to be evenly distributed. When the air flow rate is insufficient, the flow state begins to change. In the early stage of the pneumatic conveying system, the conveying of materials is generally carried out according to uniform flow or pipe bottom flow. Finally, the material transportation is close to the dense and dense flow, forming a stagnant flow. The longer the horizontal pipe section, the more obvious this phenomenon is. When the airflow speed is reduced to a certain limit, obvious pulsation will occur, and periodic impact pressure will be generated at the elbow of the pipe.