Compared with belt conveyors, vibration and screw conveyors, pneumatic conveyors are the most suitable method for continuous transportation of small particles of solid materials, but pneumatic conveying systems also have certain defects.  

 (1) Advantages of pneumatic conveyor 

 a. All solid conveying equipment Compared with pneumatic conveying systems, pneumatic conveying systems may be the most suitable method for continuous conveying of small particle solid materials, and are also suitable for intermittently conveying large quantities of granular materials from tankers, railway vehicles and cargo ships to storage silos. .   

 b. Pneumatic conveying systems offer excellent flexibility in designing to make full use of space. Belt and screw conveyors essentially only convey in one direction. If the conveyed materials need to be changed in direction or lifted, there must be a transfer point and a second separate conveyor to pick up the materials. Pneumatic conveyors can transport materials up, down, or around large equipment and other obstacles in buildings, allowing the conveyor pipe to be elevated above or out of the space occupied by other operating devices.   

 c. The various solid material transfer pumps, flow distributors and receivers used in pneumatic conveying systems are very similar to the operation of fluid equipment, so most pneumatic conveyors are easily automated and operated from a central console. Can save operator costs. 

 d. Compared with other solid material transportation methods, pneumatic conveyors have less risk of fire and explosion, so they have the advantage of safety. The application of a complete pneumatic conveying system can save insurance premiums because the potential hazards of damage and fire are reduced. 

  e. A well-designed pneumatic conveying system is often clean and eliminates environmental pollution. In the case of a vacuum conveying system, any air leakage is inward, and both vacuum and pressurization equipment are completely enclosed and sealed units, so the contamination of materials can be limited to a minimum. The main dust control points should be at the feeder inlet and solid collector outlet, which can be designed for dust-free operation. Vortex tube cooling gun

   (2) Disadvantages of pneumatic conveyor 

   a. Compared with other bulk solid material conveying equipment, the power consumption of the pneumatic conveying system is higher (referring to the higher power required to convey each ton of material compared with the mechanical conveying system). 

    b. Use restricted. Pneumatic conveying systems can only be used to convey materials that must be relatively dry, non-abrasive, and sometimes free-flowing. Generally, if the final product is not allowed to be broken, brittle and easily broken products are not suitable for transportation by pneumatic conveyors. Unless specially designed equipment is used, materials that are prone to moisture absorption and caking are not suitable for conveying by pneumatic conveying systems. Materials that are easily oxidized are not suitable for air transportation, but inert gas with gas circulation return can be used instead of air. Pipes, fans and other components are easily abraded and damaged due to contact with materials.   

   c. Conveying distance is limited. So far, pneumatic conveying systems can only be used for relatively short conveying distances, generally less than 3,000 meters. The main obstacle in designing long conveyor lines is the difficulty in designing pressurization stations along the lines. 

    d. Small changes in material properties (such as bulk density, particle size distribution, hardness, angle of repose, grindability, explosion potential) can cause operational difficulties. Annular air knife