Via pressure blowing or vacuum suction, pneumatic conveying systems can be divided as pressure system and vacuum system.

Pressure system is more common is higher conveying capacity and longer conveying distance as there is higher pressure source available while vacuum system is only up to max. 1 bar pressure drop.

Pickup device for pressure system could be an airlock (rotary valve station), a blow tank (pressure vessel), a dual flap or dual butterfly valves or an venturi ejector, depending on actual plant application.





Advantages of Pressure Conveying System 正压输送的优势

Pressure systems are more efficient; lines sizes, blowers, and destination filters are usually smaller and less costs 通常正压输送更有效率,输送管径、风机、末端气固分离除尘器都会更小,因而投资更低
At the destination: 在终点处
Easier for multiple destinations (just need diverter valve or hose switch) 适合多终点输送
Less costs (the bin vent filter doesn’t see much pressure or vacuum) 末端除尘器无须带压,成本低
Less head height 高度更低


Disadvantages of Pressure Conveying System 正压输送的劣势

At the source: 在起点处
Need Aerolock: more costs and more head height 需要锁风旋转阀,成本更高、高度要求更高
A source Aerolock is prone to wear 旋转阀可能会磨损
Dust and air leakage above the Aerolock must be considered 旋转阀的泄露风量需要考虑在内
Any leak in a pressure system will cause material to escape 系统如果发生泄露,物料将会逸出
A pressure blower / compressor heats the conveying air (can be corrected with an aftercooler) 输送风机或压缩机产生的热风可能会加热物料(因此可能需要在其后配置空气冷却器)