Pneumatic conveying is a relatively young science and technology that emerged in the latter half of the 19th century. The first pneumatic grain unloader for discharging bulk grain from ship holds appeared at the port of St. Petersburg, Russia, in 1883, followed by the introduction of stationary grain unloaders in the UK in 1893. Subsequently, pneumatic conveying systems were widely adopted at ports worldwide for grain unloading; statistics show that between 1925 and 1926, nearly 90% of seaborne grain at the ports of Rotterdam (Netherlands) and Hamburg (Germany) was unloaded using pneumatic grain unloaders-specifically, suction-type pneumatic conveying systems.
In recent years, pneumatic conveying technology has advanced rapidly and found widespread application across various industrial sectors, handling materials such as grain, cement, fly ash, chemical products, mineral powder, salt, flour, glass and enamel batch mixtures, and foundry sand. As conveying distances increased, pressure-type pneumatic conveying systems were developed. Low-pressure pneumatic conveying pumps utilize airflow to transport powdery and granular materials; essentially, they are conveying devices that employ an airflow with specific pressure and velocity to move such materials. From a fluid mechanics perspective, the medium within the conveying pipeline is a mixture of air and solid particles-constituting a gas-solid two-phase flow-and thus, the theory of pneumatic conveying focuses primarily on the fundamental principles governing gas-solid flow.
