NA-05 - Cleaning: Vehicles and Technology

Pumps

Vacuum pumps – Ejector

The maximum suction lifts of the solid-liquid-mixtures amount to between 9 m to 12 m, and can only be realized by the addition of air to the suction flow by means of openings near the end of the suction tube. These processes decrease the specific weight of the solid-liquid-mixture to be extracted and, at the same time, increase the flow velocity in the suction tube. Suction lifts between 12 to 25 m require the usage of ejectors that are positioned in the manhole.

The suction effect of the water-jet vacuum pump is based on the Bernoulli principle of negative pressure. The vacuum is created in the front part of the ejector (left branch in the above Figure), by which the solid-liquid-mixture that is backed up in the manhole is sucked in. This process is supported by adding water under pressure via a laterally installed pressure line (lower branch in the above Figure).

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