The transport of wastewater presents operators with increasing challenges for their wastewater pumps due to an increasing proportion of tear-resistant fibrous materials and new types of hygiene articles (e.g. wet wipes) in the wastewater. This paper describes the different clogging behavior of wastewater pumps, which were recorded during the functional performance tests. In addition to the findings of the points susceptible to clogging, the maximum uptake of solids by an impeller is also discussed. The maximum uptake of solids is defined as the degree of saturation. Furthermore, it is shown to what extent the different clogging behavior influence the hydraulic performance and the resulting efficiency changes.
In these tests, it became apparent that wastewater pumps react very differently to clogging. On the one hand, it can lead to a reduction in hydraulic function, which reduces the efficiency of the system. A distinction must be made here as to whether the pumps with a certain number of solids, a defined degree of saturation, retain their function or are brought to a standstill. On the other hand, the hydraulic performance can remain almost constant or, in some cases, be increased despite the clogging that occurs, but this is accompanied by an increased power requirement and can thus reduce the service life and the efficiency of the system.