For the purpose of swirling the delivery liquid when a pump is started up, provision is made for a scavenging device comprising a scavenging chamber (8) which is arranged in the pump sump (2), which exhibits an upper opening (9) with a float closure (10) and a lower discharge opening (12) directed towards the inlet (4) of the pump (1), and which is connected to a compressed-air source (14) by a line (13). <IMAGE>
