Method to operate a lifting equipment to pump contaminated liquids, in particular cooling lubricant

摘要

Process for operating a lifting device (R1) for pumping out contaminated liquid media, especially coolant, using a non-chokable circulating pump (F1) comprises permanently impinging a suction opening (7) or suction region of the pump with a liquid medium. Independent claims are also included for the following: (1) Lifting device used in the above process; and (2) Non-chokable circulating pump used in the above process. Preferred Features: The liquid medium, especially coolant, flows via a bypass (11) to the suction opening or suction region, especially the region of the flywheel (4) of the pump. The bypass opens into the housing part of the pump close to the flywheel.