Sintering of tungsten carbide cutting tools. During debinding, the cracked polymer binder vapours (frequently PEG - polyethylene glycol) enter the pump and partially condense within the compression stage.
Oil-sealed pumps operate unreliably and require very frequent maintenance and service. Over time, even in dry-compressing pumps, deposits form in the compression stage and require cleaning.
RUTA pump system with SCREWLINE dry-compressing screw pump line. Due to the internally cooled rotors, the SCREWLINE generates only a moderately warm compression temperature. In comparison to the usually very hot standard screw pumps, this significantly reduces the build-up of cracked polymer vapours entering the pump and reduces the formation of deposits on rotor and stator. The required cleaning intervals are extended to a maximum.
The removal of deposits by polyethylene glycol can be carried out by a dynamic flushing process with water. If polymers such as polypropylene or polystyrene are used, other cleaning agents can be used for a better effect. Due to the cantileverd rotor concept, the plant operator can also carry out regular manual cleanings of the SCREWLINE pump chamber to remove process deposits.
If paraffin waxes are sued as binder, the SCREWLINE is even more outstanding. Paraffin waxes evaporate and condense without thermal decomposition. If such vapours enter the SCREWLINE, the internal temperatures of the pump are exactly in the range in which the waxes condense without cracking. The condensate is discharged from the pump in the liquid phase. The pump can also be restarted without any problems after cooling down. Paraffin binder vapours do not require increased maintenance.