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Dry vacuum solutions for special duty

Dry vacuum solutions for special duty

Furnace processes such as sintering, carburizing or nitrocarburizing pose great challenges for the vacuum pumps used. During these processes, vapors or particles are released, some of which condense inside the pump and can lead to heavy contamination or even built-up of deposits.
Oil-sealed pumps wash out these contaminants, operate unreliably and require ver yfrequent maintenance or even overhaul by the service department.
The use of dry-compressing vacuum pumps offers a cost-saving alternative. Depending on the process, the vapours are simply discharged or the layer built-up at the compression stage is so slow that the layer can be removed by a cleaning step.
The best pump choice for such an application is a screw pump with internal rotor cooling and cantilevered bearing design. Here the build-up of deposits is reduced due to the moderate internal temperatures and the user has the possibility to clean the compression stage if required.

User example:
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.

Solution:
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.