Vacuum Pumps The New Dry Compressing Screw Vacuum Pump
The new Varodry is a 100 % oil-free, dry compressing screw vacuum pump. Screw pumps are currently state-of-the-art in the field of industrial vacuum pumps.
The Varodry screw vacuum pump by Leybold will initially be available in the sizes VD65 (65 m³/h) and VD100 (100 m³/h), the sizes VD160 and VD200 are already in preparation.
What qualifies the pumps of the Varodry series is their excellent suitability for the manufacturing industry, states the firm. The reason: In industrial processes, pumps do not only need to handle clean air, but also dirt, particles, outgassing of media and vapours. Processes do not always work in a stable manner, other disturbance factors might also be involved. The pump must be able to tolerate all of this. In general, screw pumps are the best choice for such demanding requirements. You can compare their function a bit to an extruder that pushes out the disturbing particles together with the regular material at its exhaust.
In addition, these pumps are able to handle vapours in the best possible way. All those advantages of the screw-pump functional principle apply to the Varodry, but next to this, due to its integrated silencer the pump also offers a quiet and pleasant sound profile, mentions the company.
However, there are other factors, which make a significant contribution to improving production processes. According to the firm, the variable inlet flange arrangement enables a flexible installation of the pump within the plant. Furthermore, the design of the silencer without ‘sponge-like’ damper materials and the exhaust flange located at the lowest point of the pump facilitates pushing-out liquids or condensed vapours, which might incur in some industrial processes. This prevents potential formation of rust and contributes significantly to process reliability.
A further process advantage is the reliability and efficiency of the pump. It can be operated continuously at any inlet pressure and is fully resistant even against repeated shock venting. Any number of cycles can be run without overload, which is still not the current market standard, adds the company.
A major differentiation of the Varodry is its complete oil-freeness. All other screw-type vacuum pumps in the market are ‘dry compressing’; nevertheless, all these pumps have gear compartments partly filled with oil to lubricate the bearings and gear wheels. The Varodry is 100 % oil-free, claims the firm.
Because of this there is no chance for oil migration from the gear chamber into the pumps compression chamber where this oil might react with the pumped gases or in worst case even migrate backwards to the process chamber.
The firm mentions that this hazard cannot happen with Varodry as it uses grease-lubricated bearings. Drive and synchronisation is done with a high-tech tooth-belt, which on demand can be exchanged in a few minutes by the user himself. This also eliminates the gear oil exchanges which are still required at other screw-type pumps. It is therefore impossible that any oil can migrate backwards to the process chamber, will be blown out of the exhaust or might leak on the floor during the gear-box exchange process.
The company claims that Varodry is therefore the first pump in the market which is 100 % oil-free and has a significant impact on cost reduction and process room cleanliness.
Another technical advantage for industrial use is the complete air cooling of the pump. This simplifies the integration of the pump into the plant as there is no need for the complicated water supply.
In contrast to most competitor products, the Varodry has a moderate temperature profile. The low internal temperatures which peak around 100 to 130°C (depending on operation point) also allow a handling of temperature sensitive media, often preventing those that react immediately and build-up layers inside the pump. This moderate heat is the optimum for many applications enabling long-time operation without the need for compression room cleaning.