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SF6 handling in industry

In the manufacture of gas insulated switchgear and in high voltage systems above 700 kV, recovery installations with much larger delivery volumes are used.

foto blog manometer 21 2018 sauer compressors SF6 handling industry v2

  foto blog manometer 21 2018 sauer compressors SF6 handling industry maintenance v2
For maintenance of gas insulated switchgear, portable recovery units are used, consisting of one or more vacuum pumps, a filter and a HAUG Sauer compressor.   In the manufacture of gas insulated switchgear and in high voltage systems above 700 kV, recovery installations with much larger delivery volumes are used.

 

HAUG Sauer Compressors provide leak-free recovery

Sulphur hexafluoride or SF6 is a chemical compound made up of sulphur and fluoride. Because of its exceptional insulating properties, the colourless and odourless gas is used in medium and high voltage technology, primarily in gas-insulated switchgear (GIS).

As one of the six recognised greenhouse gases, it may not be discharged into the atmosphere after use. Recovery of the SF6 during maintenance and manufacture of the switchgear is therefore stipulated by law. Special recovery systems must meet very tough requirements to prevent the harmful gas from escaping. Essential to this process are oil-free compressors with exceptional gas-tightness, such as those supplied by HAUG Sauer.

 

Reliable recovery for maintenance and production

The greenhouse potential of SF6 is estimated to be 23,000 times higher than that of carbon dioxide. SF6 can remain stable in the atmosphere for up to 3,200 years. As a result, it can only be used in closed circuits in industry.  For maintenance purposes, SF6 must be evacuated from gas insulated switchgear. To do this, the gas is pumped out into portable recovery systems (see photo), where it is then filtered and fed to the compressor, which compresses it. The final pressure is generally 40 barg. Once cooled, the gas can be stored in a liquid state.

 

HAUG Sauer compressors for maximum gas-tightness

Absolute gas-tightness is essential for handling SF6. This is why well-known operators of high voltage systems use environmentally friendly and reliable recovery systems with permanently tight compressors from HAUG Sauer. Since the introduction of SF6 as a high voltage insulating gas, the dry running compressors have been used successfully for recovery. Over the past 50 years, several thousand compressors have been installed for this purpose. The hermetically gas-tight compressors achieve a leak rate of less than 0.0001 mbar l/s both during operation and when idle. Every SF6 compressor is tested for permanent tightness.

 

Oil-free compressors for maximum gas purity

The interior of the HAUG Sauer compressors is completely oil-free, which rules out contamination of the SF6 gas and thus the high voltage systems as a whole. Oil-free recovery is therefore an important safety issue in energy supply.

Oil-free compression also delivers key benefits in terms of the operating reliability and costs of the recovery system – there is no need for frequent filter replacement, oil changes or an oil supply; maintenance is easy and economical. The components of the HAUG Sauer compressors are impressively robust and durable. Even in applications with long downtimes and cold starts, they guarantee reliable operation in all climatic conditions.

 

Proven technology for individual requirements

HAUG Sauer compressors allow higher inlet pressures than comparable compressors, enabling them to achieve a higher flow rate and faster gas recovery. They also have lower energy consumption. Customised compressors are available for a power range of 0.5 kW to 110 kW, with three or even four-stage models for higher final pressures.

The search for an alternative to the environmentally harmful SF6 that offers comparable properties remains a big challenge. HAUG Sauer has already supplied adapted compressors for recovery of existing SG6 alternatives.

 


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Manometer #21

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