METHODS FOR DIELECTRICALLY INSULATING ELECTRICAL ACTIVE PARTS

Abstract

Methods for dielectrically insulating electrical active parts The invention concerns methods for dielectrically insulating electrical active parts using certain fluorinated sulfone or sulfoxide derivatives, preferably fluorinated dialkyl sulfone derivatives as well as compositions and apparatus comprising such compounds.

Claims

1. A method for dielectrically insulating an electrical active part wherein the electrical active part is arranged in a gas-tight housing comprising an insulating medium comprising a compound of general formula (I):
R.sup.1SO.sub.nR.sup.2 (I) wherein n is 1 or 2 and R.sup.1 and R.sup.2 are independently fluorosubstituted alkyl, fluorosubstituted alkylene, fluorosubstituted alkylyne or fluorosubstituted aryl.

2. The method according to claim 1 wherein n is 2.

3. The method according to claim 1 wherein R.sup.1 and/or R.sup.2 are fluorosubstituted alkyl.

4. The method according to claim 1 wherein R.sup.1 and R.sup.2 are independently perfluorinated alkyl.

5. The method according to claim 1 wherein R.sup.1 and R.sup.2 are CF.sub.3.

6. The method according to claim 1 wherein the compound is trifluoro(trifluoromethylsulfonyl)methane CF.sub.3SO.sub.2CF.sub.3.

7. A composition comprising at least one compound of general formula (I)
R.sup.1SO.sub.nR.sup.2 (I) wherein n is 1 or 2 and R.sup.1 and R.sup.2 are independently fluorosubstituted alkyl, fluorosubstituted alkylene, fluorosubstituted alkylyne or fluorosubstituted aryl and at least one further compound selected from the group consisting of an inert gas, a perfluorinated or partially fluorinated ketone, a perfluorinated or partially fluorinated ether, a perfluorinated or partially fluorinated ester, a perfluorinated or partially fluorinated cyano compound and a hydrocarbon compound.

8. The composition according to claim 7 comprising CF.sub.3SO.sub.2CF.sub.3 and at least one compound selected from the group consisting of an inert gas, a perfluorinated or partially fluorinated ketone, a perfluorinated or partially fluorinated ether, a perfluorinated or partially fluorinated ester, a perfluorinated or partially fluorinated cyano compound and a hydrocarbon compound.

9. The composition of claim 8 comprising CF.sub.3SO.sub.2CF.sub.3 and at least one compound selected from the group consisting of air, synthetic air, an air component, N.sub.2, O.sub.2, CO.sub.2, N.sub.2O, He, Ne, Ar, Xe and SF.sub.6.

10. An apparatus for the generation, distribution and/or usage of electrical energy wherein the apparatus comprises an electrical active part arranged in a gas-tight housing, said gas-tight housing containing an insulating medium comprising at least one compound of general formula (I)
R.sup.1SO.sub.nR.sup.2 (I) wherein n is 1 or 2 and R.sup.1 and R.sup.2 are independently fluorosubstituted alkyl, fluorosubstituted alkylene, fluorosubstituted alkylyne or fluorosubstituted aryl; or containing an insulating medium comprising the composition according to claim 7.

11. The apparatus of claim 10 wherein the insulating medium comprises CF.sub.3SO.sub.2CF.sub.3.

12. The apparatus of claim 10 wherein the apparatus is a medium-voltage or high-voltage switchgear.

13. (canceled).

14. (canceled).

15. The composition of claim 9 comprising CF.sub.3SO.sub.2CF.sub.3 and N.sub.2.

Description

EXAMPLES

Example 1a

Manufacture of CF.SUB.3.SO.SUB.2.CF.SUB.3

[0049] CF .sub.3SO.sub.2CF .sub.3 is prepared according to L. A. Harmon, R. J. Lagow, Journal of the Chemical Society, Perkin Transactions 1, 1979, pp. 2675-2678 or van Meter, W. P.; Cady, G. H., Journal of the American Chemical Society, Vol. 82, 1960, pp. 6005-6008.

Example 1b

Manufacture of the Compositions

[0050] As described in WO98/23363, a homogenous mixture consisting CF.sub.3SO.sub.2CF.sub.3 and N.sub.2 in a volume ratio 1:4 is manufactured in an apparatus comprising a static mixer and a compressor.

Example 2

Provision of an Earth Cable Containing the Dielectrically Insulating Medium of Example 1

[0051] The composition of example 1b is directly fed into an earth cable for high voltage, until a total pressure of 10 bar (abs) is achieved in the cable.

Example 3

A Switchgear Containing CF.SUB.3.SO.SUB.2.CF.SUB.3 .and N.SUB.2 .in a Volume Ratio 1:4

[0052] A switchgear is used which contains a switch surrounded by a gas-tight metal case. The composition of example 1b is passed into the gas tight metal case via a valve until a pressure of 18 bar (abs) is achieved.