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 fluoroamines 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):
FN(C.sub.nH.sub.mF.sub.(2n+1)m)(C.sub.nH.sub.mF.sub.(2n+1)m) (I) wherein n is 1, 2, 3, 4, or 5 and m is an integer between 0 and 2n and wherein n is 2, 3, 4, or 5 and m is an integer between 0 and 2n.

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

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

4. The method according to claim 1 wherein m is 0.

5. The method according to claim 1 wherein m is 0.

6. The method according to claim 1 where the compound is pentafluoroethyl-trifluoromethyl fluoroamine NF(CF.sub.3)(C.sub.2F.sub.5).

7. A composition consisting of, consisting essentially of, or comprising at least one compound of general formula (I)
FN(C.sub.nH.sub.mF.sub.(2n+1)m)(C.sub.nH.sub.mF.sub.(2n+1)m) (I) wherein n is 1, 2, 3, 4, or 5 and m is an integer between 0 and 2n and wherein n is 2, 3, 4, or 5 and m is an integer between 0 and 2n 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 NF(CF.sub.3)(C.sub.2F.sub.5) 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 NF(CF.sub.3)(C.sub.2F.sub.5) 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)
FN(C.sub.nH.sub.mF.sub.(2n+1)m)(C.sub.nH.sub.mF.sub.(2n+1)m) (I) wherein n is 1, 2, 3, 4, or 5 and m is an integer between 0 and 2n and wherein n is 2, 3, 4, or 5 and m is an integer between 0 and 2n; or containing an insulating medium comprising the composition according to claim 7.

11. The apparatus of claim 10 wherein the insulating medium comprises NF(CF.sub.3)(C.sub.2F.sub.5).

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

13. (canceled)

14. The composition of claim 9 comprising NF(CF.sub.3)(C.sub.2F.sub.5) and N.sub.2.

Description

EXAMPLES

Example 1a

Manufacture of NF(CF.SUB.3.)(C.SUB.2.F.SUB.5.)

[0047] NF(CF.sub.3)(C.sub.2F.sub.5) is prepared according to Sartori, P., Journal of Fluorine Chemistry, 1997, 83, pp. 1-8.

Example 1b

Manufacture of the Compositions

[0048] As described in WO98/23363, a homogenous mixture consisting NF(CF.sub.3)(C.sub.2F.sub.5) 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

[0049] 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 NF(CF.SUB.3.)(C.SUB.2.F.SUB.5.) and N.SUB.2 .in a Volume Ratio 1:4

[0050] A switchgear is used which contains a switch surrounded by a gas-tight metal case. The composition of example b1 is passed into the gas tight metal case via a valve until a pressure of 18 bar (abs) is achieved.