Shielded wire for high voltage skin effect trace heating
US10959295B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2017 |
| Grant date | Mar 23, 2021 |
| Priority date | — |
| Expiry date | Dec 4, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B2214/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A skin effect heating system for long pipelines includes a heater cable disposed in a ferromagnetic or other conductive heat tube, the heater cable and heat tube cooperating to produce heat that is applied to the carrier pipe. The heater cable includes a conductor surrounded by an insulating layer, and then a semiconductive outer layer or “jacket.” The semiconductive jacket contacts the inner surface of the heat tube, where the charge density of the return current carried by the heat tube is at its highest. The semiconductive jacket material has a resistivity that is sufficiently low to reduce or eliminate arcing events such as corona discharge by allowing accumulated charge on the heat tube to dissipate. The resistivity is also high enough to prevent the return current from flowing into or through the semiconductive outer layer, so that heat production capacity of the system is maximized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.