Radiofrequency ground heating system for soil remediation
US5484985A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1994 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Aug 16, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB09C2101/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An in-situ method of extracting contaminants from a soil volume comprises applying a radiofrequency (RF) excitation signal to heat the soil with an array of electrodes. The electrodes are inserted into the contaminated volume or inserted into a matrix of holes drilled into the volume. A first row of electrodes is electrically coupled to a shield of a coaxial cable, with a second row electrically coupled to the central conductor of the coaxial cable. RF energy is applied to pairs of electrode rows through the coaxial cable and a matching network is installed in front of the electrode-row pair to maximize power flow into the electrode-row pair. This results in very evenly distributed voltages which results in even heating. A balanced-to-unbalanced transformer (balun) is installed at the input to the matching network to prevent the deposition of RF energy outside the target volume and creation of voltages that could be hazardous to personnel. The electrodes are perforated and connected to collection tubes which collect volatilized contaminant vapors and pass the vapors to a vapor treatment unit for neutralization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.