| 摘要 |
The invention relates to a gas well for extracting methane gas from landfills, comprising a borehole, which is made in the heap of refuse and inside of which a filtering tube (11) is placed. A material column is placed between the filtering tube (11) and the lateral surface of the borehole, is essentially gas-tight underneath the ground surface (GOK) and, in the areas located under the ground surface, is comprised of a gravel heap (14). The invention also relates to a method for retrofitting existing gas wells. According to the invention, at least one suction tube (15) whose diameter is less than that of the filtering tube is inserted into this filtering tube (11). Around the outer lateral surface of the suction tube, the space (19) remaining between the filtering tube (11) and the suction tube (15) or all suction tubes and the area (20) of the gravel heap (14) located at the same height are filled in with a hardened material preferably comprised of foamed plastic above a limited height up to an at least essentially gas-tight zone so that the areas (21) located underneath this gas-tight zone can be evacuated by suction only via the suction tube. |
