Arrangement for removing volatile impurities from ground water - in which efficiency of system for passing cleaning gas through water in borehole is improved by recirculating some of used cleaning gas

摘要

The filters (23,28) used in a system for removing volatile impurities from ground water have at least one pipe connection (26,29) for recirculating the cleaning gas or gas mixture to the borehole (10). The filter arrangement (23,28) has at least two stages, and at least after the first of these stages (23), and upstream of a throttling valve (25), a connection (26) is provided to the inlet pipe (17) which brings the cleaning gas or gas mixture to the borehole (10). The first filter stage (23) is a coarse filter, and at least one further stage for a finer filtration is provided. The second filtration stage (28) may take the form of a cold reactor for the removal of contaminants. The cleaning gas may be air, with or without the addition of carrier gases. USE/ADVANTAGE - This invention is used for removing volatile impurities from ground water and from the surrounding earth. The proposed arrangement improves the effectiveness and economy of existing similar devices.