Patent ID: 6790653
Filing Date: 2004-09-14
Classification: B01D,Y02A,Y10S

Abstract:
A filter apparatus for processing air laden with volatile organic compounds, the apparatus comprising:a first filter unit defining a first filter chamber and having a first air inlet for admitting air into the first filter chamber and a first air outlet for exhausting air from the first filter chamber, a second filter unit defining a second filter chamber, a second air inlet for admitting air into the second filter chamber and a second air outlet for exhausting air from the second filter chamber, a third filter unit defining a third filter chamber, a third air inlet for admitting air into the third filter chamber and a third air outlet for exhausting air from the third filter chamber, the third inlet being connected to the second air outlet, a biologically inert filter media in the first filter chamber, a biologically active filter media in the second filter chamber, and a biologically inert filter media in the third filter chamber, whereby air passing through the apparatus passes sequentially through the first biologically inert filter media, the biologically active filter media and the second biologically inert filter media and wherein the second filter unit defines a first sump for receiving water from a lower region of the second filter chamber and the third filter unit defines a second sump for receiving water from a lower region of the third filter chamber, and the apparatus comprises a first recirculation means for feeding water from the first sump to an upper region of at least one of the first and second filter chambers and a second recirculation means for feeding water from the second sump to an upper region of the third filter chamber.