Patent ID: 8440007

Claim:
A filtration system for removing fats, oils and/or grease contained in an air stream, the system comprising: an air flow-defining element adapted to define a path through which air containing fats, oils, and/or grease can flow; a water-supplying element adapted to supply water such that the water traverses the air flow path, and, on traversing the air in the air flow path, the water cools the air and thereby causes any vaporized impurities entrained therein, including fats, oils and/or grease, to condense and to fall under gravity out of the air flow path; a re-circulating element adapted to re-circulate the water after the water has contacted the air flow path; and a filter for trapping fats, oils and grease entrained in the water after the water has contacted the air flow path, and before the water is recirculated by the re-circulating element, wherein the water-supplying element comprises at least one nozzle of substantially circular cross-section and at least one plate, disposed in relation to its associated nozzle such that water emerging from each nozzle is deflected by its associated plate to create a continuous curtain of water, the water supplying element supplies a substantially continuous curtain of water which, when viewed along the air flow direction, extends substantially completely across the air flow path, the arrangement being such that the air extracted by the water is caused to traverse the water curtain, the water supplying element is arranged to generate at least two curtains of water, each of which extends only part-way across the air flow path but which overlap when viewed along the air flow direction to form a composite curtain which extends substantially completely across the air flow path, and the at least two curtains of water are located at different positions along the air flow path, so that interaction between the curtains is avoided, or at least reduced, so as to inhibit turbulent flow of water within the curtain.