Extraction system and a component therefor

An extraction system comprises a canopy for receiving fumes. An aperture is defined in the top of the canopy, and dusting extends from the canopy, in communication with the fumes at the aperture, to an in-line extractor fan. Further ducting extends from the in-line extractor fan to an external extractor fan. A path for the extraction of fumes by the system is defined by the inner surfaces of the canopy, the ductings and the casings of the extractor fans. The inner surfaces of each of these components are coated with a non-stick, heat resistant material such as polytetrafluoroethene (PTFE).

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing, there is shown an extraction system generally designated 10 which comprises a canopy 12 for receiving fumes (for example hot air gases and grease particles produced during cooking processes). An aperture 14 is defined in the top of the canopy 12 , and a conduit in the form of ducting 16 extends from the canopy 12 in communication with the fumes at the aperture 14 . The ducting 16 extends to an in-line extractor fan 18 comprising a casing housing a fan 22 driven by a motor 24 . A second conduit in the form of further ducting 26 extends from the in-line extractor fan 18 to an external extractor fan 28 comprising a casing 30 , a fan 32 and a motor 34 . A path for the extraction of fumes by the system 10 is defined by the inner surfaces of the canopy 12 , the ducting 16 , the casing 20 , the ducting 26 and the casing 30 . The inner surfaces of each of these components is coated with a non-stick, heat resistant material such as polytetrafluoroethene (PTFE). Suitable such material is sold under the wade mark TEFLON. Also, components in the form of elements of the extractor fans, for example the blades of the fans 22 , 32 and the motors 24 , 34 are also coated with PTFE. The coating of the inner surfaces, and the elements as described above means that any part of the extraction system which comes into contact with the fumes being extracted is coated with the PTFE which prevents or substantially reduces the amount of matter That sticks to the surfaces or to the elements, thereby reducing the risk of fire, In addition, since PTFE is itself heat resistant and flame retardant, the risk of fire is further reduced. The preferred embodiment of the present invention has the advantage that it facilitates cleaning, it provides a reduced fire hazard. Also, since the non-stick properties of PTFE will prevent or substantially reduce the build up of bacteria it will reduce the danger of the spread of diseases, such as legionaires disease. Various modifications can be made without departing from the scope of the invention. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.