Vacuum cleaner filter for removal of odours

摘要

A filter for the removal of odours in a vacuum cleaner is positioned after the dust filter and before the fan. The filter includes either synthetically fabricated activated carbon balls of 0.1-2 mm. diameter or small particles impregnated with pulverised activated carbon with a diameter of 0.2-1 mm, either of which are mounted on a support permeable to air. When carbon balls are used in the anti-odour filter they are obtained by carbonisation and activation of ion exchange. They have an internal surface of 900 m<2>/g. When pulverised activated carbon is used it has a diameter of 3-10 microns and is used with 20-100 parts of polyacrylate binder to carbon. The filter itself is in the form of a bag surrounding the dust filter. It is made of an air permeable material such as paper or textile which may be woven, knitted or non-woven. Carbon balls are attached to the bag by a two part adhesive of pre-polymer and a low level of solvent, which is applied to the surface in points. The carbon (in either form) covers 30-70% of the support surface. Alternatively, if carbon balls are used the filter may be made of a polyurethane foam with carbon in its pores, in the form of strips or bands. An additional fine dust filter (HEPA) may be used upstream of the anti-odour filter.