| 摘要 |
Filter elements are described in which a pleated cylindrical sheet of non-woven microporous glass fibre filter material impregnated with a binder, which may be silicone, polyurethane, phenolic resin or epoxy resin, is mounted in contact with a cylindrical supporting sheet of, for example, expanded metal for maintaining the filter material against shock pressure loads. To protect the filter material during assembly a porous layer of protective material may be interposed between the filter material and the supporting cylinder. The supporting cylinder may be a simple cylinder or pleated so as to fit the filter material. An activated carbon layer for removing odours during air filtration may be added to the filter material. When the air contains oil mist, a layer containing dye that will be taken up by the oil and discolour the filter element as a warning indication that the filter has become saturated, may be interposed between the filter material and the activated carbon layer. The filter material may comprise an organic binder holding together borosilicate glass fibres, this amorphous mass being further impregnated by a synthetic resin binder. The filter material may consist of a glass fibre filter paper with a further layer of non-woven material secured thereto by a synthetic resin binder. |
