DIN ISO 11057:2011-12

DIN ISO 11057 is a test standard for the fields of environmental protection and process technology with respect to the dust removal of emission gases (containing dust concentrations in the range of some hundred milligrams per cubic metre (mg/m³)) up to some hundred grams per cubic meter (g/m³) in large-scale industry but also in medium-sized businesses. The document is directed at representatives of all industrial sectors in which flue gases to be filtered (dust removal) occur as well as at representatives of regulatory authorities, test facilities, professional associations and planning offices. This International Standard specifies a standard reference test method regarding comparative characterization of filter media as well as the cyclical behaviour of filter media. The test method, the characteristics of the required test apparatus, the test conditions, as well as the evaluation and the presentation of the results - and the minimum requirements for equivalence apparatus - are specified. The filter media are used in filter elements (for instance, bag filters, pocket filters or cartridge filters) for dry gas cleaning under standardized test conditions and exposed to a gas flow with a dispersed test dust. Depending on the inlet dust concentrations concerned, a dust cake is more or less rapidly formed upon the surface of the filter medium which shall be periodically removed in order to maintain the filtration process. Under the standard conditions described, the test focuses on the comparison of different filter media, which demonstrate the operating and separation behaviour of different filter media during practical use. The main reason for testing is to gain information about both the operational performance during use and the particle emission of cleanable filter media. The design service life of these filters is usually 2 years to 4 years. They shall provide clean-gas concentrations in the low mg/m³ range without an excessive rise in residual pressure drop for the cleaned filter or a low cleaning frequency. The systematic characterization and evaluation of filter media with respect to their relevant long-term operational properties (filtration and cleaning behaviour) and particle emission, in addition to their well-defined textile properties, are still a major problem not only for the developers and manufacturers of filter media, but also for the producers and users of filter installations. Therefore, there is a demand for improved methods for the characterization and evaluation of cleanable filter media. The investigated test specimen is compared and assessed on the basis of the development of so-called characteristic filtration data. Additional tasks such as verifying filter media concerning PM_2,5 emissions, the classification of different filter media according to their filtration performance or the cleanability and durability of filter elements are addressed. The method described in this standard is based on VDI 3926 Part 1, whereby Application 1 of VDI 3926 Part 1 has been specified as the reference method. The International Standard has been prepared by ISO/TC 146/SC 1 "Stationary source emissions" in Working Group 23 "Test method for cleanable filter media". The secretariat of ISO/TC 146 "Air quality" is held by DIN; WG 23 is under German chairmanship. The responsible German committee is NA 134-01-59-01 UA "Nationales Spiegelgremium zu ISO/TC 146/SC 1/WG 23 'Prüfverfahren von Filtermedien für Abreinigungsfilter'" ("Mirror Committee of ISO/TC 146/SC 1/WG 23 'Test methods of filter media for cleanable filters'").