DANSK DS/ISO 11057 PDF

This International Standard presents a test method for the comparative characterization of pulse-jet cleanable filter media, to be used in filter elements (e.g. bag filters, pocket filters, cartridge filters) applied in dry gas cleaning under standardized test conditions. These test conditions have been selected among many possible ones and are intended to represent a typical operating mode of such filters so that the test will focus on comparability of different filter media under prescribed standard conditions indicating the operating and separation behaviour of various filter media during practical use. The main purpose of testing is to gain information about both, the operational performance and the particle emission of cleanable filter media. It should be noted that while one test apparatus and operating method has been chosen and described herein, it is recognized that other apparatus and operating arrangements may be found acceptable. A new apparatus will be considered acceptable when its test results demonstrate convergence with the approved apparatus and method. The criteria for convergence are defined in 4.5. The tested filter specimen is compared and assessed on the basis of the development of so called characteristic filtration data which can include the shape of pressure drop curves, the development of the residual pressure drop, the duration of the filtration/cleaning cycle, the residual dust cake mass and the dust emission. The tests are conducted under very well defined and controlled conditions concerning all relevant filtration parameters, e.g. filtration velocity, dust concentration, pressure drop prior to cleaning and the cleaning conditions [5-12]. The results obtained from this test method are not intended for predicting the absolute performance of fullscale filter facilities. However they will be helpful for the selection and development of appropriate cleanable filter media and the identification of suitable operating parameters. The results from this test will give an indicative comparison of filter media regarding their operational behaviour and particle emission to the clean gas. This International Standard describes a laboratory standard test with respect to cyclical behaviour of a filter medium. The test procedure, the characteristics of the required test facility, the test conditions and the evaluation and presentation of the results are specified. Examples of test results are demonstrated in a sample test report. It should be noted that this test will not give an accurate representation of likely field performance but an indicative comparison of filter media regarding their operational behaviour. In developing this scope other issues were considered. These included the use of woven media, reverse air cleaning, shake-deflate cleaning, single flow or double flow test rigs, test dust specification, particle charging/discharging and other limitations of the test method (see details in Annex B). Additional tasks such as verifying filter media concerning PM2.5 emissions, the classification of different media according to their filtration performance or the cleanability and durability of filter elements (i.e. projection of bag life-time) may be addressed using the introduced testing method. These topics should be dealt with in additional parts or amendments of the standard in the future (see details in Appendix C).