【国外标准】 Standard Test Method for Particle Size Distribution of Granular Activated Carbon

4.1 It is necessary to know the distribution of particle sizes of granular activated carbon in order to provide proper contact of gases or liquid in a packed bed of the material. Changes in particle size distribution can affect the pressure drop across the bed and the rate of adsorption in a bed of a given size.4.2 Mean particle diameter is a property of activated carbons that influences pressure drop.4.3 Effective size and uniformity coefficient are two properties of activated carbons often of interest in municipal water treatment applications where control of particle size is of interest.1.1 This test method covers the determination of the particle size distribution of granular activated carbon. For the purposes of this test, granular activated carbon is defined as a minimum of 90 % of the sample weight being retained on a 180 μm Standard sieve. A U.S. mesh 80 sieve is equivalent to a 180 μm Standard sieve.NOTE 1: For extruded carbons, as the length/diameter ratio of the particles increases, the validity of the test results might be affected.1.2 The data obtained may also be used to calculate mean particle diameter (MPD), effective size, and uniformity coefficient.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3.1 Exception—All mass measurements are in SI units only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.