Study On The Test System For Measuring The Filtration Efficiency Of Air Cleaner

Air cleaners are widely used in air inlet system of combustion engine, gas turbine and air compressor, to remove the dust and impurity in the inlet air of power equipment. This paper analyzes the limitation of air cleaner efficiency test by the procedure of gravimetric, and introduce the advantage of air cleaner efficiency test by particle size. It is proved that the combination of gravimetric-procedure and counting-procedure by particle size is a better way to get overall and objective knowledge, then to evaluate air cleaner performance. Therefore, the purpose is to design and assemble a test system aims at evaluating the filtration performance of air cleaner by the combined method of gravimetric efficiency and counting efficiency by particle size.On the basis of analyzing the test standards for air cleaner performance over the world,it concludes that the gravimetric efficiency could not tell the difference between high efficiency air cleaner. Through starting from the classic mathematical model in the filtration theory-single fiber model, effect factors of filtration efficiency of air cleaner are analyzed. Influencing factors such as fiber diameter, filtration velocity and fiber filling rate on single fiber model efficiency are analyzed in quantity, and it concludes that the most penetrating particle size of air cleaner is approximate at 0.4 micrometer, thus it is necessary to get the counting efficiency at the channel of 0.4 micrometer using particle counter. On the basis of this standpoint, it is recommended that method of testing general ventilation air-cleaning devices for removal efficiency by particle size can be applied for air cleaner filtration efficiency test which is used for gas turbine. A test system for air cleaner counting efficiency by particle size is created by this idea, and it can be used to measure the counting efficiency by particle size under different dust-loading quantity, and then evaluate the air cleaner filtration performance during the whole life cycle by the average counting efficiency. This test system is a computer-centered and high automatic data sample and analyzing system, with friendly user interface by Visual Basic 6.0 programming language. User can choose to either measure the initial efficiency only or measure the average efficiency during the whole life cycle according to their requirement. The accuracy and test error of the system are analyzed. Some experiments with control group are carried out on this test system, for example, relationship between filtration velocity and efficiency, filtration velocity and resistance are researched. Besides, air cleaner filtration efficiency under different dust loading quantity is measured and it is supposed to be useful in the research of relevant theory.Finally, with practical examination, this new designed test system and its test results are all proved to reach the requirement of the air cleaner efficiency test for gas turbine. The accomplishment of this test system provides manufactures a good tool to ensure the quality of their air cleaner products, and should provide some ideas and directions for the air cleaner filtration efficiency test system in the future.