Analysis of the filtration process of inlet air to an internal combustion engine in a two-stage filter
The destructive effect of mineral dust grains (SiO2 and Al2O3) on the accelerated abrasive wear of engine connections was demonstrated. It was shown that the use of two-stage (multi-cyclone-baffle) air intake filters for motor vehicle engines used in conditions of high air dustiness is necessary. The aim of the work was a theoretical and experimental analysis of the properties of paper filters operating in series behind a cyclone and without a cyclone. An original research methodology was used, which consisted in simultaneous testing of a single cyclone and a paper filter with an appropriately selected surface area. The system tests (cyclone-paper filter) were carried out using conditions that corresponded to the actual filtration conditions in a two-stage air filter, including the filtration speed in the paper bed, the dust concentration in the air sucked into the engine and the average cyclone inlet speed. The basic filtration characteristics of filtration efficiency and accuracy and pressure drop of two paper filters were determined as a function of the dust mass fed to the system (cy-clone-paper filter) or directly to the characteristic filter. It was found that the paper filter operating in series behind the cyclone achieves four times longer operating time limited by a specific value of permissible re-sistance. In the initial (short) filtration period, lower filtration efficiency values were obtained than the required value of 99.9%. On the other hand, dust grains with a maximum size of 13.5 µm were found in the air behind the paper filter. The required filtration accuracy of the engine intake air is in the range of 2-5 µm. For this reason, the initial air filtration period is an undesirable phenomenon and may cause accelerated engine wear.
Topic: Engine testing and modeling
Author: Tadeusz Dziubak
Co-authors:
