Filtration efficiency of portable air cleaner(PAC)is affected by resident perceptions and adherences to when and how to operate the PAC.Incorporating PAC with smart control and sensor technology holds the promise to e...Filtration efficiency of portable air cleaner(PAC)is affected by resident perceptions and adherences to when and how to operate the PAC.Incorporating PAC with smart control and sensor technology holds the promise to effectively reduce indoor air pollutants.This study aims to evaluate the efficiency of a PAC at removing indoor fine particulate matters(PM_(2.5))exposure under two automated operation settings:(1)a time-based mode in which the operation time is determined based on perceived time periods of indoor pollution by residents;(2)a sensor-based mode in which an air sensor monitor is used to determine the PAC based on the actual PM_(2.5) level against the indoor air quality guideline.The study was conducted in a residential room for 55 days with a rolling setting on PAC(no filtration,sensor-based,time-based fil-trations)and a continuous measurement of PM_(2.5).We found that the PAC operated with sensor-based mode removed PM_(2.5) concentrations by 47%and prolonged clean air(<35 μg/m^(3))period by 23%compared to the purifications with time-based mode which reduced PM_(2.5) by 29%and increased clean air period by 13%.The sensor-based filtration identified indoor pollution episodes that are hardly detected by personal perceptions.Our study findings support an automated sensor-based approach to optimize the use of PAC for effectively reducing indoor PM_(2.5) exposure.展开更多
Deep bed filtration of carrier water with particles occurs in numerous processes of environmental, chemical, petroleum and civil engineering. For example in the petroleum industry, deep bed filtration of drilling flui...Deep bed filtration of carrier water with particles occurs in numerous processes of environmental, chemical, petroleum and civil engineering. For example in the petroleum industry, deep bed filtration of drilling fluid happens during well drilling;it also takes place near to injection wells during seawater injection or produced water re-injection causing in- jectivity reduction. In this work, the filtration theory and its mathematical model are given and the filtration coefficient will be discussed. Then the transition time, the time at which the initial layer of external filter cake is completely formed has been derived mathematically. The transition time can be obtained by calculating the trapping efficiency as a function of the number of previously deposited particles where very few particles can invade the rock and the external filtration begins to build. The prediction of particle capturing and particle retention by mathematical model is an essen- tial stage during planning and design of above-mentioned industrial processes.展开更多
基金supported by the start-up funding of University at Buffalo.
文摘Filtration efficiency of portable air cleaner(PAC)is affected by resident perceptions and adherences to when and how to operate the PAC.Incorporating PAC with smart control and sensor technology holds the promise to effectively reduce indoor air pollutants.This study aims to evaluate the efficiency of a PAC at removing indoor fine particulate matters(PM_(2.5))exposure under two automated operation settings:(1)a time-based mode in which the operation time is determined based on perceived time periods of indoor pollution by residents;(2)a sensor-based mode in which an air sensor monitor is used to determine the PAC based on the actual PM_(2.5) level against the indoor air quality guideline.The study was conducted in a residential room for 55 days with a rolling setting on PAC(no filtration,sensor-based,time-based fil-trations)and a continuous measurement of PM_(2.5).We found that the PAC operated with sensor-based mode removed PM_(2.5) concentrations by 47%and prolonged clean air(<35 μg/m^(3))period by 23%compared to the purifications with time-based mode which reduced PM_(2.5) by 29%and increased clean air period by 13%.The sensor-based filtration identified indoor pollution episodes that are hardly detected by personal perceptions.Our study findings support an automated sensor-based approach to optimize the use of PAC for effectively reducing indoor PM_(2.5) exposure.
文摘Deep bed filtration of carrier water with particles occurs in numerous processes of environmental, chemical, petroleum and civil engineering. For example in the petroleum industry, deep bed filtration of drilling fluid happens during well drilling;it also takes place near to injection wells during seawater injection or produced water re-injection causing in- jectivity reduction. In this work, the filtration theory and its mathematical model are given and the filtration coefficient will be discussed. Then the transition time, the time at which the initial layer of external filter cake is completely formed has been derived mathematically. The transition time can be obtained by calculating the trapping efficiency as a function of the number of previously deposited particles where very few particles can invade the rock and the external filtration begins to build. The prediction of particle capturing and particle retention by mathematical model is an essen- tial stage during planning and design of above-mentioned industrial processes.
