Analysis of volatile organic compounds emitted from aircraft carpets:comparison using headspace and dynamic chamber tests

Volatile organic compounds(VOCs) emitted from three types of carpets used in aircrafts were compared by using headspace and dynamic chamber tests. The headspace samples contained many compounds that were not detected in the dynamic chamber test; in addition, the dominant VOCs found by these two methods were different. The findings indicate that for highly sorptive materials such as carpets, headspace analysis may give inaccurate indication of actual VOC emissions, and it is necessary to conduct dynamic chamber tests over a certain period of time in order to identify the true emission characteristics. From the dynamic chamber tests, 2-ethyl-1-hexanol was the main VOC emitted from all three carpets. The study also examined the emission characteristics of aircraft carpets. In all experiments, total VOC(TVOC) concentration peaked within a few hours after the start of the experiment and was followed by rapid decay. The emission parameters of TVOC emitted by all three carpets were calculated and the simulated data matched the measured data well.

Design and Characterization of an Aerosol Test Chamber for Emergency Response Patient Contamination Control Simulation and Research

Contaminated or infected patients present a risk of cross-contamination for emergency responders, attending medical personnel and medical facilities as they enter a treatment facility. The controlled conditions of an aerosol test chamber are required to examine factors of contamination, decontamination, and cross-contamination. This study presents the design, construction, and a method for characterizing an aerosol test chamber for a full-sized manikin on a standard North Atlantic Treaty Organization litter. The methodology combined air velocity measurements, aerosol particle counts and size distributions, and computational fluid dynamics modeling to describe the chamber’s performance in three dimensions. This detailed characterization facilitates future experimental design by predicting chamber performance for a variety of patient-focused research.

Numerical simulation research of heating chamber for high performance hydrogen bell-type annealers

The mathematic model of heating chamber for implementing the prediction of the annealing craft and improving the self adapting with the expansion of the new annealing furnace form, new annealing crafts and new kinds of steel coil has been established. The model developed which including the temperature for gas in heating chamber and the heating cover is based on the characteristics of anneal craft and the situations of locale production run. Firstly, the characteristic of the heating cover which limits the temperature was considered. Secondly, the locale production run condition and dispatching condition were considered. Finally, combining with the models and the simulation system, the numerical simulation research of the anneal process for the high performance hydrogen bell-type annealer as well as the spot experiment test were carried out. The results obtained from the developed models, usually finished less than thirty seconds, are in fair agreement with the test values, such as the relative errors of annealing times were within ±5%, and the quality＇ of the annealed steels were guaranteed.

Experimental Study on Purification Efficiency of Air Purifier for the Indoor Total Volatile Organic Compounds

By using total volatile organic compounds （TVOC） as the objective volatile pollutant, the purification efficiency of some representative air purifiers bought in the market was determined under the relatively independent and stable environmental conditions supplied by the self-made multi- functional environmental test chamber. Various evaluation parameters of TVOC were calculated based on the tested results, such as purification ef- ficiency and removal rate. The results showed that the TVOC purification efficiency increased with enhancing the temperature or lessening the rela- tive humidity, but this effect is not obvious. The air purifiers which use photocatalytic technology have higher TVOC purification efficiency than those which only use some adsorption technology. The purification efficiency and removal rate can be more accurate to evaluate the purification efficiency of air purifiers.

Numerical Simulation and Experimental Research on Indoor Environment Separated with Down-Feed Air Curtain

Indoor environment separated with down-feed air curtain was numerically simulated and experimen-tally researched. Indoor airflow and temperature fields separated with air curtain were numerically simulated. Re-sults show that both polluted airflow and thermal air current can be separated with a down-feed air curtain to pre-vent contaminants from spreading in the room space. In a test chamber, the smoke of burning Tibetan incense served as the source of contaminants, and the probe test shows that 1.0 μm is the prevailing diameter of the smoke particles. During the release of the smoke, the particle concentration of the indoor air was tested with a laser particle counter at the points of three different heights from the floor when the air curtain was running or not. Experimental results show that the higher the test point is located, the lower the particle concentration is, implying that the sepa-rating or isolating effect decreases as the air velocity of the curtain reduces along with the height descends. Accord-ing to both simulation and experimental results, down-feed air curtain can separate indoor environment effectively when the supply air velocity of air curtain is not less than 3 m/s. In order to strengthen separation effect, it is sug-gested that the supply air velocity be speeded up to 5 m/s.