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Guo Y.-H.,Beijing Forestry University | He Z.-B.,Beijing Forestry University | Lin Z.-X.,Beijing Forestry University | Peng Y.-Q.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Yi S.-L.,Beijing Forestry University
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2014

Poplar with the thickness of 2, 4 and 6 cm was taken as specimen in thins paper. The weight of wood samples pre-and post-treatment and the temperature field were studied under the conditions of 100 and 140℃. What's more, the pressure field inner wood was also studied at the temperature of 110℃. The results showed that the weight of samples decreased as the time went by, and the minimum value was 23.0% when the temperature was 100℃, while the maximum value was 78.27% when the temperature was 140℃; the temperature inner wood increased at the beginning of pre-treatment process, and became constant at last, the maximum value were 92 and 110℃ when the treating temperature were 100 and 140℃, respectively. Lastly, the relationship among the moisture content variation, the treating time and the treating temperature was founded. What's more, the theoretical model of the moisture decrement, which was corresponding to the practical value, was established to simulate the real production. Source


Song W.,Capital University of Economics and Business | Song W.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Song W.,Tsinghua University | Kong Q.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Li H.,Capital University of Economics and Business
Huagong Xuebao/CIESC Journal | Year: 2013

Volatile organic compound(VOC)emission from wood furniture surface is a complex process of mass transfer with negative environmental effects. To have a clear picture of mass transfer characteristics, a new fully analytical model was established by using Laplace Transform, which comprehensively considered two key mechanisms of mass transfer(diffusion and convection), resistances of changing climate chamber concentration, background concentration and concentration of air inflow, and was applicable to simulating unventilated or ventilated condition, e. g., predicting the concentration in climate chamber or furniture, evaluating the mass transfer rate or amount of emission and estimating the time for climate chamber concentration to reach an acceptable level. Then this model was analyzed to propose a convenient and rapid experimental method for simultaneously determining three significant mass transfer parameters of target VOC: emittable concentration ρ0, diffusion coefficient δ and partition coefficient β, by making use of the process concentrations in a ventilated climate chamber. On one hand, a linear relationship was established between elapsed time and logarithm of difference between process concentration and equilibrium concentration, and its slope and intercept were the simple functions of δ and β. By data fitting and analysis, the slope and intercept were easily obtained as well as δ and β. On the other hand, a relationship was also established between β and ρ0. Combined with the known β, ρ0 could be easily further obtained too. In experiments, this method was used to study ρ0, δ and β of formaldehyde and TVOC mass transfer from a piece of wood furniture made of medium density fiberboards, urea formaldehyde resin adhesive, veneer and polyurethane paint, which showed a coefficient of variation less than 5% between experimental results and calculation according to a reference treatment method by making use of mass transfer process concentration in an unventilated chamber, and effectively avoided potential troubles, such as negative pressure possibly caused by sampling in an unventilated chamber. The predicted results of climate chamber concentration in either unventilated or ventilated condition based on determined parameters and a numerical calculating model were in agreement with corresponding experimental data. In conclusion, both the proposed model and method are accurate enough to predict or determine mass transfer characteristics of VOC emission from wood furniture surface. © All Rights Reserved. Source


Song W.,Capital University of Economics and Business | Song W.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Song W.,Tsinghua University | Kong Q.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Li H.,Capital University of Economics and Business
Huagong Xuebao/CIESC Journal | Year: 2013

Emission of volatile organic compounds (VOC) from building materials is a complex process of mass transfer. To have a clear picture of mass transfer characteristics, this paper first established an explicitly fully analytical model describing VOC emission behavior from dry building materials, which is applicable to emission simulation in static chamber that is most unfavorable to human health. The VOC concentration in the chamber predicted based on the mass transfer parameters in literature is in good agreement with corresponding experimental data and numerical calculation in literature. Based on this model, an experimental method is proposed for convenient, rapid and simultaneous measurement of four important mass transfer parameters for VOC emission prediction (emittable concentration C0, diffusion coefficient D, partition coefficient K and convection mass transfer coefficient hm) by making use of emission equilibrium or process concentration in a static chamber at a series of background concentrations. With the values of C0, D, K and hm for formaldehyde emission mass transfer obtained experimentally from two different medium density fiberboards, the numerically predicted results of VOC concentration in either static or dynamic chamber are coincident with experimental data. The model and method are accurate enough for emission simulation of building materials. © All Rights Reserved. Source


Song W.,Capital University of Economics and Business | Song W.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Song W.,Tsinghua University | Kong Q.,Capital University of Economics and Business | And 2 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2013

Volatile organic compounds (VOCs) emission from wood furniture is a complex process of mass transfer that has negative environmental impacts. To have a clear picture of emission characteristics in the complete emission period, an explicit fully analytical model describing VOCs emission behavior in the static chamber was firstly established. Emission in the static chamber is the most unfavorable to human health. This model was applied to further develop an experimental method for conveniently, rapidly and simultaneously measuring three significant mass transfer parameters of target VOCs emitted from furniture by making use of emission process concentrations in a static chamber. These transfer parameters include emittable concentration C0, diffusion coefficient D and partition coefficient K. In experiments, we used this method to study twenty pieces in five classes of furniture customized from ten manufacturers with a variety of common raw materials. Nineteen key harmful chemicals were obtained according to the frequency of occurrence, negative effects on health and emittable concentration. In addition, the values of overall C0, D and K fit normal distribution well. Combined with numerical experiments and parameter regression based on common range of emission parameters, a group of dimensionless correlations was attained, which reflected the emission mechanism and could be well applied to the data analogy under different scales in time and space. The correlations indicated that both air change rate and loading factor had greater impacts on emission than that of air velocity. Source


Song W.,Capital University of Economics and Business | Song W.,National Center for Quality Supervision and Inspection of Furniture and Indoor Environment | Song W.,Beijing Products Quality Supervision and Inspection Institute | Song W.,Tsinghua University | And 4 more authors.
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2013

A new fully analytical model was established for describing volatile organic compounds (VOC) emission from wood furniture, which comprehensively considers the mechanisms and resistances in mass transfer and can be used in unventilated and ventilated conditions. Then this model was analyzed to propose a new method for conveniently, rapidly and simultaneously measuring four significant mass transfer parameters of target VOC, emittable concentration C0, diffusion coefficient D, partition coefficient K and convection mass transfer coefficient h, using several emission cycles' mass transfer equilibrium and process concentrations of the same furniture in an unventilated chamber. In experiments under (23±0.5)°C and relative humidity 45%±5%, this method was used to measure formaldehyde and total VOC (TVOC) mass transfer from a piece of furniture, for formaldehyde, C0=4994 mg/m3, D(4.05=10-10m2/s, K=499 and h=1.4×10-3 m/s, for TVOC, C0=19939 mg/m3, D=2.12×10-10 m2/s, K=1001 and h=5.0×10-4 m/s, which obeys the common range and shows a coefficient of variation less than 0.5% between the present results and calculation based on a reference treatment method. The predicted results of emission concentration in the chamber at either unventilated or ventilated condition based on measured parameters and a numerical calculating model were coincident with corresponding experimental data, showing an average deviation less than 3.5% between them. Source

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