This paper’s aim was to model the adsorption of VOC (volatile organic compound) vapor from gas streams onto fixed bed porous adsorbent particles under various operation conditions. A mathematical model based on gas plug flow was developed to predict the process dynamics. An experimental study to highlight the influence of process variables on adsorption dynamics, described by bed saturation curves, was performed in order to identify the more relevant model parameters for the laboratory scale fixed bed adsorption column used. Experimental data concerning the adsorption of n-hexane and 2-propanol from air streams onto fixed bed granular activated carbon emphasized an increase in saturation adsorption capacity of activated carbon at high values of operation temperature and species boiling point as well as at a low level of air superficial velocity. The model predicted well the real conditions, and it could facilitate the design, scale-up, and operation of fixed bed adsorption columns.

Synthesis of bacterial cellulose by Acetobacter xylinum in static conditions was performed. In order to optimize the cultivation conditions a factorial experiment with four factors (operating temperature, substrate concentration, co-substrate concentration and air specific flow rate) and two levels was used. Correlations between cellulose yield, respectively added water specific use, and process factors were established.

Pyrolysis was performed on wheat grains untreated or impregnated with nickel nitrate solutions, into a fixed bed column, in the presence of a carbon dioxide stream. This produced a char with or without nickel, pyrolytic oil and a gaseous fraction. The distribution of these fractions was dependent on variations in heat flux, carbon dioxide superficial velocity and nickel nitrate solution concentration. The paper focused on establishing the qualitative and quantitative influence of these experimental variables on pyrolysis dynamics. In order to obtain a process characterization, a factorial experiment was used, wherein the pyrolysed material mass, collected oil mass, operating time, material bed temperature, volatiles temperature and column wall temperature were the evaluated process responses. A model reproducing pyrolysis curves was proposed considering the process dynamics as a result of competition between the appearance and extension of local pyrolysis points.

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To cite this version:Tănase Dobre, Anicuţa Stoica, Gustav Iavorschi, Oana Cristina Pârvulescu.Characterization of cooling systems based on heat pipe principle to control operation temperature of hightech electronic components. Applied Thermal Engineering, Elsevier, 2010, 30 (16) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe use of cooling systems based on heat pipe principle to control operation temperature of electronic components is very efficient. They have an excellent miniaturizing capacity and this fact creates adaptability for more practical situations.Starting from the observation that these cooling systems are not precisely characterized from the thermal efficiency point of view, the present paper proposes a methodology of data acquisition for their thermal characterization. An experimental set-up and a data processing algorithm are shown to describe the cooling of a heat generating electronic device using heat pipes. A Thermalright SI-97 PC cooling system is employed as a case-study to determine the heat transfer characteristics of a fins cooler.