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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Artificial Neural Networks,Wavelet transform,Vertical liquid-liquid flow,Two–phase flow,Oil holdup,Flow pattern,Pressure fluctuations
- چکیده:
- چکیده انگلیسی: In this work, the feasibility of flow pattern and oil hold up the prediction for vertical upward oil–water two–phase flow using pressure fluctuation signals was experimentally investigated. Water and diesel fuel were selected as immiscible liquids. Oil hold up was measured by Quick Closing Valve (QCV) technique, and five flow patterns were identified using high-speed photography through a transparent test section with Inner Diameter (ID) of 0.0254 m. The observed flow patterns were Dispersed Oil in Water (D O/W), Dispersed Water in Oil (D W/O), Transition Flow (TF), Very FineDispersed Oil in Water (VFD O/W) and a new flow pattern called Dispersed Oil Slug & Water in Water (D OS& W/W). The pressure fluctuation signals were also measured by a static pressure sensor and decomposed at five levels using wavelet transform. Then, standard deviation values of decomposition levels were used as input parameters of a Probabilistic Neural Network (PNN) to train the network for predicting the flow patterns. In addition, some considered numerical values for actual flow patterns together with the signal energy value of each level were used as input parameters of a MultiLayer Perceptron (MLP) network to estimate the oil holdup. The results indicated good accuracy for recognition of the flow patterns (accuracy of 100% and 95.8% for training data and testing data, respectively) and oil holdup (AAPE=9.6%, R=0.984 for training data and AAPE=8.07%, R=0.99 for testing data).
- انتشار مقاله: 02-05-1393
- نویسندگان: Sadra Azizi,Hajir Karimi,Parviz Darvishi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Activated charcoal,Palm kernel waste,Xylene
- چکیده:
- چکیده انگلیسی: Xylene is an aromatic hydrocarbon that is a highly toxic compound. Therefore, it is essential to remove this component from wastewater before discharging it to the environment. In this research work, palm kernel biomass was activated chemically by H3PO4 and synthesized activated charcoal was applied to separate xylene from aqueous media. The prepared activated charcoal was characterized using FTIR, BET, SEM, pHzpc measurement, Boehm analysis methods. The characterization tests indicated that the produced activated carbon has acidic character with various functional groups and micropores structure. The values of external mass transfer coefficients ranged from 1.87×10-5 to 1.90×10-5. By increasing the temperature, the pore and surface diffusion coefficients were increased from 1.15×10-9 to 1.91×10-9 and 6.98×10-16 to 7.58×10-16, respectively. Sensitivity analysis indicated which the pore diffusion and film diffusion are the main mass transfer parameters. Equilibrium analysis also revealed that the multilayer model with saturation could well describe the data. The number of adsorbate ions for one site, the number of adsorption layers, density of receptor site, and the energy of adsorption at layers were determined using statistical physics modelling. The maximum capacity of prepared activated charcoal at the experimental condition for xylene adsorption was 23.48 mg g-1.
- انتشار مقاله: 01-04-1397
- نویسندگان: Hakimeh Sharififard,Asghar Lashanizadegan,Rahman Pazira,Parviz Darvishi
- مشاهده