Modeling and Simulation
Hajar seyfi; Sirous shafiei; Reza Dehghanzadeh; Parya Amirabedi
Abstract
The removal of Acrylonitrile (AN) from waste gas streams using biological methods, due to their better performance, has recently gained more attraction. The purpose of this research is modeling the AN removal by a bio-filter. The validation of the model is done by using the experimental data of a bench-scale ...
Read More
The removal of Acrylonitrile (AN) from waste gas streams using biological methods, due to their better performance, has recently gained more attraction. The purpose of this research is modeling the AN removal by a bio-filter. The validation of the model is done by using the experimental data of a bench-scale bio-filter bed column including yard waste compost and shredded hard plastics and thickened municipal activated sludge. In this work the kinetics of the biodegradation of Acrylonitrile is first investigated. Then equations of the biofilm and air are obtained at a steady state and constant temperature. The unknown parameters of the model are determined by the least square optimization method along with solving the model equations using MATLAB. For inlet concentrations less than 1 g/m3 the model results show reasonable similarities to the experimental data. The effect of various parameters on the bio-filter performance is evaluated. The Peclet number, biofilm thickness and biomass concentration are the most important parameters. The proposed model can be useful for design purposes.
Transport Phenomena,
Sh. Ghodbanan; R. Alizadeh; S. Shafiei
Volume 13, Issue 2 , April 2016, , Pages 57-70
Abstract
In this study a developed model has been used to evaluate the paper drying process and examine the pocket dryer conditions of a multi-cylinder fluting paper machine. The model has been developed based on the mass and energy balance relationships in which the heat of sorption and its variations with paper ...
Read More
In this study a developed model has been used to evaluate the paper drying process and examine the pocket dryer conditions of a multi-cylinder fluting paper machine. The model has been developed based on the mass and energy balance relationships in which the heat of sorption and its variations with paper temperature and humidity changes have been taken into account. The applied model can be used to compute the drying parameters and analyze the pocket drying conditions. Furthermore, the effects of web tension on the heat transfer have been investigated. In the available operating range of the web tension, the overall mean heat transfer coefficient will be within 300-550 W/m2.K. The pocket air temperature was between 50 and 90 oC. The dew point temperature wasn’t close to the pocket air temperature and dew drop never happened during the dryer section. Based on the modeling result and using a novel technique, the maximum level for the exhaust air in the studied machine can be estimated to be 0.2 kg H2O/kg dry air. Result shows that increasing the exhaust humidity to the optimal level will lead to 4% reduction in the required energy and 20% rise in the heat recovery potential. Accordingly the specific heat consumption per evaporated water for the studied drying section can be reduced from 3.96 to 3.81 GJ per ton water.