1 INTRODUCTIONMany different types of reactors,for example,fixed bed,moving bed,fluidized bed and spoutedbed,have been used in industrial production and laboratory in research studies.Althougheach of these coal gasifi...1 INTRODUCTIONMany different types of reactors,for example,fixed bed,moving bed,fluidized bed and spoutedbed,have been used in industrial production and laboratory in research studies.Althougheach of these coal gasifiers has its own specific advantages,there exists,generally speaking,certainwaste gas in product gas because of the direct burning of coal with oxygen or air to provide heatneeded in the endothermic process of coal gasification in gasifiers.A new type of moving展开更多
Optimization of draft tube position in a spouted bed reactor used for treatment of wastewater containing low concentration of heavy metals is investigated in this paper. Response surface methodology is used to optimiz...Optimization of draft tube position in a spouted bed reactor used for treatment of wastewater containing low concentration of heavy metals is investigated in this paper. Response surface methodology is used to optimize the draft tube height, the draft tube width and the gap between the bottom of the draft tube and the inlet nozzle. It is observed that the draft tube with a height of 60 millimeter, width of 12 millimeter and the gap of 13 millimeter between its bottom and inlet nozzle, results in optimum value of minimum spouting velocity, measured 45 cubic centimeter per second (2.7 Liter per minute) .展开更多
Open-sided draft tubes provide an optimal gas distribution through a cross flow pattern between the spout and the annulus in conical spouted beds.The design,optimization,control,and scale-up of the spouted beds requir...Open-sided draft tubes provide an optimal gas distribution through a cross flow pattern between the spout and the annulus in conical spouted beds.The design,optimization,control,and scale-up of the spouted beds require precise information on operating and peak pressure drops.In this study,a multi-layer perceptron(MLP)neural network was employed for accurate prediction of these hydrodynamic characteristics.A relatively huge number of experiments were accomplished and the most influential dimensionless groups were extracted using the Buckingham-pi theorem.Then,the dimensionless groups were used for developing the MLP model for simultaneous estimation of operating and peak pressure drops.The iterative constructive technique confirmed that 4-14-2 is the best structure for the MLP model in terms of absolute average relative deviation(AARD%),mean square error(MSE),and regression coefficient(R^(2)).The developed MLP approach has an excellent capacity to predict the transformed operating(MSE=0.00039,AARD%=1.30,and R^(2)=0.76099)and peak(MSE=0.22933,AARD%=11.88,and R2=0.89867)pressure drops.展开更多
Spouted pressure drop was one of important parameters in the design and application of spouted bed.In this paper spouted pressure drop of a new double nozzle rectangular draft tube spouted bed was studied.A 120 mm...Spouted pressure drop was one of important parameters in the design and application of spouted bed.In this paper spouted pressure drop of a new double nozzle rectangular draft tube spouted bed was studied.A 120 mm×240 mm cross section double nozzle rectangular stainless steel spouted bed was used to investigate the effects of flow rate,particle diameter,bed height,draft tube diameter and height of entrainment zone on maximum spouted pressure drop.Maximum spouted pressure drop increased with increasing flow rate, increasing particle diameter and increasing height of entrainment zone.Maximum spouted pressure drop increased and then decreased with increasing draft tube diameter.Maximum spouted pressure drop was hardly affected by bed height.By regression of experimental data,the correlation of maximum spouted pressure drop with the above parameters was obtained.展开更多
文摘1 INTRODUCTIONMany different types of reactors,for example,fixed bed,moving bed,fluidized bed and spoutedbed,have been used in industrial production and laboratory in research studies.Althougheach of these coal gasifiers has its own specific advantages,there exists,generally speaking,certainwaste gas in product gas because of the direct burning of coal with oxygen or air to provide heatneeded in the endothermic process of coal gasification in gasifiers.A new type of moving
文摘Optimization of draft tube position in a spouted bed reactor used for treatment of wastewater containing low concentration of heavy metals is investigated in this paper. Response surface methodology is used to optimize the draft tube height, the draft tube width and the gap between the bottom of the draft tube and the inlet nozzle. It is observed that the draft tube with a height of 60 millimeter, width of 12 millimeter and the gap of 13 millimeter between its bottom and inlet nozzle, results in optimum value of minimum spouting velocity, measured 45 cubic centimeter per second (2.7 Liter per minute) .
文摘Open-sided draft tubes provide an optimal gas distribution through a cross flow pattern between the spout and the annulus in conical spouted beds.The design,optimization,control,and scale-up of the spouted beds require precise information on operating and peak pressure drops.In this study,a multi-layer perceptron(MLP)neural network was employed for accurate prediction of these hydrodynamic characteristics.A relatively huge number of experiments were accomplished and the most influential dimensionless groups were extracted using the Buckingham-pi theorem.Then,the dimensionless groups were used for developing the MLP model for simultaneous estimation of operating and peak pressure drops.The iterative constructive technique confirmed that 4-14-2 is the best structure for the MLP model in terms of absolute average relative deviation(AARD%),mean square error(MSE),and regression coefficient(R^(2)).The developed MLP approach has an excellent capacity to predict the transformed operating(MSE=0.00039,AARD%=1.30,and R^(2)=0.76099)and peak(MSE=0.22933,AARD%=11.88,and R2=0.89867)pressure drops.
文摘Spouted pressure drop was one of important parameters in the design and application of spouted bed.In this paper spouted pressure drop of a new double nozzle rectangular draft tube spouted bed was studied.A 120 mm×240 mm cross section double nozzle rectangular stainless steel spouted bed was used to investigate the effects of flow rate,particle diameter,bed height,draft tube diameter and height of entrainment zone on maximum spouted pressure drop.Maximum spouted pressure drop increased with increasing flow rate, increasing particle diameter and increasing height of entrainment zone.Maximum spouted pressure drop increased and then decreased with increasing draft tube diameter.Maximum spouted pressure drop was hardly affected by bed height.By regression of experimental data,the correlation of maximum spouted pressure drop with the above parameters was obtained.
