Drying is applied to lower the moisture content of fish to a level that can prevent the growth of mould and infestation of micro-organism and thus minimizes microbial degradation.The goal of this work was to optimize ...Drying is applied to lower the moisture content of fish to a level that can prevent the growth of mould and infestation of micro-organism and thus minimizes microbial degradation.The goal of this work was to optimize the process conditions during electrical oven drying of catfish.Moisture content(MC)was quantitatively investigated during the drying process of catfish sizes using response surface methodology(RSM)to obtain minimum moisture content.The independent process variables for the drying process were temperature(50–70◦C),product thickness(10–20 mm),salt concentration(0–20%)and drying time(480–600 min.).Two factorial interaction(2FI)regression model describing the effects of independent drying process variables on the moisture content was developed.The effects of temperature and drying time were more pronounced for MC than the thickness and salt concentration.The optimum conditions were found to be temperature=63.43◦C,product thickness=14.81 mm,salt concentration=9.07%and drying time=600 min.At these optimum conditions,moisture content was found to be 2.64%w.b.Validation of experimental results with the empirical model was evaluated using coefficient of correlation(R2)which was found for the model equation as,R2=0.994.展开更多
In order to prolong the service life of the cooling zone of large scale coke dry quenching ovens,six kinds possible refractories for the cooling zone of large scale coke dry quenching ovens： SiC containing brick A,Si...In order to prolong the service life of the cooling zone of large scale coke dry quenching ovens,six kinds possible refractories for the cooling zone of large scale coke dry quenching ovens： SiC containing brick A,SiC containing brick B,mullite-andalusite brick,spinel containing brick,zirconia containing brick,corundum-mullite brick and grade B mullite brick,were analyzed in properties. It is found that the cooling zone lining adopting SiC containing bricks or mullite-andalusite bricks has much longer service life. Based on this,a new type of wear resistant brick was developed. The brick has a compressive strength of 135 MPa,a wear loss of 2. 10cm^3（only a quarter of that of the grade B mullite brick）,and a higher bulk density than the grade B mullite brick. The application of the brick in a 140t·h^（-1）coke dry quenching oven showed that it performed better than the grade B mullite brick. The cooling zone adopting the new bricks has a lower coke discharging temperature,which is beneficial to the enhancement of heat recovery efficiency and steam power generation.展开更多
The mechanical force borne by the lintel and“brackets”in the inclined channel area of CDQ and the thermal stress generated by the top-down temperature gradient were simulated by ANSYS software.The following conclusi...The mechanical force borne by the lintel and“brackets”in the inclined channel area of CDQ and the thermal stress generated by the top-down temperature gradient were simulated by ANSYS software.The following conclusions are drawn.(1)The mechanical force has very mild effect on the damage of the“brackets”.(2)The temperature gradient caused by the uneven temperature distribution of CDQ oven is the key factor affecting the“bracket”damage.The different expansion of refractory materials in various parts results in the thermal stress concentration which tears the“brackets”.(3)The structure adjustment of the“brackets”has very little effect on the thermal stress distribution.(4)The multi-phase nitride bonded silicon carbide for CDQ can effectively alleviate the stress concentration at the“brackets”,realizing the long-life and stable operation.展开更多
Drying behaviour of Jew’s mallow leaves using an oven dryer was studied.The influence of drying temperatures(50,60 and 70C)on moisture content of the leaves at stable air velocity was considered.Five drying models,i...Drying behaviour of Jew’s mallow leaves using an oven dryer was studied.The influence of drying temperatures(50,60 and 70C)on moisture content of the leaves at stable air velocity was considered.Five drying models,including,simple exponential,Page,Two-term exponential,Logarithmic,and Wang and Singh were fitted to drying data.Two-term exponential model adequately express the drying behaviour of Jew’s mallow leaves.Effective moisture diffusivity of Jew’s mallow leaves ranged from 8.18×10^-8 to 1.13×10^-7m^2/s.Dependence of the computed effective diffusivity on oven temperature was obvious.The energy required for oven drying of Jew’s mallow leaves was found to be 14.84 kJ/mol.The L^*,a^*,b^*,DE,a^*/b^*colour characteristics of the dried leaves range from 31.8 to 32.87,-3.73 to-4.37,13.6 to 16.47,69.00 to 69.73,and-0.26 to-0.34 respectively.Oven drying conditions of 50℃150 min and 70℃90min resulted to dried leaves with desirable colour characteristics.展开更多
文摘Drying is applied to lower the moisture content of fish to a level that can prevent the growth of mould and infestation of micro-organism and thus minimizes microbial degradation.The goal of this work was to optimize the process conditions during electrical oven drying of catfish.Moisture content(MC)was quantitatively investigated during the drying process of catfish sizes using response surface methodology(RSM)to obtain minimum moisture content.The independent process variables for the drying process were temperature(50–70◦C),product thickness(10–20 mm),salt concentration(0–20%)and drying time(480–600 min.).Two factorial interaction(2FI)regression model describing the effects of independent drying process variables on the moisture content was developed.The effects of temperature and drying time were more pronounced for MC than the thickness and salt concentration.The optimum conditions were found to be temperature=63.43◦C,product thickness=14.81 mm,salt concentration=9.07%and drying time=600 min.At these optimum conditions,moisture content was found to be 2.64%w.b.Validation of experimental results with the empirical model was evaluated using coefficient of correlation(R2)which was found for the model equation as,R2=0.994.
文摘In order to prolong the service life of the cooling zone of large scale coke dry quenching ovens,six kinds possible refractories for the cooling zone of large scale coke dry quenching ovens： SiC containing brick A,SiC containing brick B,mullite-andalusite brick,spinel containing brick,zirconia containing brick,corundum-mullite brick and grade B mullite brick,were analyzed in properties. It is found that the cooling zone lining adopting SiC containing bricks or mullite-andalusite bricks has much longer service life. Based on this,a new type of wear resistant brick was developed. The brick has a compressive strength of 135 MPa,a wear loss of 2. 10cm^3（only a quarter of that of the grade B mullite brick）,and a higher bulk density than the grade B mullite brick. The application of the brick in a 140t·h^（-1）coke dry quenching oven showed that it performed better than the grade B mullite brick. The cooling zone adopting the new bricks has a lower coke discharging temperature,which is beneficial to the enhancement of heat recovery efficiency and steam power generation.
文摘The mechanical force borne by the lintel and“brackets”in the inclined channel area of CDQ and the thermal stress generated by the top-down temperature gradient were simulated by ANSYS software.The following conclusions are drawn.(1)The mechanical force has very mild effect on the damage of the“brackets”.(2)The temperature gradient caused by the uneven temperature distribution of CDQ oven is the key factor affecting the“bracket”damage.The different expansion of refractory materials in various parts results in the thermal stress concentration which tears the“brackets”.(3)The structure adjustment of the“brackets”has very little effect on the thermal stress distribution.(4)The multi-phase nitride bonded silicon carbide for CDQ can effectively alleviate the stress concentration at the“brackets”,realizing the long-life and stable operation.
文摘Drying behaviour of Jew’s mallow leaves using an oven dryer was studied.The influence of drying temperatures(50,60 and 70C)on moisture content of the leaves at stable air velocity was considered.Five drying models,including,simple exponential,Page,Two-term exponential,Logarithmic,and Wang and Singh were fitted to drying data.Two-term exponential model adequately express the drying behaviour of Jew’s mallow leaves.Effective moisture diffusivity of Jew’s mallow leaves ranged from 8.18×10^-8 to 1.13×10^-7m^2/s.Dependence of the computed effective diffusivity on oven temperature was obvious.The energy required for oven drying of Jew’s mallow leaves was found to be 14.84 kJ/mol.The L^*,a^*,b^*,DE,a^*/b^*colour characteristics of the dried leaves range from 31.8 to 32.87,-3.73 to-4.37,13.6 to 16.47,69.00 to 69.73,and-0.26 to-0.34 respectively.Oven drying conditions of 50℃150 min and 70℃90min resulted to dried leaves with desirable colour characteristics.
