The High Tension Roll Separator (HTRS) is one of the main electrostatic unit operations employed to separate titanium minerals like ilmenite, rutile and leucoxene which behave as conducting from zircon, sillimanite, g...The High Tension Roll Separator (HTRS) is one of the main electrostatic unit operations employed to separate titanium minerals like ilmenite, rutile and leucoxene which behave as conducting from zircon, sillimanite, garnet and monazite which behave as non-conducting minerals when a high potential difference is applied. Three process inputs, namely roll speed, feed material temperature and roll speed have been optimized. Experiments were conducted based on the Box- Behnken factorial design;the results were analyzed using response surface methodology (RSM). A new term, called Operational Quality Index (OQI) has been defined as a process output, which is maximized by quadratic programming, to obtain the optimum operating conditions. The maximum value of OQI obtained under the constraints of grade >96% and recovery >98% is 195.53, at the following operating conditions—Temperature: 102°C, Feed Rate: 1.75 tph and Roll Speed: 132 rpm. Under these conditions, the grade and recovery obtained are 96.6% and 98.9% respectively.展开更多
The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of ＂constant flow＂. Tension is the link of the continuous rolling proce...The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of ＂constant flow＂. Tension is the link of the continuous rolling process. From the condition of clynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.展开更多
The speed difference of strip between two stands is the origin of strip tension in tandem rolling process. The relation between elastic elongation and tension meets Hooke′s law, and the elastic elongation of strip pr...The speed difference of strip between two stands is the origin of strip tension in tandem rolling process. The relation between elastic elongation and tension meets Hooke′s law, and the elastic elongation of strip produces speed difference. Based on these principles, the tension differential equations were derived for rolling strip with uniform and variant strip sections with one step or n-1 step disturbance points. The simplified forms of these equations are the same as reported in other references.展开更多
Based on the practical data of a strip hot rolling line and the flow patterns of the rolling process, the principle of the effect of the tension between mill stands on the strip width was analyzed. The results show th...Based on the practical data of a strip hot rolling line and the flow patterns of the rolling process, the principle of the effect of the tension between mill stands on the strip width was analyzed. The results show that the tension between the upstream mill stands has a significant effect on strip width. The width change takes place in the deforming region between two mill stands, the effect of back tension is more than that of forward tension, and the width narrowing takes place in the biting position of the back slip region. Reasonable tension and its gradient setup are therefore significant factors in the accuracy of the strip width control.展开更多
In this paper,such a new lateral displacement function is proposed that the lateral flow velocity is con- tinuous at the entry and the exit of deformation zone.A new kind of finite strip method—the third power B-spli...In this paper,such a new lateral displacement function is proposed that the lateral flow velocity is con- tinuous at the entry and the exit of deformation zone.A new kind of finite strip method—the third power B-spline finite strip method—is put forward to simulate strip rolling process.Front and back tension stresses are formulated.The computed results of the transverse distributions of the front and back tension stresses are close to the experimental results.The paper lays a foundation for further analysing the three-dimensional stresses and deformations of strip rolling.展开更多
The formation mechanism of the cold-rolled strip shape with high tension was studied. An advanced method to calculate the allowable variation of strip transverse profiles was established by the strip buckling criterio...The formation mechanism of the cold-rolled strip shape with high tension was studied. An advanced method to calculate the allowable variation of strip transverse profiles was established by the strip buckling criterion, which can be more properly used in cold rolling. With this method, the aim allowable variation of the product strip transverse profile and the required transverse profile range of incoming strips can be reached. Besides, this method has been successfully applied in a domestic tandem cold mill, and the transverse profile range of incoming strips suggested with this method is more practicable and complete. Consequently, the good performance is acquired.展开更多
文摘The High Tension Roll Separator (HTRS) is one of the main electrostatic unit operations employed to separate titanium minerals like ilmenite, rutile and leucoxene which behave as conducting from zircon, sillimanite, garnet and monazite which behave as non-conducting minerals when a high potential difference is applied. Three process inputs, namely roll speed, feed material temperature and roll speed have been optimized. Experiments were conducted based on the Box- Behnken factorial design;the results were analyzed using response surface methodology (RSM). A new term, called Operational Quality Index (OQI) has been defined as a process output, which is maximized by quadratic programming, to obtain the optimum operating conditions. The maximum value of OQI obtained under the constraints of grade >96% and recovery >98% is 195.53, at the following operating conditions—Temperature: 102°C, Feed Rate: 1.75 tph and Roll Speed: 132 rpm. Under these conditions, the grade and recovery obtained are 96.6% and 98.9% respectively.
文摘The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of ＂constant flow＂. Tension is the link of the continuous rolling process. From the condition of clynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.
文摘The speed difference of strip between two stands is the origin of strip tension in tandem rolling process. The relation between elastic elongation and tension meets Hooke′s law, and the elastic elongation of strip produces speed difference. Based on these principles, the tension differential equations were derived for rolling strip with uniform and variant strip sections with one step or n-1 step disturbance points. The simplified forms of these equations are the same as reported in other references.
文摘Based on the practical data of a strip hot rolling line and the flow patterns of the rolling process, the principle of the effect of the tension between mill stands on the strip width was analyzed. The results show that the tension between the upstream mill stands has a significant effect on strip width. The width change takes place in the deforming region between two mill stands, the effect of back tension is more than that of forward tension, and the width narrowing takes place in the biting position of the back slip region. Reasonable tension and its gradient setup are therefore significant factors in the accuracy of the strip width control.
文摘In this paper,such a new lateral displacement function is proposed that the lateral flow velocity is con- tinuous at the entry and the exit of deformation zone.A new kind of finite strip method—the third power B-spline finite strip method—is put forward to simulate strip rolling process.Front and back tension stresses are formulated.The computed results of the transverse distributions of the front and back tension stresses are close to the experimental results.The paper lays a foundation for further analysing the three-dimensional stresses and deformations of strip rolling.
基金supported by the National Key Technologies R & D Program of China (No.2006BAE03A13)
文摘The formation mechanism of the cold-rolled strip shape with high tension was studied. An advanced method to calculate the allowable variation of strip transverse profiles was established by the strip buckling criterion, which can be more properly used in cold rolling. With this method, the aim allowable variation of the product strip transverse profile and the required transverse profile range of incoming strips can be reached. Besides, this method has been successfully applied in a domestic tandem cold mill, and the transverse profile range of incoming strips suggested with this method is more practicable and complete. Consequently, the good performance is acquired.
