The Experts below are selected from a list of 8988 Experts worldwide ranked by ideXlab platform
Gabriel Lodewijks - One of the best experts on this subject based on the ideXlab platform.
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healthy speed control of belt Conveyors on conveying bulk materials
Powder Technology, 2018Co-Authors: Daijie He, Yusong Pang, Gabriel Lodewijks, Xiangwei LiuAbstract:Abstract Belt Conveyors play an important role in the dry bulk material handling process. Speed control is a promising method of reducing the power consumption of belt Conveyors. However, inappropriate transient operations might cause risks like material spillage away from the belt conveyor. The unexpected risks limit the applicability of speed control. Current studies on speed control mainly focus on designing energy models of belt Conveyors or building control algorithms of variable speed drives, while rare researchers take into account the risks in transient operations and the dynamic performance of belt Conveyors under speed control. The paper proposes an Estimation-Calculation-Optimization (ECO) method to determine the minimum speed adjustment time to ensure healthy transient operations. The ECO method is composed of three steps and takes both risks in transient operations and the conveyor dynamics into account. In the Estimation step, an estimator is built to approximate the permitted maximum acceleration by treating the belt as a rigid body. Taking the belt's visco-elastic property into account, the Calculation step computes the conveyor dynamics by using a finite-element-method. With respect to the risks in transient operations, the Optimization step improves the conveyor's dynamic behaviors and optimizes the speed adjustment time. A case of a long belt conveyor system is studied and the ECO method is applied. The secant method is also used to improve the optimization efficiency. According to the experimental results, the ECO method is successfully used to determine the minimum speed adjustment time to ensure healthy transient operations, including both the accelerating and the decelerating operations. With the suggested adjustment time, unexpected risks are avoided and the belt conveyor shows an appropriate dynamic behavior. Accordingly, the ECO method ensures healthy transient operations and improves the applicability of speed control with the consideration of the potential risks and the conveyor dynamics.
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green operations of belt Conveyors by means of speed control
Applied Energy, 2017Co-Authors: Daijie He, Yusong Pang, Gabriel LodewijksAbstract:Belt Conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt Conveyors. Current research of speed control rarely takes the conveyor dynamics into account so that speed control lacks applicability. Based on our previous research, this paper will provide an improved three-step method to determine the minimum speed adjustment time. This method can be summarized as Estimation-Calculation-Optimization and ECO in short. The ECO method takes both the potential risks and the conveyor dynamics into account. It is expected to keep belt Conveyors in good dynamic behaviors in transient operations. After discussing the ECO method, this research takes a long inclined belt conveyor of an import dry bulk terminal as case study. Based on the suggested acceleration time, a speed controller is built and computational simulations are carried out to evaluate the energy savings and the conveyor dynamics. Experimental results prove that the application of the ECO method ensures the healthy dynamic performance of belt Conveyors under speed control in transient operations. Annually, the average electricity consumption of the single conveyor can be reduced by over 10% with around 90tons reduction of CO2 emission. The direct economic benefit can reach up to more than €10,000 in terms of the electricity utilization per year.
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Speed control of belt Conveyors during transient operation
Powder Technology, 2016Co-Authors: Yusong Pang, Gabriel LodewijksAbstract:Abstract Belt Conveyors play an important role in continuous dry bulk material transport. Large scale belt conveyor systems consume a considerable amount of electricity. The approach of controlling the belt speed in such a way that the belt's volumetric capacity is fully utilized under all operational conditions has been proven to significantly reduce the energy consumption of a belt conveyor. Current research on speed control for belt Conveyors mainly focuses on the calculation and the prediction of possible energy savings. Few studies focus on the dynamics of belt Conveyors in transient operation. There are however no studies that describe the operation of speed controlled belt Conveyors during transient operation. This paper presents a three-step method that can be used to determine a proper way to accelerate a speed controlled belt conveyor during transient operation. This method takes the potential risks in transient operation and the conveyor dynamic performance into account. A case of horizontal conveyor system is studied and the three-step method is applied. In the case study, a predictor of the permitted maximum acceleration is calculated. Simulations with the predicted acceleration time are carried out to determine the acceleration operation and to analyse the conveyor dynamics. The simulations are based on an existing finite element model of a belt conveyor.
David G Grier - One of the best experts on this subject based on the ideXlab platform.
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universal strong and long ranged trapping by optical Conveyors
APS, 2015Co-Authors: David B Ruffner, David G GrierAbstract:Optical Conveyors are active tractor beams that selectively transport illuminated objects either upstream or downstream along their axes. Formed by the coherent superposition of coaxial Bessel beams, an optical conveyor features an axial array of equally spaced intensity maxima that act as optical traps for small objects. We demonstrate through measurements on colloidal spheres and numerical calculations based on the generalized Lorenz-Mie theory that optical Conveyors’ interferometric structure endows them with trapping characteristics far superior to those of conventional optical tweezers. Optical Conveyors form substantially stiffer traps and can transport a wider variety of materials over a much longer axial range.
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optical Conveyors a class of active tractor beams
Physical Review Letters, 2012Co-Authors: David B Ruffner, David G GrierAbstract:We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical Conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Varying the Bessel beams’ relative phase shifts the traps axially thereby selectively transports trapped objects either downstream or upstream along the length of the beam. The same methods used to project a single optical conveyor can project arrays of independent optical Conveyors, allowing bi-directional transport in three dimensions.
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optical Conveyors a class of active tractor beams
Physical Review Letters, 2012Co-Authors: David B Ruffner, David G GrierAbstract:We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical Conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Trapped objects can be moved selectively upstream or downstream along the conveyor by appropriately changing the Bessel beams' relative phase. The same methods used to project a single optical conveyor can project arrays of independent optical Conveyors, allowing bidirectional transport in three dimensions.
Yusong Pang - One of the best experts on this subject based on the ideXlab platform.
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healthy speed control of belt Conveyors on conveying bulk materials
Powder Technology, 2018Co-Authors: Daijie He, Yusong Pang, Gabriel Lodewijks, Xiangwei LiuAbstract:Abstract Belt Conveyors play an important role in the dry bulk material handling process. Speed control is a promising method of reducing the power consumption of belt Conveyors. However, inappropriate transient operations might cause risks like material spillage away from the belt conveyor. The unexpected risks limit the applicability of speed control. Current studies on speed control mainly focus on designing energy models of belt Conveyors or building control algorithms of variable speed drives, while rare researchers take into account the risks in transient operations and the dynamic performance of belt Conveyors under speed control. The paper proposes an Estimation-Calculation-Optimization (ECO) method to determine the minimum speed adjustment time to ensure healthy transient operations. The ECO method is composed of three steps and takes both risks in transient operations and the conveyor dynamics into account. In the Estimation step, an estimator is built to approximate the permitted maximum acceleration by treating the belt as a rigid body. Taking the belt's visco-elastic property into account, the Calculation step computes the conveyor dynamics by using a finite-element-method. With respect to the risks in transient operations, the Optimization step improves the conveyor's dynamic behaviors and optimizes the speed adjustment time. A case of a long belt conveyor system is studied and the ECO method is applied. The secant method is also used to improve the optimization efficiency. According to the experimental results, the ECO method is successfully used to determine the minimum speed adjustment time to ensure healthy transient operations, including both the accelerating and the decelerating operations. With the suggested adjustment time, unexpected risks are avoided and the belt conveyor shows an appropriate dynamic behavior. Accordingly, the ECO method ensures healthy transient operations and improves the applicability of speed control with the consideration of the potential risks and the conveyor dynamics.
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green operations of belt Conveyors by means of speed control
Applied Energy, 2017Co-Authors: Daijie He, Yusong Pang, Gabriel LodewijksAbstract:Belt Conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt Conveyors. Current research of speed control rarely takes the conveyor dynamics into account so that speed control lacks applicability. Based on our previous research, this paper will provide an improved three-step method to determine the minimum speed adjustment time. This method can be summarized as Estimation-Calculation-Optimization and ECO in short. The ECO method takes both the potential risks and the conveyor dynamics into account. It is expected to keep belt Conveyors in good dynamic behaviors in transient operations. After discussing the ECO method, this research takes a long inclined belt conveyor of an import dry bulk terminal as case study. Based on the suggested acceleration time, a speed controller is built and computational simulations are carried out to evaluate the energy savings and the conveyor dynamics. Experimental results prove that the application of the ECO method ensures the healthy dynamic performance of belt Conveyors under speed control in transient operations. Annually, the average electricity consumption of the single conveyor can be reduced by over 10% with around 90tons reduction of CO2 emission. The direct economic benefit can reach up to more than €10,000 in terms of the electricity utilization per year.
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Speed control of belt Conveyors during transient operation
Powder Technology, 2016Co-Authors: Yusong Pang, Gabriel LodewijksAbstract:Abstract Belt Conveyors play an important role in continuous dry bulk material transport. Large scale belt conveyor systems consume a considerable amount of electricity. The approach of controlling the belt speed in such a way that the belt's volumetric capacity is fully utilized under all operational conditions has been proven to significantly reduce the energy consumption of a belt conveyor. Current research on speed control for belt Conveyors mainly focuses on the calculation and the prediction of possible energy savings. Few studies focus on the dynamics of belt Conveyors in transient operation. There are however no studies that describe the operation of speed controlled belt Conveyors during transient operation. This paper presents a three-step method that can be used to determine a proper way to accelerate a speed controlled belt conveyor during transient operation. This method takes the potential risks in transient operation and the conveyor dynamic performance into account. A case of horizontal conveyor system is studied and the three-step method is applied. In the case study, a predictor of the permitted maximum acceleration is calculated. Simulations with the predicted acceleration time are carried out to determine the acceleration operation and to analyse the conveyor dynamics. The simulations are based on an existing finite element model of a belt conveyor.
Daijie He - One of the best experts on this subject based on the ideXlab platform.
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healthy speed control of belt Conveyors on conveying bulk materials
Powder Technology, 2018Co-Authors: Daijie He, Yusong Pang, Gabriel Lodewijks, Xiangwei LiuAbstract:Abstract Belt Conveyors play an important role in the dry bulk material handling process. Speed control is a promising method of reducing the power consumption of belt Conveyors. However, inappropriate transient operations might cause risks like material spillage away from the belt conveyor. The unexpected risks limit the applicability of speed control. Current studies on speed control mainly focus on designing energy models of belt Conveyors or building control algorithms of variable speed drives, while rare researchers take into account the risks in transient operations and the dynamic performance of belt Conveyors under speed control. The paper proposes an Estimation-Calculation-Optimization (ECO) method to determine the minimum speed adjustment time to ensure healthy transient operations. The ECO method is composed of three steps and takes both risks in transient operations and the conveyor dynamics into account. In the Estimation step, an estimator is built to approximate the permitted maximum acceleration by treating the belt as a rigid body. Taking the belt's visco-elastic property into account, the Calculation step computes the conveyor dynamics by using a finite-element-method. With respect to the risks in transient operations, the Optimization step improves the conveyor's dynamic behaviors and optimizes the speed adjustment time. A case of a long belt conveyor system is studied and the ECO method is applied. The secant method is also used to improve the optimization efficiency. According to the experimental results, the ECO method is successfully used to determine the minimum speed adjustment time to ensure healthy transient operations, including both the accelerating and the decelerating operations. With the suggested adjustment time, unexpected risks are avoided and the belt conveyor shows an appropriate dynamic behavior. Accordingly, the ECO method ensures healthy transient operations and improves the applicability of speed control with the consideration of the potential risks and the conveyor dynamics.
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green operations of belt Conveyors by means of speed control
Applied Energy, 2017Co-Authors: Daijie He, Yusong Pang, Gabriel LodewijksAbstract:Belt Conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt Conveyors. Current research of speed control rarely takes the conveyor dynamics into account so that speed control lacks applicability. Based on our previous research, this paper will provide an improved three-step method to determine the minimum speed adjustment time. This method can be summarized as Estimation-Calculation-Optimization and ECO in short. The ECO method takes both the potential risks and the conveyor dynamics into account. It is expected to keep belt Conveyors in good dynamic behaviors in transient operations. After discussing the ECO method, this research takes a long inclined belt conveyor of an import dry bulk terminal as case study. Based on the suggested acceleration time, a speed controller is built and computational simulations are carried out to evaluate the energy savings and the conveyor dynamics. Experimental results prove that the application of the ECO method ensures the healthy dynamic performance of belt Conveyors under speed control in transient operations. Annually, the average electricity consumption of the single conveyor can be reduced by over 10% with around 90tons reduction of CO2 emission. The direct economic benefit can reach up to more than €10,000 in terms of the electricity utilization per year.
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Energy saving for belt Conveyors by speed control
2017Co-Authors: Daijie HeAbstract:Belt Conveyors are widely used in bulk solids handling and conveying systems. Considering the extensive use of belt Conveyors, their operations involve a large amount of energy. Taking the relevant economic and social challenges into account, there is a strong demand for lowering the energy consumption of belt Conveyors, and for reducing the carbon footprint. Speed control is one of the promising approaches for reducing the power consumption of belt Conveyors. This thesis focuses on the application of speed control to belt Conveyors for reducing their energy consumption. Research on belt conveyor speed control has already been carried out for more than twenty years. However, rare implementations of speed control to reduce energy consumption can be found in practice. One major reason is that the current research does not cover issues like the potential risks (such as the risk of belt over-tension, the risk of belt slippage around the drive pulley and the risk of motor over-heating) and the dynamic analyses of belt Conveyors in transient operations. Therefore, speed control of belt Conveyors is not often successfully applied in practice...
David B Ruffner - One of the best experts on this subject based on the ideXlab platform.
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universal strong and long ranged trapping by optical Conveyors
APS, 2015Co-Authors: David B Ruffner, David G GrierAbstract:Optical Conveyors are active tractor beams that selectively transport illuminated objects either upstream or downstream along their axes. Formed by the coherent superposition of coaxial Bessel beams, an optical conveyor features an axial array of equally spaced intensity maxima that act as optical traps for small objects. We demonstrate through measurements on colloidal spheres and numerical calculations based on the generalized Lorenz-Mie theory that optical Conveyors’ interferometric structure endows them with trapping characteristics far superior to those of conventional optical tweezers. Optical Conveyors form substantially stiffer traps and can transport a wider variety of materials over a much longer axial range.
-
optical Conveyors a class of active tractor beams
Physical Review Letters, 2012Co-Authors: David B Ruffner, David G GrierAbstract:We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical Conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Varying the Bessel beams’ relative phase shifts the traps axially thereby selectively transports trapped objects either downstream or upstream along the length of the beam. The same methods used to project a single optical conveyor can project arrays of independent optical Conveyors, allowing bi-directional transport in three dimensions.
-
optical Conveyors a class of active tractor beams
Physical Review Letters, 2012Co-Authors: David B Ruffner, David G GrierAbstract:We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical Conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Trapped objects can be moved selectively upstream or downstream along the conveyor by appropriately changing the Bessel beams' relative phase. The same methods used to project a single optical conveyor can project arrays of independent optical Conveyors, allowing bidirectional transport in three dimensions.