Material flow

About: Material flow is a research topic. Over the lifetime, 3050 publications have been published within this topic receiving 36844 citations. The topic is also known as: material stream.

Method and apparatus for determining the flow velocity of a molten, radiation-emitting material

Abstract: The invention is related to a method and an apparatus for measuring the flow velocity of a flow, stream or jet of molten radiation emitting material, in particular a freely falling jet of molten glass. The intensity of the radiation emitted from a limited section (2, 3) of the material flow is detected by means of two radiation detectors (S1, S2) at two separate locations mutually spaced apart by a given distance (L) along the flow path of the material flow. All pulse-like amplitude variations having an amplitude exceeding a given magnitude are discriminated from the output signals of the two radiation detectors. These pulse-like amplitude variations originate from randomly occurring, local, discrete, short variations in the intensity of the radiation emitted by the material flow caused by randomly occurring inhomogeneities in the material, for instance in the form of air bubbles in a jet of molten glass. The time interval between a pulse-like amplitude variation in the output signal from the upstream detector (S1) caused by an inhomogeneity in the material flow (1) and the occurrence of a pulse-like amplitude variation in the output signal from the down-stream detector (S2) caused by the same inhomogeneity in the material flow, is measured and used as a measure of the time taken by the material flow to travel between the detector locations, for calculating the flow velocity of the material flow. Also the volumetric flow rate of the material flow can be determined by measuring also the diameter of the material flow with the aid of a linear array of photodiodes and calculating the volumetric flow rate on the basis of measured values of the flow velocity and the diameter.

Optimization for China’s coal flow based on matching supply and demand sides

Abstract: As the most significant material flow in China, coal resource flow has many problems, including unnecessary CO2 emission and energy waste. The national coal flow consists of coal moving between mines and demand enterprises. The approach to global coal flow optimization can be transformed to promote a scientific match between participant enterprises. To reach this goal, the concept of matching dependencies on coal utilization by classification and gradation was introduced. A two-sided matching method was adopted to develop an optimization model based on an appropriate index system consisting of coal type, coal quality, transport conditions, and other factors. Based on inherent differences, indexes were divided into a 0–1 feature information index, an interval number information index and a language evaluation index. After data collection and screening, a sample of 2206 production nodes and 1500 consumption nodes was evaluated. Furthermore, a scenario with the goal of minimizing the global turnover volume was compared. The results showed that in the matching scenario, approximately 10% of the ash content at the national level avoided long-distance transportation and 170 million tons of anthracite and main coking coal were reallocated from power generation to more appropriate industries. Additionally, the optimization model may also significantly reduce CO2 emissions caused by ash during transportation. On the bases of these results, some suggestions focusing on the participants of each link are proposed in the final section of this paper. Overall, the application of the matching model can be a potential solution to optimize China’s future coal flow.

Modeling Approach for the Determination of Material Flow and Welding Conditions in Porthole Die Extrusion with Gas Pocket Formation

Abstract: The material flow in porthole dies is of crucial importance with regard to the seam weld quality in aluminum extrusion. Thus, experimental as well as numerical investigations on the effect of die geometry on the material flow were conducted. The experimental tests were performed on a 10 MN laboratory extrusion press. During the experimental trials, the extrusion ratio was varied by means of exchangeable die plates. Since the modular die allows removal of the aluminum in the welding chamber as well as in the feeders after the process, the material flow could be inspected in detail. The experimental results were used to improve the accuracy of FEA simulations, which were also conducted by commercial software. An attempt was made to improve the result quality of Eulerian FEA model regarding the simulation of an extrusion process with a gas pocket in the welding chamber. The influence of the modeling approach on the predicted material flow and on the contact pressure was analyzed and finally linked to the seam weld quality.

The optimal control problem for output material flow on conveyor belt with input accumulating bunker

Abstract: The article is devoted to the synthesis of optimal control of the conveyor belt with the accumulating input bunker. Much attention is given to the model of the conveyor belt with a constant speed of the belt. Simulation of the conveyor belt is carried out in the one-moment approximation using partial differential equations. The conveyor belt is represented as a distributed system. The used PDE-model of the conveyor belt allows determining the state of the flow parameters for a given technological position as a function of time. We consider the optimal control problem for flow parameters of the conveyor belt. The problem consists in ensuring the minimum deviation of the output material flow from a given target amount. The control is carried out by the material flow amount, which comes from the accumulating bunker into the conveyor belt input. In the synthesis of optimal control, we take into account the limitations on the size of the accumulating bunker, as well as on both max and min amounts of control. We construct optimal control of the material flow amount coming from the accumulating bunker. Also, we determine the conditions to switch control modes and estimate time period between the moments of the switching.