scholarly journals Continuous Medium Hypothesis Based Study on the Screw Flight Wear Model and Wear Regularity in Screw Ship Unloader

2021 ◽  
Author(s):  
Weijie Yang ◽  
Wenjun Meng ◽  
Xiaobing Dai ◽  
Zhenxiao Yin ◽  
Fenglin Yao ◽  
...  
Keyword(s):  
Wear Rate ◽  
Continuous Medium ◽  
Calculation Model ◽  
Experimental Results ◽  
Screw Conveyor ◽  
Filling Rate ◽  
Wear Model ◽  
Spiral Blade ◽  
Wear Law

The screw flight on the vertical screw conveyor which is the spiral blade welded on the axial cylinder is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. Hence, we established a new screw flight wear model based on the Archard wear model and Continuous Medium Hypothesis. Two influencing factors, including speed and filling rate were selected to study the wear law of the screw flight, and the wear law was verified by experimental. Results indicate that the experimental results were consistent with the calculation model. The wear rate of screw flight was approximately parabola increased with the increase of rotational speed and the screw flight wear rate positively and linearly correlated with the filling rate.

scholarly journals Analysis of the Screw Flight Wear Model and Wear Regularity of the Bulk Transport in Screw Ship Unloader

2021 ◽  
Author(s):  
Weijie Yang ◽  
Wenjun Meng ◽  
Lingchong Gao ◽  
Yuan Tan ◽  
Johannes Fottner ◽  
...  
Keyword(s):  
Wear Rate ◽  
Working Conditions ◽  
Continuous Medium ◽  
Calculation Model ◽  
Filling Rate ◽  
Wear Model ◽  
Spiral Blade ◽  
Simulation Results ◽  
Wear Law

AbstractThe screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under different working conditions. Hence, we established a new screw flight wear model based on the Archard wear model and Continuous Medium Hypothesis to predict the service life of the screw flight. Three influencing factors, including speed, filling rate, and pitch, were selected to study the wear law of the screw flight, and the wear law was verified by EDEM simulation. Results indicate that the simulation results affected by the changes in various factors were consistent with the calculation model. With the increase of rotation speed and filling rate, the screw flight wear rate increased. Nevertheless, with the increase of pitch, the screw flight wear rate first increased and then decreased. The screw flight wear model can be used to calculate the wear rate under different working conditions for the screw flight life prediction.

scholarly journals Experimental and Analytical Study on Creep Characteristics of Box Section Bamboo-Steel Composite Columns under Long-Term Loading

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 983
Author(s):  
Shixu Wu ◽  
Keting Tong ◽  
Jianmin Wang ◽  
Yushun Li
Keyword(s):  
Load Level ◽  
Experimental Results ◽  
Creep Model ◽  
Composite Column ◽  
Composite Columns ◽  
Creep Coefficient ◽  
Creep Characteristics ◽  
Section Size ◽  
Steel Composite

To expand the application of bamboo as a building material, a new type of box section composite column that combined bamboo and steel was considered in this paper. The creep characteristics of eight bamboo-steel composite columns with different parameters were tested to evaluate the effects of load level, section size and interface type under long-term loading. Then, the deformation development of the composite column under long-term loading was observed and analyzed. In addition, the creep-time relationship curve and the creep coefficient were created. Furthermore, the creep model of the composite column was proposed based on the relationship between the creep of the composite column and the creep of bamboo, and the calculated value of creep was compared with the experimental value. The experimental results showed that the creep development of the composite column was fast at first, and then became stable after about 90 days. The creep characteristics were mainly affected by long-term load level and section size. The creep coefficient was between 0.160 and 0.190. Moreover, the creep model proposed in this paper was applicable to predict the creep development of bamboo-steel composite columns. The calculation results were in good agreement with the experimental results.

scholarly journals A Multilayer CARU Framework to Obtain Probability Distribution for Paragraph-Based Sentiment Analysis

2021 ◽  
Vol 11 (23) ◽  
pp. 11344
Author(s):  
Wei Ke ◽  
Ka-Hou Chan
Keyword(s):  
Probability Distribution ◽  
Information Extraction ◽  
Sentiment Analysis ◽  
State Of The Art ◽  
Final Analysis ◽  
The State ◽  
Experimental Results ◽  
Content Adaptive

Paragraph-based datasets are hard to analyze by a simple RNN, because a long sequence always contains lengthy problems of long-term dependencies. In this work, we propose a Multilayer Content-Adaptive Recurrent Unit (CARU) network for paragraph information extraction. In addition, we present a type of CNN-based model as an extractor to explore and capture useful features in the hidden state, which represent the content of the entire paragraph. In particular, we introduce the Chebyshev pooling to connect to the end of the CNN-based extractor instead of using the maximum pooling. This can project the features into a probability distribution so as to provide an interpretable evaluation for the final analysis. Experimental results demonstrate the superiority of the proposed approach, being compared to the state-of-the-art models.

scholarly journals Processes of heat and mass transfer during drying of red beetroot

2020 ◽  
Vol 6 (2) ◽  
pp. 81-87
Author(s):  
Zhanna Petrova ◽  
◽  
Kateryna Samoilenko ◽  
Vitaly Vishnevsky
Keyword(s):  
Mass Transfer ◽  
Energy Consumption ◽  
Heat And Mass Transfer ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Calculation Model ◽  
Experimental Results ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Process

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.

Guided Waves as an Online Monitoring Technology for Long-Term Operation in Nuclear Power Plants: Experimental Results on a Steam Discharge Pipe

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Francesco Bertoncini ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Complex Structure ◽  
Theoretical Background ◽  
Guided Wave ◽  
Experimental Results ◽  
Term Operation

Guided wave (GW) testing is regularly used for finding defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). By using magnetostrictive sensors, some issues, which usually limit the application to nuclear power plants (NPPs), can be fixed. The authors have already shown the basic theoretical background and simulation results concerning a real steel pipe, used for steam discharge, with a complex structure. On the basis of such theoretical framework, a new campaign has been designed and developed on the same pipe, and the obtained experimental results are now here presented as a useful benchmark for the application of GWs as nondestructive techniques. Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPPs components.

Widening Classical Wear Laws to the Concept of Third Body

2005 ◽  
Author(s):  
N. Fillot ◽  
I. Iordanoff ◽  
Y. Berthier
Keyword(s):  
Twentieth Century ◽  
Wear Rate ◽  
Applied Pressure ◽  
Third Body ◽  
Sliding Speed ◽  
Wear Law

During the second part of the twentieth century, many efforts have been done to model wear. Particularly, Archard proposes in 1953 [1] one of the first wear law, which is often written on the following form: dW/dt=K.P.V(1) with dW/dt the mass of detached particles from the rubbing materials per unit time, P the applied pressure, V the sliding speed and K the “wear rate”.

Modelling the Effects of Head Diameter and Cup Wall Thickness on Contact Mechanics and Wear of Cross-Linked UHMWPE Cups

2005 ◽  
Author(s):  
Lu Kang ◽  
Alison L. Galvin ◽  
Zhongmin Jin ◽  
John Fisher
Keyword(s):  
Wall Thickness ◽  
Three Dimensional ◽  
Volumetric Wear ◽  
Wear Model ◽  
Wear Factor ◽  
Head Diameter ◽  
Maximum Contact ◽  
Ultra High Molecular Weight ◽  
Outside Diameter

A three-dimensional contact-coupled wear model was developed and used to predict the long-term wear in both conventional and cross-linked ultra high molecular weight polyethylene (UHMWPE) cups, particular to examine the effect of the head diameter and the UHMWPE cup wall thickness. The wear factors were determined from the simulator testing of 28 mm diameter cups. The maximum contact pressure was found to decrease with the increase of head diameter up to 48 mm, corresponding to the decrease in the cup wall thickness for a fixed outside diameter of the cup. Volumetric wear rate was predicted to increase as the head size increased for the conventional UHMWPE, as well as the cross-linked UHMWPE, although at a much lower rate for the latter due to the smaller wear factor.

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