scholarly journals Numerical Modeling of Mine Hoist Disc Brake Temperature for Safer Operation

2021 ◽  
Vol 13 (5) ◽  
pp. 2874
Author(s):  
Florin Dumitru Popescu ◽  
Sorin Mihai Radu ◽  
Andrei Andraș ◽  
Ildiko Brînaș
Keyword(s):  
Raw Materials ◽  
Calculation Model ◽  
Scale Model ◽  
Temperature Threshold ◽  
Disc Brake ◽  
Emergency Braking ◽  
Drive Wheel ◽  
Real Material ◽  
Cable Drive ◽  
Mine Hoist

The sustainable exploitation of raw materials, with improved safety and increased productivity, is closely linked to the development of mechanical mining installations. Mine hoists are designed for the transport of material, equipment and personnel between the mine surface and the underground. The mine hoist braking system is of paramount importance in its safe operation. Thus, for both drum and disc brake systems, the temperature of the friction surfaces is important for ensuring efficient braking, as exceeding the temperature threshold causes a decrease in the braking capacity. In this paper we present a numerical calculation model for the temperature of the braking disc of a mine hoist in the case of emergency braking. A real-scale model was built, based on the cable drive wheel and disc brake system of a hoisting machine used in Romania. Real material characteristics were imposed for the brake discs, the cable drive wheel and the brake pads. The simulation was performed for decelerations of 3, 3.5, 4 and 4.5 m/s2. The analysis shows that regardless of the acceleration and time simulated, the disc temperature reaches its maximum after 1.35 s of emergency braking. This value does not exceed the 327 °C limit where, according to previous studies, the braking power starts to fade. It means that the emergency braking is safe for the acceleration and masses under consideration, in the case of the studied mine hoist.

scholarly journals Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091809
Author(s):  
Dagang Wang ◽  
Ruixin Wang ◽  
Jun Zhang
Keyword(s):  
Effective Mass ◽  
Coal Mine ◽  
Equivalent Stress ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Shoe ◽  
Brake Torque ◽  
Emergency Braking ◽  
Deep Coal Mine ◽  
Mine Hoist

Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist were investigated in the present study. The theoretical model of dynamic brake torque of disc brake during emergency braking was given to explore dynamic brake torque properties of disc brake. The three-dimensional thermo-mechanical coupled finite element model of brake disc–brake shoe was established to explore thermo-mechanical characteristics of disc brake during emergency braking. Effects of effective mass, hoisting acceleration and deceleration, and maximum hoisting speed on dynamic brake torques, equivalent von Mises stress, and temperature fields of disc brake during emergency braking were presented. The results show that the evolutions of brake torque, equivalent stress, and temperature of disc brake present fluctuating characteristics. The dynamic brake torque shows the largest change amplitude during emergency braking in the hoisting stage of constant speed. The largest equivalent stress and temperature are both located near the third brake shoe along the rotational direction at each side. An increase in effective mass causes overall decreases in the peak values of brake torque, equivalent stress, and temperature during emergency braking. Increases in hoisting acceleration/deceleration and maximum hoisting speed cause the increases in the maximum equivalent stress and temperature during emergency braking as compared to the slight decrease in the maximum brake torque.

scholarly journals Tribo-Brake Characteristics between Brake Disc and Brake Shoe during Emergency Braking of Deep Coal Mine Hoist with the High Speed and Heavy Load

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5094
Author(s):  
Dagang Wang ◽  
Ruixin Wang ◽  
Tong Heng ◽  
Guozheng Xie ◽  
Dekun Zhang
Keyword(s):  
Coal Mine ◽  
High Speed ◽  
Brake Disc ◽  
Disc Brake ◽  
Heavy Load ◽  
Brake Shoe ◽  
Emergency Braking ◽  
Deep Coal Mine ◽  
Friction Disc ◽  
Mine Hoist

The friction wear and thermal fatigue cracking of the brake shoe and friction-induced self-excited vibration (frictional flutter) of the disc brake can easily occur during emergency braking of a deep coal mine hoist with at high speed and with a heavy load. Therefore, tribo-brake characteristics between the brake disc and brake shoe during emergency braking of a deep coal mine hoist are investigated in the present study. Scaled parameters of the disc brake of a deep coal mine hoist are determined by employing the similarity principle. Friction tests between friction disc and brake shoe are carried out to obtain the coefficient of friction in the case of high speed and large specific pressure between the friction disc and brake shoe. Coupled thermo-mechanical finite element analyses of the brake disc and brake shoe are established to investigate temperature and stress fields of the brake disc and brake shoe during emergency braking, which is validated by the engineering failure case. Effects of braking parameters on flutter characteristics between the brake disc and brake shoe are explored by employing a double-degrees-of-freedom vibration mechanism model. The results show that the maximum temperature, equivalent Von Mises stress and contact pressure are all located at the average friction radii of contact surfaces of the brake disc and brake shoe during emergency braking. The cage crashing accident in the case of high speed and heavy load in a typical coal mine shows crack marks and discontinuous burn marks at central locations of brake shoe and brake disc surfaces, respectively, which indicates frictional flutter characteristics between brake disc and brake shoe. During emergency braking, flutter time duration decreases with increasing initial braking speed and damping parameter; the flutter amplitude and frequency of the disc brake increases with increasing normal braking load and stiffness, respectively.

A study of modeling experiments of the vibration behavior of elevated railway box girder

2018 ◽  
Vol 25 (5) ◽  
pp. 984-995 ◽  
Author(s):  
Kun Luo ◽  
Xiaoyan Lei
Keyword(s):  
High Speed ◽  
Similarity Theory ◽  
Longitudinal Direction ◽  
Calculation Model ◽  
Scale Model ◽  
Box Girder ◽  
Vibration Transmissibility ◽  
Girder Bridge ◽  
Structure Simplification ◽  
Model Similarity

Based on the model similarity theory, this article deduces the model similarity relationship of the elevated railway box girder at the elastic stage and designs a 1/10 box girder scale model by adopting a 32 m simply-supported box girder bridge from the Beijing–Shanghai Railway as the prototype. It then verifies the validity of the model design and the dynamic similarity between the 1/10 model and the prototype through constraint mode and free mode experiments on the 1/10 scale model, together with transient finite element calculation. The dynamic calculation model is utilized here for the analysis of the errors occurring in the production of the model, and the effect of the model structure simplification on the box girder mode frequency and vibration response. Finally, the article studies the vibration transmissibility characteristics between the plates and along the longitudinal direction by means of model testing. It also discusses the effect of different bridge support stiffness on the box girder vibration. The results presented in this paper can provide a method for forecasting and evaluating the existing or plan-to-build high speed railway environment vibration.

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.

Simulator Study of Heavy Truck Air Disc Brake Effectiveness During Emergency Braking

2008 ◽  
Author(s):  
Mohamed Kamel Salaani ◽  
Gary J. Heydinger ◽  
Paul A. Grygier ◽  
W. Riley Garrott
Keyword(s):  
Disc Brake ◽  
Emergency Braking ◽  
Heavy Truck ◽  
Simulator Study

Temperature Field of Disc Brake for Mine Hoist

2011 ◽  
Vol 4 (6) ◽  
pp. 2380-2384 ◽  
Author(s):  
Yuxing Peng ◽  
Zhencai Zhu ◽  
Guoan Chen ◽  
Jiusheng Bao ◽  
Binbin Liu ◽  
...  
Keyword(s):  
Temperature Field ◽  
Disc Brake ◽  
Mine Hoist

scholarly journals IMPLEMENTATION OF ECONOMIC ORDER QUANTITY (EOQ) ON INVENTORY EFFICIENCY IN PT. HEALTH TODAY INDONESIA

2020 ◽  
Vol 3 (2) ◽  
pp. 325-332
Author(s):  
Al Adawiyah ◽  
Khoirul Umam
Keyword(s):  
Inventory Management ◽  
Production Efficiency ◽  
Raw Materials ◽  
Secondary Data ◽  
Calculation Model ◽  
Economic Order Quantity ◽  
Economic Order ◽  
Actual Condition ◽  
Order Quantity ◽  
Increase Production Efficiency

Optimal inventory management is one of the main problems that is often encountered in the company's production activities which leads to the company's overall efficiency and profitability. PT. Health Today Indonesia is one of the companies experiencing this problem. Thus, this descriptive research with a quantitative approach aims to find solutions to these problems. Secondary data analysis from the 2013-2016 report uses the Economic Order Quantity (EOQ) calculation model from several divisions that are relevant to the 5 main products namely Fruit Smoothies, Bubble, Trisco, Honey and Sunfield. The results showed that the company was able to increase production efficiency, but this was not an actual condition due to externalities and the company's internal policy to delay the addition of purchases of raw materials and inventory, making the trend of inefficiency of the company's production decreased. Keyword:Economic Order Quantity, Inventory Management, Production

scholarly journals Simulation Study on Friction and Wear Law of Brake Pad in High-Power Disc Brake

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
S. Zhang ◽  
Q. Hao ◽  
Y. Liu ◽  
L. Jin ◽  
F. Ma ◽  
...  
Keyword(s):  
High Power ◽  
Friction And Wear ◽  
Element Model ◽  
Calculation Model ◽  
Brake Disc ◽  
Disc Brake ◽  
Wear Depth ◽  
Brake Pad ◽  
Wear Calculation ◽  
Wear Law

For the serious and uneven wear of the brake pad in the high-power disc brake during braking, the dynamic variation of the brake disc and the brake pad interface variable is considered, the wear calculation model is established based on the friction and wear mechanism, and the wear depth and volume of the brake pad can be calculated by equations. A finite element model of the brake disc and the brake pad is established by DEFORM software which can analyze wear of the brake pad directly. The variation trend of wear during braking is studied, and influences of braking load and initial braking speed on the wear are analyzed. The results show that the amount of the wear increases rapidly in the early wear stage of braking, and it becomes slow in the later stage; the wear of the brake pad is serious at the friction inlet and outlet, and the middle area of the brake pad is lightly worn; heavy braking load and high initial braking speed can exacerbate the wear of the brake pad.

scholarly journals Emergency Braking of a Mine Hoist in the Context of the Braking System Selection

2017 ◽  
Vol 62 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Stanisław Wolny
Keyword(s):  
Dynamic Behaviour ◽  
List Type ◽  
Operational Parameters ◽  
Emergency Braking ◽  
Braking System ◽  
Analytical Formulas ◽  
Braking Phase ◽  
System Selection ◽  
Mine Hoist ◽  
Fatigue Endurance

Abstract The paper addresses the selected aspects of the dynamic behaviour of mine hoists during the emergency braking phase. Basing on the model of the hoist and supported by theoretical backgrounds provided by the author (Wolny, 2016), analytical formulas are derived to determine the parameters of the braking system such that during an emergency braking it should guarantee that: –the maximal loading of the hoisting ropes should not exceed the rope breaking force, –deceleration of the conveyances being stopped should not exceed the admissible levels Results of the dynamic analysis of the mine hoist behaviour during an emergency braking phase summarised in this study can be utilised to support the design of conveyance and rope attachments by the fatigue endurance methods, with an aim to adapt it to the specified operational parameters of the hoisting installation (Eurokod 3).

scholarly journals Research on Contact Pressure Distribution of Pad

2018 ◽  
Vol 198 ◽  
pp. 01002
Author(s):  
Dong Chen ◽  
Guofeng Zou
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Working Condition ◽  
Great Influence ◽  
Element Model ◽  
Disc Brake ◽  
Contact Pressure Distribution ◽  
Structural Coupling ◽  
Emergency Braking ◽  
Force Characteristics

A simplified thermo-structural coupling finite element model of disc brake was developed. The contact pressure distribution of new pad was simulated under an emergency braking condition. The result shows that the contact pressure distribution of pad is not uniform when the new pad is in normal working condition. The inhomogeneity of the contact pressure is a critical cause of tangential partial wear. Compared the contact pressure distribution of new pad, uniform wear pad and tangential partial wear pad, the influence of wear amount and tangential partial wear on the contact pressure of pad was investigated. The results prove that the influence of wear amount on the contact pressure of pad is very small, while tangential partial wear has a great influence on the contact pressure of pad. The wear and force characteristics of pad are analyzed. The wear of its life cycle of pad is obtained, and the reliability and accuracy of the simulation are verified.

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