scholarly journals Aspects concerning the influence of the design of flameproof electric motors on maximum explosion pressures

2020 ◽  
Vol 305 ◽  
pp. 00008
Author(s):  
Mihai Magyari ◽  
Lucian Moldovan ◽  
Diana Sălăşan
Keyword(s):  
High Pressure ◽  
Petrochemical Industry ◽  
Mine Safety ◽  
Geometrical Shape ◽  
Electric Motors ◽  
Geometrical Shapes ◽  
Explosion Protection ◽  
Internal Volume ◽  
Large Motor ◽  
Internal Arrangement

The research carried out in the specialized Laboratory of the National Institute for Research and Development in Mine Safety and Explosion Protection INSEMEX Petrosani has identified as causes for the occurrence of high pressure peaks in the case of electric motor enclosures, the internal volume, the geometrical shape of motor enclosures and the very intricate and complex internal arrangement of such motor enclosures (especially in the case of large motor enclosures), having in mind the tendency of motor manufacturers for chemical and petrochemical industry to manufacture motors having more complex geometrical shapes.

scholarly journals Geometrical form assessment of a CFD based breathing thermal manikins, designed by simplified polygonal shapes

2019 ◽  
Vol 85 ◽  
pp. 02002
Author(s):  
Martin Ivanov ◽  
Sergey Mijorski
Keyword(s):  
Flow Characteristics ◽  
Temperature Fields ◽  
Geometrical Shape ◽  
Thermal Plume ◽  
Flow Acceleration ◽  
Geometrical Shapes ◽  
Geometrical Form ◽  
The Difference ◽  
High Degree ◽  
Positive Effect

The presented paper focuses on a CFD based analyses of the complexity in the geometrical shape of the breathing thermal manikins, associated with their main functionalities. Both impacts of the external manikin’s form were studied – over the velocity and over the temperature fields in the thermal plume zone above the head. Three different geometrical shapes are analysed – a physiologically identified (called Humanoid Manikin) and two other shapes, designed to match the overall 95th percentile of the anthropometric size of the standard person (called Polygonal Manikins). The first model represents a comprehensive multifaceted figure of a manikin with high degree of physiological identity with a female human being. The second and third one, are simplified, but still with anatomically realistic component forms, accurately representing the anthropometric size of a standard person. The difference between them is in the presence of additional flow optimization collars in the third model. The numerical results demonstrate the clear impact of the manikins’ geometrical characteristics over the simulated breathing and convective flows. The optimization with the proposed collars had a positive effect over the resulted flow acceleration at top head and chest zones. However, the improvement of the flow characteristics was observed for two of the simulated three breathing phases and further shape optimization is required.

Research and Develop on Series of LNG Coil-Wound Heat Exchanger

2014 ◽  
Vol 1070-1072 ◽  
pp. 1774-1779
Author(s):  
Zhou Wei Zhang ◽  
Ya Hong Wang ◽  
Jia Xing Xue
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Research And Development ◽  
Multiphase Flow ◽  
Petrochemical Industry ◽  
Structure Characteristics ◽  
Exchange Processes ◽  
Third Stage ◽  
Working Principle

The research and development of LNG coil-wound heat exchanger (LCWHE) were discussed in view of the heat exchange in LNG field in petrochemical industry. The basic designing methods and the multi-stream heat exchange processes were illustrated by the cryogenic and high pressure crossing heat exchange equipments of LCWHE with multi-stream and multiphase flow, including Four-stream LCWHE in first stage, Three-stream LCWHE in second stage, Two-stream LCWHE in third stage, Multi-stream main LCWHE etc. A series of LCWHE with different mixed refrigerant and different applications were described. The winding structure characteristics and the working principle of the spiral pipe bundles were elaborated to give a reference for the scientific design and calculation of LCWHE in cryogenic field. The major researched directions and the critical scientific problems were forecasted.

Design and Analysis of Buried Liquid Petroleum Gas Storage Bullets Supported on Multiple Saddles (PVP2010-25052)

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Radoslav Stefanovic ◽  
Yaser Noman
Keyword(s):  
High Pressure ◽  
Petrochemical Industry ◽  
Gas Storage ◽  
Differential Settlement ◽  
Soil Resistance ◽  
Bending Moments ◽  
Ambient Temperatures ◽  
Liquid Petroleum Gas ◽  
Simplified Method ◽  
Design Construction

The use of large, high pressure liquid petroleum gas (LPG) storage bullets has become a common, and often assumed safe, practice in the petrochemical industry. The Engineering Equipment and Materials Users Association (EEMUA) is an organization that has attempted to address design aspects related to mounded or buried bullets; Publication No. 190 published by the EEMUA (2000, Guide for the Design, Construction and Use of Mounded Horizontal Cylindrical Vessels for Pressurized Storage of LPG at Ambient Temperatures, EEMUA, London, England.) became a standard practice in the industry. However, the design recommended, and therefore addressed, by Publication 190 is for bullets directly supported by soil (i.e., without saddle supports). However, it has been noticed by the authors that many users are requesting these storage bullets be supported by saddles resting on foundations in order to minimize the chance of unexpected settling and any motion of the bullets underground. The large span of these bullets requires more than two saddles adding to the complexity of the design due to statically indeterminate construction, differential settlement, and uneven supports. This paper focuses on major issues related to the design of such bullets. First, the loads induced by mound weight, pressure due to mound, and the loads due to longitudinal thermal expansion and soil resistance to this expansion is analyzed. Next, a method for calculating the multiple saddle reactions and bending moments at spans and supports is provided. A simplified method for assessing the effect of differential settlement between saddles is proposed.

scholarly journals Characterizations of electrode geometrical shape for dielectrophoresis

2019 ◽  
Vol 15 (2) ◽  
pp. 671
Author(s):  
N. Burham ◽  
A. A. M. Shahar ◽  
A. A. Aziz ◽  
T. N. T. Yaakub ◽  
N. Khairuddin
Keyword(s):  
Magnetic Field ◽  
Blood Cell ◽  
Trapping Efficiency ◽  
Uniform Electric Field ◽  
Geometrical Shape ◽  
Biological Particles ◽  
Geometrical Shapes ◽  
Electrical Gradient ◽  
Is Design

<p>This paper presents a characterization of geometrical shape on dielectrophoresis by determining and analysing the geometrical shape of electrodes. The structure or geometrical shape of dielectrophoresis electrode is design using COMSOL software to determine the maximum trapping efficiency of particles. The trapping efficiency of particles can be evaluated by analysing the best electrical gradient and investigated the behaviour of the particles if the existence of a non-uniform electric field.  There are three geometrical shapes have been designed which is, peel chain shape, castle wall shape and comb shape. Each of the geometrical shapes have different magnetic field produce, hence each of the design have specific application. Furthermore, these three designed are analysed by varying the material of the electrode for the best trapping efficiency. From the various and previous study, for maximum trapping efficiency the shape used is peel chain shape which is suitable for biological and non-biological particles separation. But for the castle wall and comb shape is the most suitable for biological particles such as red blood cell and bacteria trapping. As for the result obtain, it is proven that peel chain shape could achieve maximum electrical gradient to trap biological or non-biological particles in the future.</p>

Analysis on Gas Drainage Based on High-Pressure Water Injection

2012 ◽  
Vol 524-527 ◽  
pp. 1147-1152
Author(s):  
Chao Zheng ◽  
Tian Hong Yang ◽  
Qing Lei Yu ◽  
Peng Hai Zhang
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Injection ◽  
Mine Safety ◽  
Gas Drainage ◽  
Damage Area ◽  
Major Disaster ◽  
Before And After ◽  
Pressure Water ◽  
Injection Technology

Gas outburst has been a major disaster in high gas mine. Flow law of gas in coal seam was studied, and gas drainage measures were proposed were extraordinarily useful for mine safety and rational use of gas. Finite element numerical method was applied to study changing law of gas pressure before and after the high-pressure water injection and damage deformation of coal under high-pressure water based on fluid-solid coupling and gas-solid coupling and damage theory. This research shows that: (1) a damage area was generated in coal seam under high-pressure water injection. Range of the damage area increase rapidly at the start of water injection and gradually slow down with the passage of time, eventually be more stable. (2) The permeability of rock mass of coal under high-pressure water injection. (3) High-pressure water injection had significant effect on gas drainage in a certain area. It provided a theoretical basis for selecting reasonable design programs to product gas by high-pressure water injection technology.

Effect of Machining of Small Tools by Means of Focused Ion Beam

2012 ◽  
Vol 565 ◽  
pp. 588-593
Author(s):  
Kohichi Miura ◽  
Syou Satoh ◽  
Takazo Yamada ◽  
Hwa Soo Lee
Keyword(s):  
Experimental Evaluation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cutting Edge ◽  
Geometrical Shape ◽  
Geometrical Shapes ◽  
Micro Holes ◽  
Made In ◽  
The Ideal

Micro holes which diameters are more than 0.1 mm are mechanically machined.　However since the ideal sharp cutting edges are difficult to be made in micro drills, fine geometrical shape of micro holes is difficult to be obtained. In this study, the influence of the geometrical shape of cutting edge is experimentally discussed. In order to carry out experimental evaluation, focused ion beam is used to make the geometrical shapes of micro drills.

Influence of Geometrical Shapes and Sheet Thicknesses on the Dimensional Accuracy of Single and Assembled Parts

2016 ◽  
Vol 716 ◽  
pp. 923-930 ◽  
Author(s):  
Tobias Konrad ◽  
Steffen Schöllhammer ◽  
Karl Roll ◽  
Marion Merklein
Keyword(s):  
Sheet Thickness ◽  
Dimensional Accuracy ◽  
Geometrical Shape ◽  
Process Chain ◽  
Novel Approach ◽  
Geometrical Shapes ◽  
Plane Sheet ◽  
Future Work ◽  
The Impact ◽  
Joining Process

Based on elastic stress and strain states after forming and joining processes, single and assembled parts show deviations regarding their dimensional accuracy. Therefore an analysis of selected influencing factors and their influence on the dimensional accuracy of assembled parts is performed in this paper. In this article a novel approach is presented that characterizes the impact of three geometrical shapes (convex/concave/straight) and different sheet thicknesses on the dimensional accuracy along a linked forming and joining process chain. The process chain consists of a deep drawing and a clinching process. Depending on sheet thickness, material and geometrical shape, the dimensional accuracy of single parts and joined assemblies varies. For the single parts the geometry of the specimen S-rail is used. Several types of assemblies are used for the proposed approach combining this specimen with a plane sheet or a second S-rail. The FEM-tools LS-DYNA and Abaqus, are used to demonstrate this approach. Simulations and experiments with aluminum alloy 6014, mild steel CR3 and sheet thicknesses of 0.7, 1.0 and 2.0 mm are conducted for single and assembled parts. In summary, a significant improvement of the dimensional accuracy of an S-rail assembly is demonstrated using two non-dimensional accurate single parts. Future work will be to analyze frequently occurring part segmentations for the joining technologies and to optimize material mix and sheet thicknesses in order to improve deviations of the assembly to the nominal CAD geometry.

scholarly journals Effect on Richtmyer-Meshkov instability of deviation from sinusoidality of the corrugated interface between two fluids

2007 ◽  
Vol 25 (3) ◽  
pp. 503-510 ◽  
Author(s):  
M.R. Gupta ◽  
S. Roy ◽  
S. Sarkar ◽  
M. Khan ◽  
H.C. Pant ◽  
...  
Keyword(s):  
Growth Rate ◽  
Laser Pulse ◽  
Geometrical Shape ◽  
Fluid Interface ◽  
Two Fluids ◽  
Optimum Stability ◽  
Geometrical Shapes ◽  
Icf Target ◽  
Two Fluid ◽  
Arbitrary Shapes

The effect of arbitrary shapes of the two fluid interface on Richtmyer-Meshkov (RM) instability is investigated. It is seen that deviation from sinusoidality in the geometrical shapes has interesting influence on the overall growth rate. In the linear theoretic domain the RM instability may be actually reduced for suitable geometrical shape of the interface. The figures given demonstrate this aspect. This result is important in designing ICF target and also gives an idea to tailor laser pulse for optimum stability of RM modes.

scholarly journals Considerations regarding the specific tests applicable to electric motors with type of protection flameproof enclosure „d” and type of protection increased safety

2020 ◽  
Vol 305 ◽  
pp. 00021
Author(s):  
Dragoş Fotău ◽  
Marcel Rad ◽  
Diana Sălăşan
Keyword(s):  
Electric Motors ◽  
Electric Machinery ◽  
Explosion Protection ◽  
Representative Samples

The purpose of this paper is to present the importance of the specific tests for electric motors with type of protection flameproof enclosure „d” and type of protection increased safety „e” designed to be used in explosive atmosphere. Most of the equipment operating in potentially explosive atmospheres is represented by electric motors, which in most situations act on various other elements (e.g. pumps, valves, fans etc.). Even if electric motors for explosive atmospheres are designed and manufactured following some of the same principles as the ones used for other electric machinery, they have certain particularities related to their field of use. Thus, a series of specific restrictions and tests are required to be considered in their case. In order to verify explosion protection, the representative samples made available by explosion-protected equipment manufacturers are tested under the most unfavorable conditions that may occur in operation.

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