scholarly journals Rail Track with Rail Compression

2021 ◽  
Vol 20 (3) ◽  
pp. 234-242
Author(s):  
V. N. Sukhodoev
Keyword(s):  
Effective Property ◽  
Operating Conditions ◽  
Design Parameters ◽  
Labor Costs ◽  
Term Operation ◽  
Rail Track ◽  
Loading And Unloading ◽  
The Stability ◽  
The Cost

The problem of damping the noise on the track, arising from the movement of the train, is solved sufficiently but it is simple, if the rail with spacers is laid inside the longitudinally located band sleeper-mechanism. The result is a layered rail thread, consisting of belts: a rail tape with elastic spacers on three sides, a tie-mechanism tape and a ballast layer. The unity of the layers is carried out due to their own mass. This is the static track without external load. Rail compression is an effective property of rail tracks. It is formed in the sleeper mechanism under the influence of vertical forces with displacements and their horizontal derivatives. When loading the track, the compression is carried out repeatedly with subsequent unloading.n this case, each previous changes in the conditions in work of the track are taken into account in the subsequent cycle of loading and unloading. A rail track with a rail compression is a kind of self-adapting linear system, which is necessary with frequent changes in load and operating conditions for silent performance of a functional purpose. The specificity of this path is that the movement of the wheel creates rail vibration and noise, which are immediately damped by compression with damping. The balance between the occurrence of noise and its suppression is achieved by the ratio of the lengths of half-sleeper shoulders as a lever. The condition for the appearance of a shift of the compression forces in the direction from vertical shoulder of the half-sleepers is the unequal settlements of the horizontal shoulder of the L-shaped half-sleepers and its eccentric loading. As a result of the research, the advantages of a rail track with rail compression have been revealed, which is a guarantor of the stability of the design parameters during long-term operation of the track. The cost of a rail track with rail reduction is halved as a result of steel savings, lower labor costs and operational needs.

Investigation of long-term operation and biomass activity in a membrane bioreactor system

2011 ◽  
Vol 63 (9) ◽  
pp. 1906-1912 ◽  
Author(s):  
Simos Malamis ◽  
Andreas Andreadakis ◽  
Daniel Mamais ◽  
Constantinos Noutsopoulos
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Operating Conditions ◽  
Term Operation ◽  
Solids Retention ◽  
Biomass Activity ◽  
Long Term Performance ◽  
Term Performance

The aim of this work was to evaluate the long-term performance of a Membrane Bioreactor (MBR) that operated continuously for 2.5 years and to assess membrane fouling and biomass activity under various operating conditions. Furthermore, a method for the characterisation of influent wastewater was developed based on its separation into various fractions. The MBR system operated at the solids retention times (SRT) of 10, 15, 20 and 33 days. The increase of SRT resulted in a decrease of the fouling rate associated with the reduction of extracellular polymeric substances. Moreover, the SRT increase resulted in a significant reduction of the Oxygen Uptake Rate (OUR) due to the lower availability of substrate and in a notable decrease of the maximum OUR since high SRT allowed the development of slower growing microorganisms. Biomass consisted of small flocs due to extensive deflocculation caused by intense aeration. Finally, the method developed for wastewater characterisation is straightforward and less time consuming than the usual method that is employed.

Detection method for stability of microcontroller accessories based on biosensor

2021 ◽  
pp. 1-14
Author(s):  
Yan Ren ◽  
Jiayong Liu
Keyword(s):  
Process Design ◽  
Detection Method ◽  
Detection Accuracy ◽  
Stability Testing ◽  
Term Operation ◽  
Existing Problems ◽  
Testing Method ◽  
And Performance ◽  
The Stability

In order to solve the problem of poor accuracy of traditional microcontroller attachment stability testing method, a microcontroller attachment stability testing method based on biosensor was designed to solve the existing problems. The reliability test index of the microcontroller is established, then the interference of the microcontroller accessory is detected and responded, and the interference detection signal of the microcontroller accessory is selected. The process design of stability detection of microcontroller accessories based on biosensor is completed. The experimental results show that the stability detection method based on biosensor designed in this paper can ensure the stability detection accuracy of microcontroller accessories above 80%, which is more accurate than traditional methods. It can be used to evaluate the stability, reliability and performance of microcontroller accessories in long-term operation.

scholarly journals Replacement and Maintenance Decision Analysis for Hydraulic Machinery Facilities at Reservoirs under Imperfect Maintenance

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2507
Author(s):  
Sou-Sen Leu ◽  
Tao-Ming Ying
Keyword(s):  
Cost Effective ◽  
Maintenance Cost ◽  
Imperfect Maintenance ◽  
Term Operation ◽  
Engineering Economics ◽  
Hydraulic Machinery ◽  
Effective Manner ◽  
The Cost ◽  
Replacement Time

After the long-term operation of reservoir facilities, they will become nonoperational due to the material deterioration and the performance degradation. One of crucial decisions is to determine the maintenance or replacement of the facilities in a cost-effective manner. Conventional replacement models seldom consider the maintenance effect. The facilities after maintenance are generally not as good as new, but are relatively restored. The target of this study is to establish a replacement decision model of the reservoir facilities under imperfect maintenance. By combining the theories of reliability analysis, imperfect maintenance, and engineering economics, the best timing of replacement that achieves cost-effectiveness is analyzed and proposed. Lastly, based on the design of experiments (DOE) and simulation, the regression curve chart for the economical replacement decision is established. Once the failure rate, the age of recovery after maintenance, and the ratio of maintenance cost to replacement cost are estimated based on historical data, the cost-effective replacement time of hydraulic machinery facilities will be efficiently determined.

Parametric Optimization of Structures Under Combined Base Motion Direct Forces and Static Loading

1998 ◽  
Vol 124 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Izhak Bucher
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Operating Conditions ◽  
Design Parameters ◽  
Power Spectral ◽  
Loading Patterns ◽  
The Cost ◽  
Selection Of ◽  
Eigenvectors And Eigenvalues

This paper deals with the optimization of vibrating structures as a mean for minimizing unwanted vibration. Presented in this work is a method for automatic determination of a set of preselected design parameters affecting the geometrical layout or shape of the structure. The parameters are selected to minimize the dynamic response to external forcing or base motion. The presented method adjusts the structural parameters by solving an optimization problem in which the constraints are dictated by engineering considerations. Several constraints are defined so that the static deflection, the stress levels and the total weight of the structure are kept within bounds. The dynamic loading acting upon the structure is described in this work by its power spectral density, with this representation the structure can be tailored to specific operating conditions. The uncertain nature of the excitation is overcome by combining all possible spectra into one PSD encompassing all possible loading patterns. An important feature of the presented method is its numerical efficiency. This feature is essential for any reasonably sized problem as such problems are usually described by thousands of degrees of freedom arising from a finite-element idealization of the structure. In this paper, efficient, closed form expressions, for the cost function and its gradients are derived. Those are computed with a partial set of eigenvectors and eigenvalues thus increasing the efficiency further. Several numerical examples are presented where both shape optimization and the selection of discrete components are illustrated.

Performance Stability of Recycle Amine-Free Water-Soluble Coolant in Long Term Operation

2014 ◽  
Vol 625 ◽  
pp. 530-535
Author(s):  
Kenji Yamaguchi ◽  
Yasuo Kondo ◽  
Satoshi Sakamoto ◽  
Mitsugu Yamaguchi ◽  
Ryoichi Nakazawa
Keyword(s):  
Environmental Effect ◽  
Free Water ◽  
Water Soluble ◽  
Water Recovery ◽  
Machining Processes ◽  
Cooling Performance ◽  
Recycling System ◽  
Term Operation ◽  
The Stability

Recently, the concern for the environment has been increasing rapidly. In machining processes, the treatment of water-soluble coolants waste has caused environmental problems. Water-soluble coolants contain surfactants, preservatives, and corrosion inhibitors for maintaining the stability and performance of the coolants. To reduce the management cost and environmental effect of water-soluble coolants, the authors have been studying a recycling system for water-soluble coolants. In the recycling system, oil-free recycle water is isolated from the coolant waste and reused as a diluent of the new coolant. The authors have been developing different types of water recovery methods for the recycling system, and the recovered water from the coolant waste has potential as a diluent for a new coolant. In this report, we focused on the amine (alkanolamine) -free water-soluble coolant. Some amine-free water-soluble coolants have been developed and are commercially available. A reduction in the environmental effect in the waste treatment of coolants is expected with amine-free coolants. We have demonstrated that the amine-free water-soluble coolant has equal or better cooling and lubricating performance compared with the conventional amine-containing coolant. In addition, the amine-free coolant shows good recyclability for the recycling system. The processing time of the recycling treatment of the amine-free coolant has been decreased by half with our recycling process compared with the conventional amine-containing coolant. In this report, we examined the stability, cooling performance and lubricating performance of the recycle amine-free water-soluble coolant in long term operation. The recycle amine-free water-soluble coolant is operated in a 3-axis machining center for several months. We observed concentration, pH, corrosion inhibition performance, cooling performance, and lubricating performance of the coolant. The results from these experiments show the amine-free water-soluble coolant has the advantage to use in the recycling system for water-soluble coolant.

Separation of Oil and Water in Oil Spill Recovery Operations

1999 ◽  
Vol 71 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Knut Gaaseidnes ◽  
Joseph Turbeville
Keyword(s):  
Oil Spill ◽  
Labor Costs ◽  
Cost Of Transport ◽  
Separation Theory ◽  
Extraction Separation ◽  
Oily Water ◽  
Future Direction ◽  
The Cost ◽  
And Storage

The separation of water from oil that is collected in any oil spill recovery operation is a continuing and necessary requirement during every stage of the effort. Its importance is reflected in the cost of transport and storage of large volumes of oily water, the salvage value of separated oil and the added labor costs associated with long-term recovery operations.This paper addresses the effects of weathering and emulsion generation which increase the problems normally associated with water extraction. Separation theory, practical separation technology and recommendations for the future direction of research and development are presented.

Fatigue Cracking Processes of a Thick-Walled Component of a Chemical Pipeline

2013 ◽  
Vol 586 ◽  
pp. 104-107 ◽  
Author(s):  
Marek Cieśla ◽  
Kazimierz Mutwil
Keyword(s):  
Mechanical Properties ◽  
Degradation Mechanism ◽  
Fatigue Cracking ◽  
Operating Conditions ◽  
Material Structure ◽  
Mechanical Loads ◽  
Factors Affecting ◽  
Term Operation ◽  
Materials Used

At present, there are no generally accepted and widely recognized procedures to determine condition of material of devices subject to complex long-term thermo-mechanical loads. Condition of pipeline material usually changes when subjected to the conditions of long-term operation. Its structure changes and, consequently, so do its mechanical properties, including fatigue characteristics and crack resistance. Therefore, the durability of a component operating under thermal and mechanical loads cannot be discussed separately from its current material properties. This applies in particular to changes that take place in the material micro-structure and to their connection with mechanical properties. This paper covers analyses of stress in the material of a selected pipeline component – pipe tee that is used in chemical plants. Thermo-mechanical interactions determining stress distribution in the component have been taken into account in the calculations. Morphology and location of the cracks indicated that a fatigue-like nature of impacts was the cause of material destruction. Loads of this type occur mainly in conditions of start-up and shut-down. For these reasons, condition of the material in the above-mentioned unstable conditions was subjected to numerical stress analysis. Due to geometric complexity of the pipeline, the distribution of stress in the T-pipe was calculated in two stages: the object was modeled from a global and local perspective. The resulting stress distributions helped to determine factors affecting durability of the tested object. Metallurgy tests were also conducted in order to ascertain factors determining the degradation of material structure and processes of crack formation and development. As a result of research one ascertained that the process of T-pipe cracking under operating conditions was a combined effect of thermo-mechanical and chemical actions determined by the course of intercrystalline corrosion. Synergic interaction of corrosion processes and variable thermal and mechanical loads caused nucleation and propagation of cracks. The crack systems in T-pipe areas subject to the highest stress showed courses characteristic for thermal fatigue of material. The results obtained will identify degradation mechanism of materials used in chemical installations.

Extensive Dynamic Analyses to Achieve Stringent Noise and Vibration Levels for an Offshore Reciprocating Compressor System

2011 ◽  
Author(s):  
Andre´ Eijk ◽  
Hans Elferink
Keyword(s):  
Operating Conditions ◽  
Reciprocating Compressor ◽  
Gas Well ◽  
Noise And Vibration ◽  
Term Operation ◽  
The North ◽  
Final Design ◽  
The North Sea ◽  
System Requirements

During the lifetime of an existing gas well, located in the D15FA/FB field in the North Sea, the pressure has dropped and consequently production is reduced. A depletion compressor had to be added to this existing platform to increase the production. This sounds easy but has been very challenging due to physical, noise and vibration restrictions. For this platform it appeared that a reciprocating compressor was the best choice based on its flexibility with respect to the specified operating conditions, available power, and efficiency. However, despite of several advantages a disadvantage of a reciprocating compressor is that it generates additional vibrations and noise in the living quarters, which are located close to the compressor system. The specified requirements, not to exceed the allowable noise limits in the living quarters and the vibration limits of the complete compressor system, could in this specific case, not be met with straightforward solutions. This presentation will explain the dynamic analysis and the efforts taken in compressor, skid, motor, piping and deck design to meet the very stringent specified requirements and to ensure a safe and reliable system for the long term operation. Special attention will be given to the measures taken to reduce the excitations acting on the platform, and the mechanical and acoustical analysis that have led to the final design of this reciprocating compressor system. The solutions that have been developed can be regarded as non-standard and have resulted in new directions in solving very demanding system requirements.

Numerical Characterization of Swirl Brakes for High Pressure Centrifugal Compressors

2013 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Mirko Micio ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Luca Innocenti ◽  
...  
Keyword(s):  
High Pressure ◽  
Tangential Velocity ◽  
Operating Conditions ◽  
Design Parameters ◽  
Centrifugal Compressors ◽  
Labyrinth Seals ◽  
Numerical Characterization ◽  
Lean Angle ◽  
The Stability ◽  
The Many

High pressure centrifugal compressors continue to experience vibrations due to rotordynamic stability. The main cause for aero-induced exciting forces that affects the stability, is the tangential velocity component of the gas entering the many labyrinth seals throughout the machine. In order to control or limit these swirling flows, swirl brakes are generally implemented both at the impeller eye seals and at the balance piston or division wall seal of a centrifugal compressor. This paper deals with the aerodynamic characterization, by means of CFD, of such kind of devices. Several design parameters, such as teeth lean, angle of attack and pitch-to-chord ratio have been considered and also the operating conditions (pressure level and swirl at the swirl brake inlet) are accounted for. This paper aims to improve the physical understanding of the fluid flow of centrifugal compressors swirl brakes allowing an optimization of such systems.

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