scholarly journals Influence of Nitrocarburizing on Increasing the Service Life of Elastic Elements of Direct Flow Valves

2021 ◽  
Author(s):  
Jan Krmela ◽  
Tetiana Hovorun ◽  
Kristina Berladir ◽  
Artem Artyukhov ◽  
Serhii Kasian
Keyword(s):  
Service Life ◽  
Direct Flow ◽  
Elastic Elements

scholarly journals Optimizing service life of conveyor belts while transporting bulk load

2019 ◽  
Vol 109 ◽  
pp. 00057
Author(s):  
Vitalii Monastyrskyi ◽  
Serhii Monastyrskyi ◽  
Borys Mostovyi
Keyword(s):  
Service Life ◽  
Objective Function ◽  
Bulk Material ◽  
Conveyor Belt ◽  
Special Device ◽  
Direct Flow ◽  
Conveyor Belts ◽  
Bulk Load ◽  
Minimum Objective Function ◽  
Motion Plane

The paper considers problems concerning optimization of service life of a conveyor belt in terms of its bulk material loading. Statement of the problem of belt life optimization is in the determining minimum of difference between squared velocity of a conveyor belt and projection of horizontal component of the load velocity when it contacts a belt onto the belt motion plane. The problem was solved numerically taking into consideration the objective function, varied parameters, and their limitation. Cases of direct-flow loading and loading with the help of special devices with straight and curved trough profiles have been analyzed. Regularities of changes in the belt service life due to significant factors in terms of direct-flow loading and loading with special device have been obtained to perform comparative analysis of different variants in terms of similar value of the objective function. The variants with maximum belt life and minimum objective function have been selected. For short conveyors, in terms of direct-flow loading, belt life decreases by 1.5–2.0 times comparing to the use of a loading device, and in terms of long conveyors, it decreases by 5–6 times, if value of the objective function is 0.5–1.0 m2/s2.

Use of titanium cassettes as a cathode on electrolytic cells of direct-flow type

2021 ◽  
pp. 43-47
Author(s):  
V. A. Pochekutov
Keyword(s):  
Stainless Steel ◽  
Service Life ◽  
Continuous Operation ◽  
Chemical Compositions ◽  
Stainless Steel Mesh ◽  
Direct Flow ◽  
Flow Models ◽  
Steel Mesh ◽  
Developed Surface ◽  
The Cost

Since the main method of obtaining gold from thiourea solutions for gold mining plants operating on sorption technology is electrolysis with insoluble anodes, it is essential to ensure continuous operation of cells and reduce the number of unscheduled downtime associated with maintenance, cathode failure or troubleshooting. Electrolyzers with a developed surface are inferior in performance to direct-flow models due to the fact that for the former this figure decreases as the cathode deposit accumulates. However, during the operation of direct-flow electrolyzers, unplanned stops occur due to the dissolution of cathodes made of stainless steel mesh in thiourea solutions. In this case, the consumption and costs of purchasing the relevant elements are quite large. Therefore, it is necessary to replace the stainless steel cathode mesh with another material that can withstand the effects of acidic environment, high temperature and direct current for a long time not compromising reducing the performance of the cell. In addition, the cost should not exceed the stainless steel mesh from which the cathode is made, and the service life of such a cathode should be many times longer than the service life of cathodes made of mesh. It is shown that such material can be titanium of VT-1-0 grade made in the form of a perforated corrugated cassette. The operating parameters of the cell with a mesh cathode and using a corrugated perforated titanium cassette are given. The chemical compositions of commodity regenerates before electrolysis and solutions at the outlet of the process at the mesh cathode are shown. The description and drawing of the corrugated perforated titanium cassette are presented. The economic calculation and substantiation of the replacement of the cathode from the stainless steel mesh with the corrugated perforated titanium cassette are performed. The cost of the stainless steel mesh used for the fabrication of the mesh cathode and the titanium sheet for the perforated cassette were analyzed. The use of corrugated perforated titanium cassette on the direct-flow cell allowed to ensure its continuous operation, increase the amount of deposited cathode sludge due to the lack of unscheduled shutdowns to replace the dissolved cathodes.

A Possible Basis for Nondestructive Characterization of Ropes of Nylon 6

1997 ◽  
Vol 503 ◽  
Author(s):  
H. Jiang ◽  
M. K. Davis ◽  
R. K. Eby ◽  
P. Arsenovic
Keyword(s):  
Tensile Strength ◽  
Service Life ◽  
Fiber Diameter ◽  
Structural Parameters ◽  
Crystal Form ◽  
Nylon 6 ◽  
Remaining Service Life ◽  
Nondestructive Characterization ◽  
Fractional Content

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.

Development of Approaches to Solving the Problems of Ensuring Strength, Service Life and Safety of the Trunk Oil Transportation

2019 ◽  
pp. 7-14 ◽  
Author(s):  
N.A. Makhutov ◽  
◽  
Ya.M. Fridlyand ◽  
A.A. Raspopov ◽  
M.V. Lisanov ◽  
...  
Keyword(s):  
Service Life ◽  
Oil Transportation

CARBONATION INDUCED CORROSION ANALYSIS OF REINFORCED CONCRETE STRUCTURES BASED ON FULL PROBABILISTIC APPROACH – AN INDONESIAN CASE STUDY

2018 ◽  
Vol 4 (1) ◽  
pp. 165
Author(s):  
Herry Prabowo ◽  
Mochamad Hilmy
Keyword(s):  
Service Life ◽  
Probabilistic Approach ◽  
Concrete Structures ◽  
Weather Condition ◽  
Analysis Data ◽  
National Standard ◽  
Concrete Carbonation ◽  
Durability Design ◽  
Starting Point ◽  
Real Performance

The assessment of the service life of concrete structures using the durability design approach is widely accepted nowadays. It is really encouraged that a simulation model can resemble the real performance of concrete during the service life. This paper investigates the concrete carbonation through probabilistic analysis. Data regarding Indonesian construction practice were taken from Indonesian National Standard (SNI). Meanwhile, data related to Indonesian weather condition for instance humidity and temperature are taken from local Meteorological, Climatological, and Geophysical Agency from 2004 until 2016. Hopefully the results can be a starting point for durability of concrete research in Indonesia.

Functional and operational risk as a criterion for assessing the durability of an autonomous energy system

2019 ◽  
Vol 12 (1) ◽  
pp. 56-62 ◽  
Author(s):  
A. O. Nedosekin ◽  
A. V. Smirnov ◽  
D. P. Makarenko ◽  
Z. I. Abdoulaeva
Keyword(s):  
Service Life ◽  
Structural Reliability ◽  
Residual Life ◽  
Fuzzy Random Variable ◽  
Operational Risk ◽  
Energy System ◽  
Technical System ◽  
Residual Service Life ◽  
Technological Parameters ◽  
Residual Service

The article presents new models and methods for estimating the residual service life of an autonomous energy system, using the functional operational risk criterion (FOR). The purpose of the article is to demonstrate a new method of durability evaluation using the fuzzy logic and soft computing framework. Durability in the article is understood as a complex property directly adjacent to the complex property of system resilience, as understood in the Western practice of assessing and ensuring the reliability of technical systems. Due to the lack of reliable homogeneous statistics on system equipment failures and recoveries, triangular fuzzy estimates of failure and recovery intensities are used as fuzzy functions of time based on incomplete data and expert estimates. The FOR in the model is the possibility for the system availability ratio to be below the standard level. An example of the evaluation of the FOR and the residual service life of a redundant cold supply system of a special facility is considered. The transition from the paradigm of structural reliability to the paradigm of functional reliability based on the continuous degradation of the technological parameters of an autonomous energy system is considered. In this case, the FOR can no longer be evaluated by the criterion of a sudden failure, nor is it possible to build a Markov’s chain on discrete states of the technical system. Assuming this, it is appropriate to predict the defi ning functional parameters of a technical system as fuzzy functions of a general form and to estimate the residual service life of the technical system as a fuzzy random variable. Then the FOR is estimated as the possibility for the residual life of the technical system to be below its warranty period, as determined by the supplier of the equipment.

On the effect of the periodicity of diagnostic measurements on improving the reliability of high-voltage transformers

2019 ◽  
Vol 12 (1) ◽  
pp. 18-21
Author(s):  
V. A. Tikhonov
Keyword(s):  
Service Life ◽  
High Voltage ◽  
Chromatographic Analysis ◽  
Aluminum Industry ◽  
Early Stage ◽  
Diagnostic Methods ◽  
Transformer Oil ◽  
Operating Voltage ◽  
Dissolved Gases ◽  
The Aluminum Industry

The influence of the periodicity of diagnostic measurements on the operational state of high-voltage transformers is considered. Examples of defects of switching devices of converter transformers and methods for their detection are given. The rationale for the importance of recognition of defects at an early stage of their occurrence is given. The influence of the multiplicity of overvoltages on the service life of converter transformers in the aluminum industry is investigated. Based on the analysis of the service life of converter transformers of one of the powerful aluminum plants, where 83% of converter transformers have exhausted their standard service life, it is shown that in 40% of cases it would be possible to avoid their failures, with timely detection and elimination of emerging defects. Examples of defects of OLR (on-load regulators) of converter transformers and methods for their detection are given. The importance of recognition of defects at an early stage of their occurrence is substantiated. A method for chromatographic analysis of dissolved gases in transformer oil has been developed for the qualitative determination of defects and ways to eliminate them. Examples of diagnostics of converter transformers at operating voltage and working load are given, providing the best quality operational characteristics of converter transformers. The periodicity of diagnostic measurements and the reduction of defects and failures has been substantiated. The question of diagnosing the state of the converter transformer TDNP-40000/10 at an enterprise of the aluminum industry is investigated. Currently, diagnostic methods are being developed based on chromatographic analysis of dissolved gases in transformer oil. The presented method of evaluating the operating parameters of transformers allows for the safe operation of high-voltage transformers and enables to increase the reliability of the power supply scheme of aluminum industry plants.

Installing sealants for long service life

2019 ◽  
Author(s):  
Gregory T. Schueneman ◽  
Steven J. Lacher ◽  
Christopher G. Hunt
Keyword(s):  
Service Life
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