Identification and Monitoring of Geotechnical Risk Areas Using Inertial Data Supplied by In-Line Inspection Tools

2015 ◽  
Author(s):  
Tom Henry Bernabe Castro ◽  
John Erick Malpartida Moya
Keyword(s):  
Noise Reduction ◽  
Action Plan ◽  
Reduction Process ◽  
Operating Conditions ◽  
Critical Conditions ◽  
Soil Movement ◽  
Additional Information ◽  
Risk Areas ◽  
Ground Motion Records ◽  
Geotechnical Risk

By their nature, Pipeline Transmission Systems are exposed to threats from various sources. These include the threat of Weather and Outside Forces (WOF), this threat has a destructive potential associated with landslides, creeping, soil erosion and scouring in rivers, etc. Their hazards increase when pipelines are installed in areas with a tropical climate, having rains of a magnitude that often tend to destabilize the soil surrounding the pipelines, affecting its integrity and therefore the safety of people and the environment. The identification and monitoring of geotechnical risk areas, using inertial data, is based on the reprocessing and analysis of the raw data provided by in line inspection tools. The result of this analysis, after the noise reduction process using a variety of filters at different intervals, reveals areas where there is possible deformation. These zones are transformed into indications that are studied by an analyst, correlating other data sources such as terrain topography, soil characteristics, hydrology, ground motion records, ILI records (caliper records, MFL records, etc.), as-built data, stress concentrators, etc. The analyst determines if they are pipeline deformations due to soil movement or if the indication is caused by another source such as the noise caused by the electronic components of the tool, the operating conditions during the inspection, the filtering process, etc. Areas with signs of strain are evaluated to determine the tensional state in critical conditions for each specific case. If the stresses are close to the limits, a field inspection and an action plan are needed for each case. In certain cases, according to the experts, field indications are evaluated to verify the data obtained by the ILI Tool and to simultaneously give feedback to the noise reduction process. The execution of the calculation process allows the monitoring and identification of geotechnical risk areas, providing better control over parameters such as limits for reporting indications, control of discrimination and selection criteria, detailed assessment of each indication, etc. Finally, this process provides the opportunity to obtain additional information from the ILI inspection such as unregistered bending, misaligned welds, areas with excess root welding, etc.

Treatment system response to transient AOX (adsorbable organic halogen) loadings

1997 ◽  
Vol 35 (2-3) ◽  
pp. 85-91
Author(s):  
D. A. Barton ◽  
J. D. Woodruff ◽  
T. M. Bousquet ◽  
A. M. Parrish
Keyword(s):  
Paper Industry ◽  
Model Development ◽  
Operating Conditions ◽  
System Response ◽  
Additional Information ◽  
Organic Halogen ◽  
Aox Removal ◽  
Variable Operating Conditions ◽  
Plant Shutdown

If promulgated as proposed, effluent guidelines for the U.S. pulp and paper industry will impose average monthly and maximum daily numerical limits of discharged AOX (adsorbable organic halogen). At this time, it is unclear whether the maximum-day variability factor used to establish the proposed effluent guidelines will provide sufficient margin for mills to achieve compliance during periods of normal but variable operating conditions within the pulping and bleaching processes. Consequently, additional information is needed to relate transient AOX loadings with final AOX discharges. This paper presents a simplistic dynamic model of AOX decay during treatment. The model consists of hydraulic characterization of an activated sludge process and a first-order decay coefficient for AOX removal. Data for model development were acquired by frequent collection of influent and effluent samples at a bleach kraft mill during a bleach plant shutdown and startup sequence.

Feasibility of High Speed Furnace Drawing of Optical Fibers

2004 ◽  
Vol 126 (5) ◽  
pp. 852-857 ◽  
Author(s):  
Xu Cheng ◽  
Yogesh Jaluria
Keyword(s):  
Optical Fibers ◽  
High Speed ◽  
Flow Instability ◽  
Fiber Quality ◽  
Domain Boundary ◽  
Operating Conditions ◽  
Furnace Temperature ◽  
Fiber Drawing ◽  
Heated Zone ◽  
Additional Information

The domain of operating conditions, in which the optical fiber-drawing process is successful, is an important consideration. Such a domain is mainly determined by the stresses acting on the fiber and by the stability of the process. This paper considers an electrical resistance furnace for fiber drawing and examines conditions for process feasibility. In actual practice, it is known that only certain ranges of furnace temperature and draw speed lead to successful fiber drawing. The results obtained here show that the length of the heated zone and the furnace temperature distribution are other important parameters that can be varied to obtain a feasible process. Physical behavior close to the boundary of the feasible domain is also studied. It is found that the iterative scheme for neck-down profile determination diverges rapidly when the draw temperature is lower than that at the acceptable domain boundary due to the lack of material flow. However, the divergence rate becomes much smaller as the temperature is brought close to the domain boundary. Additional information on the profile determination as one approaches the acceptable region is obtained. It is found that it is computationally expensive and time-consuming to locate the exact boundary of the feasible drawing domain. From the results obtained, along with practical considerations of material rupture, defect concentration, and flow instability, an optimum design of a fiber-drawing system can be obtained for the best fiber quality.

APU-Noise Reduction by Novel Muffler Concepts

2018 ◽  
Author(s):  
Karsten Knobloch ◽  
Lars Enghardt ◽  
Friedrich Bake
Keyword(s):  
Noise Reduction ◽  
Operating Conditions ◽  
Acoustic Damping ◽  
Broadband Absorption ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Absorber Material ◽  
Bias Flow ◽  
Downstream Section ◽  
Broadband Sound

For a GTCP36-28 auxiliary power unit (APU), a set of mufflers has been designed and tested for some representative operating conditions. The first muffler design uses cavities of different sizes in conjunction with a bias flow for efficient broadband sound absorption. The second design — also expected to perform well over a large frequency range — makes use of a variable perforation and some porous absorber material. The acoustic damping performance of the mufflers was assessed using a downstream section of dedicated microphone probes. Individual spectra and circumferential averages have been computed and are used for a comparison to a hard-walled duct section of the same length. Results show a reasonable broadband absorption for most configurations. For one operating point, significant differences were found while comparing the performance of the cavity muffler with and without bias flow. The results suggest, that a small amount of air — less than initially expected — is sufficient to obtain the desired noise reduction.

Pressure Transients in an Axial Piston Hydraulic Pump

1974 ◽  
Vol 188 (1) ◽  
pp. 189-199 ◽  
Author(s):  
B. O. Helgestad ◽  
K. Foster ◽  
F. K. Bannister
Keyword(s):  
Noise Reduction ◽  
Operating Conditions ◽  
Valve Plate ◽  
Hydraulic Pump ◽  
Noise Emission ◽  
Relief Valve ◽  
Pressure Transients ◽  
Theoretical Predictions ◽  
Axial Piston

A method is given for calculating pressure transients in an axial piston hydraulic pump. Some theoretical predictions are given of the effect of port timing and the effect of introducing restricting grooves at the ends of the kidney ports in the valve plate and suggestions are made of the effects of these parameters on noise emission; comparative measurements of noise are then quoted that support the general arguments. A parallel shot is recommended as the best compromise for the restrictor groove geometry to give good results over the widest range of operating conditions, including reverse rotation. Finally, mention is made of the use of a relief valve in the port plate for noise reduction.

Numerical analysis of the carbon containing pellets direct reduction process

2021 ◽  
Vol 118 (2) ◽  
pp. 209
Author(s):  
Nan Li ◽  
Feng Wang ◽  
Wei Zhang
Keyword(s):  
Direct Reduction ◽  
Reduction Process ◽  
Operating Conditions ◽  
Utilization Efficiency ◽  
Heat Absorption ◽  
Furnace Temperature ◽  
Chemical Reaction Kinetics ◽  
Direct Reduction Process ◽  
Pellet Surface ◽  
Composite Pellets

In view of the carbon-containing composite pellets direct reduction process in rotary hearth furnace, a mathematical model coupling heterogeneous chemical reaction kinetics, heat and mass transfer of this process was established. The effects of furnace temperature (from 1273.15 K to 1673.15 K) and pellet radius (from 6 mm to 16 mm) on the direct reduction of carbon-containing composite pellets were studied by adopting computational fluid dynamics software. The pellet temperature and composition changes under different operating conditions were analyzed. CO and CO2 fluxes, heat fluxes on the pellet surface were especially studied. Total heat absorption by the pellet, CO and CO2 overflow from the pellet surface together with pellet degree of metallization (DOM) and zinc removal rate (ZRR) were calculated. Results show that with the increasing of furnace temperature or the decreasing of the pellet radius, the temperature difference between pellet surface and its center and the final DOM, ZRR increased. The larger the pellet radius, the smaller the heat absorption, also the smaller CO and CO2 overflow. But heat absorption and CO overflow per unit volume are higher. There is an optimal pellet radius with high CO utilization efficiency. Pellet porosity decreases at first and then increases with reducing time. It is also found that effective thermal conductivity is a major factor limiting the pellets temperature increasing. The reduction sequence of the pellets is Fe2O3→Fe3O4→FeO→Fe.

scholarly journals Local knowledge of the Bornean Peacock-pheasant Polyplectron schleiermacheri: a critique of O'Brien et al. (1998a)

2000 ◽  
Vol 10 (4) ◽  
pp. 311-316
Author(s):  
R. Sözer ◽  
I. Setiawan ◽  
A. P. Setiadi
Keyword(s):  
Local Knowledge ◽  
Action Plan ◽  
Structured Interviews ◽  
Conservation Action ◽  
Scientific Contribution ◽  
Central Kalimantan ◽  
Additional Information ◽  
Questionnaire Surveys ◽  
Conservation Action Plan

In a recent study, O'Brien et al. (1998a) sought to provide a better understanding of the distribution and status of the Bornean Peacock-pheasant Polyplectron schleiermacheri in Central Kalimantan, Indonesia, based on an analysis of questionnaires and semi-structured interviews with local inhabitants. This was the first scientific contribution concerning this species after the launch of the Conservation Action Plan for Pheasants (McGowan and Garson 1995). Although the authors of this study acknowledged and discussed the limitations of the questionnaire approach and some of the anomalies in the replies they received, we still feel that the questions posed in this survey may have been phrased in such a way as to invite slight biases in the answers, and that some of the analyses of the replies may have created further biases. We therefore feel it may be helpful to review these uncertain areas in order to help improve questionnaire surveys in future fieldwork. Two of us (I.S. and A.P.S.) helped conduct the surveys in question, and all of us have experience of galliforms in Kalimantan.We occasionally refer to additional information concerning the survey which was presented in another publication (O'Brien et al. 1998b).

Centrifugal Pump Leak-Free Technology Introduction and Its Applications in EPR Nuclear Power Plant

2010 ◽  
Author(s):  
Guohui Cong ◽  
Ling Zhang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Centrifugal Pump ◽  
Nuclear Power ◽  
Operating Conditions ◽  
Critical Conditions ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Canned Motor ◽  
Magnetic Drive

Environmental protection requirement is more and more critical now, and it increases the request to prevent dangerous liquid to leak outside in nuclear power plant too. Centrifugal pumps are the most important active equipments in nuclear power plant, but there is a shaft clearance between rotor and stator of centrifugal pump. The shaft clearance can lead pumped fluid to the outside, so the environment may be polluted by the leakage. In some critical conditions such as transferring high radioactive fluid in the pump, the leakage shall be totally forbidden. So solutions have to be found to make centrifugal pumps totally leak-free for applications in nuclear power plant. Normally there are three leak-free technologies for centrifugal pumps: mechanical seal with auxiliary system, canned motor and magnetic drive. In this paper, all the three leak-free technologies and some of their applications in EPR 3rd generation PWR nuclear power plants are presented and discussed. The results show that in EPR nuclear power plant, canned motor pumps can be preferably used for strict environmental requirement of leak-free if the pump power and operating conditions are applicable. For other conditions, pumps with double mechanical seal can also be used with additional sealing water system support. For centrifugal pumps with magnetic drive are not so applicable in high pressure condition, and the safety aspect is weaker than canned motor pumps, generally they are not used in EPR nuclear power plant at present.

Comparative evaluation of critical operating conditions for a tubular catalytic reactor using thermal sensitivity and loss-of-stability criteria

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Gheorghe Maria ◽  
Dragoş-Nicolae Ştefan
Keyword(s):  
Thermal Sensitivity ◽  
Fixed Bed ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Raw Material ◽  
System Stability ◽  
Performance Criteria ◽  
Matrix Analysis ◽  
Critical Conditions ◽  
Catalytic Reactor

AbstractOptimal operation of a chemical reactor according to various performance criteria often drives the system towards critical boundaries. Thus, precise evaluation of runaway limits in the parametric space becomes a crucial problem not only for the reactor’s safe operation, but also for over-designing the system. However, obtaining an accurate estimate for operating limits is a difficult task due to the limited validity of kinetic models describing complex processes, as well as the inherent fluctuations of the system’s properties (catalyst, raw-material quality). This paper presents a comparison of several effective methods of deriving critical conditions for the case of a tubular fixed-bed catalytic reactor used for aniline production in the vapour phase. Even though the methods being compared are related to one another, the generalised sensitivity criterion of Morbidelli-Varma (MV) seems to be more robust, not depending on a particular parameter being perturbed, when compared to the criteria that detect an incipient loss of system stability in the critical region (i.e., div-methods based on the system’s Jacobian and Green’s function matrix analysis). Combined application of div- and MV criteria allows for an accurate evaluation of the distance from the reactor’s nominal conditions to the safety limits.

The action plan for noise reduction in Modena: methods, effects and perspectives

2009 ◽  
Vol 137 (3-4) ◽  
pp. 252-255 ◽  
Author(s):  
D. Campolieti ◽  
D. Bertoni
Keyword(s):  
Noise Reduction ◽  
Action Plan
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