Predicting Process Gas Performance of Centrifugal Compressors From Air Test Data

1962 ◽  
Vol 84 (2) ◽  
pp. 248-264
Author(s):  
Philip P. O’Neill ◽  
Herbert E. Wickli
Keyword(s):  
Test Data ◽  
Process Conditions ◽  
Centrifugal Compressors ◽  
Process Industries ◽  
Essential Information ◽  
Process Gas ◽  
The Subject ◽  
Matters Of Concern ◽  
Correlation Procedure

The application of centrifugal compressors to the handling of gases in the process industries is of increasing importance. The problems associated with performing tests at the manufacturer’s plant under process conditions and the lack of a universally accepted method of performance correlation are matters of concern. This paper presents a recommended correlation procedure evolved from the review of technical papers embracing aspects of the subject. A program for the free interchange of air and process test data between manufacturer and user is submitted. This recommended procedure and proposed program (1) provides designers with essential information previously unavailable to them, and (2) ultimately benefits the user by the production of higher-performance machines.

Phase equilibria modeling of biorefinery-related systems: a systematic review

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marcos L. Corazza ◽  
Julia Trancoso
Keyword(s):  
Phase Equilibria ◽  
Phase Behavior ◽  
Fossil Fuel ◽  
Process Conditions ◽  
Design And Optimization ◽  
Waste Reuse ◽  
Wide Range ◽  
Prisma Statement ◽  
Fuel Substitution ◽  
The Subject

Abstract The search for sustainable ideas has gained prominence in recent decades at all levels of society since it has become imperative an economic, social, and environmental development in an integrated manner. In this context, biorefineries are currently present as the technology that best covers all these parameters, as they add the benefits of waste reuse, energy cogeneration, and fossil fuel substitution. Thus, the study of the various applicable biological matrices and exploring the technical capabilities of these processes become highly attractive. Thermodynamic modeling acts in this scenario as a fundamental tool for phase behavior predictions in process modeling, design, and optimization. Thus, this work aimed to systematize, using the PRISMA statement for systematic reviews, the information published between 2010 and 2020 on phase equilibria modeling in systems related to biorefineries to organize what is already known about the subject. As a result, 236 papers were categorized in terms of the year, country, type of phase equilibria, and thermodynamic model used. Also, the phase behavior predictions of different thermodynamic models under the same process conditions were qualitatively compared, establishing PC-SAFT as the model that best represents the great diversity of interest systems for biorefineries in a wide range of conditions.

PENINGKATAN PEMAHAMAN KONSEP KONVERSI SATUAN LUAS MELALUI MODEL PEMBELAJARAN KOOPERATIF STUDENT TEAMS ACHIEVEMENT DIVISIONS

2021 ◽  
Author(s):  
Ris Tanti
Keyword(s):  
Data Analysis ◽  
Cooperative Learning ◽  
Test Data ◽  
Learning Model ◽  
Story Telling ◽  
Student Teams ◽  
The Subject ◽  
Written Test ◽  
Unit Conversion ◽  
Planning Action

The aims of this study was to improve output comprehension concept vast unit conversion using an cooperative learning model with type Student Teams Achievement Divisions (STAD). The kind of this study was action class research (ACR), teacher as a learning executor then student as a learning observer. This study used 2 cycle action class. Every cycle consisted of four stage that is planning, action implementation, observation and evaluation. This study was held on even semester, on February. The subject of this study was student at VI Mina class SD Islam Al Azhar 17 Bintaro consist of 35 students. The data obtained from observation, interviewed and written test. Data analysis used descriptive and presented in a table. The study indicated increase comprehension concept vast unit conversion of student. The first cycle showed 63% student’s score above Minimum Completeness Criteria (MCC), then on second cycle the student’s score increased up to 100% above MCC. Accordingly, cooperative learning model Student Teams Achievement Division (STAD) application can improve comprehension concept vast unit in math story telling question.

scholarly journals Comparison of Three Deoxidation Agents for Ozonated Broths Used in Anaerobic Biotechnological Processes

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 65
Author(s):  
Ewelina Pawlikowska ◽  
Jaroslaw Domanski ◽  
Piotr Dziugan ◽  
Joanna Berlowska ◽  
Weronika Cieciura-Wloch ◽  
...  
Keyword(s):  
Anaerobic Fermentation ◽  
Process Conditions ◽  
Growth Media ◽  
Nutrient Supplementation ◽  
Yeast Biomass ◽  
Residual Oxygen ◽  
The Media ◽  
Biotechnological Processes ◽  
The Subject ◽  
High Concentrations

Anaerobic fermentation of organic compounds is used in many biotechnological processes and has been the subject of much research. A variety of process conditions and different growth media can be used to obtain microbial metabolites. The media must be free from contamination before fermentation. Sterilization is most often achieved by applying heat or other treatments, such as ozonation. Sterilization of liquid media using ozone can be very beneficial, but this method introduces high concentrations of residual oxygen, which inhibit anaerobic processes. Deoxidation is therefore necessary to remove the oxygen from ozonated broths. This study evaluates the effectiveness of three deoxidation agents for two kinds of fermentation media based on malt or molasses: ultrasound, iron(II) sulfate, and Metschnikowia sp. yeast. The time needed for deoxidation varied, depending on the kind of broth and the deoxidation agent. In general, the dynamics of oxygen removal were faster in malt broth. A comparative analysis showed that yeast biomass was the most effective agent, achieving deoxidation in the shortest time. Moreover, the fully deoxidated broth was supplemented with yeast biomass, which is rich in biogenic substrates, expressed as a protein content of 0.13–0.73 g/L. Application of Metschnikowia sp. may therefore be considered as an effective strategy for simultaneous deoxidation and nutrient supplementation of broths used in anaerobic biotechnological processes.

A Novel Bulk-Flow Model for Improved Predictions of Force Coefficients in Grooved Oil Seals Operating Eccentrically

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Luis San Andrés ◽  
Adolfo Delgado
Keyword(s):  
Test Data ◽  
Flow Model ◽  
Hydrodynamic Instability ◽  
Added Mass ◽  
Operating Conditions ◽  
Bulk Flow ◽  
Squeeze Film ◽  
Accurate Estimation ◽  
Force Coefficients ◽  
Process Gas

Oil seals in centrifugal compressors reduce leakage of the process gas into the support bearings and ambient. Under certain operating conditions of speed and pressure, oil seals lock, becoming a source of hydrodynamic instability due to excessively large cross coupled stiffness coefficients. It is a common practice to machine circumferential grooves, breaking the seal land, to isolate shear flow induced film pressures in contiguous lands, and hence reducing the seal cross coupled stiffnesses. Published tests results for oil seal rings shows that an inner land groove, shallow or deep, does not actually reduce the cross-stiffnesses as much as conventional models predict. In addition, the tested grooved oil seals evidenced large added mass coefficients while predictive models, based on classical lubrication theory, neglect fluid inertia effects. This paper introduces a bulk-flow model for groove oil seals operating eccentrically and its solution via the finite element (FE) method. The analysis relies on an effective groove depth, different from the physical depth, which delimits the upper boundary for the squeeze film flow. Predictions of rotordynamic force coefficients are compared to published experimental force coefficients for a smooth land seal and a seal with a single inner groove with depth equaling 15 times the land clearance. The test data represent operation at 10 krpm and 70 bar supply pressure, and four journal eccentricity ratios (e/c= 0, 0.3, 0.5, 0.7). Predictions from the current model agree with the test data for operation at the lowest eccentricities (e/c= 0.3) with discrepancies increasing at larger journal eccentricities. The new flow model is a significant improvement towards the accurate estimation of grooved seal cross-coupled stiffnesses and added mass coefficients; the latter was previously ignored or largely under predicted.

Simulation of Surge Margin Changes due to Heat Transfer Effects in Gas Turbine Transients

1984 ◽  
Author(s):  
Jaakko Larjola
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Low Frequency ◽  
Transfer Effects ◽  
Process Gas ◽  
Surge Margin ◽  
Correct Calculation ◽  
The Subject ◽  
Heat Transfer Effects ◽  
Open Cycle

The subject of this study is the simulation of low-frequency transients (such as acceleration, deceleration) of different open cycle gas turbine types. Special attention is paid to the correct calculation of the effects of heat transfer between process gas and solid structure. Correcting equations for these effects are developed and the transient properties of each component are then evolved from the static ones with these equations. It is shown that the heat transfer effects alter significantly the surge margin of the compressor. Simulation model includes intercooler and recuperation. The programming language is CSMP.

Performance Uncertainty Quantification for Centrifugal Compressors: Part 2—Flange to Flange Variability

2012 ◽  
Author(s):  
Sivasubramaniyan Sankaran ◽  
Giuseppe Sassanelli ◽  
Giuseppe Iurisci ◽  
Andrea Panizza
Keyword(s):  
Probabilistic Approach ◽  
Sensitivity Study ◽  
Critical Parameters ◽  
Process Conditions ◽  
Centrifugal Compressors ◽  
Large Sets ◽  
Probabilistic Technique ◽  
Performance Variation ◽  
Compressor Performance ◽  
Performance Uncertainty

This paper presents a methodology to control flange to flange performance prediction of centrifugal compressors using a probabilistic approach. In order to have reliable prediction for the performance of centrifugal compressors, a thorough knowledge of critical parameters contributing to the deviation and an efficient way to control the variation of these parameters becomes necessary. This paper discusses about a robust methodology for identifying and controlling the variation of these parameters and hence the predicted performance. This probabilistic technique involves a Design of Experiments (DoE) study to handle large number of input parameters, sensitivity study to identify critical ones and a Monte-Carlo based approach to identify the uncertainty in flange to flange performance. This approach takes into consideration the compressor stage performance variability driven by impeller manufacturing tolerances, statoric component losses variability and leakages variability in order to compute overall performance variation in a compressor. An in-house developed probabilistic optimization code (PEZ) is interfaced with a well-validated & calibrated thermodynamic tool to analyse large sets of possible combinations and to provide best possible solution for a given design space. This concept is successfully applied for different compressor configurations by varying the stage numbers and process conditions. The results give an insight on the main sources and magnitude of variations on compressor performance, thus enabling to control the predictions in an efficient way. This methodology will provide a novel and an efficient way to generate robust compressor performance, where it will be possible to take into account design and manufacturing uncertainty. The use of this methodology can thus drastically improve the performance predictability and risk associated with each compressor selection.

Lead Zirconate Titanate Films Produced by ‘Facing Targets’ RF-Sputtering

1990 ◽  
Vol 200 ◽  
Author(s):  
R. A. Roy ◽  
K. F. Etzold ◽  
J. J. Cuomo
Keyword(s):  
Lead Zirconate Titanate ◽  
Silicon Oxide ◽  
Rf Sputtering ◽  
Lead Zirconate ◽  
Process Conditions ◽  
Electrical Measurements ◽  
Process Gas ◽  
Zirconate Titanate ◽  
Wide Range ◽  
Pzt Films

ABSTRACTThe growth of ferroelectric lead zirconate titanate (PZT) films by rf-sputtering using facing targets is described. This study has focused on producing thin (<500 nm) PZT films on a wide range of substrates including magnesium oxide, spinel, alumina, silicon oxide, and the respective substrates coated with platinum. Deposition was from two opposed targets separated by 10–15 cm, with the substrate plane normal to the targets and outside the cylinder defined by the two targets. This geometry was chosen to obtain compositional uniformity and avoid ion bombardment effects. The deposition temperatures ranged from RT to 700 °C and the process gas was a mixture of argon and oxygen. Effects of deposition conditions and post-deposition annealing on film composition, microstructure, and properties were evaluated using Rutherford backscattering spectroscopy (RBS), x-ray diffraction, optical and electron microscopy, and various electrical measurements. Optimization of process conditions is discussed in terms of phase purity, preferred orientation, and minimization of electrode interaction.

Auslagerung des Intellekts

2018 ◽  
Vol 9 (2) ◽  
pp. 133-144
Author(s):  
Christina Vagt
Keyword(s):  
Technological Complex ◽  
Alternative Facts ◽  
The World ◽  
Before And After ◽  
The Subject ◽  
Machine Systems ◽  
Matters Of Concern ◽  
Human Intellect ◽  
The 19Th Century ◽  
Insight Into

Worum geht es in den aktuellen Vorwürfen, die Postmoderne hätte den aktuellen populistischen Diskurs um alternative Fakten vorbereitet? Ausgehend von Latours Elend der Kritik diskutiert der Artikel die Genealogie von Wahrheits- und Evidenzkritik vor und nach den Anfängen des Computers. Dabei lässt sich zeigen, dass vor aller Wahrheits- und Evidenzkritik zunächst ein Misstrauen in den menschlichen Intellekt steht, welches in den frühen Entwürfen künstlicher Intelligenz und der Auslagerung des Intellekts in lernende Maschinensysteme ein vermeintliches Ende findet. Nicht zufällig ruft Herbert A. Simon 1969 in seinem Standardwerk The Sciences of the Artifical Arthur Schopenhauers Welt als Wille und Vorstellung auf, wenn er schreibt, dass die Welt viel mehr eine künstliche, vorgestellte als eine natürliche sei. Anders als im 19. Jahrhundert verspricht jedoch nun die Computersimulation Einsichten in bisher unzureichend verstandene Komplexitäten menschlichen Verhaltens. Das Resultat dieser maschinellen Kritik ist ein ökonomisch-technologischer Komplex, in dem Rationalität nicht mehr als Funktion des Subjektes, sondern als Funktion der Maschine interpretiert und das Politische auf die Ebene des Affektiven reduziert wird. What is really behind the recent accusations of postmodernism being responsible for preparing the current populistic argument about alternative facts? Based on Bruno Latour’s »Why has Critique Run out of Steak? From Matters of Fact to Matters of Concern«, this article discusses the genealogy of truth- and evidentness critique before and after the beginnings of the computer. This will lead to the realization that before all critique concerning truth and evidentness there is already a distrust in the human intellect which comes to an alleged end in the early drafts of artificial intelligence as well as in the outsourcing of intellect into adaptive machine-systems. It is not by accident that Herbert A. Simon refers to Arthur Schopenhauer’s Welt als Wille und Vorstellung in his standard reference work The Sciences of the Artificial from 1969 when he states that the world resembles more of an artificial, imagined one than a natural. Different from the 19th century, the computer simulation these days promises insight into the complexities of human behaviour that have until now been understood only incompletely and insufficiently. The result of machine-based critique is an economic-technological complex in which rationality is no longer interpreted as the function of the subject but as the function of the machine, while politics is reduced to the level of affect

Parametric Variation or Defects?: Statistical Post-Processing Analysis of Wafer-Sort Data

2002 ◽  
Author(s):  
W. Robert Daasch
Keyword(s):  
Spatial Patterns ◽  
Test Data ◽  
Parameter Variation ◽  
Data Driven ◽  
Normal Variation ◽  
Post Processing ◽  
Parametric Data ◽  
Original Measurement ◽  
The Subject ◽  
Measurement Variance

Abstract The subject of this paper is statistical post-processing of wafer-sort test data. Statistical post-processing (SPP) has successfully separated many of the effects of defects from normal wafer-to-wafer variation. The data-driven method is used with parametric data such as IDDQ, minVDD, and others. The neighboring die are used to form an estimate of a die’s expected value. The resulting SPP residual has smaller variance than the original measurement variance and filters most of the spatial patterns that obscure data outliers from normal variation. The method is applicable to a wide variety of process parameter variation issues of concern to both test and FA communities.

Vermarktung von Waldleistungen: Engagement, Fachwissen und Solidarität sind gefragt! (Essay) | Commercialization of forest services: active involvement, knowledge of the subject and solidarity are required (essay)

2009 ◽  
Vol 160 (8) ◽  
pp. 224-227
Author(s):  
Heinz Nigg
Keyword(s):  
Forest Policy ◽  
Development Program ◽  
Forest Sector ◽  
Private Forest ◽  
Specific Knowledge ◽  
Forest Owners ◽  
Active Involvement ◽  
The Subject ◽  
Matters Of Concern ◽  
Privately Owned

A structure of small surfaces with a large proportion of private forest owners and important stocks of wood characterize forestry conditions in canton Appenzell Outer Rhodes. The forest owners are often lacking in initiative, in specific knowledge, in personal and financial resources and in suitable structures for a successful commercialization of non-wood services. A few positive examples show ways to improve this situation and demonstrate the importance, particularly in the privately owned forest sector, of an actively involved, versatile and interested forest ranger. Increasing the awareness of the various people concerned and their mobilization is of far greater importance than the issuing of new regulations. The forest ranger can help through well-directed encouragement concerning marketing and by an integration of the forest non-wood services into the general forestry development program. One of the aims of the forest policy of the canton is that in the future services provided by the forest which are central matters of concern to the community and the greater running costs associated with these should be appropriately compensated.

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