IMEKO Event Proceedings Search

   

Page 237 of 977 Results 2361 - 2370 of 9762

T. Cousins, B. Griffith
The Production of Swirl in Oil and Method of Compensation in Multi-Path Ultrasonic FlowMeter

The paper describes a series of tests, which were initially intended to investigate performance of a two plane multi-path meter in the presence of severe swirl. With the two plane design it was clear that detailed data could be produced showing the level of the swirl, its changes with distance along the pipe and even the changes in position of the swirl centre.
Most of the work previously on swirl had been conducted at high Reynolds numbers, and the assumptions were made that it takes the same form, possibly until the transition and laminar regions. The tests described range from a Reynolds number of 2000 to just under 1,000,000, thus the data covers the complete transition region and the higher laminar region. Some unusual results were obtained, showing a substantial increase in the production of swirl in the region between 10,000 and 100,000, tailing off as the Reynolds numbers become higher. In this region the swirl appears to be large and to a degree unstable.
The paper details the data and also shows the intrinsic ability of the two plane meter to deal with the effects of swirl, even when it is not concentric.

Jan G. Drenthen, Marcel Vermeulen, Martin Kurth, Hilko den Hollander
Ultrasonic Flow Meter Diagnostics and the Impact of Fouling

Over the past decade, Ultrasonic flow meters have gained a wide acceptance. Main reasons for this are the high repeatability in combination with zero pressure loss and extensive diagnostic features. During this period meters with different path configurations have been put into the market, each of them trying to obtain the highest accuracy. Many of them show (often after multipoint linearization) almost perfect straight lines with errors close to the repeatability of the lab.
However, for a user it is not only important how good his meter is at the lab, far more important is the accuracy after installation in the field and the question how the user can be sure that the meter’s performance is not deteriorating over time.
Major factors affecting the performance of a meter installed in the field are corrosion and fouling. This is not only a problem for ultrasonic meters, but it will affect every flow meter installed. The great virtue of ultrasonic flow meters in contrast to all other meters, are their huge diagnostic capabilities. In addition to this, ultrasonic flowmeters that use reflecting paths are also capable in detecting changes of the conditions at the pipe wall. As a result these meters have huge advantages over straight path meter designs which are not capable of detecting anything occurring at the pipe wall.
While there are multiple papers on the performance in calibration laboratories, the impact that fouling and corrosion can have on the performance of an ultrasonic meter is less known. One of the first papers describing the impact of installation conditions was that of Rick Wilsack from TCPL [2]. Recently James Witte has presented a paper including also the impact that it has on the flow velocity profile [5]. Acknowledging the impact that installation conditions and fouling can have on the performance of a meter, was the basis for KROHNE to design their ALTOSONIC V12 ultrasonic flowmeter.
The present paper focuses on the impact of fouling and corrosion and addresses:
• the design considerations
• the ways to detect the various categories of fouling
• the tests performed with dirty meters
• the impact of honed versus corroded upstream pipes
• the impact of corrosion of the reflecting surface.
Next to this, a first order correction is given, based on information gathered from the reflecting paths.

William Johansen, Thomas Kegel
The Development of Ultrasonic Meter Performance Diagnostic Methods Velocity Profile Ratios

Check meters are commonly used by calibration facilities to monitor system performance. Check meters at the CEESI Iowa Natural Gas High Flow Facility have been installed in two different configurations: permanently installed check meters upstream of the customer meters and check meters installed downstream of the customer meters in variable configurations. The data from two 12” ultrasonic check meters normally placed downstream of customer meters will be examined to investigate the effect of velocity profile on the performance of ultrasonic flowmeters.

Bryan Trostel, Joel Clancy, Thomas Kegel
Ultrasonic Flowmeter Calibration Intervals

Currently no recalibration interval has been recommended by ultrasonic meter manufacturers or required by the AGA in the United States. Ten years ago the natural gas industry in the United States began acquiring ultrasonic flowmeters. A large amount of data has been collected over the past few years detailing how the performance of an ultrasonic flowmeter is affected by use in the field. The data from 35 meters calibrated at CEESI Iowa will be analyzed to investigate the effects of time on the performance of ultrasonic meters.

Ju. V. Mikhailova, S. I. Kuznetsov, I. D. Velt
Measurement of Metallic Weight of the Pulp by the Electromagnetic Method

In the paper, two methods are considered of exact measurement of the metal containing pulp mass. The first one consists in the continuous measuring of the pulp magnetic susceptibility and subsequent automatic correction when calculating the dry solid matter of the metal containing product. The second one provides for use of the special electromagnetic mass flow meters insensitive to the variations of the magnetic properties of the medium measured. The paper presents the technical solutions providing an additional electric signal characterizing the pulp magnetic susceptibility. Presence of such signal makes it possible not only to exclude the volumetric mass flow measurement uncertainty caused by the influence of the pulp magnetic constituent but also to measure the metal containing product mass. Use of such electromagnetic mass flow meters is the most prospective method of solution of the problem posed.

Tao Meng, Chi Wang, He-ming Hu, Hai-bin Chen, Tao Zhuang
Analysis of Flow Field Characteristics in the Hydroturbine Intake Penstock of Three Gorges Power Station by Model Experiment

The accuracy of ultrasonic flowmeter is closely related to flow field on the job site. Because the hydro turbine intake penstock of Three Gorges power station is very large and specially shaped, the flow field at position of ultrasonic flowmeter installed and its effect have a lot of uncertainty. A model pipe system and a model meter with 500 mm diameter were designed and machined according to penstock of Three Gorge power station. The characteristics of velocity distribution were sketched from flow rate tested by each path at different altitude of the flowmeter, while the dispersion of each path shows the degree of disturbance. Comparing several group tests result on different experimental condition, it is quite obvious that velocity distribution is asymmetry. It’s also found that ultrasonic flowmeter with double measurement planes can reduce the effect of transverse flow, but error of flowmeter is about positive 0.3% due to the special flow field of the penstock model.

Anderson Ilha, Mauro M Doria, Valter Yoshihiko Aibe
Treatment of the Time Dependent Residual Layer and Its Effects in Calibration Procedures of Liquids and Gases Inside a Volume Prover

In order to minimize the uncertainty arising from measurements of volume provers, we consider the thin liquid films that form inside the prover's inner surfaces, such as the interior walls of standard tanks and bell provers. These thin films adhere to the surface and may carry a given amount of mass and volume which can impact on the prover-side measurement uncertainties.

Valmir Ruiz, Marcos Tadeu Pereira, Nilson Massami Taira, José Fintelmam, Danieli Guimarães
Prover-by-Prover: Calibration of Provers Using Compact Prover as Master Meter

The article describes the calibration of petroleum products provers with a compact prover as reference (master prover), using the same fluid in the same conditions as used in the process line.

Rainer Engel, Hans-Joachim Baade
Water Density Determination in High-Accuracy Flowmeter Calibration - Measurement Uncertainties and Practical Aspects

In liquid flowmeter calibration, the fluid density is one of the major quantities which impact the uncertainties in the measurement process of calibration. Thus, the in-process density determination in liquid flow standards reveals to be an essential component in the measurement uncertainty analysis.
In the case when a volume-reading flowmeter is calibrated against a gravimetric reference system, the accurate density value of the actual fluid applied in the calibration facility must be available, by measurement or computation, in order to convert the respective volumetric meter reading into an equivalent mass value. That is necessary as the reading of the meter under test (MUT) has to be compared with the reading of the gravimetric reference.
Additionally, fluid-density related impacts on the measurement uncertainty in a flow standard facility occur in the intermediate pipework which connects the meter under test with the reference device, i.e. the volumetric or gravimetric standard. Due to the difference in the thermal expansion coefficients of the pipework’s material and the enclosed water, a systematic measurement deviation is caused if the temperature of the water and the pipework is varying during a calibration run. Practically, such temperature fluctuations always occur, due to varying ambient conditions and a more or less imperfect regulation of the water temperature in the flow facility. Thermal expansion implies a change in the fluid density. Thus, this effect, too, has to be taken into account for analyzing the measurement uncertainty of a flow standard facility.
This second density-related disturbing effect generally occurs in any calibration facility, regardless whether the meter reading is volume-related or mass-related, and in any combination with a gravimetric or volumetric reference standard.
A main issue of this paper is the practical aspect how to determine the water density in the calibration facility under real conditions or referred to real conditions and to derive approximation functions which describe the temperature behavior of water density and which are suitable to be applied for uncertainty analysis purposes.

Li Chuanjing, Chen Yunqi, Guo Aihua, Wang Jizhong, Yue Jian, Gu Shunfeng
Establishment of Air Flow Test Bench with Interact-Check Standards

To enlarge the calibration capacity of existing air flow test bench in SIPAI with turbine master meters traced to bell prover, a newly-designed 4500 m³/h flow test bench using critical nozzles as secondary standard traced to pVTt primary standard is successfully paralleled to the existing flow test bench for doubling the flow rate of original calibration capacity. It is proved that not only different secondary standards in kind, traced to both volumetric and gravimetric standards respectively, can be integrated to form an entire flow test bench, but the dependability of the test bench can be increased simply by interact-check principle instead of multi-laboratory inter-comparison test campaign. This flow test bench has been running for months, as a result a control chart of measurement uncertainty has been made. It shows the layout of this test bench is feasible and beneficial to improve the performance of the facility. Along with the running time goes by, an acceptable limitation between the divergent test results obtained from turbine and nozzle benches in accordance with regular interact-check procedure can be determined.

Page 237 of 977 Results 2361 - 2370 of 9762