Reliable interface level measurement is a must for many companies operating in the petrochemical industry, as applications that require the separation of oil in water and even multilayer liquids are commonplace. Endress+Hauser offers a range of solutions to measure this process, each option tailored to specific process requirements.
The first step in reliable measurement is selecting the right technology for the particular application as the company’s interface level measurement solutions cover the spectrum from basic interface layers through to complex interfaces such as in crude oil extraction.
Some questions to consider:
* Is overall level consistent or variable?
* Is the overall level to be available as a measured value in addition to the interface layer?
* Does emulsion occur during measurement?
Note: Beware of making the initial purchase cost the primary consideration as this is often far outweighed by future maintenance costs or loss of accuracy over time.
Capacitance interface measurement – Liquicap FMI51/52
The Liquicap M capacitance devices offer tried and tested interface level measurement in applications that have clear or emulsive liquid-to-liquid interface levels (where the dielectric constant between the two liquids is greater than 10).
Benefits
* Tried and tested instrumentation.
* No wet calibration required.
* Unaffected by the density of the medium.
* Can be used with emulsion layers.
* Ideal for very small measuring ranges.
* Extremely fast response time.
* Applications up to 200°C/100 bar.
Application limits
* Difference of the dielectric constant between the two media must be >10.
* The upper medium may not be conductive.
* Accuracy impairment in case of non-conductive build-up on the probe.
* The smaller the vessel the higher the influence of DK changes in the upper medium.
* The bigger the difference between the two DKs, the better the accuracy.
* Overall level is not measured.
* Probe length up to 10 m.
Guided wave radar interface measurement – Levelflex FMP51/52/54
Ideal for use in the petrochemical industry, the new Levelflex FMP5x range offers excellent price-performance ratio. Severe conditions are not a problem as the sensors handle low/high pressures (vacuum up to 400 bar), low/high temperatures (-200 to +450°C) and corrosive or abrasive materials. The Levelflex range offers documented 2 mm accuracy as standard in per the final inspection report.
Benefits
* Simultaneous acquisition of interface and overall levels – if clear interface.
* Unaffected by the density of the medium.
* No wet calibration required.
* Direct replacement of displacers in existing displacer chambers.
* Applications up to 450°C/400 bar.
* Rod probes can be shortened.
Application limits
* DK of the upper medium must be determined and constant.
* DK value changes of the upper medium influence accuracy.
* DK value of the upper medium >10.
* Difference in the DKs between the two media must be >10.
* Probe length up to 10 m (larger on request).
* The thickness of the upper layer must be at least 60 mm.
* Emulsion layers must be less than 50 mm.
Multiparameter interface measurement – Levelflex FMP55
Designed specifically for the petrochemical industry, the new Levelflex FMP55 guided wave radar is enhanced with ground breaking SensorFusion technology to offer best-in-class guided radar measurement for interface levels with emulsion layers. It combines the tried and trusted level monitoring capabilities of capacitance level measurement with all the advantages of guided radar continuous monitoring in a single instrument to provide accurate, reliable interface level and overall level measurement.
Benefits
* Simultaneous acquisition of interface layer and overall level, even with emulsion layers.
* Precise, reliable measurement independent of medium density.
* Wet calibration not required.
* Applications up to 200°C.
* PTFE-coated probe.
Application limits
* DK value of the upper medium must be determined.
* DK value changes of the upper medium affect accuracy.
* DK value of the upper medium <10.
* DK value difference >10.
* Probe length up to 10 m (larger upon request).
* The thickness of the upper layer must be at least 60 mm.
Radiometric interface measurement – Gammapilot FMG60
The non-invasive Gammapilot is perfect for applications where other methods have failed. The device is suitable for extreme process or mechanical, geometric or construction conditions. When used for interface measurement, the radiation of media with different densities is attenuated differently. If the transmitter is calibrated to the medium with the lower density using wet calibration and then to the medium with the higher density, a correlation for the measurement of the interface layer automatically results.
Benefits
* Non-invasive and maintenance-free measuring method.
* Unaffected by pressure and temperature.
* Only slightly influenced by build-up.
* For use with emulsion layers.
* Multiphase measurements using several detectors.
Application limits
* Medium density changes influence the accuracy.
* Overall level is not measured (but possible with a further source and detector).
* Calibration with the medium is required.
* Radiation Protection Law.
For more information contact Jan Gerritsen, Endress+Hauser, +27 (0)11 262 8000, info@za.endress.com, www.za.endress.com
| Tel: | +27 11 262 8000 |
| Email: | info.za.sc@endress.com |
| www: | www.endress.com |
| Articles: | More information and articles about Endress+Hauser South Africa |
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version