Level Measurement & Control


Continuous level measurement

April 2010 Level Measurement & Control

Nuclear technology for level measuring in delayed coke drums.

The production of coke is a finely monitored process, which requires efficient managing to achieve increased throughput and avoid the risk of shutdown in the refinery.

Liquid hydrocarbon is converted to coke in a heating process, and the gaseous materials are removed from the top of the coke drum as it fills. Just ahead of the coke level a foam front develops, with a density greater than the gaseous material but not as great as the coke. Once the proper charge is achieved the coke is quenched with water and then drained. The coke is removed from the drum by drilling with a water jet (known as coke cutting).

Efficient foam control and careful monitoring of the levels of foam, gas and solids is required to prevent over-fill of the drum. In this process, interface density measurement is the only method that will produce the necessary control.

Over the years several methods of level control have been tried, including radar gauges, neutron back scatter and gamma point detectors. The latter method was introduced by Ohmart as far back as the late 1950s. This involved a series of measurement points located on the same side of the coke drum, which measured the coke and the foam. It was a good method but limited to fixed points and some sources were cut off and lost in the coke as it was being cut.

Then in 1999, Ohmart/Vega patented FibreFlex technology, which utilises a special fibre-optic bundle as the scintillator. This flexible, gamma-based level gauge can manage continuous level measurement and allows for long measurement ranges of up to 7 metres. The FibreFlex measures the top of the process, regardless of whether it is foam, liquid or coke and measures across the diameter of the drum not just at a localised point.

Nuclear continuous level measurement works by directing a narrow fan of radiation through the vessel to a detector on the other side. The FibreFlex uses small source size, which gives it favourable cost and safety advantages. Mounted on the outside of the coke drum, its flexibility and light weight makes it easy to install. No rigging is required and the shape can be adjusted to fit existing platforms.

For more information contact John Groom, Vega Instruments SA, +27 (0)11 958 1901, [email protected], www.vega.com



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

VEGA is redefining synthetic fuel production
VEGA Controls SA Level Measurement & Control
Polish company, Ekobenz specialises in producing bio-hydrocarbons. The company utilises advanced manufacturing techniques where VEGA sensors monitor levels and interfaces, essentially overseeing separation layers in the process.

Read more...
Water under pressure
VEGA Controls SA Pressure Measurement & Control
The need for real-time monitoring and precise control over water distribution has never been more critical. VEGA’s range of pressure sensors and level instruments plays an important role in ensuring that water systems operate efficiently.

Read more...
Precision in paper processing
VEGA Controls SA Editor's Choice Level Measurement & Control
Paper manufacturing is a demanding process that relies on consistency, precision and control at every stage. The VEGABAR 82 pressure transmitter is well-suited to these harsh environments.

Read more...
VEGA’s Lunch-and-Learn success in KZN
VEGA Controls SA News
VEGA has rolled out its new Lunch-and-Learn series to the coastal regions of South Africa, designed to bring practical training and real-world insights directly to engineers and technicians.

Read more...
Where every grain counts
VEGA Controls SA Level Measurement & Control
VEGA’s advanced level and pressure measurement solutions offer transformative technologies to improve grain storage management in sub-Saharan Africa.

Read more...
Paper might carry the message, but pressure carries the process
VEGA Controls SA Pressure Measurement & Control
VEGABAR pressure transmitters are designed to address the unique challenges faced by the pulp and paper industry. Built for durability and precision, they ensure reliable pressure monitoring in aggressive environments.

Read more...
Capsules, steam and cream
VEGA Controls SA Pressure Measurement & Control
African cosmetic brands are increasingly outsourcing production to specialised contract manufacturers who use automation and high-precision tools to ensure quality and adapt quickly to regulatory changes. VEGA’s suite of level and pressure measurement solutions offers a robust foundation for profitability and quality assurance.

Read more...
Differential pressure measurement made simple
VEGA Controls SA Pressure Measurement & Control
The VEGADIF 85 serves as an exemplary model of a differential pressure sensor. It combines universal applicability with high operational dependability and integrated overload protection, ensuring consistent performance even in the harshest conditions.

Read more...
Small, inexpensive radar level transmitters
VEGA Controls SA Level Measurement & Control
Anyone who needs to keep processes running needs level measurement technology that measures reliably. However, what is needed is not always the most ‘fully featured’ solution, but the smartest one. This is exactly what VEGAPULS radar transmitters of the BASIC series do.

Read more...
Meeting the challenges of tank obstructions interfering with radar
Level Measurement & Control
One of the most challenging applications for non-contacting radar level transmitters is measuring level in tanks with internal obstructions, such as agitators, heating coils, pipes, ladders or baffles. Rosemount non-contacting radar level transmitters from Emerson feature an advanced solution that enables accurate and reliable level measurements in tanks with obstructions.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved