Berthold's solution for fluid catalytic cracking (FCC) processes

Graphic of Fluid catalytic cracking unit FCC process

Level measurement of catalyst fines in cyclone separators

Catalyst fines have to be removed from the regenerator flue gas to fulfill regulatory requirements and to protect downstream equipment. Thus, cyclonic separators are used to filter out the remaining catalyst fines. The solid particles settle down at the bottom of the separator, where their level is controlled by radiometric level systems from Berthold. The noncontact technology is ideally suited for this kind of application since dust and temperature have no impact on measurement performance.

Customer benefits

  • Improved catalyst removal
  • Reliable process control
  • Ideal utilitzation of vessel capacity


  • Continuous level measurement, typically 2-4 m measuring range
  • Installed at the bottom conical part
  • Typical arrangement uses Cs-137 point sources and scintillation rod detectors
  • Noncontact, nonintrusive technology
  • No recalibrations required

Article "Made to measure"

Do you need reliable control of your fluid catalytic cracking (FCC) process, but the extreme process conditions are beyond the limitaitons of standard measurement technologies? Read the article “Made to measure” to learn why the use of radiometric measurement systems can help to optimize level control in FCC units, and how Berthold systems can help you to control your process more reliably to ensure safe operation while increasing efficiency.

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SIL certified detectors available

The SENSseries LB 480 detectors offer versions that are certified for use in SIL2 applications. SIL3 is achieved by adding an identical redundant SIL2 detector using the same source for homogenous redundancy. The certificate covers all measurement applications, from high level or low level alarms to continuous level. Thus the safe measurement of critical processes is guaranteed.

More about SIL


Long-term stability

A reliable measurement, requiring no recalibration, is vital for the operation of the FCC, and is our highest priority. Berthold’s detectors offer stability in the face of changes in ambient temperature. Even drastic temperature shifts, e.g. from winter to summer do not cause measurement drift. Our patented method for detector stabilization compensates for temperature changes and aging.

Detector Stability

X-ray Interference Protection (XIP)

With this function, weld tests no longer cause sudden fluctuations in the measured value. When weld tests are detected, the measured value is frozen until the external radiation event ends. A digital output can be set to signal the detection of interfering radiation.
All of our level measurement detectors are equipped with XIP.

More about XIP


Further applications

Vessels that use radiometric devices in the FCC besides cyclone separators include electrostatic precipitation hoppers and the FCC fractionator tower bottoms. The radiometeric level measurement on the fractionator tower bottom is unaffected by the changing percent catalyst fines, unlike differential pressure detectors. This increases the reliability of the level,  proventing tray damage if level gets too high, or pump damage if level were to become too low. Level and density measurements of the fluidized bed in the standpipe are also an often required measurement task in the FCC.


Measurement solutions for the refining industry Industry brochure

English | PDF | 2.6 MB

Made to measure Publication

English | PDF | 6.8 MB