Can anybody give an alternative to displacer type level instrument for column bottom level indication and control. Some vendors are offering waveguide based level instruments --How far is it successful in column bottom level application.

 

Depending upon the temperature and pressure of the product, give consideration to using remote seal dP transmitters, expecially the "smart" type for ease of calibration. The major caveat is high fluid temperatures (> 600 F ) and very low pressure (< 20 mmHg), which may cause boiling of the fill fluid of the remote seal. Calculation of the appropriate upper and lower values is easily done.

This has worked quite well on the bottom level of a crude oil distillation tower (700 F and 10 psig).

I have an excel spreadsheet which will do the calculations for you. If interested, contact me off list.

John Beck
Control Systems Specialist, Retired
([email protected])