Chemical Process Industries Benefit From Liquid Level Control

Level measurement is critically important for chemical process industries and the safety of the equipment they use. Technologies such as chemical reactors, fermentation vessels, and steam and surge drums benefit from accurate level instrumentation. In this blog post, part of Magnetrol’s series on chemical processing applications, we will explore how chemical process industries can utilize level control instrumentation to aid their efficiency. Don’t forget to check out the other blog posts in this series if you missed them. We discussed level and flow solutions for the distilling process on February 10 and solutions for liquid extraction, mixing and blending, and other processes on February 17.

Chemical Reactor

Chemical_Process_Industries_1Application: Chemical, polymerization and pharmaceutical processes utilize reactor vessels to contain chemical reactions. Chemical reaction speed and product quality are frequently controlled by an external heat exchanger for elevating temperature and a cryogenic system for lowering temperature. Reactors typically contain impellers for product mixing.

Challenges: Level instrumentation in a tank-type reactor vessel must contend with diverse and often aggressive product chemistries, agitation, mixing, surface foam and temperature and pressure variations. Low level monitoring in the discharge line, high level monitoring in the vessel, and interfacial measurement of the foam/emulsion interface is recommended.

Level Technologies:
-Series 3 Float-Actuated External Cage Level Switch for point level
– Eclipse® Model 706 Guided Wave Radar Transmitter for continuous level
– Orion Instruments® Atlas™ or Aurora® Magnetic Level Indicators for visual indication

Fermentation Vessel

Application: Industrial fermentation is the process of breaking down organic substancesChemical_Process_Industries_2 and re-assembling them in order to produce other chemical compounds. Alternative fuels like ethanol and chemicals such as methanol and a wide range of acids can be developed using this process. Chemical fermentation takes place in large tanks called fermenters in a process that can either be aerobic or anaerobic.

Challenges: Depending upon the type of fermentation vessel and the media being processed, the level control often must contend with agitation and aeration. Froth or foam is typically generated because fermentation agents have surfactant properties. When processing acids, contact level controls must tolerate the very aggressive media.

Level Technologies:
Echotel® Model 961 Ultrasonic Level Switch for point level
ECLIPSE Model 706 Guided Wave Radar Transmitter for continuous level
ORION INSTRUMENTS ATLAS or AURORA Magnetic Level Indicators for visual indication

Steam Drum

Chemical_Process_Industries_3Application: Chemical manufacturers are major users of steam for cleaning, drying, fermentation, steam stripping, and chemical recovery. Steaming-in-place (SIP) is a widely used method for in-line sterilization of vessels, valves, process lines, and filter assemblies. Steam is created in a boiler where heat transforms water under pressure into steam.

Challenges: Boiler drum level control is critical for safe and efficient steam generation. Drum level control maintains level at constant steam load. Too low a level may expose boiler tubes, which will overheat and sustain damage. Too high a level may interfere with separating moisture from steam, which reduces boiler efficiency and carries moisture into the process.

Level Technologies:
– Series 3 Float-Actuated External Cage Level Switch for point level
– ECLIPSE Model 706 Guided Wave Radar Transmitter or E3 Modulevel® Displacer-Actuated Transmitter for continuous level
– ORION INSTRUMENTS ATLAS or AURORA Magnetic Level Indicators for visual indication

Surge Drum

Application: Surge drums are frequently located between process units to help reduce Chemical_Process_Industries_4the effect of flow rate variations between interconnected process units. A low surge drum level can result in reduced capacity while a high level can cause liquid carry-over. In an application characterized by alternating inertia and turbulence, stable level output is highly desirable.

Challenges: Contrary to the normal control objective of keeping a measurement at set point, the purpose of a surge drum level control is to dampen the changes in controlled flow while keeping the liquid level in the vessel between limits. For surge drums it is generally more important to allow levels to “float” in order to minimize flow rate variations.

Level Technologies:
Model A15 Displacer-Actuated Level Switch for point level
– ECLIPSE Model 706 Guided Wave Radar Transmitter or E3 MODULEVEL Displacer-Actuated Transmitter for continuous level
– ORION INSTRUMENTS ATLAS or AURORA Magnetic Level Indicators for visual indication

Be sure to follow our blog as we continue to discuss important level control applications for equipment in the chemical process industries, including catalysis vessels, the chlor-alkali process, chemical injection, and deionization. 

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