Reliable corrosion monitoring – now available for Cryo-Lock agitators

Continuos Corrosion monitoring for Cryo-Lock agitators

Continuous monitoring of the glass lining inside a vessel during operation is indispensable in highly corrosive processes, in order to rule out large and costly tantalum repairs or even rupture of vessels. A corrosion detection system is the solution. Where multi-piece glass-lined agitators are used, it has never before been possible to monitor the entire agitator assembly. The use of the Corrosion Detector in conjunction with Pfaulder’s new Conductive Cryo-Lock technology has now made this possible.

The moving parts in a reactor are most prone to damage, but can now be monitored for integrity with Pfaudler’s new Conductive Cryo-Lock technology. This continuous in-process glass lining monitoring system is suitable for all Pfaudler Cryo-Lock agitators.

The Pfaudler glass lining monitoring works based on the principle of decomposition voltage analysis, which eliminates the need for a continuous current load on the precious metal electrodes and thus prevents electrochemical reactions on the electrodes. A voltage is applied periodically between the two electrodes and used as a reference to generate an “alarm window”. If the measured value is repeatedly within this alarm window due to a damaged glass layer, the Corrosion Detector will output an alarm. Pfaudler has offered this technology for years as a reliable way to monitor the glass lining of vessels, but it was impossible to monitor multi-piece agitators completely. A non-metallic inductive contact between the turbine and the agitator shaft has now solved the problem. In contrast to solutions with welded-on metal rings made from resistant materials, this ensures a completely homogeneous enamel surface. There are no differences in temperature expansion coefficients caused by different materials – another source of inevitable damage to the glass lining is avoided. Pfaudler’s Conductive Cryo-Lock technology thus provides comprehensive vessel monitoring, including the entire multi-piece agitator, for excellent process reliability.

No more false alarms!

The Corrosion Detector will only output an alarm if metal corrosion has actually occurred, so false alarms caused by corrosion-resistant conductive fittings and materials are ruled out. The system tolerates inlet pipes and repair plugs made from precious metals. This method offers fundamental advantages over conventional glass monitoring equipment, which works according to the principle of conductivity analysis. Such systems are not capable of distinguishing between real and false alarms. A false alarm is defined as conductive contact between the product and the equipotential bonding system that is not caused by glass damage. Such links can be the result of production-specific operating conditions, e.g. condensate bridges in the vessel’s gas compartment, or when filling or draining the vessel. Regular false alarms can cause plant operators to respond to real alarms too slowly, or even to ignore them altogether. This is a considerable risk to people and the plant, and leads to significant disruption in the production process. All the Corrosion Detector needs to work is a sufficiently conductive medium.

Corrosion monitoring on the move

Comprising a P probe and its evaluation electronics, the Pfaudler corrosion monitoring system can be installed in baffles, ring probes or valves. A mobile version is available for vessels without integrated corrosion monitoring: the Corrosion Detector Portable. All solutions are ATEX-approved.