Success story: maintenance-free acid conductivity measurement

Continuous measurement of specific and acid conductivity is of vital importance. It ensures the quality of the steam generated, the availability of the plant and the prevention of damage during the operation of the power plants.

As we already analyzed in detail in the article “Expenditure reduction in the measurement of cationic or acidic conductivity” the tasks of replacement and regeneration of cation exchange resins have a negative impact on plant costs, on the availability of the measure, in the safety of workers and the environment.

With the aim of solving all these problems, SWAN Analytical Instruments developed the AMI CACE analyzer. The equipment has a very innovative system for self-regeneration of resin by EDI electrodeionization.


Image 1 . Location of the AMI CACE analyzer in the analyzer rack


Results with the AMI CACE parser

In its policy of continuous improvement, the Amorebieta Combined Cycle Power Plant (Bizkaia Energía) more than a year ago incorporated into its SWAS (Fig. 1) an AMI CACE analyzer for the measurement of acid and specific conductivity in Low Pressure Steam samples . The result in the words of the Plant Chemical Manager Roberto Martín:

“Given the high pH of the sample, the amount of NH4 that the resins must absorb is very high. With the new equipment, it is very appreciated not having to change them daily, especially in periods when occurs with the 2 groups at the same time. ”

“We installed the equipment in the most critical sample of the water-vapor cycle in terms of NH4 concentration. After a year in use, the equipment adequately fulfills its function”


Operation of the AMI CACE analyzer

From a technical point of view, the state of the resin, which has been automatically regenerated by the analyzer itself, and therefore without the need for human intervention, remains good more than 1 year after its commissioning (Img. 2 ).


Image 2: it can be seen that the operating time is 1 year and 19 days.


This fact is confirmed by the voltage value of the EDI module; 4079 mV, considering correct between 3000 and 8000 mV (Fig. 3).


Image 3: Current voltage 4079mV.


This resin will still be able to be self-regenerated for many more cycles without the need for any intervention by plant operators.

Given the high pH values ​​at the sampling point, the time for exhaustion of the existing resins was especially short, reaching daily resin changes.

Each resin change involved:

  1. Disassemble and accumulate spent resin from various equipment (10 liters).
  2. Regenerate it in the laboratory with acid.
  3. Rinse it properly and reassemble it on the instrument.


Advantages of AMI CACE analyzers

The installation of AMI CACE analyzers makes it possible to optimize maintenance operations in about 8 hours a week. Not so with the traditional acid conductivity. Previously these hours were dedicated to resin regeneration. Operators’ exposure to highly hazardous chemicals used during regeneration is also reduced.

In each change from exhausted resin to regenerated resin, the traditional analyzer requires an average of 1 hour for adaptation and / or rinsing of the resin, until real process measurements are achieved.

During all this time, either the plant is operated without real-time control of the acid conductivity, or the entry of steam to turbines is delayed, if the change coincides with a plant start-up.

The availability of the measure for the Ami CACE analyzer is total and immediate. So this problem disappears completely with the new scanner.


1) With traditional analyzers:

  • Frequent resin changes require significant maintenance on acid conductivity analyzers, around 100 hours per year.
  • The regeneration of resins occupies the client around 416 hours per year.
  • The regeneration of resins involves exposing the technician to dangerous substances (acid fuerte).
  • Each resin change implies a delay in the availability of reliable measurements, an average of 1 hour for each equipment.

2) OUR SOLUTION , with the AMI CACE analyzer:

  • No resin change is required, as it self-regenerates fully automatically and autonomously by the analyzer itself.
  • Laboratory and maintenance personnel have extra time, which they used to spend on maintaining the analyzer and regenerating resin.
  • Measurement availability with Ami CACE analyzers is now total and immediate, allowing to ensure optimal quality of the steam used for energy production.

For more information, contact MATELCO, SA at