Introduction
Process liquid analyzers such as pH meters, conductivity meters, ORP meters, and density meters play an important role at electrolysis plants in the control of concentrations of various process solutions. This requires both precision and stability under harsh conditions that include highly corrosive substances, high temperatures, and many impurities.
Expected Benefits
- Ensures stable, continuous measurement in heavily contaminated liquids
- Reduces operating costs
- Eliminates the need for manual cleaning
List of Analyzers
| Type | Measurement point | Objective |
|---|---|---|
| pH meter | 1) Supersaturated brine at raw salt dissolver outlet *1 | pH control for impurity removal in brine Control value: 10.8 to 11.0 pH |
| 2) Refined brine *2 | Control of precipitation of impurities Acid range | |
| 3) Brine at electrolysis tank inlet *3 | pH control of electrolysis tank brine inflow: 3 to 6 pH | |
| 4) Return brine at electrolysis tank outlet *4 | Efficiency control in dechlorination tank Acid range | |
| 5) Desalinated water at dechlorination tank outlet *5 | Desalinated water control | |
| 6) Hydrochloric acid plant drainage *6 | Drainage control | |
| Conductivity meter | 1) Supersaturated brine at electrolysis tank outlet *7 | Brine concentration control: concentration: 300 to 320 g/l |
| 2) Refined brine *8 | Refined brine concentration control | |
| 3) Sulfuric acid concentration used for drying in chlorine gas drying line *9 | Concentration control of recovered sulfuric acid: approximately 74 % | |
| 4) Hydrochloric acid concentration in hydrochloric acid plant *10 | Hydrochloric acid concentration control: approximately 35 wt% | |
| 5) Sodium hypochlorite concentration in a soda hypochlorite plant *11 | Sodium hypochlorite concentration control: Available chlorine: 10 to 15 % Residual caustic soda: 0.1 to 1% (approximately 10 g/l) |
|
| Oxidation reduction Potential (ORP) meter | 1) Desalinated water at dechlorination tank outlet *12 | Confirmation of dechlorination reaction |
| 2) Soda hypochlorite plant adsorption tank outlet *13 | End control of caustic soda chlorination reaction | |
| Vibration type liquid density meter | 1) Anode solution at electrolysis tank outlet *14 | Anode solution caustic soda concentration control |
| 2) Caustic soda concentration at concentrate drum outlet *15 | Product caustic soda concentration control |
Solution Details
Conclusion
Yokogawa process solution analyzers deliver stable, long-term measurements under the harsh conditions present in electrolysis plants. The FLXA202/FLXA21 Inductive Conductivity Meter is specially designed to detect the concentrations of hydrochloric acid, sulfuric acid, and caustic soda. The PH4C pH Sensor for Chemical Processes can measure pH in a wide variety of processes.
Field Data
Each graph shows a correlation between concentration and conductivity at measurement points, the numbers of which correspond to the ones in the previous page. The ISC inductive conductivity meter's range can be specified, thereby allowing high-resolution measurements in the target concentration range.
The correlation between concentration and conductivity is largely affected by solution temperature. The ISC inductive conductivity meter provides automatic temperature compensation using the build-in temperature sensor.
Industries
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Chemical
Chemical plants rely on continuous and batch production processes, each posing different requirements for a control system. A continuous process calls for a robust and stable control system that will not fail and cause the shutdown of a production line, whereas the emphasis with a batch process is on having a control system that allows great flexibility in making adjustments to formulas, procedures, and the like. Both kinds of systems need to be managed in available quality history of product, and to be able to execute non-routine operations. With its extensive product portfolio, experienced systems engineers, and global sales and service network, Yokogawa has a solution for every plant process.
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Specialty & Fine Chemical
Yokogawa has long served customers in the specialty and fine chemicals market. With a market leading batch solution that offers the best in class reliability and flexibility as well as industry experts who understand the complex requirements in designing a batch solution, you can be assured that in your partnership with Yokogawa you will have a system that will enable you to produce products that meet your customers’ needs in the future while maintaining safety and regulatory compliance.
Related Products & Solutions
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2-Wire Transmitter/Analyzer FLXA202
- FLEXA™ series analyzers FLXA202
- Continuous on-line industrial measurements
- Most flexible two-wire analyzer available
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2-Wire Transmitter/Analyzer FLXA21
The FLEXA™ series analyzers are used for continuous on-line measurements in industrial installations. With an option for single or dual sensor measurement, they are the most flexible two-wire analyzer available.
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All-in-One pH/ORP Sensor Series FU20 and FU24
The FU20 and FU24, all-in-one pH and ORP, sensors show how Yokogawa applies the motto "Simple is best" to sensor technology.
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Digital SMART SENCOM™ Adapter, SA11
Reusable SMART adapter, requiring only the analog sensor to be disposed of when it reaches the end of its lifetime. With the SENCOM 4.0 platform, Yokogawa delivers reduced costs and waste while contributing to its long-term business goals of a sustainable future for all.
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Flow/NPT Fittings FF20/FS20
- FF20/FS20 Fittings for pH and ORP
- Full range of fittings
- Emphasis on designs that reduce installation and maintenance time
- Save operation costs
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Hot-Tap Holder PR10
On-line measurements often present extra challenges, especially when routine maintenance is required. The PR10 is ideally suitable for applications where the sensors must be removed without interrupting or shutting down the process. Without any special tools the PR10 can be retracted safely from the process at pressures up to 5 bar (72 psi). Using the PR10 allows us to place any dissolved oxygen sensor that has a PG13.5 connenction into a retractable assembly.
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Industrial pH/ORP Electrodes
The heart of a pH measuring loop is the electrode system. Yokogawa has designed a wide range of electrodes to ensure this heart keeps beating under the most severe conditions.
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Multi Channel 4-Wire Analyzer FLXA402
The FLEXA™ series analyzers are modular-designed analyzers used for continuous online measurements in industrial installations. They offer single or multi-sensor measurement.
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Sensors for ppb Applications
Dissolved oxygen measurements in the parts per billion range are critical in, but not limited to power generating plants. Maintaining a low level of dissolved oxygen in boiler feedwater assures that corrosion of certain components is minimized. A reliable measurement of ppb dissolved oxygen helps to reduce downtime and improve efficiency.
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Toroidal/Inductive Conductivity Sensor ISC40
- Model ISC40 toroidal/inductive conductivity sensors
- EXA ISC analyzers
- Exceeds expectations for conductivity measurement reliability, accuracy, rangeability, price performance
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pH and ORP Sensors
- pH and ORP sensors
- Proper pH electrode/sensor selection critical for optimal measurement results
- Installation options include retractable, flow thru, immersion, and direct insertion
Have Questions?
Contact a Yokogawa Expert to learn how we can help you solve your challenges.