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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Chimie
Les usines chimiques s'appuient sur des processus de production continus et discontinus, chacun posant des exigences différentes en matière de système de contrôle. Un processus continu nécessite un système de contrôle robuste et stable qui ne tombera pas en panne et n'entraînera pas l'arrêt d'une ligne de production, alors que dans le cas d'un processus discontinu, l'accent est mis sur un système de contrôle qui permet une grande flexibilité dans les ajustements des formules, des procédures, etc. Les deux types de systèmes doivent être gérés en fonction de l'historique de la qualité du produit et être en mesure d'exécuter des opérations non routinières. Avec son large portefeuille de produits, ses ingénieurs systèmes expérimentés et son réseau mondial de vente et de service, Yokogawa a une solution pour chaque processus d'usine.
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Chimie Fine et de Spéciclité
Yokogawa est depuis longtemps au service des clients du marché de la chimie fine et de spécialité. Avec une solution de dosage leader sur le marché qui offre la meilleure fiabilité et flexibilité de sa catégorie ainsi que des experts industriels qui comprennent les exigences complexes dans la conception d'une solution de dosage, vous pouvez être assuré que dans votre partenariat avec Yokogawa vous aurez un système qui vous permettra de produire des produits qui répondent aux besoins de vos clients à l'avenir tout en maintenant la sécurité et la conformité réglementaire.
Les produits et solutions liés
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2-Wire Transmitter/Analyzer FLXA202
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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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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Contacting Conductivity Sensors SC42/SC4A(J)
The measurement of specific conductivity in aqueous solutions is becoming increasingly important for the determination of impurities in water. Yokogawa has designed a full range of precision sensors and instruments to cope with these measurements, even under extreme conditions.
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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
Yokogawa has invested considerable design and development time in producing a full range of fittings with particular emphasis on designs that reduce installation and maintenance time and consequently 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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Inductive (Torodial, Electrodeless) Conductivity Sensor ISC40
The model ISC40 sensors are designed for use with the FLEXA ISC analyzers. This combination exceeds all expectations for conductivity measurement in terms of reliability, accuracy, rangeability and price performance.
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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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InfraSpec NR800
NR800 is a FT-NIR analyzer offering unparalleled reliability and stability for a wide range of process and laboratory applications from Yokogawa. Its high wavelength resolution, outstanding accuracy and wide scanning range deliver a new level of process information, opening up new possibilities. Direct transfer of a calibration model from the laboratory to the process, or among processes, is also possible. And of course, ease of operation and user-friendly software are key design concepts of the NR800.
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Liquid Density Analyzer DM8C, VD6
The DM8 liquid density analyzer measures liquid density of general process liquids with high sensitivity and excellent stability. It has a measuring density range of 0 to 2.0 g/cm3, and unaffected by flow rate and viscosity. Besides general-purpose sensor, sanitary and explosionproof sensor are also available.
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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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pH and ORP Sensors
pH electrodes and sensors are the sensing portions of a pH measurement. Various installation options including retractable, flow thru, immersion, and direct insertion. Proper pH electrode/sensor selection is critical for optimal measurement results.