Capacitance Empty Detection In Sulfuric Acid

Capacitance Empty Detection In Sulfuric Acid

Level indicators working with the capacitive measurement principle can be used in all types and shapes of tanks, regardless of whether these are metallic or non-metallic. Due to their high sensitivity, their compactness and the range of probes, they are suitable for a wide variety of industrial process requirements. A well-known manufacturer of aluminum sulfate in Peru was looking for a compact level measurement for its raw material tanks with 98% sulfuric acid. Due to the strong corrosion caused by the acidic material, the decision was made to implement the robust capacitance point lever switch Capanivo® CN 7120 from UWT GmbH.

PPS probe with ½ inch process connection chemical resistance & compact design

Sulfuric acid is extracted from sulfur in a number of ways and is one of the most dangerous acids known in the world. The colorless and odorless chemical is viscous, water-soluble, hygroscopic and hardly corrosive. Due to its properties, sulfuric acid is used in a large number of different industries and is one of the most widely produced chemical raw materials in the world. Different sulfates are produced by reacting appropriate salts with sulfuric acid, such as aluminum sulfate obtained from aluminum hydroxide.

In the production of aluminum sulfate by a well-known chemical plant operator in Peru, 98% sulfuric acid is stored in tanks at a process temperature of around 80 °C (176 °F) and a process pressure of around 0.8 bar (11.6 psi). There is a high degree of humidity inside the container and the atmosphere is clean. The DK value is over 4. In order to coordinate a constant flow of material in the discharge pipes of the process vessel, timed to match the manufacturing process, the operations manager was looking for a robust and compact level monitoring system.

Together with the local partner SIERRA Servicios Industriales SAC. it was decided to implement the Capanivo® CN 7120 capacitance point level indicator from UWT GmbH. The devices have a robust, certified design and can be easily adapted to the respective process conditions and proportions by variable versions. The probe is pretty short and has a very small ½ inch process connection made of stainless steel.

That makes it ideal for recording the fill level within the narrow pipes of only around 200 mm (7.87 inches) diameter and for implementing reliable empty messages. The IP68 housing is made of polyester and polycarbonate, so it is environmentally friendly and ensures a long-term, permanent seal, even within aggressive applications. In addition, the Capanivo® sensor to be installed was equipped with a PPS probe (polyphenylene sulfide), a high-performance plastic that has a high chemical resistance to aggressive media.

Functionality, easy handling and a long product operational lifetime in accordance with the high requirements and standards of the chemical company could thus be implemented for smooth plant process support.

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Solution partner for level measurement since 1977 with comprehensive expertise in all industries and process applications. UWT is a medium-sized German family owned business and has become one of the world’s leading experts in the field of level measurement technology offering innovative sensors for continuous and point level measurement in any ...