Anti-Corrosion Tuning Fork Liquid Level Switch——Optimal Choice for Sulfuric Acid Level Measurement

Guangzhou Chemical Plant expects to measure and control the liquid level of each sulfuric acid storage tank in the workshop, to realize high level alarm through liquid level sensor and control the liquid level in time, and  also to achieve overflow protection, so as to avoid the safety accident caused by sulfuric acid tank overflow.

The sulfuric acid stored in the chemical plant has high concentration, strong corrosivity and strong irritation, which can cause burns and carbonization of skin and flesh. If reacts with other substances may cause fire outbreak or explosion; if contacts with metal, combustible gas will be produced; and when mixed with water, a large amount of heat will be released. If high-level measurement is not accurate and results in overflow, not only results in polluting the environment, but also threatening the property and personal safety. For 60% concentrated sulfuric acid, 316L + coating material is a significant element to achieve anti-corrosion effect. Therefore, the liquid level switch for concentrated sulfuric acid measurement requires accuracy, strong corrosion resistance and explosion-proof function design.

However, domestic liquid level switch cannot meet above measurement requirements:

1. Most domestic tuning fork liquid level switches are designed for both solid and liquid measurements with amplitude change detection principle, so the fork body is generally bulky and long as well as poor reliability.

2. The sensitivity and reliability are greatly reduced by using amplitude change detection principle.

3. Due to the large amplitude of fork body, it is easy to cause fork coating fall off and crack, so it is impossible to add an appropriate thickness (generally 0.5mm) coating. At the same time, the added coating interferes fork resonance, reduces fork amplitude also the measurement reliability. However, the tuning fork level switch without coating cannot resist the strong corrosion of concentrated sulfuric acid.

4. To make the coating and fork firmly combined, the coating requires to be baked with high temperature. The domestic tuning fork liquid level switch mostly uses domestic piezoelectric ceramics, the Curie temperature is generally low, so high temperature baking is easy to damage the piezoelectric ceramic components that used for vibration drive and detection, resulting in lower reliability and shorter service life.

How to select a high reliability instrument for sulfuric acid liquid level measurement has been troubled by the chemical plant. Imported brands are expensive, and after-sales maintenance cannot respond in time. After comparing similar products at home and abroad, the user finally selected Ring-11 Anti-Corrosion Tuning Fork Liquid Level Switch that is made of 316L and coated (ECTFE).

Jiwei Ring-11 Anti-Corrosion Tuning Fork Liquid Level Switch has high sensitivity due to the precisely pre-adjusted harmonic resonant frequency of the fork, the lowest measurable medium density can be as low as 0.5g/cｍ³. The fork body is only as short as 40mm long, which makes the tuning fork has slight amplitude (cannot be observed by naked eyes). In the coating process, 0.5mm ECTFE coating is sprayed. The high-temperature imported piezoelectric ceramic components can withstand the baking temperature of 250 ℃ during coating process. After coating process, the coating and the fork body are perfectly combined without falling off and cracking, so the whole instrument has the characteristics of stronger corrosion resistance and longer service life.

Specifically, Ring-11 series Tuning Fork Liquid Level Switch has the following advantages:

●　With only 40mm fork length, specially designed for pipelines and other applications with constricted space.

●　High sensitivity due to the precisely pre-adjusted harmonic resonant frequency of the fork, the lowest measurable medium density can be as low as 0.5g/cｍ³.

●　With strong disturbance resistance ability, not influenced by foam, bubbles, viscosity, vibration and other liquid characteristics.

●　Industry-leading performance for high temperature working environment. Process temperature can reach up to 250℃.

●　Three optional output methods: relay output, two-wire system and Namur.

●　Optional air-tight high pressure protection insulation sleeve, special for pressurized or corrosive liquids level measurement.

●　Meet the food safety standards and applicable for liquids level measurement in food industry.

●　Certified for CE, and both Intrinsic Safety and Flameproof Enclosure explosion protection.

●　High reliability due to the detection of vibration frequency.

As shown above, its outstanding characteristics have convinced the end user. Since all Ring-11 were put into use in the chemical plant, the accurate measurement, stable operation, high reliability and cost performance ratio are favored by the end users.