Displacer Type Level Transmitters: Working Principle, Components and Applications

In the world of level measurement technology, Displacer Type Level Transmitters have gained significant popularity due to their reliability and versatility. These instruments are widely used in various industrial applications where accurate and consistent liquid level measurements are essential. In this article, we will delve into the workings, principles, and diverse applications of Displacer Type Level Transmitters.

Mostly used in Level switches & Level Transmitters. It has specific weight. Displacer loses his weight according the principle of Archimedes’ buoyancy. If water increases, water bouncy power will try to move the displacer upward. It moves few mm upward because of weight. This movement is transferred through torque tube to transmitter to convert 4~20mADC and transmitter will transmit this signal to control room to show level on indicator or recorder and control.

Understanding Displacer Type Level Transmitters

Displacer Type Level Transmitters are instruments designed to measure liquid levels in tanks, vessels, and other containers. They operate based on the Archimedes principle, which states that an immersed object displaces an amount of liquid equal to its own volume. Displacer Level Transmitters typically consist of a buoyant displacer element, a suspension cable, and a measuring device, such as a force sensor or torque tube.

Components of Displacer Type Level Transmitters:

1. Displacer Element: The heart of a Displacer Type Level Transmitter is the displacer element. It is typically a cylindrical, elliptical, or other shaped object made of materials that are denser than the liquid being measured. The displacer is attached to the suspension cable and partially immersed in the liquid.
2. Suspension Cable: The suspension cable connects the displacer to the measuring device. It provides support and ensures that the displacer remains submerged in the liquid at all times.
3. Measuring Device: The measuring device is responsible for detecting the changes in tension or torque in the suspension cable caused by the buoyancy of the displacer. These changes are proportional to the liquid level and are converted into a level measurement signal.

Principle of Operation

The operation of a Displacer Type Level Transmitter is based on the buoyant force experienced by the displacer immersed in the liquid. When the liquid level rises or falls, it affects the buoyancy force acting on the displacer. This, in turn, causes changes in the tension or torque in the suspension cable.

As the liquid level increases, the buoyant force on the displacer increases, causing the suspension cable to experience more tension. Conversely, as the liquid level decreases, the buoyant force decreases, leading to reduced tension in the cable. The measuring device detects these changes and converts them into an electrical or mechanical output signal, which is proportional to the liquid level.

Applications of Displacer Type Level Transmitters

Displacer Type Level Transmitters find applications in a wide range of industries and processes where accurate and reliable level measurements are critical. Some common applications include:

1. Oil and Gas Industry: Displacer Level Transmitters are used in oil refineries and storage tanks to measure liquid levels in challenging and corrosive environments.
2. Chemical Processing: They are employed in chemical plants to monitor and control liquid levels in various vessels and reactors.
3. Water and Wastewater Treatment: Displacer transmitters are used to measure liquid levels in water treatment plants, sewage systems, and reservoirs.
4. Marine Industry: These transmitters are used in ships and offshore platforms to monitor fuel and ballast tank levels.
5. Food and Beverage Production: Displacer Type Level Transmitters are used in food and beverage processing plants to ensure precise ingredient measurements and batch consistency.
6. Power Generation: They find applications in power plants to monitor water levels in steam boilers and condensate tanks.

Conclusion

Displacer Type Level Transmitters are reliable and versatile instruments that play a crucial role in ensuring accurate liquid level measurements across various industries. Their principle of operation, based on Archimedes’ buoyancy principle, provides consistent and dependable results in a wide range of applications. As technology continues to advance, Displacer Type Level Transmitters are expected to remain an integral part of industrial processes, contributing to safer and more efficient operations.

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