An internal float is a floating seal installed inside a vertical cylindrical storage tank. It is primarily used to reduce evaporation losses when storing volatile liquids such as light oils and chemicals.It also provides fire and pollution prevention, and improves tank safety. With increasingly stringent environmental regulations and increasing energy efficiency requirements, internal float technology has gained widespread application in the petrochemical, warehousing, and logistics industries.
Structure and Working Principle of Internal Float
An internal float typically consists of a buoyancy unit, a sealing system, a frame structure, and accessories. The buoyancy unit is typically made of aluminum alloy or stainless steel. Its honeycomb or box-like structure provides sufficient buoyancy, ensuring the float moves smoothly with rising and falling liquid levels. The sealing system is a key component of the internal float. Common seal types include mechanical seals, elastic seals, and bladder seals. Its function is to reduce the oil and gas space between the float and the tank wall, thereby reducing evaporation losses. The frame structure provides overall stability, ensuring the float remains level during operation. The internal float operates based on Archimedes' law of buoyancy. As the liquid level in the tank fluctuates, the float rises and falls accordingly, maintaining a constant position above the liquid surface and forming a dynamic seal. This design not only reduces oil vapor evaporation but also prevents moisture and impurities from entering the tank, extending the oil's storage life.
Key Advantages of the Internal Float
1.Reduced Evaporation Loss: The internal float effectively reduces oil vapor evaporation from lightweight oils, minimizing environmental pollution and economic losses. Research shows that tanks equipped with internal floats can reduce evaporation losses by over 90%.
2.Improved Safety: By reducing oil vapor accumulation, the internal float reduces the risk of explosion or fire in the tank, while also preventing static electricity accumulation and enhancing overall tank safety.
3.Improved Oil Quality: The sealed design prevents air, moisture, and dust from entering the tank, preventing oil oxidation and contamination. It is particularly suitable for storing chemicals requiring high purity.
4.Energy Saving and Environmental Protection: Reduces volatile organic compound (VOC) emissions, complying with modern environmental regulations such as China's "Technical Guidelines for Volatile Organic Compound Control in Storage Tank Areas."
Application Scenarios for Internal Floating Plates
Internal floating plates are widely used in various types of storage tanks, particularly those storing volatile liquids such as gasoline, diesel, aviation kerosene, benzene, and alcohols. They have become standard equipment in oil refining, chemical production, finished oil depots, and LNG receiving terminals. Furthermore, with the advancement of LNG (liquefied natural gas) and LPG (liquefied petroleum gas) storage and transportation technologies, internal floating plate technology is also being explored and applied in cryogenic storage tanks.
Technological Development Trends
Modern internal floating plate technology is evolving towards lightweight, corrosion-resistant, and intelligent design. The use of new composite materials improves the chemical resistance of floating plates, while the introduction of intelligent monitoring systems enables real-time monitoring of key parameters such as floating plate displacement and sealing status, further enhancing tank operation safety and management efficiency. In the future, with advances in materials science and automation technology, internal floating plates will play a vital role in a wider range of industrial sectors.
Conclusion
As a core component of tank sealing technology, internal floats offer irreplaceable advantages in reducing evaporation losses and improving safety and environmental performance. With the global emphasis on energy conservation, emission reduction, and safe production, the optimization and innovation of internal float technology will continue to promote efficient and green development in the storage and transportation industry.