What is mechanical seal?
What is mechanical seal?
Mechanical seals are a type of packing that are installed on the shafts that transmit the power of rotating machinery, such as pumps and mixers in industrial plants such as oil refineries, chemicals, food, and pharmaceuticals, and in social infrastructure facilities such as water and sewerage. They consist of a "rotating ring" that rotates with the shaft and a "fixed ring" that does not rotate, and slide on a surface perpendicular to the shaft to prevent leakage of fluids (liquids, gases, powders), restrict the intrusion of foreign objects from the outside, and maintain pressure.
Mechanical seals and rotating machinery
A typical example of a machine that uses mechanical seals is a centrifugal pump. There is always a gap between the shaft and the casing, and without a seal, water will leak from that gap and the pump will not be able to perform at its full potential. Pumps may sound a little complicated, but washing machines, which are rotating machines familiar to our daily lives, are also equipped with seals to prevent water from leaking, just like pumps.
Mechanical seals are installed on rotating machinery with a wide variety of specifications (temperature and pressure). Each mechanical seal is individually designed and manufactured, contributing to the prevention of environmental pollution, energy saving through more efficient machine operation, and even machine safety. Although we do not see them in our daily lives, they play an important role behind the scenes, "limiting leakage while not interfering with the movement (rotation) of the rotating shaft."
Mechanical seals are installed on rotating machinery with a wide variety of specifications (temperature and pressure). Each mechanical seal is individually designed and manufactured, contributing to the prevention of environmental pollution, energy saving through more efficient machine operation, and even machine safety. Although we do not see them in our daily lives, they play an important role behind the scenes, "limiting leakage while not interfering with the movement (rotation) of the rotating shaft."
Mechanical seals and petrochemical plants
Oil refineries, petrochemical plants, and chemical plants handle a variety of fluids. These often require difficult sealing conditions, such as harmful substances that could cause environmental problems if leaked outside, and high-temperature, high-pressure fluids that could cause accidents. Compared to gland packings, mechanical seals have a more complex structure, but safety and reliability can be ensured by selecting the appropriate type depending on the application and conditions.
Recently, attention has been focused on innovative products that consider the environmental impact, such as SAF (sustainable aviation fuel) and ammonia production plants that use hydrogen derived from renewable energy. In order to respond to these new technologies, research and development of mechanical seals is progressing day by day.
Mechanical seals and food factories
Factories are required to produce products safely and efficiently under sanitation management. Tanks equipped with agitators are essential for this. Let's take the production of mayonnaise as an example. Mayonnaise is made from three main ingredients (egg yolks, vegetable oil, and vinegar). These ingredients and seasonings are mixed and emulsified in a vacuum tank with an agitator rotating to make mayonnaise. As it is a food product, contamination is essential. The mechanical seal is attached to the top of the tank and plays the role of preventing foreign matter from entering from the outside and maintaining the vacuum.
Mechanical seal and hot and cold water pump for air conditioning
Do you know how air conditioning works in high-rise buildings? Generally, it uses hot and cold water to exchange heat with the air and deliver cold and hot air to each floor. Hot and cold water is pumped from the lower floors to the higher floors using a centrifugal pump. In the past, gland packing was often used, but hygiene and maintainability have become issues, and mechanical seals are increasingly being used. Imagine the air conditioning stopping in the middle of summer or winter due to a pump problem. Mechanical seals are what support this everyday routine.
