What is carbon ring mechanical seal

What is a carbon ring mechanical seal:

Generally speaking, carbon ring seals are widely used in various fan factories and are easy to install.

The structure of the carbon ring seal includes an annular sealing chamber and an annular shaft sleeve. There is an annular groove in the sealing chamber, and at least two annular graphite sealing rings with a rectangular cross section are installed in the groove. The inner diameter of the graphite sealing ring and the annular shaft sleeve There is a gap of 0.01~0.04mm, and the outer surface of the shaft sleeve is coated with a wear-resistant layer. The coating material is generally aluminum oxide or aluminum oxide.

Carbon ring seals sometimes need to increase isolation gas, usually nitrogen is used, and the nitrogen consumption can be controlled at 25~4nm3/h, which is mainly used for sealing flammable and toxic media.

The carbon ring seal is a seal developed for compressors and fans with stable and reliable performance and extremely convenient assembly and disassembly.

The sealing cavity is a split structure up and down, the sealing ring is a three-lobe structure, the shaft sleeve is generally integral (also can be designed as split), and the surface is sprayed with HRC >70 ceramics. The split ring is sleeved on the sprayed part of the shaft sleeve, and the outside is tensioned by a spring, and is stuck in the groove of the sealing cavity through the stopper. When working, the shaft sleeve rotates with the shaft, while the sealing ring and sealing body are stationary.

This seal has two kinds of sealing points, the dynamic sealing point is the inner diameter of the sealing ring and the outer diameter of the shaft sleeve. The static sealing point is the end face of the sealing ring and the two sides of the sealing body groove. Strictly controlling the roughness and dimensional tolerance of the outer diameter of the shaft sleeve and the inner diameter of the sealing ring can control the leakage of the medium at the dynamic sealing point, and strictly control the flatness, parallelism and dimensional tolerance of the two ends of the sealing ring and the two sides of the sealing body groove, and can control the leakage of the medium. Leaks at static seals.

The carbon ring seal achieves the purpose of sealing through the above principles. Carbon ring seals generally seal gaseous media. For flammable, explosive, toxic and other harmful gases, isolation gas or isolation fluid can be introduced. The pressure of the spacer gas or spacer fluid should be 0.1~0.2MPa higher than the medium pressure, so that zero leakage of the medium can be achieved.

Carbon ring seals can be divided into three categories: general carbon ring seals, inflatable carbon ring seals, and water-filled carbon ring seals. Among them, the inflatable carbon ring seal is the most common application, and the isolation gas is generally nitrogen, and its consumption is about 6m3/h (when the outer diameter of the shaft sleeve is Φ100). The carbon ring seal can withstand the pressure below 2MPa, and it is applicable to the working conditions where the temperature is below 200°C and the speed is within 150m/s.

Therefore, the carbon ring seal is widely used because of its simple operation and maintenance and good sealing performance.