Overview of dual cartridge mechanical seal Structure for Desulfurization Pump

With the development of the social economy and the emphasis on environmental protection, the performance requirements for desulfurization pumps, as critical equipment for controlling atmospheric pollution, are increasingly higher. Dual cartridge mechanical seals are widely used in desulfurization systems due to their low power loss and almost no leakage, making them an ideal choice for desulfurization pumps. This article will provide a detailed introduction to the structure and function of dual cartridge mechanical seals used in desulfurization pumps.

Classification and Features of Dual Cartridge Mechanical Seals

In the application of desulfurization pumps, dual cartridge mechanical seals are mainly divided into two types: back-to-back dual cartridge mechanical seals and tandem dual cartridge mechanical seals. Both structures aim to handle the corrosive and abrasive slurry in desulfurization systems.

Back-to-back Dual Cartridge Mechanical Seal

The design of the back-to-back dual cartridge mechanical seal ensures the effective operation of the sealing surface under high-pressure conditions. The stationary ring on the medium side does not rotate and is sealed by an O-ring on the outer ring. The rotating dynamic ring is guided and sealed by the dynamic ring seat and O-ring. The friction surface between the dynamic and stationary rings on the medium side operates under the pressure of the shaft sealing water, which requires the shaft sealing water pressure to be 0.15 to 0.2 MPa higher than the maximum pressure of the sealed medium.

This design makes the leakage rate of the dual cartridge mechanical seal extremely low, as the liquid film between the friction end faces is subjected to centrifugal force, effectively enhancing the sealing effect. The high-pressure shaft sealing water not only prevents medium leakage but also provides lubrication and cooling, thereby reducing wear on the friction surfaces and extending the service life of the mechanical seal.

Tandem Dual Cartridge Mechanical Seal

In contrast to the back-to-back design, the tandem dual cartridge mechanical seal has the dynamic ring close to the medium, while the stationary ring is axially sealed by an O-ring. Because the medium pressure is usually higher than the shaft sealing water pressure, the stationary ring will not fall off, so no additional retaining ring is needed. The shaft sealing water pressure is relatively low, mainly used for cooling the friction pairs of the dynamic and stationary rings and cleaning impurities in the sealing chamber.

This design also effectively solves the potential leakage problem during the operation of the desulfurization pump. Through reasonable structural design, the tandem dual cartridge mechanical seal can maintain stable performance in a variable work environment.

Material Selection and Technical Requirements

Double-cylinder mechanical seals' performance not only depends on their structural design but is also closely related to the materials used. For the medium side, the dynamic and stationary rings are usually made of corrosion-resistant and wear-resistant pressureless sintered silicon carbide, which exhibits excellent performance when facing corrosive and abrasive media.

On the atmospheric side, common friction pair materials include hard alloys like YG6 and YG8. Since clean water is used as the shaft sealing water, the sealing performance is stable, with almost no failure. Additionally, O-rings are usually made of fluororubber to improve sealing performance due to the highly corrosive and abrasive limestone slurry used in desulfurization pumps.

Meanwhile, the metal structural parts are made of duplex stainless steel or 316L stainless steel to ensure long-term stable operation in special medium environments.

The dual cartridge mechanical seals used in desulfurization pumps significantly enhance the sealing performance of the equipment and reduce leakage risk through their unique structural design and material selection. Both back-to-back and tandem dual cartridge mechanical seals have distinct features that can effectively handle complex working conditions in desulfurization systems. With increasing environmental protection requirements, the application of dual cartridge mechanical seals in desulfurization pumps will become more widespread, contributing to cleaner production and environmental protection. I hope this article helps you better understand the structure and function of dual cartridge mechanical seals used in desulfurization pumps.