Integrated mechanical seal for process screw compressor

Abstract

The invention discloses an integrated mechanical seal for a process screw compressor. The integrated mechanical seal comprises a sealing cavity and a shaft sleeve penetrating into an inner cavity of the sealing cavity, wherein a main seal and an auxiliary seal are arranged between the outer portion of the shaft sleeve and the inner portion of the sealing cavity correspondingly and are installed onthe two sides of the sealing cavity in the axial direction in a back-to-back manner; the shaft sleeve, the sealing cavity, the main seal and the auxiliary seal are integrated into an integrated structure; the side, close to the main seal, of the sealing cavity is further provided with a containing cavity; and a lip seal assembly is arranged between the open end of the containing cavity and the outer side wall of an installation boss at one end of the shaft sleeve, so that the containing cavity forms a first sealing cavity used for preventing process gas compressed in the process compressor from entering a work sealing cavity of the mechanical seal. The integrated mechanical seal for the process screw compressor can better adapt to the work condition of the process screw compressor, the sealing performance is more stable, and the service life is long.

Description

technical field [0001] The invention relates to the technical field of mechanical seals, in particular to a cartridge mechanical seal for process screw compressors. Background technique [0002] Screw compressors have the advantages of centrifugal and piston compressors, while avoiding their disadvantages. This outstanding pan-adaptability makes it very good in the world from small chemical processes to large chemical plants. applicable. Therefore, process screw compressors are preferred in many chemical and petrochemical industry operations and processes, while oil-injected twin-screw compressors have the advantages of high reliability and low operating costs and are ideal compression equipment for process gases and applications. [0003] Because the gas compressed by the process screw compressor is mostly process gas, which may contain toxic, harmful, flammable, explosive, and corrosive gases, the compression chamber must be isolated from the atmosphere and the bearing mu...

AI Technical Summary

Problems solved by technology

[0007] 2. Labyrinth seal: It has the advantages of simple structure and low cost, but it also has the disadvantages of short service life, large leakage (and gradually increases with the use time), high energy consumption (requires continuous ventilation and isolation) , under the increasingly stringent environmental protection requirements and energy-saving requirements, it is difficult for the labyrinth seal to meet the higher requirements for the use of process screw compressors. The proportion of its use is gradually decreasing, and it has reached a lower use level.

[0008] 3. Mechanical seal: Mechanical seal has the advantages of small leakage, long service life, energy saving and environmental protection, and simple maintenance, but it also has disadvantages such as relatively complicated structure, high cost of parts, high installation technical requirements, and lack of targeted design. However, compared with other shaft seals, there is a small amount of leakage and small shaft power consumption, which is in line with the current energy-saving and environmental protection requirements of the entire society. Mechanical seals have become the main shaft seal method for process screw compressors.

[0009] 3.1. Dry non-contact mechanical seal: the advantage is that the end face does not touch during operation, and there is no wear, so the service life is long and the leakage is small. The disadvantage is that the isolation gas must be continuously consumed, and the energy consumption is high, and it must be matched. The expensive auxiliary system itself is also very expensive to seal, and the cost performance is low

The disadvantage is that the theoretical service life is lower than that of dry gas seals, but it is far better than other forms of shaft seals. It is an ideal shaft seal solution for process screw compressors

However, since the working condition of the process screw compressor is a gas-liquid mixed state, mechanical seals are prone to dry friction, excessive wear, and severe heat generation, which restricts the application of wet contact mechanical seals in process screw compressors

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