Barrier fluid circulation system for mechanical seals

Abstract

The invention relates to a spacer fluid circulating system used for a mechanical seal. The spacer fluid circulating system comprises a fluid storage tank; the fluid storage tank comprises a tank body (1); and a fluid supplementing opening, a fluid outlet (9) and a fluid inlet (15) are arranged on the tank body (1). The spacer fluid circulating system is characterized in that a tubular sandwich wall (4) for dividing the tank body (1) into an inner chamber and an outer chamber is also arranged in the tank body (1); the chamber positioned at an outer layer is a sandwich chamber (3); a piston (13) is mounted in a main chamber (21) positioned at an inner layer; the piston (13) divides the main chamber (21) into a first part positioned at an upper part and a second part positioned at a lower part through a sealing ring (26); the second part is communicated with the chamber used for containing a sealing medium through a pressure source interface (12); and the upper end surface of the piston (13) is also connected with a piston rod (14). The invention provides the spacer fluid circulating system used for the mechanical seal, and the spacer fluid circulating system is higher in stability.

Description

technical field [0001] The invention relates to the technical field of mechanical seals, in particular to an isolation fluid circulation system for mechanical seals. Background technique [0002] A mechanical seal is a shaft seal device for a rotating machine. For example, in centrifugal pumps, centrifuges, reactors, compressors and other equipment, the transmission shaft runs through the inside and outside of the equipment, so there is a circular gap between the shaft and the equipment, and the medium in the equipment will leak out through this gap, so there must be a Shaft sealing device to prevent leakage. There are many types of shaft sealing devices. Because mechanical seals have the advantages of less leakage and long life, mechanical seals are the most important shaft sealing method used in these equipments in the world today. Mechanical seals are also called end face seals. In the prior art, in order to meet the high requirements of shaft seals on the rotating mech...

AI Technical Summary

Problems solved by technology

The spacer fluid circulation system in the prior art includes a liquid storage tank, a spacer fluid pushing mechanism, a liquid replenishment pump, a cooling coil, a pressure gauge and a pressure switch, and the two ends of the liquid storage tank form a circulation with the mechanical seal cavity through pipelines circuit, the cooling coil is wound on the liquid storage tank, the liquid outlet on the replenishment pump is connected to the liquid storage tank, the spacer fluid pushing mechanism is connected in series to the circuit, and the pressure gauge and pressure switch are installed on the liquid storage tank , in the actual use process, it is found that the spacer liquid circulation system with this structure has the following shortcomings: the liquid storage tank is a tank used only for liquid storage, which cannot cope with the complex working conditions of the reactor during the reaction process, that is to say When the pressure of the sealing medium in the reactor (the pressure of the medium mentioned in this article essentially corresponds to the pressure in the physical concept, the unit is commonly used in MPa, which belongs to the common sense of technicians in the industry, and will not be explained one by one later) fluctuates greatly When the pressure in the mechanical seal cavity cannot be adjusted accordingly, it is easy to cause the sealing medium to leak into the mechanical seal cavity, and even cause the seal end face to fully open and cause serious leakage.

However, in aseptic fields such as medicine, food, biology, and genetic technology, the reactor needs a sterile environment, and no contact with the outside world is allowed. At the same time, when the reactor is running, it often encounters uneven stirring liquid, too low liquid level or There are situations such as eddy current, uneven feeding, or uncontrolled reaction. These situations will lead to drastic changes in the internal pressure of the reactor. At this time, if the pressure of the mechanical seal chamber is not adjusted accordingly, it will be lower than the pressure of the sealing medium, which is easy to cause The sealing medium leaks into the mechanical seal cavity, which may even cause serious leakage due to the complete opening of the sealing end face

To sum up, the spacer fluid circulation system for mechanical seals in the prior art has the disadvantage that the pressure in the mechanical seal chamber cannot be adjusted at any time as the pressure of the sealing medium changes, so the stability is not high

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