Design and Solution of Centrifugal Pump Mechanical Seal Parts

1. There is a large amount of channeling in the pump shaft of the mechanical seal of the centrifugal pump

During the operation of the centrifugal pump, the sealing surface of the mechanical seal needs to have a certain specific pressure, and only in this way can the function of the mechanical seal be guaranteed. Therefore, it is required that the spring of the mechanical seal must have a certain amount of compression. With the help of this compression amount, the end face of the seal is given a thrust, and after rotating, the seal face has a standard specific pressure. In order to maintain the stability of this specific pressure, it is required that the channeling amount of the centrifugal pump mechanical seal pump shaft should be controlled within the scientific range. However, when the mechanical seal is designed, due to the influence of unscientific design and other factors, the pump shaft often has a large channeling amount, which affects the use effect of the mechanical seal of the centrifugal pump.

Solution: Scientifically design the balance device of axial force to eliminate axial channeling to the greatest extent. When designing the mechanical seal of a centrifugal pump, first, it can be improved by adding a balance disc and an axial bearing. The second is the way of balancing drum and axial bearing. These two schemes can reduce the problem of large shaft channeling of centrifugal pump to a certain extent, and provide effective technical improvement and support for prolonging the effect of mechanical seal of centrifugal pump.

2. The axial force of the mechanical seal of the centrifugal pump is too large

The mechanical seal of centrifugal pump cannot withstand axial force when in use, because when the mechanical seal is subjected to axial force, it will cause the temperature of the seal gland to rise rapidly, causing the polyendene-based medium to melt, and It affects the effect of the mechanical seal of the centrifugal pump. When the centrifugal pump is delicate, the seal end face has problems such as intermittent spray leakage.

Solution: When designing the mechanical seal of the centrifugal pump, the balance mechanism of the axial force should be reasonably designed to ensure that it can effectively balance the axial force. At the same time, in the process of manufacturing the mechanical seal, it is necessary to improve the design and processing accuracy of the mechanical seal of the centrifugal pump to ensure the good contact between the mechanical seal and the machine, so as to prolong the service life and effect of the mechanical seal.

3. The deflection of the centrifugal pump mechanical seal pump shaft is too high

The centrifugal pump mechanical seal is a contact type mechanical dynamic seal in the rotating axial direction. Its function is realized under the dual action of the fluid medium and the elastic element. When in action, the two parts of the mechanical seal are perpendicular to the axis. The sealing end face of the wire is closely attached, and then the sealing effect is achieved when the relative rotation is performed. Therefore, when designing, the force of the two sealing end faces must be uniform, and there should be no too much deflection.

Solution: When the horizontal multi-stage centrifugal pump is working, the number of stages of the pump impeller should not be too many by reducing the distance between the bearings at both ends. When the total lift of the pump is required to be large, it is necessary to maximize each stage The lift of the impeller reduces the number of stages of the impeller. Secondly, when designing the diameter of the pump shaft, the level of transmitted power cannot be simply considered, but the mechanical seal, shaft deflection, etc. need to be integrated and designed uniformly. The third is to improve the grade of the pump shaft material to ensure the manufacturing quality.

4. Influence of cavitation factors of centrifugal pump mechanical seal pump port

In the process of functioning of the centrifugal pump mechanical seal parts, due to the unreasonable operation of the device system and the poor cavitation performance of the centrifugal pump, it will have an adverse effect on the outer surface of the mechanical sealing surface of the centrifugal pump, resulting in centrifugal Damage to the outer surface of the pump mechanical seal. At the same time, it will also cause bubbles to appear in the flow film of the anastomotic surface of the dynamic and static rings, thereby affecting the stability of the flow film between the anastomotic surfaces. This results in an increase in the dynamic friction of the anastomotic surface, resulting in aggravated wear of the mechanical seal of the centrifugal pump.

Solution: In the process of performing the function of the mechanical seal, the cavitation at the inlet of the centrifugal pump has a great influence on the mechanical seal. First of all, it is necessary to improve the cavitation performance of the centrifugal pump so that the cavitation performance of the on-site device can meet the standard. In the field installation, it is necessary to realize the uniformity of the cavitation performance level of the centrifugal pump. Favorable conditions should be created in the process of on-site installation and adjustment. Secondly, when designing centrifugal pump products, it is necessary to do a good job of analyzing the vibration source. In the process of manufacturing and assembling centrifugal pump products, strict compliance with standards and procedures is required. In this way, the service life of the mechanical seal of the centrifugal pump is comprehensively improved.