What are the reasons for the damage to the mechanical seal of the mixer

The mechanical seal for agitator plays an important role in the use of equipment, and it is helpful for the use effect and function, so once damaged, it will affect the use of the agitator, so what is the reason for the damage of the mechanical seal? Only by finding the real cause can the problem be dealt with better.

1. The installation of the static ring seat lacks precision

Under normal circumstances, there is no corresponding positioning member between the agitator static ring seat and the sealing chamber. The concentricity during the installation of the shaft sleeve and the time static ring is mainly determined by the experience of the staff, resulting in its installation efficiency. directly affected by human factors.

Among them, the distance between the shaft sleeve and the static ring is relatively small, and the half-edge distance is 0.5 mm. Therefore, under the influence of the large swing of the agitator shaft and the error before the installation of the static ring seat, the gap between the static ring and the shaft sleeve is The friction phenomenon often occurs and leads to its rupture, which further leads to the occurrence of damage to the mechanical seal of the agitator.

2. Stirring shaft swing and stirrer vibration

Under normal circumstances, the thickness of the melamine slurry tank wall of the agitator itself is relatively small, and its positive rigidity cannot well meet the relevant requirements, resulting in a large vibration of the agitator during actual operation. The wear at the position connection is serious, and the matching distance between the shaft and the shaft sleeve is relatively large, which further causes the stirring shaft to swing to a large extent during operation. The strength of the sleeve is relatively short, and the cantilever length of the stirring shaft is large, and the deflection of the stirring shaft is high. Although the relevant staff of the company have strengthened its design, the spacing between the shaft sleeve at the connection between the gearbox and the stirring shaft, as well as the increase and fixation, lead to the oscillation phenomenon of the stirring shaft during operation cannot be changed. During the continuous operation of the agitator, the wear phenomenon between the shaft sleeve and the shaft is gradually serious, which will lead to the continuous increase of the running swing of the agitator shaft. Under the influence of the vibration of the stirring shaft, the overall vibration frequency of the agitator will gradually increase. On the contrary, the violent vibration of the agitator will also promote the wear of the stirring shaft and the shaft sleeve of the reducer, and further increase the amplitude of the vibration. In this vicious circle, the mechanical seal damage of agitator often occurs.

3. There are problems in the selection of friction materials for mechanical seals

In the past, the friction pair materials used in mechanical seals were mainly emery and carbon graphite, which were mainly composed of soft and hard materials according to their physical properties. At the same time, the processing material is melamine slurry, which contains a large amount of granular melamine crystalline material, which is very easy to produce strong wear on the soft ring (that is, the moving ring), resulting in a decrease in the mechanical sealing effect and leakage problems. .

When considering the damage of the mechanical seal of the agitator, you can first judge the cause of the damage according to the above conditions, and then deal with or replace it accordingly.