How to use wear-resistant and corrosion-resistant flexible materials in kneaders

For the needs of the reaction process, the kneading machine needs to use vacuum and pressure type. If such kneading machines only use packing seals, it is generally difficult to meet the design requirements. At present, most domestic equipment manufacturers use mechanical seals. The mechanical seal uses two sealing elements, the moving ring and the static ring, to combine with each other on the smooth and straight surface perpendicular to the axis and rotate relative to each other. Therefore, through this structure, the axial seal, which is extremely easy to leak, is changed into an end face seal that is not easy to leak. Compared with the packing seal, the mechanical seal is characterized by changing the sealing method, and the surface of the shaft is not worn to overcome a series of drawbacks of the packing seal, but the following points are worth noting in the use of the mechanical seal.

The friction pair composed of the moving ring and the static ring is an important component of the mechanical seal. The hardness of the moving ring and the static ring are different. At present, the materials for moving and static rings are available: silicon carbide, stainless steel surfacing hard alloy, alumina ceramic, alumina tetrafluoro L pad, filled with polytetrafluoroethylene, impregnated with phenolic graphite, impregnated with furan graphite, etc. When selecting materials, we should combine the characteristics of our industry. When refined cotton is alkalized and etherified in vacuum kneading machine, due to large vibration and various reasons such as equipment assembly and installation, it is inappropriate to choose materials with high hardness such as silicon carbide and ceramics but poor rigidity in the selection of static rings. Due to the uneven force of the shaft caused by the beating of the slurry during operation, it is easy to break the static ring, especially the static ring of the mechanical seal on the opposite side of the gearbox, which is far away from the transmission power point and is more likely to break. Practice has proved that the static ring is made of stainless steel surfacing hard alloy, and the moving ring is made of silicon carbide or other anti-wear and anti-corrosion flexible materials. Under the condition that the vacuum degree reaches 650~700mmHg or the pressure is 0.5 ~ 0.6MPa, no other abnormalities are found in the operation of the equipment for half a year.