The environment of the shaft sealing device of the reactor
1. Stirring shaft side-entry reactor. From the perspective of lubrication, mechanical seals for this type of reactor generally do not have poor lubrication problems, but the media page in the reactor must be maintained at a certain height.
2. Plug-in reactor at the bottom of the stirring shaft The polymerization reactor has gradually developed in the direction of large volume, and its stirring shaft has also changed from the top plug-in type to the bottom plug-in type. The feature of the bottom insertion type is that the mixing shaft is short and the bending stress on the shaft is small, so the calculation of the shaft diameter is small, which saves labor and materials. The short shaft is more rigid than the long shaft and has less deformation.
3. The plug-in reactor at the top of the stirring shaft The top plug-in reactor with stirring shaft is widely used, and the problems encountered in its sealing are different from the previous ones. Because the seal is placed in the upper part of the kettle, it is in the gas phase space (the material is in the liquid phase when the kettle is full). In order to avoid dry friction of the seal, a certain lubricating cooling method is required. A vertically installed stirring shaft is inserted at the top, and the ratio of length to diameter is large, and the processing and installation accuracy may be low, so it will inevitably produce a large deflection.
Examples of mechanical seals for reactors
1. Although the form and structure of the mechanical seal for the reactor and the mechanical seal for the pump are different in structure, their functions and principles are the same. Generally speaking, the speed of the seal for the kettle is low, and the spring specific pressure should be larger; the stirring shaft vibration is large, and the seal should be designed to be firmer, and the friction ring should adopt an integral structure when sealing the air. Considering the large swing of the rotating shaft, the gap between the stationary ring and the shaft should be larger. The weight of the compensation ring cannot be ignored when calculating the specific pressure of the end face of the large shaft diameter plug-in reactor at the top. Commonly used mechanical seal models for kettles are 202 series, 212 series, 204 series and so on.