Mechanical seal for kettle characteristic
1. The mixing shaft is relatively long, and there is a mixing paddle at the lower end, so the mechanical seal for the pump has a large swing and oscillation contrast, which makes the dynamic ring and the static ring can not fit perfectly. Usually, the mixing shaft needs to be equipped with a bottom bearing or a central bearing. In order to reduce the influence of shaft swing and oscillation on the seal, add a bearing near the seal, and first consider that the dynamic ring and static ring have better floating performance.
2. Since the mixing kettle is seldom operated with full kettle, the sealing medium of mechanical seal for kettle is gas, and the working conditions of sealing end face are relatively poor. Generally, the mechanical seal for kettle is in a dry conflict state, and the end face is severely worn; Because of strong gas permeability, the request for sealing information is high. In order to smooth and cool the sealing face, hydrodynamic double face seal is usually selected as the kettle seal, and smooth oil or smooth outstanding liquid is introduced between the two sealing faces for smoothing and cooling. Single face seal is only used for occasions with low or unimportant pressure contrast.
3. Because of the large scale of mixing shaft, heavy sealing parts and the influence of mixing support, it is difficult to disassemble and replace mechanical seals. In order to facilitate the disassembly and assembly of the seal, a short coupling is usually installed between the mixing shaft and the transmission shaft. When the seal needs to be disassembled, remove the short coupling first, and then remove the seal after adhering to a certain dimension of space.
4. The mixing shaft speed is low, and the pv value (p is the pressure of the sealing medium, v is the uniform linear speed of the sealing end face) is low. It is easy to select and compare the data of the dynamic ring and the static ring.
5. Because the journal is large, the tension spring has a large compression force under the same tension spring pressure condition, and it is difficult to install and adjust the mechanical seal. In order to ensure the installation quality, most of the kettle mechanical seals developed at that time were planned to be of chuck structure (or container structure). This structural seal can be installed in advance in the seal manufacturer or maintenance workshop, and can be installed on site without skilled workers.
