Maintenance method of mechanical seal for kettle

Maintenance method of mechanical seal for kettle The service life of mechanical seal for kettle varies with different conditions and environments, and is closely related to working temperature, working pressure, material in the kettle, rotational speed, sealing liquid medium, offset, vibration and movement of the stirring shaft . Therefore, to improve the service life of mechanical seals, careful operation and maintenance are very important. 1. It should be noted that when starting the stirring equipment for the kettle, the pressure of the circulating protection system must be slowly increased first, and then the pressure in the kettle can be slowly increased. The pressure of the circulation protection system should always be 0.05~0.10MPa higher than the pressure in the kettle (at least not lower than the pressure in the kettle). 2. When shutting down, stop the stirring transmission system first, and close the circulation system and cooling water after the temperature and pressure in the kettle drop to normal temperature and pressure. 3. During the work of the mechanical seal, attention should be paid to maintaining the specified liquid level in the lubricating tank or the circulation system. Any position lower than the specified position should be filled to prevent dry grinding (except for type 202F), and keep the outlet of seal leakage fluid unobstructed. 4. When driving, if there is a slight leak at the seal, you can wait for a period of time to make it automatically run and adjust, and it will gradually decrease with the extension of the running time, indicating that it can be eliminated with continuous operation. 5. If there is sudden leakage and continuous leakage, it usually means that the auxiliary sealing ring is damaged or foreign matter enters the sealing surface, and the sealing surface is damaged and should be dealt with. 6. If the whistle is found to indicate that the sealing surface is in a state of insufficient liquid supply and dry grinding occurs, the flow rate of the sealing liquid in the circulation system should be checked immediately, but not all dry grinding will have whistling. 7. The temperature of the inlet and outlet of the sealing liquid should meet the requirements of the third point of the selection principle of the isolation liquid (sealing liquid); the cooling water outlet should meet the requirements of the third point of the second point of the cooling and lubrication of the mechanical seal for the kettle. 8. When the leakage exceeds the allowable value, check and analyze the cause of the leakage: 1) Whether the sealing fluid contains solid impurities such as scale and rust; 2) Whether the axial movement and radial swing of the shaft exceed the specified value; 3) Speed, Whether the temperature, pressure, etc. exceed the standard; 4) Whether the circulation system works normally and whether the pressure meets the requirements; 5) Whether the cooling water is smooth and has a cooling effect; 6) The leaked liquid is turbid and black, indicating that the graphite ring is seriously worn. 9. Generally, the mechanical seal used in the kettle should not be easily disassembled. Except when absolutely necessary, it can be disassembled for inspection and maintenance, but it should be carried out by maintenance personnel with certain technical skills. 10. The disassembly and assembly of various types of mechanical seals should be carried out according to each structural drawing, as follows: 1) The disassembled parts should be cleaned and checked; 2) The wear of the moving ring and the static ring should be checked. The height of the static ring (soft ring) step is generally 3mm. When it is less than 1mm after wear, it must be replaced with a new one; 3) The dynamic and static rings can still be used after inspection, but the sealing end face must be reground. The flatness after grinding should reach 0.0009mm, the roughness Ra value of the hard ring is ≤ 0.2mm, and the soft ring 4) For all auxiliary seal rings (including oil seals), all aged, expanded, damaged and worn bearings should be replaced with new ones; 5) The repaired and assembled mechanical seal should be carried out in accordance with the installation procedures and key points of various types of mechanical seals in this manual.